refactor: handle layer plans outside of buffer (CURA-3339)

allocation is handled outside buffer
writing gcode is handled outside buffer
buffer processing is handled separately from adding to the buffer

.gitignore

@@ -7,15 +7,36 @@
 NUL
 *.gcode
 
+## Directories used for other stuff
+Trash/*
+output/*
+callgrind/*
+
 ## Building result.
 build/*
+debug_build/*
 *.pyc
 *.exe
+*.a
 *.o
 CuraEngine
 _bin
 _obj
 
+## CMake files
+cmake_install.cmake         
+CMakeCache.txt
+CMakeFiles/
+CPackSourceConfig.cmake
+
+# Visual Studio files generated by CMake
+*.vcxproj
+*.vcxproj.filters
+CuraEngine.sln
+
+# Makefile generated by CMake
+Makefile
+
 ## IDE project files.
 CuraEngine.layout
 CuraEngine.cbp
@@ -32,3 +53,4 @@ documentation/latex/*
 
 ## Test results.
 tests/output.xml
+callgrind.out.*

CMakeLists.txt

@@ -28,9 +28,11 @@ set(CURA_ENGINE_VERSION "master" CACHE STRING "Version name of Cura")
 option(BUILD_TESTS OFF)
 
 # Add a compiler flag to check the output for insane values if we are in debug mode.
-if(CMAKE_BUILD_TYPE MATCHES DEBUG)
+if(CMAKE_BUILD_TYPE MATCHES DEBUG OR CMAKE_BUILD_TYPE MATCHES RelWithDebInfo)
     message(STATUS "Building debug release of CuraEngine.")
     add_definitions(-DASSERT_INSANE_OUTPUT)
+    add_definitions(-DUSE_CPU_TIME)
+    add_definitions(-DDEBUG)
 endif()
 
 # Add warnings
@@ -40,18 +42,30 @@ if(NOT APPLE AND NOT WIN32)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -static-libstdc++")
 endif()
 
+option (ENABLE_OPENMP
+    "Use OpenMP for parallel code" ON)
+
+if (ENABLE_OPENMP)
+    FIND_PACKAGE( OpenMP )
+    if( OPENMP_FOUND )
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}" )
+    endif()
+endif()
+
 include_directories(${CMAKE_CURRENT_BINARY_DIR} libs)
 
 add_library(clipper STATIC libs/clipper/clipper.cpp)
 
 set(engine_SRCS # Except main.cpp.
     src/bridge.cpp
-    src/comb.cpp
     src/commandSocket.cpp
+    src/ConicalOverhang.cpp
+    src/ExtruderTrain.cpp
     src/FffGcodeWriter.cpp
     src/FffPolygonGenerator.cpp
     src/FffProcessor.cpp
     src/gcodeExport.cpp
+    src/GCodePathConfig.cpp
     src/gcodePlanner.cpp
     src/infill.cpp
     src/WallsComputation.cpp
@@ -62,10 +76,11 @@ set(engine_SRCS # Except main.cpp.
     src/MeshGroup.cpp
     src/multiVolumes.cpp
     src/pathOrderOptimizer.cpp
+    src/Preheat.cpp
     src/PrimeTower.cpp
     src/raft.cpp
     src/skin.cpp
-    src/skirt.cpp
+    src/SkirtBrim.cpp
     src/sliceDataStorage.cpp
     src/slicer.cpp
     src/support.cpp
@@ -80,10 +95,18 @@ set(engine_SRCS # Except main.cpp.
     src/infill/ZigzagConnectorProcessorDisconnectedEndPieces.cpp
     src/infill/ZigzagConnectorProcessorEndPieces.cpp
     src/infill/ZigzagConnectorProcessorNoEndPieces.cpp
+    src/infill/SubDivCube.cpp
+
+    src/pathPlanning/Comb.cpp
+    src/pathPlanning/GCodePath.cpp
+    src/pathPlanning/LinePolygonsCrossings.cpp
+    src/pathPlanning/NozzleTempInsert.cpp
+    src/pathPlanning/TimeMaterialEstimates.cpp
 
     src/progress/Progress.cpp
     src/progress/ProgressStageEstimator.cpp
 
+    src/settings/PathConfigStorage.cpp
     src/settings/SettingConfig.cpp
     src/settings/SettingContainer.cpp
     src/settings/SettingRegistry.cpp
@@ -94,9 +117,12 @@ set(engine_SRCS # Except main.cpp.
     src/utils/Date.cpp
     src/utils/gettime.cpp
     src/utils/LinearAlg2D.cpp
+    src/utils/ListPolyIt.cpp
     src/utils/logoutput.cpp
+    src/utils/PolygonProximityLinker.cpp
     src/utils/polygonUtils.cpp
     src/utils/polygon.cpp
+    src/utils/ProximityPointLink.cpp
 )
 
 # List of tests. For each test there must be a file tests/${NAME}.cpp and a file tests/${NAME}.h.
@@ -106,9 +132,11 @@ set(engine_TEST
 set(engine_TEST_INFILL
 )
 set(engine_TEST_UTILS
-    BucketGrid2DTest
+    SparseGridTest
     LinearAlg2DTest
     PolygonUtilsTest
+    PolygonTest
+    StringTest
 )
 
 # Generating ProtoBuf protocol
@@ -160,4 +188,4 @@ add_custom_command(TARGET CuraEngine POST_BUILD
 # Installing CuraEngine.
 include(GNUInstallDirs)
 install(TARGETS CuraEngine DESTINATION ${CMAKE_INSTALL_BINDIR})
-include(CPackConfig.cmake)
+include(CPackConfig.cmake)

Cura.proto

@@ -5,12 +5,21 @@ package cura.proto;
 message ObjectList
 {
     repeated Object objects = 1;
-    repeated Setting settings = 2;
+    repeated Setting settings = 2; // meshgroup settings (for one-at-a-time printing)
 }
 
 message Slice
 {
-    repeated ObjectList object_lists = 1;
+    repeated ObjectList object_lists = 1; // The meshgroups to be printed one after another
+    SettingList global_settings = 2; // The global settings used for the whole print job
+    repeated Extruder extruders = 3; // The settings sent to each extruder object
+    repeated SettingExtruder limit_to_extruder = 4; // From which stack the setting would inherit if not defined per object
+}
+
+message Extruder
+{
+    int32 id = 1;
+    SettingList settings = 2;
 }
 
 message Object
@@ -29,10 +38,10 @@ message Progress
 
 message Layer {
     int32 id = 1;
-    float height = 2;
-    float thickness = 3;
+    float height = 2; // Z position
+    float thickness = 3; // height of a single layer
 
-    repeated Polygon polygons = 4;
+    repeated Polygon polygons = 4; // layer data
 }
 
 message Polygon {
@@ -47,20 +56,48 @@ message Polygon {
         SupportInfillType = 7;
         MoveCombingType = 8;
         MoveRetractionType = 9;
+        SupportInterfaceType = 10;
     }
-    Type type = 1;
-    bytes points = 2;
-    float line_width = 3;
+    Type type = 1; // Type of move
+    bytes points = 2; // The points of the polygon, or two points if only a line segment (Currently only line segments are used)
+    float line_width = 3; // The width of the line being laid down
 }
 
+message LayerOptimized {
+    int32 id = 1;
+    float height = 2; // Z position
+    float thickness = 3; // height of a single layer
+
+    repeated PathSegment path_segment = 4; // layer data
+}
+
+
+message PathSegment {
+    int32 extruder = 1; // The extruder used for this path segment
+    enum PointType {
+        Point2D = 0;
+        Point3D = 1;
+    }
+    PointType point_type = 2;
+    bytes points = 3; // The points defining the line segments, bytes of float[2/3] array of length N+1
+    bytes line_type = 4; // Type of line segment as an unsigned char array of length 1 or N, where N is the number of line segments in this path
+    bytes line_width = 5; // The widths of the line segments as bytes of a float array of length 1 or N
+}
+
+
 message GCodeLayer {
     bytes data = 2;
 }
 
-message ObjectPrintTime {
+
+message PrintTimeMaterialEstimates { // The print time for the whole print and material estimates for the extruder
+    float time = 1; // Total time estimate
+    repeated MaterialEstimates materialEstimates = 2; // materialEstimates data
+}
+
+message MaterialEstimates {
     int64 id = 1;
-    float time = 2;
-    float material_amount = 3;
+    float material_amount = 2; // material used in the extruder
 }
 
 message SettingList {
@@ -68,13 +105,19 @@ message SettingList {
 }
 
 message Setting {
-    string name = 1;
+    string name = 1; // Internal key to signify a setting
 
-    bytes value = 2;
+    bytes value = 2; // The value of the setting
+}
+
+message SettingExtruder {
+    string name = 1; //The setting key.
+
+    int32 extruder = 2; //From which extruder stack the setting should inherit.
 }
 
 message GCodePrefix {
-    bytes data = 2;
+    bytes data = 2; //Header string to be prepended before the rest of the g-code sent from the engine.
 }
 
 message SlicingFinished {

Doxyfile

@@ -832,7 +832,7 @@ EXAMPLE_RECURSIVE      = NO
 # that contain images that are to be included in the documentation (see the
 # \image command).
 
-IMAGE_PATH             = documentation/assets
+IMAGE_PATH             = docs/assets
 
 # The INPUT_FILTER tag can be used to specify a program that doxygen should
 # invoke to filter for each input file. Doxygen will invoke the filter program

README.md

@@ -19,38 +19,41 @@ But in general it boils down to: You need to share the source of any CuraEngine
 How to Install
 ==============
 1. Clone the repository from https://github.com/Ultimaker/CuraEngine.git (the URL at the right hand side of this page).
-2. Install Protobuf (see below)
+2. Install Protobuf >= 3.0.0 (see below)
 3. Install libArcus (see https://github.com/Ultimaker/libArcus)
 
 In order to compile CuraEngine, either use CMake or start a project in your preferred IDE. 
 CMake compilation:
 
 1. Navigate to the CuraEngine directory and execute the following commands
-2. $ mkdir build && cd build
-3. $ cmake ..
-4. $ make
+2. ```$ mkdir build && cd build```
+3. ```$ cmake ..```
+4. ```$ make```
 
 Project files generation:
+
 1. Navigate to the CuraEngine directory and execute the following commands
-2. cmake . -G "CodeBlocks - Unix Makefiles"
+2. ```cmake . -G "CodeBlocks - Unix Makefiles"```
 3. (for a list of supported IDE's see http://www.cmake.org/Wiki/CMake_Generator_Specific_Information#Code::Blocks_Generator)
 
 Installing Protobuf
 -------------------
 1. Be sure to have libtool installed.
-2. Download protobuf from https://github.com/google/protobuf/ (download ZIP and unZIP at desired location, or clone the repo) The protocol buffer is used for communication between the CuraEngine and the GUI.
-3. Before installing protobuf, change autogen.sh : comment line 18 to line 38 using '#'s. This removes the dependency on gtest-1.7.0.
-4. Run autogen.sh from the protobuf directory: 
-   $ ./autogen.sh
-5. $ ./configure
-6. $ make
-7. $ make install     # Requires superused priviliges.
-8. (In case the shared library cannot be loaded, you can try "sudo ldconfig" on Linux systems)
+2. Download protobuf from https://github.com/google/protobuf/releases (download ZIP and unZIP at desired location, or clone the repo). The protocol buffer is used for communication between the CuraEngine and the GUI.
+3. Run ```autogen.sh``` from the protobuf directory: 
+   ```$ ./autogen.sh```
+4. ```$ ./configure```
+5. ```$ make```
+6. ```# make install```  
+   (Please note the ```#```. It indicates the need of superuser, as known as root, priviliges.)
+7. (In case the shared library cannot be loaded, you can try ```sudo ldconfig``` on Linux systems)
 
 Running
 =======
 Other than running CuraEngine from a frontend, such as Ultimaker/Cura, one can run CuraEngine from the command line.
 For that one needs a settings JSON file, which can be found in the Ultimaker/Cura repository.
+Note that the structure of the json files has changed since 2.1. In the corresponding branch of the Cura repository you can find how the json files used to be structured.
+
 An example run for an UM2 machine looks as follows:
 * Navigate to the CuraEngine directory and execute the following
 ```

docs/mainpage.md

@@ -7,4 +7,4 @@ This is the documentation for CuraEngine, the back-end slicer of Cura.
 
 [Glossary](documentation/glossary.md)
 
-[Code Conventions](documentation/code_conventions.md)
+[Code Conventions](https://github.com/Ultimaker/Meta/blob/master/code_conventions.md)

documentation/Link_to_index.html

@@ -1 +0,0 @@
-html/index.html

libs/clipper/License.txt

@@ -1,26 +1,24 @@
-The Clipper Library (including Delphi, C++ & C# source code, other accompanying
-code, examples and documentation), hereafter called "the Software", has been 
-released under the following license, terms and conditions:
-
 Boost Software License - Version 1.0 - August 17th, 2003
 http://www.boost.org/LICENSE_1_0.txt
 
-Permission is hereby granted, free of charge, to any person or organization 
-obtaining a copy of the Software covered by this license to use, reproduce, 
-display, distribute, execute, and transmit the Software, and to prepare 
-derivative works of the Software, and to permit third-parties to whom the 
-Software is furnished to do so, all subject to the following:
+Permission is hereby granted, free of charge, to any person or organization
+obtaining a copy of the software and accompanying documentation covered by
+this license (the "Software") to use, reproduce, display, distribute,
+execute, and transmit the Software, and to prepare derivative works of the
+Software, and to permit third-parties to whom the Software is furnished to
+do so, all subject to the following:
 
-The copyright notices in the Software and this entire statement, including the 
-above license grant, this restriction and the following disclaimer, must be 
-included in all copies of the Software, in whole or in part, and all derivative 
-works of the Software, unless such copies or derivative works are solely in the 
-form of machine-executable object code generated by a source language processor.
+The copyright notices in the Software and this entire statement, including
+the above license grant, this restriction and the following disclaimer,
+must be included in all copies of the Software, in whole or in part, and
+all derivative works of the Software, unless such copies or derivative
+works are solely in the form of machine-executable object code generated by
+a source language processor.
 
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
-FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT SHALL 
-THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE FOR ANY 
-DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, ARISING 
-FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
-THE SOFTWARE.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

libs/clipper/README

@@ -1,8 +1,39 @@
 =====================================================================
 Clipper Change Log
 =====================================================================
+v6.2.1 (31 October 2014) Rev 482
+* Bugfix in ClipperOffset.Execute where the Polytree.IsHole property 
+  was returning incorrect values with negative offsets
+* Very minor improvement to join rounding in ClipperOffset
+* Fixed CPP OpenGL demo.
 
-v6.1.3 (19 January 2014)
+v6.2.0 (17 October 2014) Rev 477
+* Numerous minor bugfixes, too many to list. 
+  (See revisions 454-475 in Sourceforge Repository)
+* The ZFillFunction (custom callback function) has had its parameters 
+  changed. 
+* Curves demo removed (temporarily).
+* Deprecated functions have been removed. 
+
+v6.1.5 (26 February 2014) Rev 460
+* Improved the joining of output polygons sharing a common edge 
+  when those common edges are horizontal.
+* Fixed a bug in ClipperOffset.AddPath() which would produce
+  incorrect solutions when open paths were added before closed paths.
+* Minor code tidy and performance improvement
+
+v6.1.4 (6 February 2014)
+* Fixed bugs in MinkowskiSum
+* Fixed minor bug when using Clipper.ForceSimplify.
+* Modified use_xyz callback so that all 4 vertices around an
+  intersection point are now passed to the callback function.
+
+v6.1.3a (22 January 2014) Rev 453
+* Fixed buggy PointInPolygon function (C++ and C# only). 
+  Note this bug only affected the newly exported function, the 
+  internal PointInPolygon function used by Clipper was OK.
+ 
+v6.1.3 (19 January 2014) Rev 452
 * Fixed potential endless loop condition when adding open 
   paths to Clipper.
 * Fixed missing implementation of SimplifyPolygon function 
@@ -13,11 +44,11 @@ v6.1.3 (19 January 2014)
 * Overloaded MinkowskiSum function to accommodate multi-contour 
   paths.  
 
-v6.1.2 (15 December 2013)
+v6.1.2 (15 December 2013) Rev 444
 * Fixed broken C++ header file.
 * Minor improvement to joining polygons.
 
-v6.1.1 (13 December 2013)
+v6.1.1 (13 December 2013) Rev 441
 * Fixed a couple of bugs affecting open paths that could 
   raise unhandled exceptions.
   

libs/clipper/clipper.hpp

@@ -1,8 +1,8 @@
 /*******************************************************************************
 *                                                                              *
 * Author    :  Angus Johnson                                                   *
-* Version   :  6.1.3a                                                          *
-* Date      :  22 January 2014                                                 *
+* Version   :  6.2.1                                                           *
+* Date      :  31 October 2014                                                 *
 * Website   :  http://www.angusj.com                                           *
 * Copyright :  Angus Johnson 2010-2014                                         *
 *                                                                              *
@@ -34,7 +34,7 @@
 #ifndef clipper_hpp
 #define clipper_hpp
 
-#define CLIPPER_VERSION "6.1.3"
+#define CLIPPER_VERSION "6.2.0"
 
 //use_int32: When enabled 32bit ints are used instead of 64bit ints. This
 //improve performance but coordinate values are limited to the range +/- 46340
@@ -44,11 +44,10 @@
 //#define use_xyz
 
 //use_lines: Enables line clipping. Adds a very minor cost to performance.
-//#define use_lines
+#define use_lines
   
-//use_deprecated: Enables support for the obsolete OffsetPaths() function
-//which has been replace with the ClipperOffset class.
-#define use_deprecated  
+//use_deprecated: Enables temporary support for the obsolete functions
+//#define use_deprecated  
 
 #include <vector>
 #include <set>
@@ -57,6 +56,7 @@
 #include <cstdlib>
 #include <ostream>
 #include <functional>
+#include <queue>
 
 namespace ClipperLib {
 
@@ -69,11 +69,16 @@ enum PolyType { ptSubject, ptClip };
 enum PolyFillType { pftEvenOdd, pftNonZero, pftPositive, pftNegative };
 
 #ifdef use_int32
-typedef int cInt;
-typedef unsigned int cUInt;
+  typedef int cInt;
+  static cInt const loRange = 0x7FFF;
+  static cInt const hiRange = 0x7FFF;
 #else
-typedef signed long long cInt;
-typedef unsigned long long cUInt;
+  typedef signed long long cInt;
+  static cInt const loRange = 0x3FFFFFFF;
+  static cInt const hiRange = 0x3FFFFFFFFFFFFFFFLL;
+  typedef signed long long long64;     //used by Int128 class
+  typedef unsigned long long ulong64;
+
 #endif
 
 struct IntPoint {
@@ -117,15 +122,12 @@ struct DoublePoint
 //------------------------------------------------------------------------------
 
 #ifdef use_xyz
-typedef void (*TZFillCallback)(IntPoint& z1, IntPoint& z2, IntPoint& pt);
+typedef void (*ZFillCallback)(IntPoint& e1bot, IntPoint& e1top, IntPoint& e2bot, IntPoint& e2top, IntPoint& pt);
 #endif
 
 enum InitOptions {ioReverseSolution = 1, ioStrictlySimple = 2, ioPreserveCollinear = 4};
 enum JoinType {jtSquare, jtRound, jtMiter};
 enum EndType {etClosedPolygon, etClosedLine, etOpenButt, etOpenSquare, etOpenRound};
-#ifdef use_deprecated
-  enum EndType_ {etClosed, etButt = 2, etSquare, etRound};
-#endif
 
 class PolyNode;
 typedef std::vector< PolyNode* > PolyNodes;
@@ -134,6 +136,7 @@ class PolyNode
 { 
 public:
     PolyNode();
+    virtual ~PolyNode(){};
     Path Contour;
     PolyNodes Childs;
     PolyNode* Parent;
@@ -168,11 +171,6 @@ bool Orientation(const Path &poly);
 double Area(const Path &poly);
 int PointInPolygon(const IntPoint &pt, const Path &path);
 
-#ifdef use_deprecated
-  void OffsetPaths(const Paths &in_polys, Paths &out_polys,
-    double delta, JoinType jointype, EndType_ endtype, double limit = 0);
-#endif
-
 void SimplifyPolygon(const Path &in_poly, Paths &out_polys, PolyFillType fillType = pftEvenOdd);
 void SimplifyPolygons(const Paths &in_polys, Paths &out_polys, PolyFillType fillType = pftEvenOdd);
 void SimplifyPolygons(Paths &polys, PolyFillType fillType = pftEvenOdd);
@@ -183,8 +181,7 @@ void CleanPolygons(const Paths& in_polys, Paths& out_polys, double distance = 1.
 void CleanPolygons(Paths& polys, double distance = 1.415);
 
 void MinkowskiSum(const Path& pattern, const Path& path, Paths& solution, bool pathIsClosed);
-void MinkowskiSum(const Path& pattern, const Paths& paths, 
-  Paths& solution, PolyFillType pathFillType, bool pathIsClosed);
+void MinkowskiSum(const Path& pattern, const Paths& paths, Paths& solution, bool pathIsClosed);
 void MinkowskiDiff(const Path& poly1, const Path& poly2, Paths& solution);
 
 void PolyTreeToPaths(const PolyTree& polytree, Paths& paths);
@@ -202,7 +199,7 @@ enum EdgeSide { esLeft = 1, esRight = 2};
 //forward declarations (for stuff used internally) ...
 struct TEdge;
 struct IntersectNode;
-struct LocalMinima;
+struct LocalMinimum;
 struct Scanbeam;
 struct OutPt;
 struct OutRec;
@@ -213,7 +210,6 @@ typedef std::vector < TEdge* > EdgeList;
 typedef std::vector < Join* > JoinList;
 typedef std::vector < IntersectNode* > IntersectList;
 
-
 //------------------------------------------------------------------------------
 
 //ClipperBase is the ancestor to the Clipper class. It should not be
@@ -236,12 +232,14 @@ protected:
   void PopLocalMinima();
   virtual void Reset();
   TEdge* ProcessBound(TEdge* E, bool IsClockwise);
-  void InsertLocalMinima(LocalMinima *newLm);
   void DoMinimaLML(TEdge* E1, TEdge* E2, bool IsClosed);
   TEdge* DescendToMin(TEdge *&E);
   void AscendToMax(TEdge *&E, bool Appending, bool IsClosed);
-  LocalMinima      *m_CurrentLM;
-  LocalMinima      *m_MinimaList;
+
+  typedef std::vector<LocalMinimum> MinimaList;
+  MinimaList::iterator m_CurrentLM;
+  MinimaList           m_MinimaList;
+
   bool              m_UseFullRange;
   EdgeList          m_edges;
   bool             m_PreserveCollinear;
@@ -268,7 +266,7 @@ public:
   void StrictlySimple(bool value) {m_StrictSimple = value;};
   //set the callback function for z value filling on intersections (otherwise Z is 0)
 #ifdef use_xyz
-  void ZFillFunction(TZFillCallback zFillFunc);
+  void ZFillFunction(ZFillCallback zFillFunc);
 #endif
 protected:
   void Reset();
@@ -279,7 +277,8 @@ private:
   JoinList          m_GhostJoins;
   IntersectList     m_IntersectList;
   ClipType          m_ClipType;
-  std::set< cInt, std::greater<cInt> > m_Scanbeam;
+  typedef std::priority_queue<cInt> ScanbeamList;
+  ScanbeamList      m_Scanbeam;
   TEdge           *m_ActiveEdges;
   TEdge           *m_SortedEdges;
   bool             m_ExecuteLocked;
@@ -289,7 +288,7 @@ private:
   bool             m_UsingPolyTree; 
   bool             m_StrictSimple;
 #ifdef use_xyz
-  TZFillCallback   m_ZFill; //custom callback 
+  ZFillCallback   m_ZFill; //custom callback 
 #endif
   void SetWindingCount(TEdge& edge);
   bool IsEvenOddFillType(const TEdge& edge) const;
@@ -308,21 +307,19 @@ private:
   bool IsTopHorz(const cInt XPos);
   void SwapPositionsInAEL(TEdge *edge1, TEdge *edge2);
   void DoMaxima(TEdge *e);
-  void PrepareHorzJoins(TEdge* horzEdge, bool isTopOfScanbeam);
   void ProcessHorizontals(bool IsTopOfScanbeam);
   void ProcessHorizontal(TEdge *horzEdge, bool isTopOfScanbeam);
   void AddLocalMaxPoly(TEdge *e1, TEdge *e2, const IntPoint &pt);
   OutPt* AddLocalMinPoly(TEdge *e1, TEdge *e2, const IntPoint &pt);
   OutRec* GetOutRec(int idx);
   void AppendPolygon(TEdge *e1, TEdge *e2);
-  void IntersectEdges(TEdge *e1, TEdge *e2,
-    const IntPoint &pt, bool protect = false);
+  void IntersectEdges(TEdge *e1, TEdge *e2, IntPoint &pt);
   OutRec* CreateOutRec();
   OutPt* AddOutPt(TEdge *e, const IntPoint &pt);
   void DisposeAllOutRecs();
   void DisposeOutRec(PolyOutList::size_type index);
-  bool ProcessIntersections(const cInt botY, const cInt topY);
-  void BuildIntersectList(const cInt botY, const cInt topY);
+  bool ProcessIntersections(const cInt topY);
+  void BuildIntersectList(const cInt topY);
   void ProcessIntersectList();
   void ProcessEdgesAtTopOfScanbeam(const cInt topY);
   void BuildResult(Paths& polys);
@@ -344,7 +341,7 @@ private:
   void FixupFirstLefts1(OutRec* OldOutRec, OutRec* NewOutRec);
   void FixupFirstLefts2(OutRec* OldOutRec, OutRec* NewOutRec);
 #ifdef use_xyz
-  void SetZ(IntPoint& pt, TEdge& e);
+  void SetZ(IntPoint& pt, TEdge& e1, TEdge& e2);
 #endif
 };
 //------------------------------------------------------------------------------

meta/HOWTO.txt

@@ -9,7 +9,7 @@ cd ~/Development/CuraEngine/output/reflection/
 run setting inheritance reflection
 
 cd ~/Development/CuraEngine
-./build/CuraEngine analyse ../Cura/resources/machines/fdmprinter.json meta/refl_ff.gv output/reflection/engineSettingLiterals.txt -piew
+./build/CuraEngine analyse ../Cura/resources/definitions/fdmprinter.def.json meta/refl_ff.gv output/reflection/engineSettingLiterals.txt -piew
 
 dot meta/refl_ff.gv -Tpng > meta/rafl_ff_dotted.png
 

resources/command_line_settings.json

@@ -1,42 +0,0 @@
-{
-    "version": 1, 
-    "name": "Command line setting defaults CuraEngine",
-    "author": "Ultimaker B.V.",
-    "categories": {
-        "command_line_settings": {
-            "label": "Command Line Settings",
-            "settings": {
-                "center_object": {
-                    "description": "Whether to center the object on the middle of the build platform (0,0), instead of using the coordinate system in which the object was saved.",
-                    "type": "boolean",
-                    "default": false
-                },
-                "machine_print_temp_wait": {
-                    "description": "Whether to wait for the nozzle temperature to be reached when preheating the nozzles at the start of the gcode.",
-                    "type": "boolean",
-                    "default": true
-                },
-                "mesh_position_x": {
-                    "description": "Offset applied to the object in the x direction.",
-                    "type": "float",
-                    "default": 0
-                },
-                "mesh_position_y": {
-                    "description": "Offset applied to the object in the y direction.",
-                    "type": "float",
-                    "default": 0
-                },
-                "mesh_position_z": {
-                    "description": "Offset applied to the object in the z direction. With this you can perform what was used to call 'Object Sink'.",
-                    "type": "float",
-                    "default": 0
-                },
-                "prime_tower_dir_outward": {
-                    "description": "Whether to start printing in the middle of the prime tower and end up at the perimeter, or the other way around. This is only used for certain types of prime tower.",
-                    "type": "boolean",
-                    "default": false
-                }
-            }
-        }
-    }
-}

src/ConicalOverhang.cpp

@@ -0,0 +1,35 @@
+/** Copyright (C) 2016 Tim Kuipers - Released under terms of the AGPLv3 License */
+#include "ConicalOverhang.h"
+
+
+namespace cura {
+
+
+void ConicalOverhang::apply(Slicer* slicer, double angle, int layer_thickness)
+{
+    double tanAngle = tan(angle);  // the XY-component of the angle
+    int max_dist_from_lower_layer = tanAngle * layer_thickness; // max dist which can be bridged
+
+    for (unsigned int layer_nr = slicer->layers.size() - 2; static_cast<int>(layer_nr) >= 0; layer_nr--)
+    {
+        SlicerLayer& layer = slicer->layers[layer_nr];
+        SlicerLayer& layer_above = slicer->layers[layer_nr + 1];
+        if (std::abs(max_dist_from_lower_layer) < 5)
+        { // magically nothing happens when max_dist_from_lower_layer == 0
+            // below magic code solves that
+            int safe_dist = 20;
+            Polygons diff = layer_above.polygons.difference(layer.polygons.offset(-safe_dist));
+            layer.polygons = layer.polygons.unionPolygons(diff);
+            layer.polygons = layer.polygons.smooth(safe_dist);
+            layer.polygons.simplify(safe_dist, safe_dist * safe_dist / 4);
+            // somehow layer.polygons get really jagged lines with a lot of vertices
+            // without the above steps slicing goes really slow
+        }
+        else
+        {
+            layer.polygons = layer.polygons.unionPolygons(layer_above.polygons.offset(-max_dist_from_lower_layer));
+        }
+    }
+}
+
+}//namespace cura

src/ConicalOverhang.h

@@ -0,0 +1,30 @@
+/** Copyright (C) 2016 Tim Kuipers - Released under terms of the AGPLv3 License */
+#ifndef CONICAL_OVERHANG_H
+#define CONICAL_OVERHANG_H
+
+#include "slicer.h"
+
+
+namespace cura {
+
+
+/*!
+ * A class for changing the geometry of a model such that it is printable without support -
+ * Or at least with at least support as possible
+ */
+class ConicalOverhang
+{
+public:
+    /*!
+     * Change the slice data such that the model becomes more printable
+     * 
+     * \param[in,out] slicer The slice data
+     * \param angle The maximum angle which can be printed without generating support (or at least generating least support)
+     * \param layer_thickness The general layer thickness
+     */
+    static void apply(Slicer* slicer, double angle, int layer_thickness);
+};
+
+}//namespace cura
+
+#endif // CONICAL_OVERHANG_H

src/ExtruderTrain.cpp

@@ -0,0 +1,27 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#include "ExtruderTrain.h"
+
+namespace cura 
+{
+int ExtruderTrain::getExtruderNr()
+{
+    return extruder_nr;
+}
+ExtruderTrain::ExtruderTrain(SettingsBaseVirtual* settings, int extruder_nr)
+: SettingsBase(settings)
+, extruder_nr(extruder_nr)
+{
+}
+
+bool ExtruderTrain::getIsUsed() const
+{
+    return is_used;
+}
+
+void ExtruderTrain::setIsUsed(bool used)
+{
+    is_used = used;
+}
+
+
+}//namespace cura

src/ExtruderTrain.h

@@ -1,3 +1,4 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
 #ifndef EXTRUDER_TRAIN_H
 #define EXTRUDER_TRAIN_H
 
@@ -9,14 +10,15 @@ namespace cura
 class ExtruderTrain : public SettingsBase
 {
     int extruder_nr;
+    bool is_used = false; //!< whether this extruder train is (probably) used during printing the current meshgroup
 public:
-    int getExtruderNr() { return extruder_nr; }
-    
-    ExtruderTrain(SettingsBaseVirtual* settings, int extruder_nr)
-    : SettingsBase(settings)
-    , extruder_nr(extruder_nr)
-    { }
-    
+    int getExtruderNr();
+
+    bool getIsUsed() const; //!< return whether this extruder train is (probably) used during printing the current meshgroup
+    void setIsUsed(bool used); //!< set whether this extruder train is (probably) used during printing the current meshgroup
+
+    ExtruderTrain(SettingsBaseVirtual* settings, int extruder_nr);
+
 };
 
 }//namespace cura

src/FanSpeedLayerTime.h

@@ -11,6 +11,7 @@ struct FanSpeedLayerTimeSettings
 public:
     double cool_min_layer_time;
     double cool_min_layer_time_fan_speed_max;
+    double cool_fan_speed_0;
     double cool_fan_speed_min;
     double cool_fan_speed_max;
     double cool_min_speed;

src/FffGcodeWriter.h

@@ -60,32 +60,34 @@ private:
     std::ofstream output_file;
 
     /*!
-     * Layer number of the last layer in which a prime tower has been printed per extruder train.  
-     * 
-     * This is recorded per extruder to account for a prime tower per extruder, instead of the mixed prime tower.
+     * Whether the skirt or brim polygons have been processed into planned paths
+     * for each extruder train.
      */
-    int last_prime_tower_poly_printed[MAX_EXTRUDERS]; 
+    bool skirt_brim_is_processed[MAX_EXTRUDERS];
 
-    bool skirt_is_processed[MAX_EXTRUDERS]; //!< Whether the skirt polygons have been processed into planned paths for each extruder train
+    std::vector<std::vector<unsigned int>> mesh_order_per_extruder; //!< For each extruder, the cyclic order of the meshes (the first element is not the starting element per se)
 
-    FanSpeedLayerTimeSettings fan_speed_layer_time_settings; //!< The settings used relating to minimal layer time and fan speeds.
+    /*!
+     * For each extruder whether priming has already been planned
+     */
+    bool extruder_prime_is_planned[MAX_EXTRUDERS];
+
+    std::vector<FanSpeedLayerTimeSettings> fan_speed_layer_time_settings_per_extruder; //!< The settings used relating to minimal layer time and fan speeds. Configured for each extruder.
+
+
+    GCodePlanner::PlanningState planner_state;
 
-    Point last_position_planned; //!< The position of the head before planning the next layer
-    int current_extruder_planned; //!< The extruder train in use before planning the next layer
-    bool is_inside_mesh_layer_part; //!< Whether the last position was inside a layer part (used in combing)
 public:
     FffGcodeWriter(SettingsBase* settings_)
     : SettingsMessenger(settings_)
+    , max_object_height(0)
     , layer_plan_buffer(this, gcode)
-    , last_position_planned(no_point)
-    , current_extruder_planned(0) // TODO: make configurable
-    , is_inside_mesh_layer_part(false)
+    , extruder_prime_is_planned {} // initialize all values in array with [false]
+    , planner_state{ no_point
+                    , 0 // changed somewhere early in FffGcodeWriter::writeGCode
+                    , false
+                    }
     {
-        max_object_height = 0;
-        for (unsigned int extruder_nr = 0; extruder_nr < MAX_EXTRUDERS; extruder_nr++)
-        {
-            skirt_is_processed[extruder_nr] = false;
-        }
     }
 
     /*!
@@ -153,8 +155,10 @@ public:
 private:
     /*!
      * Set the FffGcodeWriter::fan_speed_layer_time_settings by retrieving all settings from the global/per-meshgroup settings.
+     * 
+     * \param[out] storage The data storage to which to save the configuration
      */
-    void setConfigFanSpeedLayerTime();
+    void setConfigFanSpeedLayerTime(SliceDataStorage& storage);
 
     /*!
      * Create and set the SliceDataStorage::coasting_config for each extruder.
@@ -169,58 +173,79 @@ private:
      * \param[out] storage The data storage to which to save the configurations
      */
     void setConfigRetraction(SliceDataStorage& storage);
-    
+
     /*!
-     * Initialize the GcodePathConfig config parameters which don't change over all layers, for each feature.
+     * Get the extruder with which to start the print.
      * 
-     * The features are: skirt, support and for each mesh: outer wall, inner walls, skin, infill (and combined infill)
+     * Generally this is the adhesion_extruder_nr, but in case the platform adhesion type is none,
+     * the extruder with lowest number which is used on the first layer is used as initial extruder.
      * 
-     * \param[out] storage The data storage to which to save the configurations
+     * \param[in] storage where to get settings from.
      */
-    void initConfigs(SliceDataStorage& storage);
-    
+    unsigned int getStartExtruder(const SliceDataStorage& storage);
+
     /*!
      * Set temperatures and perform initial priming.
      * 
      * Write a stub header if CuraEngine is in command line tool mode. (Cause writing the header afterwards would entail moving all gcode down.)
      * 
      * \param[in] storage where the slice data is stored.
+     * \param[in] start_extruder_nr The extruder with which to start the print.
      */
-    void processStartingCode(SliceDataStorage& storage);
+    void processStartingCode(const SliceDataStorage& storage, const unsigned int start_extruder_nr);
 
     /*!
      * Move up and over the already printed meshgroups to print the next meshgroup.
      * 
      * \param[in] storage where the slice data is stored.
      */
-    void processNextMeshGroupCode(SliceDataStorage& storage);
+    void processNextMeshGroupCode(const SliceDataStorage& storage);
     
     /*!
      * Add raft layer plans onto the FffGcodeWriter::layer_plan_buffer
      * 
-     * \param[in] storage where the slice data is stored.
+     * \param[in,out] storage where the slice data is stored.
      * \param total_layers The total number of layers.
      */
-    void processRaft(SliceDataStorage& storage, unsigned int total_layers);
-    
+    void processRaft(const SliceDataStorage& storage, unsigned int total_layers);
+
     /*!
      * Convert the polygon data of a layer into a layer plan on the FffGcodeWriter::layer_plan_buffer
      * 
+     * In case of negative layer numbers, create layers only containing the data from
+     * the helper parts (support etc) to fill up the gap between the raft and the model.
+     * 
      * \param[in] storage where the slice data is stored.
      * \param layer_nr The index of the layer to write the gcode of.
      * \param total_layers The total number of layers.
-     * \param has_raft Whether a raft is used for this print.
+     * \return The layer plans
      */
-    void processLayer(SliceDataStorage& storage, unsigned int layer_nr, unsigned int total_layers, bool has_raft);
-    
+    GCodePlanner& processLayer(const SliceDataStorage& storage, int layer_nr, unsigned int total_layers) const;
+
     /*!
-     * Add the skirt to the layer plan \p gcodeLayer.
+     * Whether the extruders need to be primed separately just before they are used.
      * 
-     * \param[in] storage where the slice data is stored.
-     * \param gcodeLayer The initial planning of the gcode of the layer.
-     * \param extruder_nr The extrudewr train for which to process the skirt
+     * \return whether the extruders need to be primed separately just before they are used
      */
-    void processSkirt(SliceDataStorage& storage, GCodePlanner& gcodeLayer, unsigned int extruder_nr);
+    bool getExtrudersNeedPrimeDuringFirstLayer() const;
+
+    /*!
+     * Plan priming of all used extruders which haven't been primed yet
+     * \param[in] storage where the slice data is stored.
+     * \param layer_plan The initial planning of the g-code of the layer.
+     * \param layer_nr The index of the layer to write the gcode of.
+     */
+    void ensureAllExtrudersArePrimed(const SliceDataStorage& storage, GCodePlanner& layer_plan, const int layer_nr) const;
+
+    /*!
+     * Add the skirt or the brim to the layer plan \p gcodeLayer.
+     * 
+     * \param Storage where the slice data is stored.
+     * \param gcodeLayer The initial planning of the g-code of the layer.
+     * \param extruder_nr The extruder train for which to process the skirt or
+     * brim.
+     */
+    void processSkirtBrim(const SliceDataStorage& storage, GCodePlanner& gcodeLayer, unsigned int extruder_nr) const;
     
     /*!
      * Adds the ooze shield to the layer plan \p gcodeLayer.
@@ -229,7 +254,7 @@ private:
      * \param gcodeLayer The initial planning of the gcode of the layer.
      * \param layer_nr The index of the layer to write the gcode of.
      */
-    void processOozeShield(SliceDataStorage& storage, GCodePlanner& gcodeLayer, unsigned int layer_nr);
+    void processOozeShield(const SliceDataStorage& storage, GCodePlanner& gcodeLayer, unsigned int layer_nr) const;
     
     /*!
      * Adds the draft protection screen to the layer plan \p gcodeLayer.
@@ -238,123 +263,155 @@ private:
      * \param gcodeLayer The initial planning of the gcode of the layer.
      * \param layer_nr The index of the layer to write the gcode of.
      */
-    void processDraftShield(SliceDataStorage& storage, GCodePlanner& gcodeLayer, unsigned int layer_nr);
-    
+    void processDraftShield(const SliceDataStorage& storage, GCodePlanner& gcodeLayer, unsigned int layer_nr) const;
+
     /*!
-     * Calculate in which order to print the meshes.
+     * Calculate in which order to plan the extruders
      * 
      * \param[in] storage where the slice data is stored.
      * \param current_extruder The current extruder with which we last printed
-     * \return A vector of mesh indices ordered on print order.
+     * \return A vector of pairs of extruder numbers coupled with the mesh indices ordered on print order for that extruder.
      */
-    std::vector<unsigned int> calculateMeshOrder(SliceDataStorage& storage, int current_extruder);
-        
+    std::vector<int> calculateExtruderOrder(const SliceDataStorage& storage, int current_extruder) const;
+
+    /*!
+     * Calculate in which order to plan the meshes of a specific extruder
+     * 
+     * \param[in] storage where the slice data is stored.
+     * \param extruder_nr The extruder for which to determine the order
+     * \return A vector of pairs of extruder numbers coupled with the mesh indices ordered on print order for that extruder.
+     */
+    std::vector<unsigned int> calculateMeshOrder(const SliceDataStorage& storage, int extruder_nr) const;
+
     /*!
      * Add a single layer from a single mesh-volume to the layer plan \p gcodeLayer in mesh surface mode.
      * 
      * \param[in] storage where the slice data is stored.
      * \param mesh The mesh to add to the layer plan \p gcodeLayer.
+     * \param mesh_config the line config with which to print a print feature
      * \param gcodeLayer The initial planning of the gcode of the layer.
      * \param layer_nr The index of the layer to write the gcode of.
      * 
      */
-    void addMeshLayerToGCode_meshSurfaceMode(SliceDataStorage& storage, SliceMeshStorage* mesh, GCodePlanner& gcodeLayer, int layer_nr);
+    void addMeshLayerToGCode_meshSurfaceMode(const SliceDataStorage& storage, const SliceMeshStorage* mesh, const PathConfigStorage::MeshPathConfigs& mesh_config, GCodePlanner& gcodeLayer, int layer_nr) const;
     
     /*!
      * Add the open polylines from a single layer from a single mesh-volume to the layer plan \p gcodeLayer for mesh the surface modes.
      * 
      * \param[in] storage where the slice data is stored.
      * \param mesh The mesh for which to add to the layer plan \p gcodeLayer.
+     * \param mesh_config the line config with which to print a print feature
      * \param gcodeLayer The initial planning of the gcode of the layer.
      * \param layer_nr The index of the layer to write the gcode of.
      * 
      */
-    void addMeshOpenPolyLinesToGCode(SliceDataStorage& storage, SliceMeshStorage* mesh, GCodePlanner& gcode_layer, int layer_nr);
+    void addMeshOpenPolyLinesToGCode(const SliceDataStorage& storage, const SliceMeshStorage* mesh, const PathConfigStorage::MeshPathConfigs& mesh_config, GCodePlanner& gcode_layer, int layer_nr) const;
     
     /*!
-     * Add a single layer from a single mesh-volume to the layer plan \p gcodeLayer.
+     * Add a single layer from a single mesh-volume to the layer plan \p gcode_layer.
      * 
      * \param[in] storage where the slice data is stored.
-     * \param mesh The mesh to add to the layer plan \p gcodeLayer.
-     * \param gcodeLayer The initial planning of the gcode of the layer.
+     * \param mesh The mesh to add to the layer plan \p gcode_layer.
+     * \param mesh_config the line config with which to print a print feature
+     * \param gcode_layer The initial planning of the gcode of the layer.
      * \param layer_nr The index of the layer to write the gcode of.
      * 
      */
-    void addMeshLayerToGCode(SliceDataStorage& storage, SliceMeshStorage* mesh, GCodePlanner& gcodeLayer, int layer_nr);
+    void addMeshLayerToGCode(const SliceDataStorage& storage, const SliceMeshStorage* mesh, const PathConfigStorage::MeshPathConfigs& mesh_config, GCodePlanner& gcode_layer, int layer_nr) const;
+
+    /*!
+     * Add a single part from a given layer of a mesh-volume to the layer plan \p gcode_layer.
+     * 
+     * \param[in] storage where the slice data is stored.
+     * \param mesh The mesh to add to the layer plan \p gcode_layer.
+     * \param mesh_config the line config with which to print a print feature
+     * \param part The part to add
+     * \param gcode_layer The initial planning of the gcode of the layer.
+     * \param layer_nr The index of the layer to write the gcode of.
+     * 
+     */
+    void addMeshPartToGCode(const SliceDataStorage& storage, const SliceMeshStorage* mesh, const PathConfigStorage::MeshPathConfigs& mesh_config, const SliceLayerPart& part, GCodePlanner& gcode_layer, int layer_nr) const;
     
     /*!
      * Add thicker (multiple layers) sparse infill for a given part in a layer plan.
      * 
      * \param gcodeLayer The initial planning of the gcode of the layer.
      * \param mesh The mesh for which to add to the layer plan \p gcodeLayer.
+     * \param mesh_config the line config with which to print a print feature
      * \param part The part for which to create gcode
      * \param layer_nr The current layer number.
      * \param infill_line_distance The distance between the infill lines
      * \param infill_overlap The distance by which the infill overlaps with the wall insets.
      * \param fillAngle The angle in the XY plane at which the infill is generated.
-     * \param extrusionWidth extrusionWidth
      */
-    void processMultiLayerInfill(GCodePlanner& gcodeLayer, SliceMeshStorage* mesh, SliceLayerPart& part, unsigned int layer_nr, int infill_line_distance, int infill_overlap, int fillAngle, int extrusionWidth); 
+    void processMultiLayerInfill(GCodePlanner& gcodeLayer, const SliceMeshStorage* mesh, const PathConfigStorage::MeshPathConfigs& mesh_config, const SliceLayerPart& part, unsigned int layer_nr, int infill_line_distance, int infill_overlap, int fillAngle) const;
     
     /*!
      * Add normal sparse infill for a given part in a layer.
      * \param gcodeLayer The initial planning of the gcode of the layer.
      * \param mesh The mesh for which to add to the layer plan \p gcodeLayer.
+     * \param mesh_config the line config with which to print a print feature
      * \param part The part for which to create gcode
      * \param layer_nr The current layer number.
      * \param infill_line_distance The distance between the infill lines
      * \param infill_overlap The distance by which the infill overlaps with the wall insets.
      * \param fillAngle The angle in the XY plane at which the infill is generated.
-     * \param extrusionWidth extrusionWidth
      */
-    void processSingleLayerInfill(GCodePlanner& gcodeLayer, SliceMeshStorage* mesh, SliceLayerPart& part, unsigned int layer_nr, int infill_line_distance, int infill_overlap, int fillAngle, int extrusionWidth);
+    void processSingleLayerInfill(GCodePlanner& gcodeLayer, const SliceMeshStorage* mesh, const PathConfigStorage::MeshPathConfigs& mesh_config, const SliceLayerPart& part, unsigned int layer_nr, int infill_line_distance, int infill_overlap, int fillAngle) const;
     
     /*!
      * Generate the insets for the walls of a given layer part.
      * \param gcodeLayer The initial planning of the gcode of the layer.
      * \param mesh The mesh for which to add to the layer plan \p gcodeLayer.
+     * \param mesh_config the line config with which to print a print feature
      * \param part The part for which to create gcode
      * \param layer_nr The current layer number.
      * \param z_seam_type dir3ective for where to start the outer paerimeter of a part
+     * \param z_seam_pos The location near where to start the outer inset in case \p z_seam_type is 'back'
      */
-    void processInsets(GCodePlanner& gcodeLayer, SliceMeshStorage* mesh, SliceLayerPart& part, unsigned int layer_nr, EZSeamType z_seam_type);
+    void processInsets(GCodePlanner& gcodeLayer, const SliceMeshStorage* mesh, const PathConfigStorage::MeshPathConfigs& mesh_config, const SliceLayerPart& part, unsigned int layer_nr, EZSeamType z_seam_type, Point z_seam_pos) const;
     
     
     /*!
-     * Add the gcode of the top/bottom skin of the given part.
+     * Add the gcode of the top/bottom skin of the given part and of the perimeter gaps.
+     * 
+     * Perimter gaps are generated for skin outlines and printed while the skin fill of the skin part is printed.
+     * Perimeter gaps between the walls are added to the gcode afterwards.
+     * 
      * \param gcodeLayer The initial planning of the gcode of the layer.
      * \param mesh The mesh for which to add to the layer plan \p gcodeLayer.
+     * \param mesh_config the line config with which to print a print feature
      * \param part The part for which to create gcode
      * \param layer_nr The current layer number.
-     * \param skin_overlap The distance by which the skinfill overlaps with the wall insets.
+     * \param skin_overlap The distance by which the skin overlaps with the wall insets and the distance by which the perimeter gaps overlap with adjacent print features.
      * \param fillAngle The angle in the XY plane at which the infill is generated.
-     * \param extrusionWidth extrusionWidth
      */
-    void processSkin(cura::GCodePlanner& gcode_layer, cura::SliceMeshStorage* mesh, cura::SliceLayerPart& part, unsigned int layer_nr, int skin_overlap, int infill_angle, int extrusion_width);
-    
+    void processSkinAndPerimeterGaps(GCodePlanner& gcode_layer, const SliceMeshStorage* mesh, const PathConfigStorage::MeshPathConfigs& mesh_config, const SliceLayerPart& part, unsigned int layer_nr, int skin_overlap, int infill_angle) const;
+
     /*!
-     * Add the support to the layer plan \p gcodeLayer of the current layer.
+     * Add the support to the layer plan \p gcodeLayer of the current layer for all support parts with the given \p extruder_nr.
      * \param[in] storage where the slice data is stored.
      * \param gcodeLayer The initial planning of the gcode of the layer.
      * \param layer_nr The index of the layer to write the gcode of.
-     * \param extruder_nr_before The extruder number at the start of the layer (before other print parts aka the rest)
-     * \param before_rest Whether the function has been called before adding the rest to the layer plan \p gcodeLayer, or after.
+     * \return whether any support was added to the layer plan
      */
-    void addSupportToGCode(SliceDataStorage& storage, GCodePlanner& gcodeLayer, int layer_nr, int extruder_nr_before, bool before_rest);
+    bool addSupportToGCode(const SliceDataStorage& storage, GCodePlanner& gcodeLayer, int layer_nr, int extruder_nr) const;
     /*!
      * Add the support lines/walls to the layer plan \p gcodeLayer of the current layer.
      * \param[in] storage where the slice data is stored.
      * \param gcodeLayer The initial planning of the gcode of the layer.
      * \param layer_nr The index of the layer to write the gcode of.
+     * \return whether any support infill was added to the layer plan
      */
-    void addSupportInfillToGCode(SliceDataStorage& storage, GCodePlanner& gcodeLayer, int layer_nr);
+    bool addSupportInfillToGCode(const SliceDataStorage& storage, GCodePlanner& gcodeLayer, int layer_nr) const;
     /*!
-     * Add the support roofs to the layer plan \p gcodeLayer of the current layer.
+     * Add the support skins to the layer plan \p gcodeLayer of the current layer.
      * \param[in] storage where the slice data is stored.
      * \param gcodeLayer The initial planning of the gcode of the layer.
      * \param layer_nr The index of the layer to write the gcode of.
+     * \return whether any support skin was added to the layer plan
      */
-    void addSupportRoofsToGCode(SliceDataStorage& storage, GCodePlanner& gcodeLayer, int layer_nr);
+    bool addSupportRoofsToGCode(const SliceDataStorage& storage, GCodePlanner& gcodeLayer, int layer_nr) const;
     
     /*!
      * Change to a new extruder, and add the prime tower instructions if the new extruder is different from the last.
@@ -366,7 +423,7 @@ private:
      * \param layer_nr The index of the layer to write the gcode of.
      * \param extruder_nr The extruder to which to switch
      */
-    void setExtruder_addPrime(SliceDataStorage& storage, GCodePlanner& gcode_layer, int layer_nr, int extruder_nr);
+    void setExtruder_addPrime(const SliceDataStorage& storage, GCodePlanner& gcode_layer, int layer_nr, int extruder_nr) const;
     
     /*!
      * Add the prime tower gcode for the current layer.
@@ -375,7 +432,7 @@ private:
      * \param layer_nr The index of the layer to write the gcode of.
      * \param prev_extruder The current extruder with which we last printed.
      */
-    void addPrimeTower(SliceDataStorage& storage, GCodePlanner& gcodeLayer, int layer_nr, int prev_extruder);
+    void addPrimeTower(const SliceDataStorage& storage, GCodePlanner& gcodeLayer, int layer_nr, int prev_extruder) const;
     
     /*!
      * Add the end gcode and set all temperatures to zero.

src/FffPolygonGenerator.cpp

@@ -2,7 +2,10 @@
 
 #include <algorithm>
 #include <map> // multimap (ordered map allowing duplicate keys)
+#include <omp.h>
 
+#include "utils/math.h"
+#include "utils/algorithm.h"
 #include "slicer.h"
 #include "utils/gettime.h"
 #include "utils/logoutput.h"
@@ -11,13 +14,13 @@
 #include "multiVolumes.h"
 #include "layerPart.h"
 #include "WallsComputation.h"
-#include "skirt.h"
+#include "SkirtBrim.h"
 #include "skin.h"
 #include "infill.h"
 #include "raft.h"
-#include "debug.h"
 #include "progress/Progress.h"
 #include "PrintFeature.h"
+#include "ConicalOverhang.h"
 #include "progress/ProgressEstimator.h"
 #include "progress/ProgressStageEstimator.h"
 #include "progress/ProgressEstimatorLinear.h"
@@ -26,7 +29,7 @@
 namespace cura
 {
 
-    
+
 bool FffPolygonGenerator::generateAreas(SliceDataStorage& storage, MeshGroup* meshgroup, TimeKeeper& timeKeeper)
 {
     if (!sliceModel(meshgroup, timeKeeper, storage)) 
@@ -39,6 +42,22 @@ bool FffPolygonGenerator::generateAreas(SliceDataStorage& storage, MeshGroup* me
     return true;
 }
 
+unsigned int FffPolygonGenerator::getDraftShieldLayerCount(const unsigned int total_layers) const
+{
+    if (!getSettingBoolean("draft_shield_enabled"))
+    {
+        return 0;
+    }
+    switch (getSettingAsDraftShieldHeightLimitation("draft_shield_height_limitation"))
+    {
+        default:
+        case DraftShieldHeightLimitation::FULL:
+            return total_layers;
+        case DraftShieldHeightLimitation::LIMITED:
+            return std::max((coord_t)0, (getSettingInMicrons("draft_shield_height") - getSettingInMicrons("layer_height_0")) / getSettingInMicrons("layer_height") + 1);
+    }
+}
+
 bool FffPolygonGenerator::sliceModel(MeshGroup* meshgroup, TimeKeeper& timeKeeper, SliceDataStorage& storage) /// slices the model
 {
     Progress::messageProgressStage(Progress::Stage::SLICING, &timeKeeper);
@@ -61,8 +80,8 @@ bool FffPolygonGenerator::sliceModel(MeshGroup* meshgroup, TimeKeeper& timeKeepe
         return false;
     }
     int initial_slice_z = initial_layer_thickness - layer_thickness / 2;
-    int layer_count = (storage.model_max.z - initial_slice_z) / layer_thickness + 1;
-    if(layer_count <= 0) //Model is shallower than layer_height_0, so not even the first layer is sliced. Return an empty model then.
+    int slice_layer_count = (storage.model_max.z - initial_slice_z) / layer_thickness + 1;
+    if (slice_layer_count <= 0) //Model is shallower than layer_height_0, so not even the first layer is sliced. Return an empty model then.
     {
         return true; //This is NOT an error state!
     }
@@ -71,7 +90,7 @@ bool FffPolygonGenerator::sliceModel(MeshGroup* meshgroup, TimeKeeper& timeKeepe
     for(unsigned int mesh_idx = 0; mesh_idx < meshgroup->meshes.size(); mesh_idx++)
     {
         Mesh& mesh = meshgroup->meshes[mesh_idx];
-        Slicer* slicer = new Slicer(&mesh, initial_slice_z, layer_thickness, layer_count, mesh.getSettingBoolean("meshfix_keep_open_polygons"), mesh.getSettingBoolean("meshfix_extensive_stitching"));
+        Slicer* slicer = new Slicer(&mesh, initial_slice_z, layer_thickness, slice_layer_count, mesh.getSettingBoolean("meshfix_keep_open_polygons"), mesh.getSettingBoolean("meshfix_extensive_stitching"));
         slicerList.push_back(slicer);
         /*
         for(SlicerLayer& layer : slicer->layers)
@@ -83,25 +102,79 @@ bool FffPolygonGenerator::sliceModel(MeshGroup* meshgroup, TimeKeeper& timeKeepe
         */
         Progress::messageProgress(Progress::Stage::SLICING, mesh_idx + 1, meshgroup->meshes.size());
     }
-    
-    log("Layer count: %i\n", layer_count);
 
     meshgroup->clear();///Clear the mesh face and vertex data, it is no longer needed after this point, and it saves a lot of memory.
 
-    Progress::messageProgressStage(Progress::Stage::PARTS, &timeKeeper);
-    //carveMultipleVolumes(storage.meshes);
-    generateMultipleVolumesOverlap(slicerList);
-    // TODO!!! dont generate multi volume overlap with infill meshes!
-    
-    storage.meshes.reserve(slicerList.size()); // causes there to be no resize in meshes so that the pointers in sliceMeshStorage._config to retraction_config don't get invalidated.
+
     for(unsigned int meshIdx=0; meshIdx < slicerList.size(); meshIdx++)
     {
-        storage.meshes.emplace_back(&meshgroup->meshes[meshIdx]); // new mesh in storage had settings from the Mesh
-        SliceMeshStorage& meshStorage = storage.meshes.back();
         Mesh& mesh = storage.meshgroup->meshes[meshIdx];
-        
-        
-        createLayerParts(meshStorage, slicerList[meshIdx], mesh.getSettingBoolean("meshfix_union_all"), mesh.getSettingBoolean("meshfix_union_all_remove_holes"));
+        if (mesh.getSettingBoolean("conical_overhang_enabled") && !mesh.getSettingBoolean("anti_overhang_mesh"))
+        {
+            ConicalOverhang::apply(slicerList[meshIdx], mesh.getSettingInAngleRadians("conical_overhang_angle"), layer_thickness);
+        }
+    }
+
+    Progress::messageProgressStage(Progress::Stage::PARTS, &timeKeeper);
+
+    if (storage.getSettingBoolean("carve_multiple_volumes"))
+    {
+        carveMultipleVolumes(slicerList, storage.getSettingBoolean("alternate_carve_order"));
+    }
+    generateMultipleVolumesOverlap(slicerList);
+
+    storage.print_layer_count = 0;
+    for (unsigned int meshIdx = 0; meshIdx < slicerList.size(); meshIdx++)
+    {
+        Mesh& mesh = storage.meshgroup->meshes[meshIdx];
+        Slicer* slicer = slicerList[meshIdx];
+        if (!mesh.getSettingBoolean("anti_overhang_mesh") && !mesh.getSettingBoolean("infill_mesh"))
+        {
+            storage.print_layer_count = std::max(storage.print_layer_count, (unsigned int)slicer->layers.size());
+        }
+    }
+    storage.support.supportLayers.resize(storage.print_layer_count);
+
+    storage.meshes.reserve(slicerList.size()); // causes there to be no resize in meshes so that the pointers in sliceMeshStorage._config to retraction_config don't get invalidated.
+    for (unsigned int meshIdx = 0; meshIdx < slicerList.size(); meshIdx++)
+    {
+        Slicer* slicer = slicerList[meshIdx];
+        Mesh& mesh = storage.meshgroup->meshes[meshIdx];
+
+        // always make a new SliceMeshStorage, so that they have the same ordering / indexing as meshgroup.meshes
+        storage.meshes.emplace_back(&meshgroup->meshes[meshIdx], slicer->layers.size()); // new mesh in storage had settings from the Mesh
+        SliceMeshStorage& meshStorage = storage.meshes.back();
+
+        if (mesh.getSettingBoolean("anti_overhang_mesh"))
+        {
+            for (unsigned int layer_nr = 0; layer_nr < slicer->layers.size(); layer_nr++)
+            {
+                SupportLayer& support_layer = storage.support.supportLayers[layer_nr];
+                SlicerLayer& slicer_layer = slicer->layers[layer_nr];
+                support_layer.anti_overhang = support_layer.anti_overhang.unionPolygons(slicer_layer.polygons);
+                meshStorage.layers[layer_nr].printZ =
+                    slicer_layer.z
+                    + getSettingInMicrons("layer_height_0")
+                    - initial_slice_z;
+            }
+            continue;
+        }
+        if (mesh.getSettingBoolean("support_mesh"))
+        {
+            for (unsigned int layer_nr = 0; layer_nr < slicer->layers.size(); layer_nr++)
+            {
+                SupportLayer& support_layer = storage.support.supportLayers[layer_nr];
+                SlicerLayer& slicer_layer = slicer->layers[layer_nr];
+                support_layer.support_mesh.add(slicer_layer.polygons);
+                meshStorage.layers[layer_nr].printZ =
+                    slicer_layer.z
+                    + getSettingInMicrons("layer_height_0")
+                    - initial_slice_z;
+            }
+            continue;
+        }
+
+        createLayerParts(meshStorage, slicer, mesh.getSettingBoolean("meshfix_union_all"), mesh.getSettingBoolean("meshfix_union_all_remove_holes"));
         delete slicerList[meshIdx];
 
         bool has_raft = getSettingAsPlatformAdhesion("adhesion_type") == EPlatformAdhesion::RAFT;
@@ -116,9 +189,7 @@ bool FffPolygonGenerator::sliceModel(MeshGroup* meshgroup, TimeKeeper& timeKeepe
             {
                 ExtruderTrain* train = storage.meshgroup->getExtruderTrain(getSettingAsIndex("adhesion_extruder_nr"));
                 layer.printZ += 
-                    train->getSettingInMicrons("raft_base_thickness") 
-                    + train->getSettingInMicrons("raft_interface_thickness") 
-                    + train->getSettingAsCount("raft_surface_layers") * train->getSettingInMicrons("raft_surface_thickness")
+                    Raft::getTotalThickness(storage)
                     + train->getSettingInMicrons("raft_airgap")
                     - train->getSettingInMicrons("layer_0_z_overlap"); // shift all layers (except 0) down
                 if (layer_nr == 0)
@@ -126,19 +197,13 @@ bool FffPolygonGenerator::sliceModel(MeshGroup* meshgroup, TimeKeeper& timeKeepe
                     layer.printZ += train->getSettingInMicrons("layer_0_z_overlap"); // undo shifting down of first layer
                 }
             }
-    
- 
+
             if (layer.parts.size() > 0 || (mesh.getSettingAsSurfaceMode("magic_mesh_surface_mode") != ESurfaceMode::NORMAL && layer.openPolyLines.size() > 0) )
             {
                 meshStorage.layer_nr_max_filled_layer = layer_nr; // last set by the highest non-empty layer
             } 
-                
-            if (CommandSocket::isInstantiated())
-            {
-                CommandSocket::getInstance()->sendLayerInfo(layer_nr, layer.printZ, layer_nr == 0? getSettingInMicrons("layer_height_0") : getSettingInMicrons("layer_height"));
-            }
         }
-        
+
         Progress::messageProgress(Progress::Stage::PARTS, meshIdx + 1, slicerList.size());
     }
     return true;
@@ -148,12 +213,12 @@ void FffPolygonGenerator::slices2polygons(SliceDataStorage& storage, TimeKeeper&
 {
     // compute layer count and remove first empty layers
     // there is no separate progress stage for removeEmptyFisrtLayer (TODO)
-    unsigned int total_layers = 0;
+    unsigned int slice_layer_count = 0;
     for (SliceMeshStorage& mesh : storage.meshes)
     {
-        if (!mesh.getSettingBoolean("infill_mesh"))
+        if (!mesh.getSettingBoolean("infill_mesh") && !mesh.getSettingBoolean("anti_overhang_mesh"))
         {
-            total_layers = std::max<unsigned int>(total_layers, mesh.layers.size());
+            slice_layer_count = std::max<unsigned int>(slice_layer_count, mesh.layers.size());
         }
     }
 
@@ -178,65 +243,95 @@ void FffPolygonGenerator::slices2polygons(SliceDataStorage& storage, TimeKeeper&
             mesh_order.push_back(order_and_mesh_idx.second);
         }
     }
-    for (unsigned int mesh_idx : mesh_order)
+    for (unsigned int mesh_order_idx(0); mesh_order_idx < mesh_order.size(); ++mesh_order_idx)
     {
-        processBasicWallsSkinInfill(storage, mesh_idx, mesh_order, total_layers, inset_skin_progress_estimate);
-        Progress::messageProgress(Progress::Stage::INSET_SKIN, mesh_idx + 1, storage.meshes.size());
+        processBasicWallsSkinInfill(storage, mesh_order_idx, mesh_order, inset_skin_progress_estimate);
+        Progress::messageProgress(Progress::Stage::INSET_SKIN, mesh_order_idx + 1, storage.meshes.size());
     }
+
+    for (unsigned int layer_nr = 0; layer_nr < slice_layer_count; layer_nr++)
+    {
+        SliceLayer* layer = nullptr;
+        for (unsigned int mesh_idx = 0; mesh_idx < storage.meshes.size(); mesh_idx++)
+        { // find first mesh which has this layer
+            SliceMeshStorage& mesh = storage.meshes[mesh_idx];
+            if (int(layer_nr) <= mesh.layer_nr_max_filled_layer)
+            {
+                layer = &mesh.layers[layer_nr];
+                break;
+            }
+        }
+        if (layer != nullptr)
+        {
+            if (CommandSocket::isInstantiated())
+            { // send layer info
+                CommandSocket::getInstance()->sendOptimizedLayerInfo(layer_nr, layer->printZ, layer_nr == 0? getSettingInMicrons("layer_height_0") : getSettingInMicrons("layer_height"));
+            }
+        }
+    }
+
+    log("Layer count: %i\n", storage.print_layer_count);
+
     //layerparts2HTML(storage, "output/output.html");
 
+    Progress::messageProgressStage(Progress::Stage::SUPPORT, &time_keeper);
+
+    AreaSupport::generateSupportAreas(storage, storage.print_layer_count);
+
     // we need to remove empty layers after we have procesed the insets
     // processInsets might throw away parts if they have no wall at all (cause it doesn't fit)
     // brim depends on the first layer not being empty
-    removeEmptyFirstLayers(storage, getSettingInMicrons("layer_height"), total_layers); // changes total_layers!
-    if (total_layers == 0)
+    // only remove empty layers if we haven't generate support, because then support was added underneath the model.
+    //   for some materials it's better to print on support than on the buildplate.
+    removeEmptyFirstLayers(storage, getSettingInMicrons("layer_height"), storage.print_layer_count); // changes storage.print_layer_count!
+    if (storage.print_layer_count == 0)
     {
         log("Stopping process because there are no non-empty layers.\n");
         return;
     }
-
-    Progress::messageProgressStage(Progress::Stage::SUPPORT, &time_keeper);  
-
-    AreaSupport::generateSupportAreas(storage, total_layers);
     
     /*
     if (storage.support.generated)
     {
-        for (unsigned int layer_idx = 0; layer_idx < total_layers; layer_idx++)
+        for (unsigned int layer_idx = 0; layer_idx < storage.print_layer_count; layer_idx++)
         {
             Polygons& support = storage.support.supportLayers[layer_idx].supportAreas;
-            if (CommandSocket::isInstantiated()) 
-            {
-                CommandSocket::getInstance()->sendPolygons(PrintFeatureType::Infill, layer_idx, support, 100); //getSettingInMicrons("support_line_width"));
-            }
+            ExtruderTrain* infill_extr = storage.meshgroup->getExtruderTrain(storage.getSettingAsIndex("support_infill_extruder_nr"));
+            CommandSocket::sendPolygons(PrintFeatureType::Infill, support, 100); // infill_extr->getSettingInMicrons("support_line_width"));
         }
     }
     */
 
+    computePrintHeightStatistics(storage);
+
     // handle helpers
-    storage.primeTower.computePrimeTowerMax(storage);
-    storage.primeTower.generatePaths(storage, total_layers);
+    storage.primeTower.generatePaths(storage);
+    storage.primeTower.subtractFromSupport(storage);
+    
+    logDebug("Processing ooze shield\n");
+    processOozeShield(storage);
 
-    processOozeShield(storage, total_layers);
-
-    processDraftShield(storage, total_layers);
+    logDebug("Processing draft shield\n");
+    processDraftShield(storage);
 
+    logDebug("Processing platform adhesion\n");
     processPlatformAdhesion(storage);
     
     // meshes post processing
     for (SliceMeshStorage& mesh : storage.meshes)
     {
-        processDerivedWallsSkinInfill(mesh, total_layers);
+        processDerivedWallsSkinInfill(mesh);
     }
 }
 
-void FffPolygonGenerator::processBasicWallsSkinInfill(SliceDataStorage& storage, unsigned int mesh_idx, std::vector<unsigned int>& mesh_order, size_t total_layers, ProgressStageEstimator& inset_skin_progress_estimate)
+void FffPolygonGenerator::processBasicWallsSkinInfill(SliceDataStorage& storage, unsigned int mesh_order_idx, std::vector<unsigned int>& mesh_order, ProgressStageEstimator& inset_skin_progress_estimate)
 {
-    
+    unsigned int mesh_idx = mesh_order[mesh_order_idx];
     SliceMeshStorage& mesh = storage.meshes[mesh_idx];
+    size_t mesh_layer_count = mesh.layers.size();
     if (mesh.getSettingBoolean("infill_mesh"))
     {
-        processInfillMesh(storage, mesh_idx, mesh_order, total_layers);
+        processInfillMesh(storage, mesh_order_idx, mesh_order);
     }
     
     // TODO: make progress more accurate!!
@@ -246,21 +341,52 @@ void FffPolygonGenerator::processBasicWallsSkinInfill(SliceDataStorage& storage,
     
     inset_skin_progress_estimate.nextStage(mesh_inset_skin_progress_estimator); // the stage of this function call
     
-    ProgressEstimatorLinear* inset_estimator = new ProgressEstimatorLinear(total_layers);
+    ProgressEstimatorLinear* inset_estimator = new ProgressEstimatorLinear(mesh_layer_count);
     mesh_inset_skin_progress_estimator->nextStage(inset_estimator);
     
     
     // walls
-    for(unsigned int layer_number = 0; layer_number < total_layers; layer_number++)
+    unsigned int processed_layer_count = 0;
+#pragma omp parallel for default(none) shared(mesh_layer_count, mesh, inset_skin_progress_estimate, processed_layer_count) schedule(dynamic)
+    for (unsigned int layer_number = 0; layer_number < mesh.layers.size(); layer_number++)
     {
+        logDebug("Processing insets for layer %i of %i\n", layer_number, mesh_layer_count);
         processInsets(mesh, layer_number);
-        double progress = inset_skin_progress_estimate.progress(layer_number);
-        Progress::messageProgress(Progress::Stage::INSET_SKIN, progress * 100, 100);
+#ifdef _OPENMP
+        if (omp_get_thread_num() == 0)
+#endif
+        { // progress estimation is done only in one thread so that no two threads message progress at the same time
+            int _processed_layer_count;
+#pragma omp atomic read
+                _processed_layer_count = processed_layer_count;
+            double progress = inset_skin_progress_estimate.progress(_processed_layer_count);
+            Progress::messageProgress(Progress::Stage::INSET_SKIN, progress * 100, 100);
+        }
+#pragma omp atomic
+        processed_layer_count++;
     }
 
-    ProgressEstimatorLinear* skin_estimator = new ProgressEstimatorLinear(total_layers);
+    ProgressEstimatorLinear* skin_estimator = new ProgressEstimatorLinear(mesh_layer_count);
     mesh_inset_skin_progress_estimator->nextStage(skin_estimator);
-    
+
+    bool process_infill = mesh.getSettingInMicrons("infill_line_distance") > 0;
+    if (!process_infill)
+    { // do process infill anyway if it's modified by modifier meshes
+        for (unsigned int other_mesh_order_idx(mesh_order_idx + 1); other_mesh_order_idx < mesh_order.size(); ++other_mesh_order_idx)
+        {
+            unsigned int other_mesh_idx = mesh_order[other_mesh_order_idx];
+            SliceMeshStorage& other_mesh = storage.meshes[other_mesh_idx];
+            if (other_mesh.getSettingBoolean("infill_mesh"))
+            {
+                AABB3D aabb = storage.meshgroup->meshes[mesh_idx].getAABB();
+                AABB3D other_aabb = storage.meshgroup->meshes[other_mesh_idx].getAABB();
+                if (aabb.hit(other_aabb))
+                {
+                    process_infill = true;
+                }
+            }
+        }
+    }
     // skin & infill
 //     Progress::messageProgressStage(Progress::Stage::SKIN, &time_keeper);
     int mesh_max_bottom_layer_count = 0;
@@ -268,34 +394,54 @@ void FffPolygonGenerator::processBasicWallsSkinInfill(SliceDataStorage& storage,
     {
         mesh_max_bottom_layer_count = std::max(mesh_max_bottom_layer_count, mesh.getSettingAsCount("bottom_layers"));
     }
-    for(unsigned int layer_number = 0; layer_number < total_layers; layer_number++)
+
+    processed_layer_count = 0;
+#pragma omp parallel default(none) shared(mesh_layer_count, mesh, mesh_max_bottom_layer_count, process_infill, inset_skin_progress_estimate, processed_layer_count)
     {
-        if (!mesh.getSettingBoolean("magic_spiralize") || static_cast<int>(layer_number) < mesh_max_bottom_layer_count)    //Only generate up/downskin and infill for the first X layers when spiralize is choosen.
+
+#pragma omp for schedule(dynamic)
+        for (unsigned int layer_number = 0; layer_number < mesh.layers.size(); layer_number++)
         {
-            processSkinsAndInfill(mesh, layer_number);
+            logDebug("Processing skins and infill layer %i of %i\n", layer_number, mesh_layer_count);
+            if (!mesh.getSettingBoolean("magic_spiralize") || static_cast<int>(layer_number) < mesh_max_bottom_layer_count)    //Only generate up/downskin and infill for the first X layers when spiralize is choosen.
+            {
+                processSkinsAndInfill(mesh, layer_number, process_infill);
+            }
+#ifdef _OPENMP
+            if (omp_get_thread_num() == 0)
+#endif
+            { // progress estimation is done only in one thread so that no two threads message progress at the same time
+                int _processed_layer_count;
+#pragma omp atomic read
+                    _processed_layer_count = processed_layer_count;
+                double progress = inset_skin_progress_estimate.progress(_processed_layer_count);
+                Progress::messageProgress(Progress::Stage::INSET_SKIN, progress * 100, 100);
+            }
+#pragma omp atomic
+                processed_layer_count++;
+        }
         }
-        double progress = inset_skin_progress_estimate.progress(layer_number);
-        Progress::messageProgress(Progress::Stage::INSET_SKIN, progress * 100, 100);
-    }
 }
 
-void FffPolygonGenerator::processInfillMesh(SliceDataStorage& storage, unsigned int mesh_idx, std::vector<unsigned int>& mesh_order, size_t total_layers)
+void FffPolygonGenerator::processInfillMesh(SliceDataStorage& storage, unsigned int mesh_order_idx, std::vector<unsigned int>& mesh_order)
 {
+    unsigned int mesh_idx = mesh_order[mesh_order_idx];
     SliceMeshStorage& mesh = storage.meshes[mesh_idx];
+    mesh.layer_nr_max_filled_layer = -1;
     for (unsigned int layer_idx = 0; layer_idx < mesh.layers.size(); layer_idx++)
     {
         SliceLayer& layer = mesh.layers[layer_idx];
         std::vector<PolygonsPart> new_parts;
 
         for (unsigned int other_mesh_idx : mesh_order)
-        {
+        { // limit the infill mesh's outline to within the infill of all meshes with lower order
             if (other_mesh_idx == mesh_idx)
             {
                 break; // all previous meshes have been processed
             }
             SliceMeshStorage& other_mesh = storage.meshes[other_mesh_idx];
             if (layer_idx >= other_mesh.layers.size())
-            {
+            { // there can be no interaction between the infill mesh and this other non-infill mesh
                 continue;
             }
 
@@ -304,29 +450,30 @@ void FffPolygonGenerator::processInfillMesh(SliceDataStorage& storage, unsigned
             for (SliceLayerPart& part : layer.parts)
             {
                 for (SliceLayerPart& other_part : other_layer.parts)
-                {
+                { // limit the outline of each part of this infill mesh to the infill of parts of the other mesh with lower infill mesh order
                     if (!part.boundaryBox.hit(other_part.boundaryBox))
-                    {
+                    { // early out
                         continue;
                     }
-                    Polygons& infill = other_part.infill_area;
-                    Polygons new_outline = part.outline.intersection(infill);
+                    Polygons new_outline = part.outline.intersection(other_part.getOwnInfillArea());
                     if (new_outline.size() == 1)
-                    {
+                    { // we don't have to call splitIntoParts, because a single polygon can only be a single part
                         PolygonsPart outline_part_here;
                         outline_part_here.add(new_outline[0]);
                         new_parts.push_back(outline_part_here);
                     }
                     else if (new_outline.size() > 1)
-                    {
+                    { // we don't know whether it's a multitude of parts because of newly introduced holes, or because the polygon has been split up
                         std::vector<PolygonsPart> new_parts_here = new_outline.splitIntoParts();
                         for (PolygonsPart& new_part_here : new_parts_here)
                         {
                             new_parts.push_back(new_part_here);
                         }
                     }
-                    infill = infill.difference(part.outline);
-                    other_part.infill_area_per_combine.back() = infill;
+                    // change the infill area of the non-infill mesh which is to be filled with e.g. lines
+                    other_part.infill_area_own = other_part.getOwnInfillArea().difference(part.outline);
+                    // note: don't change the part.infill_area, because we change the structure of that area, while the basic area in which infill is printed remains the same
+                    //       the infill area remains the same for combing
                 }
             }
         }
@@ -338,14 +485,28 @@ void FffPolygonGenerator::processInfillMesh(SliceDataStorage& storage, unsigned
             layer.parts.back().outline = part;
             layer.parts.back().boundaryBox.calculate(part);
         }
+
+        if (layer.parts.size() > 0 || (mesh.getSettingAsSurfaceMode("magic_mesh_surface_mode") != ESurfaceMode::NORMAL && layer.openPolyLines.size() > 0) )
+        {
+            mesh.layer_nr_max_filled_layer = layer_idx; // last set by the highest non-empty layer
+        } 
     }
     
 }
 
-void FffPolygonGenerator::processDerivedWallsSkinInfill(SliceMeshStorage& mesh, size_t total_layers)
+void FffPolygonGenerator::processDerivedWallsSkinInfill(SliceMeshStorage& mesh)
 {
+    // create gradual infill areas
+    SkinInfillAreaComputation::generateGradualInfill(mesh, mesh.getSettingInMicrons("gradual_infill_step_height"), mesh.getSettingAsCount("gradual_infill_steps"));
+
+    //SubDivCube Pre-compute Octree
+    if (mesh.getSettingAsFillMethod("infill_pattern") == EFillMethod::CUBICSUBDIV)
+    {
+        SubDivCube::precomputeOctree(mesh);
+    }
+
     // combine infill
-    unsigned int combined_infill_layers = mesh.getSettingInMicrons("infill_sparse_thickness") / std::max(getSettingInMicrons("layer_height"), 1); //How many infill layers to combine to obtain the requested sparse thickness.
+    unsigned int combined_infill_layers = std::max(1U, round_divide(mesh.getSettingInMicrons("infill_sparse_thickness"), std::max(getSettingInMicrons("layer_height"), (coord_t)1))); //How many infill layers to combine to obtain the requested sparse thickness.
     combineInfillLayers(mesh,combined_infill_layers);
 
     // fuzzy skin
@@ -355,52 +516,64 @@ void FffPolygonGenerator::processDerivedWallsSkinInfill(SliceMeshStorage& mesh,
     }
 }
 
+/*
+ * This function is executed in a parallel region based on layer_nr.
+ * When modifying make sure any changes does not introduce data races.
+ *
+ * processInsets only reads and writes data for the current layer
+ */
 void FffPolygonGenerator::processInsets(SliceMeshStorage& mesh, unsigned int layer_nr) 
 {
     SliceLayer* layer = &mesh.layers[layer_nr];
     if (mesh.getSettingAsSurfaceMode("magic_mesh_surface_mode") != ESurfaceMode::SURFACE)
     {
         int inset_count = mesh.getSettingAsCount("wall_line_count");
-        if (mesh.getSettingBoolean("magic_spiralize") && static_cast<int>(layer_nr) < mesh.getSettingAsCount("bottom_layers") && layer_nr % 2 == 1)//Add extra insets every 2 layers when spiralizing, this makes bottoms of cups watertight.
+        if (mesh.getSettingBoolean("magic_spiralize") && static_cast<int>(layer_nr) < mesh.getSettingAsCount("bottom_layers") && ((layer_nr % 2) + 2) % 2 == 1)//Add extra insets every 2 layers when spiralizing, this makes bottoms of cups watertight.
             inset_count += 5;
         int line_width_x = mesh.getSettingInMicrons("wall_line_width_x");
         int line_width_0 = mesh.getSettingInMicrons("wall_line_width_0");
         if (mesh.getSettingBoolean("alternate_extra_perimeter"))
-            inset_count += layer_nr % 2; 
+        {
+            inset_count += ((layer_nr % 2) + 2) % 2;
+        }
         bool recompute_outline_based_on_outer_wall = mesh.getSettingBoolean("support_enable");
         WallsComputation walls_computation(mesh.getSettingInMicrons("wall_0_inset"), line_width_0, line_width_x, inset_count, recompute_outline_based_on_outer_wall);
         walls_computation.generateInsets(layer);
     }
-    if (mesh.getSettingAsSurfaceMode("magic_mesh_surface_mode") != ESurfaceMode::NORMAL)
-    {
-        for (PolygonRef polyline : layer->openPolyLines)
-        {
-            Polygons segments;
-            for (unsigned int point_idx = 1; point_idx < polyline.size(); point_idx++)
-            {
-                PolygonRef segment = segments.newPoly();
-                segment.add(polyline[point_idx-1]);
-                segment.add(polyline[point_idx]);
-            }
-        }
-    }
 }
 
 void FffPolygonGenerator::removeEmptyFirstLayers(SliceDataStorage& storage, const int layer_height, unsigned int& total_layers)
-{ 
+{
     int n_empty_first_layers = 0;
     for (unsigned int layer_idx = 0; layer_idx < total_layers; layer_idx++)
     { 
         bool layer_is_empty = true;
-        for (SliceMeshStorage& mesh : storage.meshes)
+        if (storage.support.generated && layer_idx < storage.support.supportLayers.size())
         {
-            SliceLayer& layer = mesh.layers[layer_idx];
-            if (layer.parts.size() > 0 || (mesh.getSettingAsSurfaceMode("magic_mesh_surface_mode") != ESurfaceMode::NORMAL && layer.openPolyLines.size() > 0) )
+            SupportLayer& support_layer = storage.support.supportLayers[layer_idx];
+            if (support_layer.supportAreas.size() > 0 || support_layer.skin.size() > 0)
             {
                 layer_is_empty = false;
                 break;
             }
         }
+        for (SliceMeshStorage& mesh : storage.meshes)
+        {
+            SliceLayer& layer = mesh.layers[layer_idx];
+            if (mesh.getSettingAsSurfaceMode("magic_mesh_surface_mode") != ESurfaceMode::NORMAL && layer.openPolyLines.size() > 0)
+            {
+                layer_is_empty = false;
+                break;
+            }
+            for (const SliceLayerPart& part : layer.parts)
+            {
+                if (part.print_outline.size() > 0)
+                {
+                    layer_is_empty = false;
+                    break;
+                }
+            }
+        }
         
         if (layer_is_empty) 
         {
@@ -422,87 +595,154 @@ void FffPolygonGenerator::removeEmptyFirstLayers(SliceDataStorage& storage, cons
             {
                 layer.printZ -= n_empty_first_layers * layer_height;
             }
+            mesh.layer_nr_max_filled_layer -= n_empty_first_layers;
         }
         total_layers -= n_empty_first_layers;
+        storage.support.layer_nr_max_filled_layer -= n_empty_first_layers;
+        std::vector<SupportLayer>& support_layers = storage.support.supportLayers;
+        support_layers.erase(support_layers.begin(), support_layers.begin() + n_empty_first_layers);
     }
 }
-  
-void FffPolygonGenerator::processSkinsAndInfill(SliceMeshStorage& mesh, unsigned int layer_nr) 
+
+/*
+ * This function is executed in a parallel region based on layer_nr.
+ * When modifying make sure any changes does not introduce data races.
+ *
+ * generateSkins read (depend on) data from mesh.layers[*].parts[*].insets and write mesh.layers[n].parts[*].skin_parts
+ * generateInfill read mesh.layers[n].parts[*].{insets,skin_parts,boundingBox} and write mesh.layers[n].parts[*].infill_area
+ *
+ * processSkinsAndInfill read (depend on) mesh.layers[*].parts[*].{insets,boundingBox}.
+ *                       write mesh.layers[n].parts[*].{skin_parts,infill_area}.
+ */
+void FffPolygonGenerator::processSkinsAndInfill(SliceMeshStorage& mesh, unsigned int layer_nr, bool process_infill)
 {
     if (mesh.getSettingAsSurfaceMode("magic_mesh_surface_mode") == ESurfaceMode::SURFACE) 
     { 
         return;
     }
-    
-    int wall_line_count = mesh.getSettingAsCount("wall_line_count");
-    int skin_extrusion_width = mesh.getSettingInMicrons("skin_line_width");
-    int innermost_wall_extrusion_width = (wall_line_count == 1)? mesh.getSettingInMicrons("wall_line_width_0") : mesh.getSettingInMicrons("wall_line_width_x");
-    generateSkins(layer_nr, mesh, skin_extrusion_width, mesh.getSettingAsCount("bottom_layers"), mesh.getSettingAsCount("top_layers"), wall_line_count, innermost_wall_extrusion_width, mesh.getSettingAsCount("skin_outline_count"), mesh.getSettingBoolean("skin_no_small_gaps_heuristic"));
-    if (mesh.getSettingInMicrons("infill_line_distance") > 0)
-    {
+
+    const int wall_line_count = mesh.getSettingAsCount("wall_line_count");
+    const int innermost_wall_line_width = (wall_line_count == 1) ? mesh.getSettingInMicrons("wall_line_width_0") : mesh.getSettingInMicrons("wall_line_width_x");
+    generateSkins(layer_nr, mesh, mesh.getSettingAsCount("bottom_layers"), mesh.getSettingAsCount("top_layers"), wall_line_count, innermost_wall_line_width, mesh.getSettingAsCount("skin_outline_count"), mesh.getSettingBoolean("skin_no_small_gaps_heuristic"));
+
+    if (process_infill)
+    { // process infill when infill density > 0
+        // or when other infill meshes want to modify this infill
         int infill_skin_overlap = 0;
         bool infill_is_dense = mesh.getSettingInMicrons("infill_line_distance") < mesh.getSettingInMicrons("infill_line_width") + 10;
         if (!infill_is_dense && mesh.getSettingAsFillMethod("infill_pattern") != EFillMethod::CONCENTRIC)
         {
-            infill_skin_overlap = skin_extrusion_width / 2;
+            infill_skin_overlap = innermost_wall_line_width / 2;
         }
-        generateInfill(layer_nr, mesh, innermost_wall_extrusion_width, infill_skin_overlap, wall_line_count);
+        generateInfill(layer_nr, mesh, innermost_wall_line_width, infill_skin_overlap, wall_line_count);
     }
 }
 
-void FffPolygonGenerator::processOozeShield(SliceDataStorage& storage, unsigned int total_layers)
+void FffPolygonGenerator::computePrintHeightStatistics(SliceDataStorage& storage)
+{
+    int extruder_count = storage.meshgroup->getExtruderCount();
+
+    std::vector<int>& max_print_height_per_extruder = storage.max_print_height_per_extruder;
+    assert(max_print_height_per_extruder.size() == 0 && "storage.max_print_height_per_extruder shouldn't have been initialized yet!");
+    max_print_height_per_extruder.resize(extruder_count, -1); //Initialize all as -1.
+    { // compute max_object_height_per_extruder
+        //Height of the meshes themselves.
+        for (SliceMeshStorage& mesh : storage.meshes)
+        {
+            if (mesh.getSettingBoolean("anti_overhang_mesh") || mesh.getSettingBoolean("support_mesh"))
+            {
+                continue; //Special type of mesh that doesn't get printed.
+            }
+            const unsigned int extr_nr = mesh.getSettingAsIndex("extruder_nr");
+            max_print_height_per_extruder[extr_nr] = std::max(max_print_height_per_extruder[extr_nr], mesh.layer_nr_max_filled_layer);
+        }
+
+        //Height of where the support reaches.
+        const unsigned int support_infill_extruder_nr = storage.getSettingAsIndex("support_infill_extruder_nr"); // TODO: support extruder should be configurable per object
+        max_print_height_per_extruder[support_infill_extruder_nr] =
+            std::max(max_print_height_per_extruder[support_infill_extruder_nr],
+                     storage.support.layer_nr_max_filled_layer);
+        const unsigned int support_skin_extruder_nr = storage.getSettingAsIndex("support_interface_extruder_nr"); // TODO: support skin extruder should be configurable per object
+        max_print_height_per_extruder[support_skin_extruder_nr] =
+            std::max(max_print_height_per_extruder[support_skin_extruder_nr],
+                     storage.support.layer_nr_max_filled_layer);
+
+        //Height of where the platform adhesion reaches.
+        if (storage.getSettingAsPlatformAdhesion("adhesion_type") != EPlatformAdhesion::NONE)
+        {
+            const unsigned int adhesion_extruder_nr = storage.getSettingAsIndex("adhesion_extruder_nr");
+            max_print_height_per_extruder[adhesion_extruder_nr] =
+                std::max(0, max_print_height_per_extruder[adhesion_extruder_nr]);
+        }
+    }
+
+    storage.max_print_height_order = order(max_print_height_per_extruder);
+    if (extruder_count >= 2)
+    {
+        int second_highest_extruder = storage.max_print_height_order[extruder_count - 2];
+        storage.max_print_height_second_to_last_extruder = max_print_height_per_extruder[second_highest_extruder];
+    }
+    else
+    {
+        storage.max_print_height_second_to_last_extruder = -1;
+    }
+}
+
+
+void FffPolygonGenerator::processOozeShield(SliceDataStorage& storage)
 {
     if (!getSettingBoolean("ooze_shield_enabled"))
     {
         return;
     }
-    
-    int ooze_shield_dist = getSettingInMicrons("ooze_shield_dist");
-    
-    for(unsigned int layer_nr=0; layer_nr<total_layers; layer_nr++)
+
+    const int ooze_shield_dist = getSettingInMicrons("ooze_shield_dist");
+
+    for (int layer_nr = 0; layer_nr <= storage.max_print_height_second_to_last_extruder; layer_nr++)
     {
-        storage.oozeShield.push_back(storage.getLayerOutlines(layer_nr, true).offset(ooze_shield_dist));
+        storage.oozeShield.push_back(storage.getLayerOutlines(layer_nr, true).offset(ooze_shield_dist, ClipperLib::jtRound));
     }
-    
-    int largest_printed_radius = MM2INT(1.0); // TODO: make var a parameter, and perhaps even a setting?
-    for(unsigned int layer_nr=0; layer_nr<total_layers; layer_nr++)
+
+    double angle = getSettingInAngleDegrees("ooze_shield_angle");
+    if (angle <= 89)
     {
-        storage.oozeShield[layer_nr] = storage.oozeShield[layer_nr].offset(-largest_printed_radius).offset(largest_printed_radius); 
+        int allowed_angle_offset = tan(getSettingInAngleRadians("ooze_shield_angle")) * getSettingInMicrons("layer_height"); // Allow for a 60deg angle in the oozeShield.
+        for (int layer_nr = 1; layer_nr <= storage.max_print_height_second_to_last_extruder; layer_nr++)
+        {
+            storage.oozeShield[layer_nr] = storage.oozeShield[layer_nr].unionPolygons(storage.oozeShield[layer_nr - 1].offset(-allowed_angle_offset));
+        }
+        for (int layer_nr = storage.max_print_height_second_to_last_extruder; layer_nr > 0; layer_nr--)
+        {
+            storage.oozeShield[layer_nr - 1] = storage.oozeShield[layer_nr - 1].unionPolygons(storage.oozeShield[layer_nr].offset(-allowed_angle_offset));
+        }
     }
-    int allowed_angle_offset = tan(getSettingInAngleRadians("ooze_shield_angle")) * getSettingInMicrons("layer_height");//Allow for a 60deg angle in the oozeShield.
-    for(unsigned int layer_nr=1; layer_nr<total_layers; layer_nr++)
+
+    const float largest_printed_area = 1.0; // TODO: make var a parameter, and perhaps even a setting?
+    for (int layer_nr = 0; layer_nr <= storage.max_print_height_second_to_last_extruder; layer_nr++)
     {
-        storage.oozeShield[layer_nr] = storage.oozeShield[layer_nr].unionPolygons(storage.oozeShield[layer_nr-1].offset(-allowed_angle_offset));
-    }
-    for(unsigned int layer_nr=total_layers-1; layer_nr>0; layer_nr--)
-    {
-        storage.oozeShield[layer_nr-1] = storage.oozeShield[layer_nr-1].unionPolygons(storage.oozeShield[layer_nr].offset(-allowed_angle_offset));
+        storage.oozeShield[layer_nr].removeSmallAreas(largest_printed_area);
     }
 }
 
-void FffPolygonGenerator::processDraftShield(SliceDataStorage& storage, unsigned int total_layers)
+void FffPolygonGenerator::processDraftShield(SliceDataStorage& storage)
 {
-    int draft_shield_height = getSettingInMicrons("draft_shield_height");
-    int draft_shield_dist = getSettingInMicrons("draft_shield_dist");
-    int layer_height_0 = getSettingInMicrons("layer_height_0");
-    int layer_height = getSettingInMicrons("layer_height");
-    
-    if (draft_shield_height < layer_height_0)
+    const unsigned int draft_shield_layers = getDraftShieldLayerCount(storage.print_layer_count);
+    if (draft_shield_layers <= 0)
     {
         return;
     }
-    
-    unsigned int max_screen_layer = (draft_shield_height - layer_height_0) / layer_height + 1;
-    
-    int layer_skip = 500 / layer_height + 1;
-    
+    const int layer_height = getSettingInMicrons("layer_height");
+
+    const unsigned int layer_skip = 500 / layer_height + 1;
+
     Polygons& draft_shield = storage.draft_protection_shield;
-    for (unsigned int layer_nr = 0; layer_nr < total_layers && layer_nr < max_screen_layer; layer_nr += layer_skip)
+    for (unsigned int layer_nr = 0; layer_nr < storage.print_layer_count && layer_nr < draft_shield_layers; layer_nr += layer_skip)
     {
         draft_shield = draft_shield.unionPolygons(storage.getLayerOutlines(layer_nr, true));
     }
-    
-    storage.draft_protection_shield = draft_shield.convexHull(draft_shield_dist);
+
+    const int draft_shield_dist = getSettingInMicrons("draft_shield_dist");
+    storage.draft_protection_shield = draft_shield.approxConvexHull(draft_shield_dist);
 }
 
 void FffPolygonGenerator::processPlatformAdhesion(SliceDataStorage& storage)
@@ -511,22 +751,20 @@ void FffPolygonGenerator::processPlatformAdhesion(SliceDataStorage& storage)
     switch(getSettingAsPlatformAdhesion("adhesion_type"))
     {
     case EPlatformAdhesion::SKIRT:
-        if (train->getSettingInMicrons("draft_shield_height") == 0)
-        { // draft screen replaces skirt
-            generateSkirt(storage, train->getSettingInMicrons("skirt_gap"), train->getSettingAsCount("skirt_line_count"), train->getSettingInMicrons("skirt_minimal_length"));
+        {
+            constexpr bool outside_polygons_only = true;
+            SkirtBrim::generate(storage, train->getSettingInMicrons("skirt_gap"), train->getSettingAsCount("skirt_line_count"), outside_polygons_only);
         }
         break;
     case EPlatformAdhesion::BRIM:
-        generateSkirt(storage, 0, train->getSettingAsCount("brim_line_count"), train->getSettingInMicrons("skirt_minimal_length"));
+        SkirtBrim::generate(storage, 0, train->getSettingAsCount("brim_line_count"), train->getSettingBoolean("brim_outside_only"));
         break;
     case EPlatformAdhesion::RAFT:
-        generateRaft(storage, train->getSettingInMicrons("raft_margin"));
+        Raft::generate(storage, train->getSettingInMicrons("raft_margin"));
+        break;
+    case EPlatformAdhesion::NONE:
         break;
     }
-    
-    Polygons skirt_sent = storage.skirt[0];
-    for (int extruder = 1; extruder < storage.meshgroup->getExtruderCount(); extruder++)
-        skirt_sent.add(storage.skirt[extruder]);
 }
 
 

src/FffPolygonGenerator.h

@@ -46,7 +46,19 @@ public:
     bool generateAreas(SliceDataStorage& storage, MeshGroup* object, TimeKeeper& timeKeeper);
   
 private:
-    
+    /*!
+     * \brief Helper function to get the actual height of the draft shield.
+     *
+     * The draft shield is the height of the print if we've set the draft shield
+     * limitation to FULL. Otherwise the height is set to the height limit
+     * setting. If the draft shield is disabled, the height is always 0.
+     *
+     * \param total_layers The total number of layers in the print (the height
+     * of the draft shield if the limit is FULL.
+     * \return The actual height of the draft shield.
+     */
+    unsigned int getDraftShieldLayerCount(unsigned int total_layers) const;
+
     /*!
      * Slice the \p object and store the outlines in the \p storage.
      * 
@@ -70,31 +82,28 @@ private:
      * Processes the outline information as stored in the \p storage: generates inset perimeter polygons, skin and infill
      * 
      * \param storage Input and Output parameter: fetches the outline information (see SliceLayerPart::outline) and generates the other reachable field of the \p storage
-     * \param mesh_idx The index of the mesh to process in the vector of meshes in \p storage
+     * \param mesh_order_idx The index of the mesh_idx in \p mesh_order to process in the vector of meshes in \p storage
      * \param mesh_order The order in which the meshes are processed (used for infill meshes)
-     * \param total_layers The total number of layers over all objects
      * \param inset_skin_progress_estimate The progress stage estimate calculator
      */
-    void processBasicWallsSkinInfill(SliceDataStorage& storage, unsigned int mesh_idx, std::vector<unsigned int>& mesh_order, size_t total_layers, ProgressStageEstimator& inset_skin_progress_estimate);
+    void processBasicWallsSkinInfill(SliceDataStorage& storage, unsigned int mesh_order_idx, std::vector<unsigned int>& mesh_order, ProgressStageEstimator& inset_skin_progress_estimate);
     
     /*!
      * Process the mesh to be an infill mesh: limit all outlines to within the infill of normal meshes and subtract their volume from the infill of those meshes
      * 
      * \param storage Input and Output parameter: fetches the outline information (see SliceLayerPart::outline) and generates the other reachable field of the \p storage
-     * \param mesh_idx The index of the mesh to process in the vector of meshes in \p storage
+     * \param mesh_order_idx The index of the mesh_idx in \p mesh_order to process in the vector of meshes in \p storage
      * \param mesh_order The order in which the meshes are processed
-     * \param total_layers The total number of layers over all objects
      */
-    void processInfillMesh(SliceDataStorage& storage, unsigned int mesh_idx, std::vector<unsigned int>& mesh_order, size_t total_layers);
+    void processInfillMesh(SliceDataStorage& storage, unsigned int mesh_order_idx, std::vector<unsigned int>& mesh_order);
     
     /*!
      * Process features which are derived from the basic walls, skin, and infill:
      * fuzzy skin, infill combine
      * 
      * \param mesh Input and Output parameter: fetches the outline information (see SliceLayerPart::outline) and generates the other reachable field of the \p storage
-     * \param total_layers The total number of layers over all objects
      */
-    void processDerivedWallsSkinInfill(SliceMeshStorage& mesh, size_t total_layers);
+    void processDerivedWallsSkinInfill(SliceMeshStorage& mesh);
     
     /*!
      * Remove all bottom layers which are empty.
@@ -106,7 +115,14 @@ private:
      * \param total_layers The total number of layers
      */
     void removeEmptyFirstLayers(SliceDataStorage& storage, const int layer_height, unsigned int& total_layers);
-    
+
+    /*!
+     * Set \ref SliceDataStorage::max_print_height_per_extruder and \ref SliceDataStorage::max_print_height_order and \ref SliceDataStorage::max_print_height_second_to_last_extruder
+     * 
+     * \param[in,out] storage Where to retrieve mesh and support etc settings from and where the print height statistics are saved.
+     */
+    void computePrintHeightStatistics(SliceDataStorage& storage);
+
     /*!
      * Generate the inset polygons which form the walls.
      * \param mesh Input and Output parameter: fetches the outline information (see SliceLayerPart::outline) and generates the other reachable field of the \p storage
@@ -117,40 +133,42 @@ private:
     /*!
      * Generate the outline of the ooze shield.
      * \param storage Input and Output parameter: fetches the outline information (see SliceLayerPart::outline) and generates the other reachable field of the \p storage
-     * \param total_layers The total number of layers 
      */
-    void processOozeShield(SliceDataStorage& storage, unsigned int total_layers);
+    void processOozeShield(SliceDataStorage& storage);
     
     /*!
      * Generate the skin areas.
      * \param mesh Input and Output parameter: fetches the outline information (see SliceLayerPart::outline) and generates the other reachable field of the \p storage
      * \param layer_nr The layer for which to generate the skin areas.
+     * \param process_infill Generate infill areas
      */
-    void processSkinsAndInfill(SliceMeshStorage& mesh, unsigned int layer_nr); 
+    void processSkinsAndInfill(SliceMeshStorage& mesh, unsigned int layer_nr, bool process_infill); 
 
     /*!
      * Generate the polygons where the draft screen should be.
      * 
      * \param storage Input and Output parameter: fetches the outline information (see SliceLayerPart::outline) and generates the other reachable field of the \p storage
-     * \param total_layers The total number of layers 
      */
-    void processDraftShield(SliceDataStorage& storage, unsigned int total_layers);
+    void processDraftShield(SliceDataStorage& storage);
+
     /*!
      * Generate the skirt/brim/raft areas/insets.
      * \param storage Input and Output parameter: fetches the outline information (see SliceLayerPart::outline) and generates the other reachable field of the \p storage
      */
     void processPlatformAdhesion(SliceDataStorage& storage);
-    
-    
-    
+
     /*!
      * Make the outer wall 'fuzzy'
+     * 
+     * Introduce new vertices and move existing vertices in or out by a random distance, based on the fuzzy skin settings.
+     * 
+     * This only changes the outer wall.
+     * 
+     * \param[in,out] mesh where the outer wall is retrieved and stored in.
      */
     void processFuzzyWalls(SliceMeshStorage& mesh);
-    
-    
 
-    
+
 };
 }//namespace cura
 #endif // FFF_AREA_GENERATOR_H

src/FffProcessor.cpp

@@ -45,29 +45,6 @@ std::string FffProcessor::getAllSettingsString(MeshGroup& meshgroup, bool first_
     return sstream.str();
 }
 
-bool FffProcessor::processFiles(const std::vector< std::string >& files)
-{
-    time_keeper.restart();
-    MeshGroup* meshgroup = new MeshGroup(this);
-    
-    for(std::string filename : files)
-    {
-        log("Loading %s from disk...\n", filename.c_str());
-
-        FMatrix3x3 matrix;
-        if (!loadMeshIntoMeshGroup(meshgroup, filename.c_str(), matrix))
-        {
-            logError("Failed to load model: %s\n", filename.c_str());
-            return false;
-        }
-    }
-    
-    meshgroup->finalize();
-
-    log("Loaded from disk in %5.3fs\n", time_keeper.restart());
-    return processMeshGroup(meshgroup);
-}
-
 bool FffProcessor::processMeshGroup(MeshGroup* meshgroup)
 {
     if (SHOW_ALL_SETTINGS) { logWarning(getAllSettingsString(*meshgroup, meshgroup_number == 0).c_str()); }
@@ -83,7 +60,7 @@ bool FffProcessor::processMeshGroup(MeshGroup* meshgroup)
     bool empty = true;
     for (Mesh& mesh : meshgroup->meshes)
     {
-        if (!mesh.getSettingBoolean("infill_mesh"))
+        if (!mesh.getSettingBoolean("infill_mesh") && !mesh.getSettingBoolean("anti_overhang_mesh"))
         {
             empty = false;
         }
@@ -126,7 +103,7 @@ bool FffProcessor::processMeshGroup(MeshGroup* meshgroup)
     if (CommandSocket::isInstantiated())
     {
         CommandSocket::getInstance()->flushGcode();
-        CommandSocket::getInstance()->sendLayerData();
+        CommandSocket::getInstance()->sendOptimizedLayerData();
     }
     log("Total time elapsed %5.2fs.\n", time_keeper_total.restart());
 

src/FffProcessor.h

@@ -151,13 +151,6 @@ public:
         gcode_writer.finalize();
     }
 
-    /*!
-     * Process all files into one meshgroup
-     * 
-     * \warning Unused!
-     */
-    bool processFiles(const std::vector<std::string> &files);
-
     /*!
      * Generate gcode for a given \p meshgroup
      * The primary function of this class.

src/GCodePathConfig.cpp

@@ -0,0 +1,80 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+
+#include "utils/intpoint.h" // INT2MM
+#include "GCodePathConfig.h"
+
+namespace cura 
+{
+
+GCodePathConfig::GCodePathConfig(const GCodePathConfig& other)
+: type(other.type)
+, speed_derivatives(other.speed_derivatives)
+, line_width(other.line_width)
+, layer_thickness(other.layer_thickness)
+, flow(other.flow)
+, extrusion_mm3_per_mm(other.extrusion_mm3_per_mm)
+{
+}
+
+
+
+GCodePathConfig::GCodePathConfig(PrintFeatureType type, int line_width, int layer_height, double flow, GCodePathConfig::SpeedDerivatives speed_derivatives)
+: type(type)
+, speed_derivatives(speed_derivatives)
+, line_width(line_width)
+, layer_thickness(layer_height)
+, flow(flow)
+, extrusion_mm3_per_mm(calculateExtrusion())
+{
+}
+
+void GCodePathConfig::smoothSpeed(GCodePathConfig::SpeedDerivatives first_layer_config, int layer_nr, int max_speed_layer_nr) 
+{
+    double max_speed_layer = max_speed_layer_nr;
+    speed_derivatives.speed = (speed_derivatives.speed * layer_nr) / max_speed_layer + (first_layer_config.speed * (max_speed_layer - layer_nr) / max_speed_layer);
+    speed_derivatives.acceleration = (speed_derivatives.acceleration * layer_nr) / max_speed_layer + (first_layer_config.acceleration * (max_speed_layer - layer_nr) / max_speed_layer);
+    speed_derivatives.jerk = (speed_derivatives.jerk * layer_nr) / max_speed_layer + (first_layer_config.jerk * (max_speed_layer - layer_nr) / max_speed_layer);
+}
+
+double GCodePathConfig::getExtrusionMM3perMM() const
+{
+    return extrusion_mm3_per_mm;
+}
+
+double GCodePathConfig::getSpeed() const
+{
+    return speed_derivatives.speed;
+}
+
+double GCodePathConfig::getAcceleration() const
+{
+    return speed_derivatives.acceleration;
+}
+
+double GCodePathConfig::getJerk() const
+{
+    return speed_derivatives.jerk;
+}
+
+int GCodePathConfig::getLineWidth() const
+{
+    return line_width;
+}
+
+bool GCodePathConfig::isTravelPath() const
+{
+    return line_width == 0;
+}
+
+double GCodePathConfig::getFlowPercentage() const
+{
+    return flow;
+}
+
+double GCodePathConfig::calculateExtrusion() const
+{
+    return INT2MM(line_width) * INT2MM(layer_thickness) * double(flow) / 100.0;
+}
+
+
+}//namespace cura

src/GCodePathConfig.h

@@ -0,0 +1,88 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef G_CODE_PATH_CONFIG_H
+#define G_CODE_PATH_CONFIG_H
+
+#include "RetractionConfig.h"
+#include "PrintFeature.h"
+
+namespace cura 
+{
+
+/*!
+ * The GCodePathConfig is the configuration for moves/extrusion actions. This defines at which width the line is printed and at which speed.
+ */
+class GCodePathConfig
+{
+    friend class GCodePlannerTest;
+public:
+    /*!
+     * A simple wrapper class for all derivatives of position which are used when printing a line
+     */
+    struct SpeedDerivatives
+    {
+        double speed; //!< movement speed (mm/s)
+        double acceleration; //!< acceleration of head movement (mm/s^2)
+        double jerk; //!< jerk of the head movement (around stand still) as instantaneous speed change (mm/s)
+    };
+    const PrintFeatureType type; //!< name of the feature type
+private:
+    SpeedDerivatives speed_derivatives; //!< The speed settings (and acceleration and jerk) of the extruded line. May be changed when smoothSpeed is called.
+    const int line_width; //!< width of the line extruded
+    const int layer_thickness; //!< current layer height in micron
+    const double flow; //!< extrusion flow modifier in %
+    const double extrusion_mm3_per_mm;//!< current mm^3 filament moved per mm line traversed
+public:
+    GCodePathConfig(PrintFeatureType type, int line_width, int layer_height, double flow, SpeedDerivatives speed_derivatives); // , SpeedDerivatives slowdown_speed_derivatives, int layer_nr, int max_speed_layer_nr);
+
+    /*!
+     * copy constructor
+     */
+    GCodePathConfig(const GCodePathConfig& other);
+
+    /*!
+     * Set the speed to somewhere between the speed of @p first_layer_config and the iconic speed.
+     * 
+     * \warning This functions should not be called with @p layer_nr > @p max_speed_layer !
+     * 
+     * \warning Calling this function twice will smooth the speed more toward \p first_layer_config
+     * 
+     * \param first_layer_config The speed settings at layer zero
+     * \param layer_nr The layer number 
+     * \param max_speed_layer The layer number for which the speed_iconic should be used.
+     */
+    void smoothSpeed(SpeedDerivatives first_layer_config, int layer_nr, int max_speed_layer);
+
+    /*!
+     * Can only be called after the layer height has been set (which is done while writing the gcode!)
+     */
+    double getExtrusionMM3perMM() const;
+
+    /*!
+     * Get the movement speed in mm/s
+     */
+    double getSpeed() const;
+
+    /*!
+     * Get the current acceleration of this config
+     */
+    double getAcceleration() const;
+
+    /*!
+     * Get the current jerk of this config
+     */
+    double getJerk() const;
+
+    int getLineWidth() const;
+
+    bool isTravelPath() const;
+
+    double getFlowPercentage() const;
+
+private:
+    double calculateExtrusion() const;
+};
+
+
+}//namespace cura
+
+#endif // G_CODE_PATH_CONFIG_H

src/LayerPlanBuffer.cpp

@@ -13,11 +13,11 @@ void LayerPlanBuffer::flush()
 {
     if (buffer.size() > 0)
     {
-        insertPreheatCommands(); // insert preheat commands of the very last layer
+        insertTempCommands(); // insert preheat commands of the very last layer
     }
     while (!buffer.empty())
     {
-        buffer.front().writeGCode(gcode);
+        buffer.front()->writeGCode(gcode);
         if (CommandSocket::isInstantiated())
         {
             CommandSocket::getInstance()->flushGcode();
@@ -30,120 +30,346 @@ void LayerPlanBuffer::flush()
 void LayerPlanBuffer::insertPreheatCommand(ExtruderPlan& extruder_plan_before, double time_after_extruder_plan_start, int extruder, double temp)
 {
     double acc_time = 0.0;
-    for (unsigned int path_idx = 0; path_idx < extruder_plan_before.paths.size(); path_idx++)
+    for (unsigned int path_idx = extruder_plan_before.paths.size() - 1; int(path_idx) != -1 ; path_idx--)
     {
         GCodePath& path = extruder_plan_before.paths[path_idx];
-        acc_time += path.estimates.getTotalTime();
+        const double time_this_path = path.estimates.getTotalTime();
+        acc_time += time_this_path;
         if (acc_time > time_after_extruder_plan_start)
         {
-//                 logError("Inserting %f\t seconds too early!\n", acc_time - time_after_extruder_plan_start);
-            extruder_plan_before.insertCommand(path_idx, extruder, temp, false, acc_time - time_after_extruder_plan_start);
+            const double time_before_path_end = acc_time - time_after_extruder_plan_start;
+            bool wait = false;
+            extruder_plan_before.insertCommand(path_idx, extruder, temp, wait, time_this_path - time_before_path_end);
             return;
         }
     }
-    extruder_plan_before.insertCommand(extruder_plan_before.paths.size(), extruder, temp, false); // insert at end of extruder plan if time_after_extruder_plan_start > extruder_plan.time 
-    // = special insert after all extruder plans
+    bool wait = false;
+    unsigned int path_idx = 0;
+    extruder_plan_before.insertCommand(path_idx, extruder, temp, wait); // insert at start of extruder plan if time_after_extruder_plan_start > extruder_plan.time
 }
 
-double LayerPlanBuffer::timeBeforeExtruderPlanToInsert(std::vector<GCodePlanner*>& layers, unsigned int layer_plan_idx, unsigned int extruder_plan_idx)
+Preheat::WarmUpResult LayerPlanBuffer::timeBeforeExtruderPlanToInsert(std::vector<ExtruderPlan*>& extruder_plans, unsigned int extruder_plan_idx)
 {
-    ExtruderPlan& extruder_plan = layers[layer_plan_idx]->extruder_plans[extruder_plan_idx];
+    ExtruderPlan& extruder_plan = *extruder_plans[extruder_plan_idx];
     int extruder = extruder_plan.extruder;
-    double required_temp = extruder_plan.required_temp;
-    
-    unsigned int extruder_plan_before_idx = extruder_plan_idx - 1;
-    bool first_it = true;
+    double initial_print_temp = extruder_plan.initial_printing_temperature;
+
     double in_between_time = 0.0;
-    for (unsigned int layer_idx = layer_plan_idx; int(layer_idx) >= 0; layer_idx--)
-    {
-        GCodePlanner& layer = *layers[layer_idx];
-        if (!first_it)
+    for (unsigned int extruder_plan_before_idx = extruder_plan_idx - 1; int(extruder_plan_before_idx) >= 0; extruder_plan_before_idx--)
+    { // find a previous extruder plan where the same extruder is used to see what time this extruder wasn't used
+        ExtruderPlan& extruder_plan_before = *extruder_plans[extruder_plan_before_idx];
+        if (extruder_plan_before.extruder == extruder)
         {
-            extruder_plan_before_idx = layer.extruder_plans.size() - 1;
-        }
-        for ( ; int(extruder_plan_before_idx) >= 0; extruder_plan_before_idx--)
-        {
-            ExtruderPlan& extruder_plan = layer.extruder_plans[extruder_plan_before_idx];
-            if (extruder_plan.extruder == extruder)
+            double temp_before = preheat_config.getFinalPrintTemp(extruder);
+            if (temp_before == 0)
             {
-                return preheat_config.timeBeforeEndToInsertPreheatCommand_coolDownWarmUp(in_between_time, extruder, required_temp);
+                temp_before = extruder_plan_before.printing_temperature;
             }
-            in_between_time += extruder_plan.estimates.getTotalTime();
+            constexpr bool during_printing = false;
+            Preheat::WarmUpResult warm_up = preheat_config.getWarmUpPointAfterCoolDown(in_between_time, extruder, temp_before, preheat_config.getStandbyTemp(extruder), initial_print_temp, during_printing);
+            warm_up.heating_time = std::min(in_between_time, warm_up.heating_time + extra_preheat_time);
+            return warm_up;
         }
-        first_it = false;
+        in_between_time += extruder_plan_before.estimates.getTotalTime();
     }
     // The last extruder plan with the same extruder falls outside of the buffer
     // assume the nozzle has cooled down to strandby temperature already.
-    return preheat_config.timeBeforeEndToInsertPreheatCommand_warmUp(preheat_config.getStandbyTemp(extruder), extruder, required_temp, false);
+    Preheat::WarmUpResult warm_up;
+    warm_up.total_time_window = in_between_time;
+    warm_up.lowest_temperature = preheat_config.getStandbyTemp(extruder);
+    constexpr bool during_printing = false;
+    warm_up.heating_time = preheat_config.getTimeToGoFromTempToTemp(extruder, warm_up.lowest_temperature, initial_print_temp, during_printing);
+    if (warm_up.heating_time > in_between_time)
+    {
+        warm_up.heating_time = in_between_time;
+        warm_up.lowest_temperature = in_between_time / preheat_config.getTimeToHeatup1Degree(extruder, during_printing);
+    }
+    warm_up.heating_time = warm_up.heating_time + extra_preheat_time;
+    return warm_up;
     
 }
 
 void LayerPlanBuffer::insertPreheatCommand_singleExtrusion(ExtruderPlan& prev_extruder_plan, int extruder, double required_temp)
 {
     // time_before_extruder_plan_end is halved, so that at the layer change the temperature will be half way betewen the two requested temperatures
-    double time_before_extruder_plan_end = 0.5 * preheat_config.timeBeforeEndToInsertPreheatCommand_warmUp(prev_extruder_plan.required_temp, extruder, required_temp, true);
-    double time_after_extruder_plan_start = prev_extruder_plan.estimates.getTotalTime() - time_before_extruder_plan_end;
-    if (time_after_extruder_plan_start < 0)
-    {
-        time_after_extruder_plan_start = 0; // don't override the extruder plan with same extruder of the previous layer
-    }
-        
-    insertPreheatCommand(prev_extruder_plan, time_after_extruder_plan_start, extruder, required_temp);
+    constexpr bool during_printing = true;
+    double time_before_extruder_plan_end = 0.5 * preheat_config.getTimeToGoFromTempToTemp(extruder, prev_extruder_plan.printing_temperature, required_temp, during_printing);
+    time_before_extruder_plan_end = std::min(prev_extruder_plan.estimates.getTotalTime(), time_before_extruder_plan_end);
+
+    insertPreheatCommand(prev_extruder_plan, time_before_extruder_plan_end, extruder, required_temp);
 }
 
-void LayerPlanBuffer::insertPreheatCommand_multiExtrusion(std::vector<GCodePlanner*>& layers, unsigned int layer_plan_idx, unsigned int extruder_plan_idx)
+
+void LayerPlanBuffer::handleStandbyTemp(std::vector<ExtruderPlan*>& extruder_plans, unsigned int extruder_plan_idx, double standby_temp)
 {
-    ExtruderPlan& extruder_plan = layers[layer_plan_idx]->extruder_plans[extruder_plan_idx];
+    ExtruderPlan& extruder_plan = *extruder_plans[extruder_plan_idx];
     int extruder = extruder_plan.extruder;
-    double required_temp = extruder_plan.required_temp;
-    
-    extruder_plan.insertCommand(0, extruder, required_temp, true); // just after the extruder switch, wait for the destination temperature to be reached
-    
-    double time_before_extruder_plan_to_insert = timeBeforeExtruderPlanToInsert(layers, layer_plan_idx, extruder_plan_idx);
-    
-    unsigned int extruder_plan_before_idx = extruder_plan_idx - 1;
-    bool first_it = true; // Whether it's the first iteration of the for loop below
-    for (unsigned int layer_idx = layer_plan_idx; int(layer_idx) >= 0; layer_idx--)
+    for (unsigned int extruder_plan_before_idx = extruder_plan_idx - 2; int(extruder_plan_before_idx) >= 0; extruder_plan_before_idx--)
     {
-        GCodePlanner& layer = *layers[layer_idx];
-        if (!first_it)
+        if (extruder_plans[extruder_plan_before_idx]->extruder == extruder)
         {
-            extruder_plan_before_idx = layer.extruder_plans.size() - 1;
+            extruder_plans[extruder_plan_before_idx + 1]->prev_extruder_standby_temp = standby_temp;
+            return;
         }
-        for ( ; int(extruder_plan_before_idx) >= 0; extruder_plan_before_idx--)
-        {
-            ExtruderPlan& extruder_plan_before = layer.extruder_plans[extruder_plan_before_idx];
-            assert (extruder_plan_before.extruder != extruder);
-            
-            double time_here = extruder_plan_before.estimates.getTotalTime();
-            if (time_here >= time_before_extruder_plan_to_insert)
-            {
-                insertPreheatCommand(extruder_plan_before, time_here - time_before_extruder_plan_to_insert, extruder, required_temp);
-                return;
-            }
-            time_before_extruder_plan_to_insert -= time_here;
-            
-        }
-        first_it = false;
     }
-    
-    // time_before_extruder_plan_to_insert falls before all plans in the buffer
-    ExtruderPlan& first_extruder_plan = layers[0]->extruder_plans[0];
-    first_extruder_plan.insertCommand(0, extruder, required_temp, false); // insert preheat command at verfy beginning of buffer
+    logWarning("Warning: Couldn't find previous extruder plan so as to set the standby temperature. Inserting temp command in earliest available layer.\n");
+    ExtruderPlan& earliest_extruder_plan = *extruder_plans[0];
+    constexpr bool wait = false;
+    earliest_extruder_plan.insertCommand(0, extruder, standby_temp, wait);
 }
 
-void LayerPlanBuffer::insertPreheatCommand(std::vector<GCodePlanner*>& layers, unsigned int layer_plan_idx, unsigned int extruder_plan_idx)
-{   
-    ExtruderPlan& extruder_plan = layers[layer_plan_idx]->extruder_plans[extruder_plan_idx];
+void LayerPlanBuffer::insertPreheatCommand_multiExtrusion(std::vector<ExtruderPlan*>& extruder_plans, unsigned int extruder_plan_idx)
+{
+    ExtruderPlan& extruder_plan = *extruder_plans[extruder_plan_idx];
     int extruder = extruder_plan.extruder;
-    double required_temp = extruder_plan.required_temp;
+    double initial_print_temp = extruder_plan.initial_printing_temperature;
     
-    
-    ExtruderPlan* prev_extruder_plan = nullptr;
-    if (extruder_plan_idx == 0)
+    Preheat::WarmUpResult heating_time_and_from_temp = timeBeforeExtruderPlanToInsert(extruder_plans, extruder_plan_idx);
+
+    if (heating_time_and_from_temp.total_time_window < preheat_config.getMinimalTimeWindow(extruder))
     {
-        if (layer_plan_idx == 0)
+        handleStandbyTemp(extruder_plans, extruder_plan_idx, initial_print_temp);
+        return; // don't insert preheat command and just stay on printing temperature
+    }
+    else
+    {
+        handleStandbyTemp(extruder_plans, extruder_plan_idx, heating_time_and_from_temp.lowest_temperature);
+    }
+
+    // handle preheat command
+    double time_before_extruder_plan_to_insert = heating_time_and_from_temp.heating_time;
+    for (unsigned int extruder_plan_before_idx = extruder_plan_idx - 1; int(extruder_plan_before_idx) >= 0; extruder_plan_before_idx--)
+    {
+        ExtruderPlan& extruder_plan_before = *extruder_plans[extruder_plan_before_idx];
+        assert (extruder_plan_before.extruder != extruder);
+
+        double time_here = extruder_plan_before.estimates.getTotalTime();
+        if (time_here >= time_before_extruder_plan_to_insert)
+        {
+            insertPreheatCommand(extruder_plan_before, time_before_extruder_plan_to_insert, extruder, initial_print_temp);
+            return;
+        }
+        time_before_extruder_plan_to_insert -= time_here;
+    }
+
+    // time_before_extruder_plan_to_insert falls before all plans in the buffer
+    bool wait = false;
+    unsigned int path_idx = 0;
+    extruder_plans[0]->insertCommand(path_idx, extruder, initial_print_temp, wait); // insert preheat command at verfy beginning of buffer
+}
+
+void LayerPlanBuffer::insertTempCommands(std::vector<ExtruderPlan*>& extruder_plans, unsigned int extruder_plan_idx)
+{   
+    ExtruderPlan& extruder_plan = *extruder_plans[extruder_plan_idx];
+    int extruder = extruder_plan.extruder;
+    
+    
+    ExtruderPlan* prev_extruder_plan = extruder_plans[extruder_plan_idx - 1];
+    
+    int prev_extruder = prev_extruder_plan->extruder;
+    
+    if (prev_extruder != extruder)
+    { // set previous extruder to standby temperature
+        extruder_plan.prev_extruder_standby_temp = preheat_config.getStandbyTemp(prev_extruder);
+    }
+    
+    if (prev_extruder == extruder)
+    {
+        insertPreheatCommand_singleExtrusion(*prev_extruder_plan, extruder, extruder_plan.printing_temperature);
+        prev_extruder_plan->printing_temperature_command = --prev_extruder_plan->inserts.end();
+    }
+    else 
+    {
+        insertPreheatCommand_multiExtrusion(extruder_plans, extruder_plan_idx);
+        insertFinalPrintTempCommand(extruder_plans, extruder_plan_idx - 1);
+        insertPrintTempCommand(extruder_plan);
+    }
+}
+
+void LayerPlanBuffer::insertPrintTempCommand(ExtruderPlan& extruder_plan)
+{
+    unsigned int extruder = extruder_plan.extruder;
+    double print_temp = extruder_plan.printing_temperature;
+
+    double heated_pre_travel_time = 0;
+    if (preheat_config.getInitialPrintTemp(extruder) != 0)
+    { // handle heating from initial_print_temperature to printing_tempreature
+        unsigned int path_idx;
+        for (path_idx = 0; path_idx < extruder_plan.paths.size(); path_idx++)
+        {
+            GCodePath& path = extruder_plan.paths[path_idx];
+            heated_pre_travel_time += path.estimates.getTotalTime();
+            if (!path.isTravelPath())
+            {
+                break;
+            }
+        }
+        bool wait = false;
+        extruder_plan.insertCommand(path_idx, extruder, print_temp, wait);
+    }
+    extruder_plan.heated_pre_travel_time = heated_pre_travel_time;
+}
+
+void LayerPlanBuffer::insertFinalPrintTempCommand(std::vector<ExtruderPlan*>& extruder_plans, unsigned int last_extruder_plan_idx)
+{
+    ExtruderPlan& last_extruder_plan = *extruder_plans[last_extruder_plan_idx];
+    int extruder = last_extruder_plan.extruder;
+
+    double final_print_temp = preheat_config.getFinalPrintTemp(extruder);
+    if (final_print_temp == 0)
+    {
+        return;
+    }
+
+    double heated_post_travel_time = 0; // The time after the last extrude move toward the end of the extruder plan during which the nozzle is stable at the final print temperature
+    { // compute heated_post_travel_time
+        unsigned int path_idx;
+        for (path_idx = last_extruder_plan.paths.size() - 1; int(path_idx) >= 0; path_idx--)
+        {
+            GCodePath& path = last_extruder_plan.paths[path_idx];
+            if (!path.isTravelPath())
+            {
+                break;
+            }
+            heated_post_travel_time += path.estimates.getTotalTime();
+        }
+    }
+
+    double time_window = 0; // The time window within which the nozzle needs to heat from the initial print temp to the printing temperature and then back to the final print temp; i.e. from the first to the last extrusion move with this extruder
+    double weighted_average_print_temp = 0; // The average of the normal printing temperatures of the extruder plans (which might be different due to flow dependent temp or due to initial layer temp) Weighted by time
+    double initial_print_temp = -1; // The initial print temp of the first extruder plan with this extruder
+    { // compute time window and print temp statistics
+        double heated_pre_travel_time = -1; // The time before the first extrude move from the start of the extruder plan during which the nozzle is stable at the initial print temperature
+        for (unsigned int prev_extruder_plan_idx = last_extruder_plan_idx; (int)prev_extruder_plan_idx >= 0; prev_extruder_plan_idx--)
+        {
+            ExtruderPlan& prev_extruder_plan = *extruder_plans[prev_extruder_plan_idx];
+            if (prev_extruder_plan.extruder != extruder)
+            {
+                break;
+            }
+            double prev_extruder_plan_time = prev_extruder_plan.estimates.getTotalTime();
+            time_window += prev_extruder_plan_time;
+            heated_pre_travel_time = prev_extruder_plan.heated_pre_travel_time;
+
+            if (prev_extruder_plan.estimates.getTotalUnretractedTime() > 0)
+            { // handle temp statistics
+                assert(prev_extruder_plan.printing_temperature != -1 && "Previous extruder plan should already have a temperature planned");
+                weighted_average_print_temp += prev_extruder_plan.printing_temperature * prev_extruder_plan_time;
+                initial_print_temp = prev_extruder_plan.initial_printing_temperature;
+            }
+        }
+        weighted_average_print_temp /= time_window;
+        time_window -= heated_pre_travel_time + heated_post_travel_time;
+        assert(heated_pre_travel_time != -1 && "heated_pre_travel_time must have been computed; there must have been an extruder plan!");
+    }
+
+    assert((time_window >= 0 || last_extruder_plan.estimates.getMaterial() == 0) && "Time window should always be positive if we actually extrude");
+
+    //          ,layer change                                                                                   .
+    //          :     ,precool command                   ,layer change                                          .
+    //          : ____:                                  :     ,precool command                                 .
+    //          :/    \                             _____:_____:                                                .
+    //     _____/      \                           /           \                                                .
+    //    /             \                         /             \                                               .
+    //   /                                       /                                                              .
+    //  /                                       /                                                               .
+    //                                                                                                          .
+    // approximate ^               by                   ^                                                       .
+    // This approximation is quite ok since it only determines where to insert the precool temp command,
+    // which means the stable temperature of the previous extruder plan and the stable temperature of the next extruder plan couldn't be reached
+    constexpr bool during_printing = true;
+    Preheat::CoolDownResult warm_cool_result = preheat_config.getCoolDownPointAfterWarmUp(time_window, extruder, initial_print_temp, weighted_average_print_temp, final_print_temp, during_printing);
+    double cool_down_time = warm_cool_result.cooling_time;
+    assert(cool_down_time >= 0);
+
+    // find extruder plan in which to insert cooling command
+    ExtruderPlan* precool_extruder_plan = &last_extruder_plan;
+    {
+        for (unsigned int precool_extruder_plan_idx = last_extruder_plan_idx; (int)precool_extruder_plan_idx >= 0; precool_extruder_plan_idx--)
+        {
+            precool_extruder_plan = extruder_plans[precool_extruder_plan_idx];
+            if (precool_extruder_plan->printing_temperature_command)
+            { // the precool command ends up before the command to go to the print temperature of the next extruder plan, so remove that print temp command
+                precool_extruder_plan->inserts.erase(*precool_extruder_plan->printing_temperature_command);
+            }
+            double time_here = precool_extruder_plan->estimates.getTotalTime();
+            if (cool_down_time < time_here)
+            {
+                break;
+            }
+            cool_down_time -= time_here;
+        }
+    }
+
+    // at this point cool_down_time is what time is left if cool down time of extruder plans after precool_extruder_plan (up until last_extruder_plan) are already taken into account
+
+    { // insert temp command in precool_extruder_plan
+        double extrusion_time_seen = 0;
+        unsigned int path_idx;
+        for (path_idx = precool_extruder_plan->paths.size() - 1; int(path_idx) >= 0; path_idx--)
+        {
+            GCodePath& path = precool_extruder_plan->paths[path_idx];
+            extrusion_time_seen += path.estimates.getTotalTime();
+            if (extrusion_time_seen >= cool_down_time)
+            {
+                break;
+            }
+        }
+        bool wait = false;
+        double time_after_path_start = extrusion_time_seen - cool_down_time;
+        precool_extruder_plan->insertCommand(path_idx, extruder, final_print_temp, wait, time_after_path_start);
+    }
+}
+
+
+void LayerPlanBuffer::insertTempCommands()
+{
+    if (buffer.back()->extruder_plans.size() == 0 || (buffer.back()->extruder_plans.size() == 1 && buffer.back()->extruder_plans[0].paths.size() == 0))
+    { // disregard empty layer
+        buffer.pop_back();
+        return;
+    }
+
+    std::vector<ExtruderPlan*> extruder_plans;
+    extruder_plans.reserve(buffer.size() * 2);
+    for (GCodePlanner* layer_plan : buffer)
+    {
+        for (ExtruderPlan& extr_plan : layer_plan->extruder_plans)
+        {
+            extruder_plans.push_back(&extr_plan);
+        }
+    }
+
+
+    // insert commands for all extruder plans on this layer
+    GCodePlanner& layer_plan = *buffer.back();
+    for (unsigned int extruder_plan_idx = 0; extruder_plan_idx < layer_plan.extruder_plans.size(); extruder_plan_idx++)
+    {
+        unsigned int overall_extruder_plan_idx = extruder_plans.size() - layer_plan.extruder_plans.size() + extruder_plan_idx;
+        ExtruderPlan& extruder_plan = layer_plan.extruder_plans[extruder_plan_idx];
+        int extruder = extruder_plan.extruder;
+        double time = extruder_plan.estimates.getTotalUnretractedTime();
+        if (time <= 0.0)
+        {
+            continue;
+        }
+        
+        double avg_flow = extruder_plan.estimates.getMaterial() / time;
+        extruder_plan.printing_temperature = preheat_config.getTemp(extruder, avg_flow, extruder_plan.is_initial_layer);
+        extruder_plan.initial_printing_temperature = preheat_config.getInitialPrintTemp(extruder);
+        if (extruder_plan.initial_printing_temperature == 0
+            || !extruder_used_in_meshgroup[extruder]
+            || (overall_extruder_plan_idx > 0 && extruder_plans[overall_extruder_plan_idx - 1]->extruder == extruder)
+        )
+        {
+            extruder_plan.initial_printing_temperature = extruder_plan.printing_temperature;
+            extruder_used_in_meshgroup[extruder] = true;
+        }
+        assert(extruder_plan.printing_temperature != -1 && "extruder_plan.printing_temperature should now have been set");
+
+        if (buffer.size() == 1 && extruder_plan_idx == 0)
         { // the very first extruder plan of the current meshgroup
+            int extruder = extruder_plan.extruder;
             for (int extruder_idx = 0; extruder_idx < getSettingAsCount("machine_extruder_count"); extruder_idx++)
             { // set temperature of the first nozzle, turn other nozzles down
                 if (FffProcessor::getInstance()->getMeshgroupNr() == 0)
@@ -153,7 +379,7 @@ void LayerPlanBuffer::insertPreheatCommand(std::vector<GCodePlanner*>& layers, u
                     // see  FffGcodeWriter::processStartingCode
                     if (extruder_idx == extruder)
                     {
-                        gcode.setInitialTemp(extruder_idx, required_temp);
+                        gcode.setInitialTemp(extruder_idx, extruder_plan.printing_temperature);
                     }
                     else 
                     {
@@ -162,80 +388,16 @@ void LayerPlanBuffer::insertPreheatCommand(std::vector<GCodePlanner*>& layers, u
                 }
                 else
                 {
-                    if (extruder_idx == extruder)
-                    {
-                        extruder_plan.insertCommand(0, extruder, required_temp, true);
-                    }
-                    else 
-                    {
-                        extruder_plan.insertCommand(0, extruder_idx, preheat_config.getStandbyTemp(extruder_idx), false);
+                    if (extruder_idx != extruder)
+                    { // TODO: do we need to do this?
+                        extruder_plan.prev_extruder_standby_temp = preheat_config.getStandbyTemp(extruder_idx);
                     }
                 }
             }
-            return;
-        }
-        prev_extruder_plan = &layers[layer_plan_idx - 1]->extruder_plans.back();
-    }
-    else 
-    {
-        prev_extruder_plan = &layers[layer_plan_idx]->extruder_plans[extruder_plan_idx - 1];
-    }
-    assert(prev_extruder_plan != nullptr);
-    
-    int prev_extruder = prev_extruder_plan->extruder;
-    
-    if (prev_extruder != extruder)
-    { // set previous extruder to standby temperature
-        prev_extruder_plan->insertCommand(prev_extruder_plan->paths.size(), prev_extruder, preheat_config.getStandbyTemp(prev_extruder), false);
-    }
-    
-    if (prev_extruder == extruder)
-    {
-        if (preheat_config.usesFlowDependentTemp(extruder))
-        {
-            insertPreheatCommand_singleExtrusion(*prev_extruder_plan, extruder, required_temp);
-        }
-    }
-    else 
-    {
-        insertPreheatCommand_multiExtrusion(layers, layer_plan_idx, extruder_plan_idx);
-    }
-    
-}
-
-void LayerPlanBuffer::insertPreheatCommands()
-{
-    if (buffer.back().extruder_plans.size() == 0 || (buffer.back().extruder_plans.size() == 1 && buffer.back().extruder_plans[0].paths.size() == 0))
-    { // disregard empty layer
-        buffer.pop_back();
-        return;
-    }
-    
-    std::vector<GCodePlanner*> layers;
-    layers.reserve(buffer.size());
-    for (GCodePlanner& layer_plan : buffer)
-    {
-        layers.push_back(&layer_plan);
-    }
-    
-    unsigned int layer_idx = layers.size() - 1;
-
-    // insert commands for all extruder plans on this layer
-    GCodePlanner& layer_plan = *layers[layer_idx];
-    for (unsigned int extruder_plan_idx = 0; extruder_plan_idx < layer_plan.extruder_plans.size(); extruder_plan_idx++)
-    {
-        ExtruderPlan& extruder_plan = layer_plan.extruder_plans[extruder_plan_idx];
-        double time = extruder_plan.estimates.getTotalUnretractedTime();
-        if (time <= 0.0 
-            || extruder_plan.estimates.getMaterial() == 0.0 // extruder plan only consists of moves (when an extruder switch occurs at the beginning of a layer)
-        )
-        {
             continue;
         }
-        double avg_flow = extruder_plan.estimates.getMaterial() / time; // TODO: subtract retracted travel time
-        extruder_plan.required_temp = preheat_config.getTemp(extruder_plan.extruder, avg_flow);
-        
-        insertPreheatCommand(layers, layer_idx, extruder_plan_idx);
+
+        insertTempCommands(extruder_plans, overall_extruder_plan_idx);
     }
 }
 

src/LayerPlanBuffer.h

@@ -1,3 +1,4 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
 #ifndef LAYER_PLAN_BUFFER_H
 #define LAYER_PLAN_BUFFER_H
 
@@ -15,6 +16,19 @@
 namespace cura 
 {
 
+/*!
+ * Class for buffering multiple layer plans (\ref GCodePlanner) / extruder plans within those layer plans, so that temperature commands can be inserted in earlier layer plans.
+ * 
+ * This class handles where to insert temperature commands for:
+ * - initial layer temperature
+ * - flow dependent temperature
+ * - starting to heat up from the standby temperature
+ * - initial printing temperature | printing temperature | final printing temperature
+ * 
+ * \image html assets/precool.png "Temperature Regulation" width=10cm
+ * \image latex assets/precool.png "Temperature Regulation" width=10cm
+ * 
+ */
 class LayerPlanBuffer : SettingsMessenger
 {
     GCodeExport& gcode;
@@ -23,69 +37,83 @@ class LayerPlanBuffer : SettingsMessenger
     
     static constexpr unsigned int buffer_size = 5; // should be as low as possible while still allowing enough time in the buffer to heat up from standby temp to printing temp // TODO: hardcoded value
     // this value should be higher than 1, cause otherwise each layer is viewed as the first layer and no temp commands are inserted.
-    
+
+    static constexpr const double extra_preheat_time = 1.0; //!< Time to start heating earlier than computed to avoid accummulative discrepancy between actual heating times and computed ones.
+
+    std::vector<bool> extruder_used_in_meshgroup; //!< For each extruder whether it has already been planned once in this meshgroup. This is used to see whether we should heat to the initial_print_temp or to the printing_temperature
 public:
-    std::list<GCodePlanner> buffer; //!< The buffer containing several layer plans (GCodePlanner) before writing them to gcode.
+    std::list<GCodePlanner*> buffer; //!< The buffer containing several layer plans (GCodePlanner) before writing them to gcode.
     
     LayerPlanBuffer(SettingsBaseVirtual* settings, GCodeExport& gcode)
     : SettingsMessenger(settings)
     , gcode(gcode)
+    , extruder_used_in_meshgroup(MAX_EXTRUDERS, false)
     { }
     
     void setPreheatConfig(MeshGroup& settings)
     {
         preheat_config.setConfig(settings);
     }
-    
+
     /*!
-     * Place a new layer plan (GcodePlanner) by constructing it with the given arguments.
-     * Pop back the oldest layer plan is it exceeds the buffer size and write it to gcode.
+     * Push a new layer plan into the buffer
      */
-    template<typename... Args>
-    GCodePlanner& emplace_back(Args&&... constructor_args)
+    void push(GCodePlanner& layer_plan)
+    {
+        buffer.push_back(&layer_plan);
+    }
+
+    /*!
+     * Process all layers in the buffer
+     * This inserts the temperature commands to start warming for a given layer in earlier layers
+     * 
+     * Pop out the earliest layer in the buffer if the buffer size is exceeded
+     * \return A nullptr or the popped gcode_layer
+     */
+    GCodePlanner* processBuffer()
     {
         if (buffer.size() > 0)
         {
-            insertPreheatCommands(); // insert preheat commands of the just completed layer plan (not the newly emplaced one)
+            insertTempCommands(); // insert preheat commands of the just completed layer plan (not the newly emplaced one)
         }
-        buffer.emplace_back(constructor_args...);
         if (buffer.size() > buffer_size)
         {
-            buffer.front().writeGCode(gcode);
+            GCodePlanner* ret = buffer.front();
             if (CommandSocket::isInstantiated())
             {
                 CommandSocket::getInstance()->flushGcode();
             }
             buffer.pop_front();
+            return ret;
         }
-        return buffer.back();
+        return nullptr;
     }
     
     /*!
      * Write all remaining layer plans (GCodePlanner) to gcode and empty the buffer.
      */
     void flush();
-    
+
+private:
     /*!
      * Insert the preheat command for @p extruder into @p extruder_plan_before
      * 
      * \param extruder_plan_before An extruder plan before the extruder plan for which the temperature is computed, in which to insert the preheat command
-     * \param time_after_extruder_plan_start The time after the start of the extruder plan, before which to insert the preheat command
+     * \param time_before_extruder_plan_end The time before the end of the extruder plan, before which to insert the preheat command
      * \param extruder The extruder for which to set the temperature
      * \param temp The temperature of the preheat command
      */
-    void insertPreheatCommand(ExtruderPlan& extruder_plan_before, double time_after_extruder_plan_start, int extruder, double temp);
+    void insertPreheatCommand(ExtruderPlan& extruder_plan_before, double time_before_extruder_plan_end, int extruder, double temp);
     
     /*!
      * Compute the time needed to preheat, based either on the time the extruder has been on standby 
      * or based on the temp of the previous extruder plan which has the same extruder nr.
      * 
-     * \param layers The layers in the buffer, moved to a vector
-     * \param layer_plan_idx The index into @p layers in which to find the extruder plan
-     * \param extruder_plan_idx The index of the extruder plan in the layer corresponding to @p layer_plan_idx for which to find the preheat time needed
-     * \return the time needed to preheat
+     * \param extruder_plans The extruder plans in the buffer, moved to a temporary vector (from lower to upper layers)
+     * \param extruder_plan_idx The index of the extruder plan in \p extruder_plans for which to find the preheat time needed
+     * \return the time needed to preheat and the temperature from which heating starts
      */
-    double timeBeforeExtruderPlanToInsert(std::vector<GCodePlanner*>& layers, unsigned int layer_plan_idx, unsigned int extruder_plan_idx);
+    Preheat::WarmUpResult timeBeforeExtruderPlanToInsert(std::vector<ExtruderPlan*>& extruder_plans, unsigned int extruder_plan_idx);
     
     /*!
      * For two consecutive extruder plans of the same extruder (so on different layers), 
@@ -105,25 +133,55 @@ public:
      * and compute at what time the preheat command needs to be inserted.
      * Then insert the preheat command in the right extruder plan.
      * 
-     * \param layers The layers in the buffer, moved to a vector
-     * \param layer_plan_idx The index into @p layers in which to find the extruder plan
-     * \param extruder_plan_idx The index of the extruder plan in the layer corresponding to @p layer_plan_idx for which to find the preheat time needed
+     * \param extruder_plans The extruder plans in the buffer, moved to a temporary vector (from lower to upper layers)
+     * \param extruder_plan_idx The index of the extruder plan in \p extruder_plans for which to find the preheat time needed
      */
-    void insertPreheatCommand_multiExtrusion(std::vector<GCodePlanner*>& layers, unsigned int layer_plan_idx, unsigned int extruder_plan_idx);
+    void insertPreheatCommand_multiExtrusion(std::vector<ExtruderPlan*>& extruder_plans, unsigned int extruder_plan_idx);
     
     /*!
      * Insert the preheat command for the extruder plan corersponding to @p extruder_plan_idx of the layer corresponding to @p layer_plan_idx.
      * 
-     * \param layers The layers of the buffer, moved to a temporary vector (from lower to upper layers)
-     * \param layer_plan_idx The index of the layer plan for which to generate a preheat command
-     * \param extruder_plan_idx The index of the extruder plan in the layer corresponding to @p layer_plan_idx for which to generate the preheat command
+     * \param extruder_plans The extruder plans in the buffer, moved to a temporary vector (from lower to upper layers)
+     * \param extruder_plan_idx The index of the extruder plan in \p extruder_plans for which to generate the preheat command
      */
-    void insertPreheatCommand(std::vector<GCodePlanner*>& layers, unsigned int layer_plan_idx, unsigned int extruder_plan_idx);
+    void insertTempCommands(std::vector<ExtruderPlan*>& extruder_plans, unsigned int extruder_plan_idx);
+
+    /*!
+     * Insert the temperature command to heat from the initial print temperature to the printing temperature
+     * 
+     * The temperature command is insert at the start of the very first extrusion move
+     * 
+     * \param extruder_plan The extruder plan in which to insert the heat up command
+     */
+    void insertPrintTempCommand(ExtruderPlan& extruder_plan);
+
+    /*!
+     * Insert the temp command to start cooling from the printing temperature to the final print temp
+     * 
+     * The print temp is inserted before the last extrusion move of the extruder plan corresponding to \p last_extruder_plan_idx
+     * 
+     * The command is inserted at a timed offset before the end of the last extrusion move
+     * 
+     * \param extruder_plans The extruder plans in the buffer, moved to a temporary vector (from lower to upper layers)
+     * \param last_extruder_plan_idx The index of the last extruder plan in \p extruder_plans with the same extruder as previous extruder plans
+     */
+    void insertFinalPrintTempCommand(std::vector<ExtruderPlan*>& extruder_plans, unsigned int last_extruder_plan_idx);
 
     /*!
      * Insert the preheat commands for the last added layer (unless that layer was empty)
      */
-    void insertPreheatCommands();
+    void insertTempCommands();
+
+    /*!
+     * Reconfigure the standby temperature during which we didn't print with this extruder.
+     * Find the previous extruder plan with the same extruder as layers[layer_plan_idx].extruder_plans[extruder_plan_idx]
+     * Set the prev_extruder_standby_temp in the next extruder plan
+     * 
+     * \param extruder_plans The extruder plans in the buffer, moved to a temporary vector (from lower to upper layers)
+     * \param extruder_plan_idx The index of the extruder plan in \p extruder_plans before which to reconfigure the standby temperature
+     * \param standby_temp The temperature to which to cool down when the extruder is in standby mode.
+     */
+    void handleStandbyTemp(std::vector<ExtruderPlan*>& extruder_plans, unsigned int extruder_plan_idx, double standby_temp);
 };
 
 

src/MergeInfillLines.cpp

@@ -11,14 +11,18 @@ void MergeInfillLines::writeCompensatedMove(Point& to, double speed, GCodePath&
 {
     double old_line_width = INT2MM(last_path.config->getLineWidth());
     double new_line_width_mm = INT2MM(new_line_width);
-    double speed_mod = old_line_width / new_line_width_mm;
     double extrusion_mod = new_line_width_mm / old_line_width;
-    double new_speed = std::min(speed * speed_mod, 150.0); // TODO: hardcoded value: max extrusion speed is 150 mm/s = 9000 mm/min
-    sendPolygon(last_path.config->type, gcode.getPositionXY(), to, last_path.getLineWidth());
+    double new_speed = speed;
+    if (speed_equalize_flow_enabled)
+    {
+        double speed_mod = old_line_width / new_line_width_mm;
+        new_speed = std::min(speed * speed_mod, speed_equalize_flow_max);
+    }
+    sendLineTo(last_path.config->type, to, last_path.getLineWidth());
     gcode.writeMove(to, new_speed, last_path.getExtrusionMM3perMM() * extrusion_mod);
 }
     
-bool MergeInfillLines::mergeInfillLines(double speed, unsigned int& path_idx)
+bool MergeInfillLines::mergeInfillLines(unsigned int& path_idx)
 { //Check for lots of small moves and combine them into one large line
     Point prev_middle;
     Point last_middle;
@@ -31,12 +35,12 @@ bool MergeInfillLines::mergeInfillLines(double speed, unsigned int& path_idx)
             GCodePath& move_path = paths[path_idx];
             for(unsigned int point_idx = 0; point_idx < move_path.points.size() - 1; point_idx++)
             {
-                gcode.writeMove(move_path.points[point_idx], speed, move_path.getExtrusionMM3perMM());
+                gcode.writeMove(move_path.points[point_idx], move_path.config->getSpeed() * extruder_plan.getTravelSpeedFactor(), move_path.getExtrusionMM3perMM());
             }
             gcode.writeMove(prev_middle, travelConfig.getSpeed(), 0);
             GCodePath& last_path = paths[path_idx + 3];
             
-            writeCompensatedMove(last_middle, speed, last_path, line_width);
+            writeCompensatedMove(last_middle, last_path.config->getSpeed() * extruder_plan.getExtrudeSpeedFactor(), last_path, line_width);
         }
         
         path_idx += 2;
@@ -45,7 +49,7 @@ bool MergeInfillLines::mergeInfillLines(double speed, unsigned int& path_idx)
         {
             extruder_plan.handleInserts(path_idx, gcode);
             GCodePath& last_path = paths[path_idx + 3];
-            writeCompensatedMove(last_middle, speed, last_path, line_width);
+            writeCompensatedMove(last_middle, last_path.config->getSpeed() * extruder_plan.getExtrudeSpeedFactor(), last_path, line_width);
         }
         path_idx = path_idx + 1; // means that the next path considered is the travel path after the converted extrusion path corresponding to the updated path_idx
         extruder_plan.handleInserts(path_idx, gcode);
@@ -227,4 +231,4 @@ void MergeInfillLines::merge(Point& from, Point& p0, Point& p1)
      
      
      
-}//namespace cura
+}//namespace cura

src/MergeInfillLines.h

@@ -4,6 +4,7 @@
 #include "utils/intpoint.h"
 #include "gcodeExport.h"
 #include "gcodePlanner.h"
+#include "GCodePathConfig.h"
 
 namespace cura
 {
@@ -16,8 +17,10 @@ class MergeInfillLines
     std::vector<GCodePath>& paths; //!< The paths currently under consideration
     ExtruderPlan& extruder_plan; //!< The extruder plan of the paths currently under consideration
     
-    GCodePathConfig& travelConfig; //!< The travel settings used to see whether a path is a travel path or an extrusion path
+    const GCodePathConfig& travelConfig; //!< The travel settings used to see whether a path is a travel path or an extrusion path
     int64_t nozzle_size; //!< The diameter of the hole in the nozzle
+    bool speed_equalize_flow_enabled; //!< Should the speed be varied with extrusion width
+    double speed_equalize_flow_max; //!< Maximum speed when adjusting speed for flow
 
     /*!
      * Whether the next two extrusion paths are convertible to a single line segment, starting from the end point the of the last travel move at \p path_idx_first_move
@@ -61,9 +64,18 @@ public:
     /*!
      * Simple constructor only used by MergeInfillLines::isConvertible to easily convey the environment
      */
-    MergeInfillLines(GCodeExport& gcode, int layer_nr, std::vector<GCodePath>& paths, ExtruderPlan& extruder_plan, GCodePathConfig& travelConfig, int64_t nozzle_size) 
-    : gcode(gcode), layer_nr(layer_nr), paths(paths), extruder_plan(extruder_plan), travelConfig(travelConfig), nozzle_size(nozzle_size) { }
-    
+    MergeInfillLines(GCodeExport& gcode, int layer_nr, std::vector<GCodePath>& paths, ExtruderPlan& extruder_plan, const GCodePathConfig& travelConfig, int64_t nozzle_size, bool speed_equalize_flow_enabled, double speed_equalize_flow_max)
+    : gcode(gcode)
+    , layer_nr(layer_nr)
+    , paths(paths)
+    , extruder_plan(extruder_plan)
+    , travelConfig(travelConfig)
+    , nozzle_size(nozzle_size)
+    , speed_equalize_flow_enabled(speed_equalize_flow_enabled)
+    , speed_equalize_flow_max(speed_equalize_flow_max)
+    {
+    }
+
     /*!
      * Check for lots of small moves and combine them into one large line.
      * Updates \p path_idx to the next path which is not combined.
@@ -72,28 +84,19 @@ public:
      * \param paths The paths currently under consideration
      * \param travelConfig The travel settings used to see whether a path is a travel path or an extrusion path
      * \param nozzle_size The diameter of the hole in the nozzle
-     * \param speed A factor used to scale the movement speed
      * \param path_idx Input/Output parameter: The current index in \p paths where to start combining and the current index after combining as output parameter.
      * \return Whether lines have been merged and normal path-to-gcode generation can be skipped for the current resulting \p path_idx .
      */
-    bool mergeInfillLines(double speed, unsigned int& path_idx);
+    bool mergeInfillLines(unsigned int& path_idx);
     
     /*!
-     * send a polygon through the command socket from the previous point to the given point
+     * send a line segment through the command socket from the previous point to the given point \p to
      */
-    void sendPolygon(PrintFeatureType print_feature_type, Point from, Point to, int line_width)
+    void sendLineTo(PrintFeatureType print_feature_type, Point to, int line_width)
     {
-        if (CommandSocket::isInstantiated()) 
-        {
-            // we should send this travel as a non-retraction move
-            cura::Polygons pathPoly;
-            PolygonRef path = pathPoly.newPoly();
-            path.add(from);
-            path.add(to);
-            CommandSocket::getInstance()->sendPolygons(print_feature_type, layer_nr, pathPoly, line_width);
-        }
+        CommandSocket::sendLineTo(print_feature_type, to, line_width);
     }
 };
 
 }//namespace cura
-#endif // MERGE_INFILL_LINES_H
+#endif // MERGE_INFILL_LINES_H

src/MeshGroup.cpp

@@ -4,9 +4,12 @@
 #include <stdio.h>
 
 #include "MeshGroup.h"
+#include "utils/gettime.h"
 #include "utils/logoutput.h"
 #include "utils/string.h"
 
+#include "settings/SettingRegistry.h" // loadExtruderJSONsettings
+
 namespace cura
 {
 
@@ -44,7 +47,7 @@ MeshGroup::~MeshGroup()
     }
 }
 
-int MeshGroup::getExtruderCount()
+int MeshGroup::getExtruderCount() const
 {
     if (extruder_count == -1)
     {
@@ -54,13 +57,20 @@ int MeshGroup::getExtruderCount()
 }
 
 ExtruderTrain* MeshGroup::createExtruderTrain(unsigned int extruder_nr)
+{
+    assert((int)extruder_nr >= 0 && (int)extruder_nr < getSettingAsCount("machine_extruder_count") && "only valid extruder trains may be requested!");
+    if (!extruders[extruder_nr])
     {
-        if (!extruders[extruder_nr])
+        extruders[extruder_nr] = new ExtruderTrain(this, extruder_nr);
+        int err = SettingRegistry::getInstance()->loadExtruderJSONsettings(extruder_nr, extruders[extruder_nr]);
+        if (err)
         {
-            extruders[extruder_nr] = new ExtruderTrain(this, extruder_nr);
+            logError("Couldn't load extruder.def.json for extruder %i\n", extruder_nr);
+            std::exit(1);
         }
-        return extruders[extruder_nr];
     }
+    return extruders[extruder_nr];
+}
 
 ExtruderTrain* MeshGroup::getExtruderTrain(unsigned int extruder_nr)
 {
@@ -118,6 +128,44 @@ void MeshGroup::clear()
 
 void MeshGroup::finalize()
 {
+    extruder_count = getSettingAsCount("machine_extruder_count");
+
+    for (int extruder_nr = 0; extruder_nr < extruder_count; extruder_nr++)
+    {
+        createExtruderTrain(extruder_nr); // create it if it didn't exist yet
+
+        if (getSettingAsIndex("adhesion_extruder_nr") == extruder_nr && getSettingAsPlatformAdhesion("adhesion_type") != EPlatformAdhesion::NONE)
+        {
+            getExtruderTrain(extruder_nr)->setIsUsed(true);
+            continue;
+        }
+
+        for (const Mesh& mesh : meshes)
+        {
+            if (mesh.getSettingBoolean("support_enable")
+                && (
+                    getSettingAsIndex("support_infill_extruder_nr") == extruder_nr
+                    || getSettingAsIndex("support_extruder_nr_layer_0") == extruder_nr
+                    || (getSettingBoolean("support_interface_enable") && getSettingAsIndex("support_interface_extruder_nr") == extruder_nr)
+                    )
+                )
+            {
+                getExtruderTrain(extruder_nr)->setIsUsed(true);
+                break;
+            }
+        }
+    }
+
+    for (const Mesh& mesh : meshes)
+    {
+        if (!mesh.getSettingBoolean("anti_overhang_mesh")
+            && !mesh.getSettingBoolean("support_mesh")
+        )
+        {
+            getExtruderTrain(mesh.getSettingAsIndex("extruder_nr"))->setIsUsed(true);
+        }
+    }
+
     //If the machine settings have been supplied, offset the given position vertices to the center of vertices (0,0,0) is at the bed center.
     Point3 meshgroup_offset(0, 0, 0);
     if (!getSettingBoolean("machine_center_is_zero"))
@@ -283,6 +331,8 @@ bool loadMeshSTL(Mesh* mesh, const char* filename, const FMatrix3x3& matrix)
 
 bool loadMeshIntoMeshGroup(MeshGroup* meshgroup, const char* filename, const FMatrix3x3& transformation, SettingsBaseVirtual* object_parent_settings)
 {
+    TimeKeeper load_timer;
+
     const char* ext = strrchr(filename, '.');
     if (ext && (strcmp(ext, ".stl") == 0 || strcmp(ext, ".STL") == 0))
     {
@@ -290,6 +340,7 @@ bool loadMeshIntoMeshGroup(MeshGroup* meshgroup, const char* filename, const FMa
         if(loadMeshSTL(&mesh,filename,transformation)) //Load it! If successful...
         {
             meshgroup->meshes.push_back(mesh);
+            log("loading '%s' took %.3f seconds\n",filename,load_timer.restart());
             return true;
         }
     }

src/MeshGroup.h

@@ -18,9 +18,9 @@ namespace cura
 class MeshGroup : public SettingsBase, NoCopy
 {
     ExtruderTrain* extruders[MAX_EXTRUDERS] = {nullptr};
-    int extruder_count;
+    mutable int extruder_count; //!< The number of extruders. (mutable because of lazy evaluation)
 public:
-    int getExtruderCount();
+    int getExtruderCount() const;
 
     MeshGroup(SettingsBaseVirtual* settings_base);
     

src/Preheat.cpp

@@ -0,0 +1,184 @@
+#include "Preheat.h"
+
+namespace cura 
+{
+
+void Preheat::setConfig(const MeshGroup& meshgroup)
+{
+    for (int extruder_nr = 0; extruder_nr < meshgroup.getExtruderCount(); extruder_nr++)
+    {
+        assert(meshgroup.getExtruderTrain(extruder_nr) != nullptr);
+        const ExtruderTrain& extruder_train = *meshgroup.getExtruderTrain(extruder_nr);
+        config_per_extruder.emplace_back();
+        Config& config = config_per_extruder.back();
+        double machine_nozzle_cool_down_speed = extruder_train.getSettingInSeconds("machine_nozzle_cool_down_speed");
+        double machine_nozzle_heat_up_speed = extruder_train.getSettingInSeconds("machine_nozzle_heat_up_speed");
+        double material_extrusion_cool_down_speed = extruder_train.getSettingInSeconds("material_extrusion_cool_down_speed");
+        assert(material_extrusion_cool_down_speed < machine_nozzle_heat_up_speed && "The extrusion cooldown speed must be smaller than the heat up speed; otherwise the printing temperature cannot be reached!");
+        config.time_to_cooldown_1_degree[0] = 1.0 / machine_nozzle_cool_down_speed;
+        config.time_to_heatup_1_degree[0] = 1.0 / machine_nozzle_heat_up_speed;
+        config.time_to_cooldown_1_degree[1] = 1.0 / (machine_nozzle_cool_down_speed + material_extrusion_cool_down_speed);
+        config.time_to_heatup_1_degree[1] = 1.0 / (machine_nozzle_heat_up_speed - material_extrusion_cool_down_speed);
+        config.standby_temp = extruder_train.getSettingInSeconds("material_standby_temperature");
+
+        config.min_time_window = extruder_train.getSettingInSeconds("machine_min_cool_heat_time_window");
+
+        config.material_print_temperature = extruder_train.getSettingInDegreeCelsius("material_print_temperature");
+        config.material_print_temperature_layer_0 = extruder_train.getSettingInDegreeCelsius("material_print_temperature_layer_0");
+        config.material_initial_print_temperature = extruder_train.getSettingInDegreeCelsius("material_initial_print_temperature");
+        config.material_final_print_temperature = extruder_train.getSettingInDegreeCelsius("material_final_print_temperature");
+
+        config.flow_dependent_temperature = extruder_train.getSettingBoolean("material_flow_dependent_temperature"); 
+
+        config.flow_temp_graph = extruder_train.getSettingAsFlowTempGraph("material_flow_temp_graph"); // [[0.1,180],[20,230]]
+    }
+}
+
+double Preheat::getTimeToGoFromTempToTemp(int extruder, double temp_before, double temp_after, bool during_printing)
+{
+    Config& config = config_per_extruder[extruder];
+    double time;
+    if (temp_after > temp_before)
+    {
+        time = (temp_after - temp_before) * config.time_to_heatup_1_degree[during_printing];
+    }
+    else
+    {
+        time = (temp_before - temp_after) * config.time_to_cooldown_1_degree[during_printing];
+    }
+    return std::max(0.0, time);
+}
+
+double Preheat::getTemp(unsigned int extruder, double flow, bool is_initial_layer)
+{
+    if (is_initial_layer && config_per_extruder[extruder].material_print_temperature_layer_0 != 0)
+    {
+        return config_per_extruder[extruder].material_print_temperature_layer_0;
+    }
+    return config_per_extruder[extruder].flow_temp_graph.getTemp(flow, config_per_extruder[extruder].material_print_temperature, config_per_extruder[extruder].flow_dependent_temperature);
+}
+
+Preheat::WarmUpResult Preheat::getWarmUpPointAfterCoolDown(double time_window, unsigned int extruder, double temp_start, double temp_mid, double temp_end, bool during_printing)
+{
+    WarmUpResult result;
+    const Config& config = config_per_extruder[extruder];
+    double time_to_cooldown_1_degree = config.time_to_cooldown_1_degree[during_printing];
+    double time_to_heatup_1_degree = config.time_to_heatup_1_degree[during_printing];
+    result.total_time_window = time_window;
+
+    //                    ,temp_end
+    //                   /                                    .
+    //     ,temp_start  /                                     .
+    //      \ ' ' ' ' '/ ' ' '> outer_temp                    .
+    //       \________/                                       .
+    //               "-> temp_mid
+    //      ^^^^^^^^^^
+    //      limited_time_window
+    double outer_temp;
+    double limited_time_window;
+    if (temp_start < temp_end)
+    { // extra time needed during heating
+        double extra_heatup_time = (temp_end - temp_start) * time_to_heatup_1_degree;
+        result.heating_time = extra_heatup_time;
+        limited_time_window = time_window - extra_heatup_time;
+        outer_temp = temp_start;
+    }
+    else
+    {
+        double extra_cooldown_time = (temp_start - temp_end) * time_to_cooldown_1_degree;
+        result.heating_time = 0;
+        limited_time_window = time_window - extra_cooldown_time;
+        outer_temp = temp_end;
+    }
+    if (limited_time_window < 0.0)
+    {
+        result.heating_time = 0.0;
+        result.lowest_temperature = std::min(temp_start, temp_end);
+        return result;
+    }
+
+    double time_ratio_cooldown_heatup = time_to_cooldown_1_degree / time_to_heatup_1_degree;
+    double time_to_heat_from_standby_to_print_temp = getTimeToGoFromTempToTemp(extruder, temp_mid, outer_temp, during_printing);
+    double time_needed_to_reach_standby_temp = time_to_heat_from_standby_to_print_temp * (1.0 + time_ratio_cooldown_heatup);
+    if (time_needed_to_reach_standby_temp < limited_time_window)
+    {
+        result.heating_time += time_to_heat_from_standby_to_print_temp;
+        result.lowest_temperature = temp_mid;
+    }
+    else 
+    {
+        result.heating_time += limited_time_window * time_to_heatup_1_degree / (time_to_cooldown_1_degree + time_to_heatup_1_degree);
+        result.lowest_temperature = std::max(temp_mid, temp_end - result.heating_time / time_to_heatup_1_degree);
+    }
+
+    if (result.heating_time > time_window || result.heating_time < 0.0)
+    {
+        logWarning("getWarmUpPointAfterCoolDown returns result outside of the time window!");
+    }
+    return result;
+}
+
+Preheat::CoolDownResult Preheat::getCoolDownPointAfterWarmUp(double time_window, unsigned int extruder, double temp_start, double temp_mid, double temp_end, bool during_printing)
+{
+    CoolDownResult result;
+    const Config& config = config_per_extruder[extruder];
+    double time_to_cooldown_1_degree = config.time_to_cooldown_1_degree[during_printing];
+    double time_to_heatup_1_degree = config.time_to_heatup_1_degree[during_printing];
+
+    assert(temp_start != -1 && temp_mid != -1 && temp_end != -1 && "temperatures must be initialized!");
+
+    result.total_time_window = time_window;
+
+    //      limited_time_window
+    //     :^^^^^^^^^^^^:
+    //     :  ________. : . . .> temp_mid
+    //     : /        \ :                                     .
+    //     :/ . . . . .\:. . .> outer_temp                    .
+    //     ^temp_start  \                                     .
+    //                   \                                    .
+    //                    ^temp_end
+    double outer_temp;
+    double limited_time_window;
+    if (temp_start < temp_end)
+    { // extra time needed during heating
+        double extra_heatup_time = (temp_end - temp_start) * time_to_heatup_1_degree;
+        result.cooling_time = 0;
+        limited_time_window = time_window - extra_heatup_time;
+        outer_temp = temp_end;
+    }
+    else
+    {
+        double extra_cooldown_time = (temp_start - temp_end) * time_to_cooldown_1_degree;
+        result.cooling_time = extra_cooldown_time;
+        limited_time_window = time_window - extra_cooldown_time;
+        outer_temp = temp_start;
+    }
+    if (limited_time_window < 0.0)
+    {
+        result.cooling_time = 0.0;
+        result.highest_temperature = std::max(temp_start, temp_end);
+        return result;
+    }
+    double time_ratio_cooldown_heatup = time_to_cooldown_1_degree / time_to_heatup_1_degree;
+    double cool_down_time = getTimeToGoFromTempToTemp(extruder, temp_mid, outer_temp, during_printing);
+    double time_needed_to_reach_temp1 = cool_down_time * (1.0 + time_ratio_cooldown_heatup);
+    if (time_needed_to_reach_temp1 < limited_time_window)
+    {
+        result.cooling_time += cool_down_time;
+        result.highest_temperature = temp_mid;
+    }
+    else 
+    {
+        result.cooling_time += limited_time_window * time_to_heatup_1_degree / (time_to_cooldown_1_degree + time_to_heatup_1_degree);
+        result.highest_temperature = std::min(temp_mid, temp_end + result.cooling_time / time_to_cooldown_1_degree);
+    }
+
+    if (result.cooling_time > time_window || result.cooling_time < 0.0)
+    {
+        logWarning("getCoolDownPointAfterWarmUp returns result outside of the time window!");
+    }
+    return result;
+}
+
+
+}//namespace cura

src/Preheat.h

@@ -26,15 +26,21 @@ class Preheat
     class Config
     {
     public:
-        double time_to_heatup_1_degree; //!< average time it takes to heat up one degree (in the range of normal print temperatures and standby temperature)
-        double time_to_cooldown_1_degree; //!< average time it takes to cool down one degree (in the range of normal print temperatures and standby temperature)
-        
-        double heatup_cooldown_time_mod_while_printing; //!< The time to be added to Preheat::time_to_heatup_1_degree and subtracted from Preheat::time_to_cooldown_1_degree to get the timings while printing
+        double time_to_heatup_1_degree[2]; //!< average time it takes to heat up one degree (in the range of normal print temperatures and standby temperature), while not-printing and while printing
+        double time_to_cooldown_1_degree[2]; //!< average time it takes to cool down one degree (in the range of normal print temperatures and standby temperature), while not-printing and while printing
 
         double standby_temp; //!< The temperature at which the nozzle rests when it is not printing.
 
+        double min_time_window; //!< Minimal time (in seconds) to allow an extruder to cool down and then warm up again.
+
         double material_print_temperature; //!< default print temp (backward compatilibily)
-        
+
+        double material_print_temperature_layer_0; //!< initial layer print temp
+
+        double material_initial_print_temperature; //!< print temp when first starting to extrude after a layer switch
+
+        double material_final_print_temperature; //!< print temp at the end of all extrusion moves of an extruder to which it's cooled down just before - during the extrusion
+
         bool flow_dependent_temperature; //!< Whether to make the temperature dependent on flow
     
         FlowTempGraph flow_temp_graph; //!< The graph linking flows to corresponding temperatures
@@ -42,6 +48,26 @@ class Preheat
 
     std::vector<Config> config_per_extruder;//!< the nozzle and material temperature settings for each extruder train.
 public:
+    /*!
+     * The type of result when computing when to start heating up a nozzle before it's going to be used again.
+     */
+    struct WarmUpResult
+    {
+        double total_time_window; //!< The total time in which cooling and heating takes place.
+        double heating_time; //!< The total time needed to heat to the required temperature.
+        double lowest_temperature; //!< The lower temperature from which heating starts.
+    };
+
+    /*!
+     * The type of result when computing when to start cooling down a nozzle before it's not going to be used again.
+     */
+    struct CoolDownResult
+    {
+        double total_time_window; //!< The total time in which heating and cooling takes place.
+        double cooling_time; //!< The total time needed to cool down to the required temperature.
+        double highest_temperature; //!< The upper temperature from which cooling starts.
+    };
+
     /*!
      * Get the standby temperature of an extruder train
      * \param extruder the extruder train for which to get the standby tmep
@@ -51,126 +77,124 @@ public:
     {
         return config_per_extruder[extruder].standby_temp;
     }
-    
+
+    /*!
+     * Get the time it takes to heat up one degree celsius
+     * 
+     * \param extruder the extruder train for which to get time it takes to heat up one degree celsius
+     * \param during_printing whether the heating takes time during printing or when idle
+     * \return the time it takes to heat up one degree celsius
+     */
+    double getTimeToHeatup1Degree(int extruder, bool during_printing)
+    {
+        return config_per_extruder[extruder].time_to_heatup_1_degree[during_printing];
+    }
+
+    /*!
+     * Get the initial print temperature when starting to extrude.
+     * \param during_printing whether the heating takes time during printing or when idle
+     */
+    double getInitialPrintTemp(int extruder)
+    {
+        return config_per_extruder[extruder].material_initial_print_temperature;
+    }
+
+    /*!
+     * Get the final print temperature at the end of all extrusion moves with the current extruder
+     */
+    double getFinalPrintTemp(int extruder)
+    {
+        return config_per_extruder[extruder].material_final_print_temperature;
+    }
+
     /*!
      * Set the nozzle and material temperature settings for each extruder train.
+     * \param meshgroup Where to get settings from
      */
-    void setConfig(MeshGroup& settings)
-    {
-        for (int extruder_nr = 0; extruder_nr < settings.getExtruderCount(); extruder_nr++)
-        {
-            assert(settings.getExtruderTrain(extruder_nr) != nullptr);
-            ExtruderTrain& extruder_train = *settings.getExtruderTrain(extruder_nr);
-            config_per_extruder.emplace_back();
-            Config& config = config_per_extruder.back();
-            config.time_to_cooldown_1_degree = 1.0 / extruder_train.getSettingInSeconds("machine_nozzle_cool_down_speed"); // 0.5
-            config.time_to_heatup_1_degree = 1.0 / extruder_train.getSettingInSeconds("machine_nozzle_heat_up_speed"); // 0.5
-            config.heatup_cooldown_time_mod_while_printing = 1.0 / extruder_train.getSettingInSeconds("material_extrusion_cool_down_speed"); // 0.1
-            config.standby_temp = extruder_train.getSettingInSeconds("material_standby_temperature"); // 150
-            
-            config.material_print_temperature = extruder_train.getSettingInDegreeCelsius("material_print_temperature"); // 220
-            
-            config.flow_dependent_temperature = extruder_train.getSettingBoolean("material_flow_dependent_temperature"); 
-            
-            config.flow_temp_graph = extruder_train.getSettingAsFlowTempGraph("material_flow_temp_graph"); // [[0.1,180],[20,230]]
-        }
-    }
-    
+    void setConfig(const MeshGroup& meshgroup);
+
     bool usesFlowDependentTemp(int extruder_nr)
     {
         return config_per_extruder[extruder_nr].flow_dependent_temperature;
     }
-private:
     /*!
-     * Calculate time to heat up from standby temperature to a given temperature.
-     * Assumes @p temp is higher than the standby temperature.
+     * Get the optimal temperature corresponding to a given average flow,
+     * or the initial layer temperature.
      * 
-     * \param extruder The extruder for which to get the time
-     * \param temp The temperature to be reached
-     */
-    double timeToHeatFromStandbyToPrintTemp(unsigned int extruder, double temp)
-    {
-        return (temp - config_per_extruder[extruder].standby_temp) * config_per_extruder[extruder].time_to_heatup_1_degree; 
-    }
-
-public:
-    
-    /*!
-     * Get the optimal temperature corresponding to a given average flow.
      * \param extruder The extruder train
      * \param flow The flow for which to get the optimal temperature
+     * \param is_initial_layer Whether the initial layer temperature should be returned instead of flow-based temperature
      * \return The corresponding optimal temperature
      */
-    double getTemp(unsigned int extruder, double flow)
-    {
-        return config_per_extruder[extruder].flow_temp_graph.getTemp(flow, config_per_extruder[extruder].material_print_temperature, config_per_extruder[extruder].flow_dependent_temperature);
-    }
-    
+    double getTemp(unsigned int extruder, double flow, bool is_initial_layer);
+
     /*!
-     * Decide when to start warming up again after starting to cool down towards the standby temperature.
+     * Return the minimal time window of a specific extruder for letting an unused extruder cool down and warm up again
+     * \param extruder The extruder for which to get the minimal time window
+     * \return the minimal time window of a specific extruder for letting an unused extruder cool down and warm up again
+     */
+    double getMinimalTimeWindow(unsigned int extruder)
+    {
+        return config_per_extruder[extruder].min_time_window;
+    }
+
+    /*!
+     * Decide when to start warming up again after starting to cool down towards \p temp_mid.
      * Two cases are considered: 
      * the case where the standby temperature is reached  \__/    .
      * and the case where it isn't  \/    .
      * 
-     * IT is assumed that the printer is not printing during this cool down and warm up time.
-     * 
-     * Assumes from_temp is approximately the same as @p temp
+     * \warning it is assumed that \p temp_mid is lower than both \p temp_start and \p temp_end. If not somewhat weird results may follow.
      * 
+    //                    ,temp_end
+    //                   /                                    .
+    //     ,temp_start  /                                     .
+    //      \          /                                      .
+    //       \________/                                       .
+    //               "-> temp_mid
      * \param window_time The time window within which the cooldown and heat up must take place.
      * \param extruder The extruder used
-     * \param temp The temperature to which to heat
-     * \return The time before the end of the @p time_window to insert the preheat command
+     * \param temp_start The temperature from which to start cooling down
+     * \param temp_mid The temeprature to which we try to cool down
+     * \param temp_end The temperature to which we need to have heated up at the end of the \p time_window
+     * \param during_printing Whether the warming up and cooling down is performed during printing
+     * \return The time before the end of the @p time_window to insert the preheat command and the temperature from which the heating starts
      */
-    double timeBeforeEndToInsertPreheatCommand_coolDownWarmUp(double time_window, unsigned int extruder, double temp)
-    {
-        double time_ratio_cooldown_heatup = config_per_extruder[extruder].time_to_cooldown_1_degree / config_per_extruder[extruder].time_to_heatup_1_degree;
-        double time_to_heat_from_standby_to_print_temp = timeToHeatFromStandbyToPrintTemp(extruder, temp);
-        double time_needed_to_reach_standby_temp = time_to_heat_from_standby_to_print_temp * (1.0 + time_ratio_cooldown_heatup);
-        if (time_needed_to_reach_standby_temp < time_window)
-        {
-            return time_to_heat_from_standby_to_print_temp;
-        }
-        else 
-        {
-            return time_window * config_per_extruder[extruder].time_to_heatup_1_degree / (config_per_extruder[extruder].time_to_cooldown_1_degree + config_per_extruder[extruder].time_to_heatup_1_degree);
-        }
-    }
+    WarmUpResult getWarmUpPointAfterCoolDown(double time_window, unsigned int extruder, double temp_start, double temp_mid, double temp_end, bool during_printing);
+
     /*!
-     * Calculate time needed to warm up the nozzle from a given temp to a given temp.
-     * If the printer is printing in the mean time the warming up will take longer.
+     * Decide when to start cooling down again after starting to warm up towards the \p temp_mid
+     * Two cases are considered: 
+     * the case where the temperature is reached  /"""\    .
+     * and the case where it isn't  /\    .
      * 
+     * \warning it is assumed that \p temp_mid is higher than both \p temp_start and \p temp_end. If not somewhat weird results may follow.
      * 
-     * \param from_temp The temperature at which the nozzle was before
+    //               _> temp_mid
+    //       /""""""""\                                       .
+    //      /          \                                      .
+    //     ^temp_start  \                                     .
+    //                   \                                    .
+    //                    ^temp_end
+     * \param window_time The time window within which the cooldown and heat up must take place.
      * \param extruder The extruder used
-     * \param temp The temperature to which to heat
-     * \param printing Whether the printer is printing in the time to heat up the nozzle
-     * \return The time needed to reach the desired temperature (@p temp)
+     * \param temp_start The temperature from which to start heating up
+     * \param temp_mid The temeprature to which we try to heat up
+     * \param temp_end The temperature to which we need to have cooled down after \p time_window time
+     * \param during_printing Whether the warming up and cooling down is performed during printing
+     * \return The time before the end of the \p time_window to insert the preheat command and the temperature from which the cooling starts
      */
-    double timeBeforeEndToInsertPreheatCommand_warmUp(double from_temp, unsigned int extruder, double temp, bool printing)
-    {
-        if (temp > from_temp)
-        {
-            if (printing)
-            {
-                return (temp - from_temp) * (config_per_extruder[extruder].time_to_heatup_1_degree + config_per_extruder[extruder].heatup_cooldown_time_mod_while_printing); 
-            }
-            else 
-            {
-                return (temp - from_temp) * config_per_extruder[extruder].time_to_heatup_1_degree; 
-            }
-        }
-        else 
-        {
-            if (printing)
-            {
-                return (from_temp - temp) * config_per_extruder[extruder].time_to_cooldown_1_degree; 
-            }
-            else 
-            {
-                return (from_temp - temp) * std::max(0.0, config_per_extruder[extruder].time_to_cooldown_1_degree - config_per_extruder[extruder].heatup_cooldown_time_mod_while_printing); 
-            }
-        }
-    }
+    CoolDownResult getCoolDownPointAfterWarmUp(double time_window, unsigned int extruder, double temp_start, double temp_mid, double temp_end, bool during_printing);
+
+    /*!
+     * Get the time to go from one temperature to another temperature
+     * \param extruder The extruder number for which to perform the heatup / cooldown
+     * \param temp_before The before temperature
+     * \param temp_after The after temperature
+     * \param during_printing Whether the planned cooldown / warmup occurs during printing or while in standby mode
+     * \return The time needed
+     */
+    double getTimeToGoFromTempToTemp(int extruder, double temp_before, double temp_after, bool during_printing);
 };
 
 } // namespace cura 

src/PrimeTower.cpp

@@ -1,5 +1,7 @@
 #include "PrimeTower.h"
 
+#include <limits>
+
 #include "ExtruderTrain.h"
 #include "sliceDataStorage.h"
 #include "gcodeExport.h"
@@ -9,101 +11,33 @@
 
 namespace cura 
 {
-    
-    
-PrimeTower::PrimeTower()
+
+PrimeTower::PrimeTower(const SliceDataStorage& storage)
+: is_hollow(false)
+, wipe_from_middle(false)
 {
-}
-
-
-
-void PrimeTower::initConfigs(MeshGroup* meshgroup, std::vector<RetractionConfig>& retraction_config_per_extruder)
-{
-    extruder_count = meshgroup->getSettingAsCount("machine_extruder_count");
-    
-    for (int extr = 0; extr < extruder_count; extr++)
+    enabled = storage.getSettingBoolean("prime_tower_enable")
+           && storage.getSettingInMicrons("prime_tower_wall_thickness") > 10
+           && storage.getSettingInMicrons("prime_tower_size") > 10;
+    if (enabled)
     {
-        config_per_extruder.emplace_back(&retraction_config_per_extruder[extr], PrintFeatureType::Support);// so that visualization in the old Cura still works (TODO)
-    }
-    for (int extr = 0; extr < extruder_count; extr++)
-    {
-        ExtruderTrain* train = meshgroup->getExtruderTrain(extr);
-        config_per_extruder[extr].init(train->getSettingInMillimetersPerSecond("speed_prime_tower"), train->getSettingInMicrons("prime_tower_line_width"), train->getSettingInPercentage("prime_tower_flow"));
+        generateGroundpoly(storage);
     }
 }
 
-void PrimeTower::setConfigs(MeshGroup* meshgroup, int layer_thickness)
+void PrimeTower::generateGroundpoly(const SliceDataStorage& storage)
 {
-    
-    extruder_count = meshgroup->getSettingAsCount("machine_extruder_count");
-    
-    for (int extr = 0; extr < extruder_count; extr++)
+    extruder_count = storage.meshgroup->getExtruderCount();
+
+    int64_t prime_tower_wall_thickness = storage.getSettingInMicrons("prime_tower_wall_thickness");
+    int64_t tower_size = storage.getSettingInMicrons("prime_tower_size");
+
+    if (prime_tower_wall_thickness * 2 < tower_size)
     {
-        GCodePathConfig& conf = config_per_extruder[extr];
-        conf.setLayerHeight(layer_thickness);
+        is_hollow = true;
     }
-}
 
-    
-
-void PrimeTower::computePrimeTowerMax(SliceDataStorage& storage)
-{ // compute storage.max_object_height_second_to_last_extruder, which is used to determine the highest point in the prime tower
-        
-    extruder_count = storage.getSettingAsCount("machine_extruder_count");
-    
-    int max_object_height_per_extruder[extruder_count]; 
-    std::fill_n(max_object_height_per_extruder, extruder_count, -1); // unitialize all as -1
-    { // compute max_object_height_per_extruder
-        for (SliceMeshStorage& mesh : storage.meshes)
-        {
-            unsigned int extr_nr = mesh.getSettingAsIndex("extruder_nr");
-            max_object_height_per_extruder[extr_nr] = 
-                std::max(   max_object_height_per_extruder[extr_nr]
-                        ,   mesh.layer_nr_max_filled_layer  ); 
-        }
-        int support_infill_extruder_nr = storage.getSettingAsIndex("support_infill_extruder_nr"); // TODO: support extruder should be configurable per object
-        max_object_height_per_extruder[support_infill_extruder_nr] = 
-        std::max(   max_object_height_per_extruder[support_infill_extruder_nr]
-                ,   storage.support.layer_nr_max_filled_layer  ); 
-        int support_roof_extruder_nr = storage.getSettingAsIndex("support_roof_extruder_nr"); // TODO: support roof extruder should be configurable per object
-        max_object_height_per_extruder[support_roof_extruder_nr] = 
-        std::max(   max_object_height_per_extruder[support_roof_extruder_nr]
-                ,   storage.support.layer_nr_max_filled_layer  ); 
-    }
-    { // // compute max_object_height_second_to_last_extruder
-        int extruder_max_object_height = 0;
-        for (int extruder_nr = 1; extruder_nr < extruder_count; extruder_nr++)
-        {
-            if (max_object_height_per_extruder[extruder_nr] > max_object_height_per_extruder[extruder_max_object_height])
-            {
-                extruder_max_object_height = extruder_nr;
-            }
-        }
-        int extruder_second_max_object_height = -1;
-        for (int extruder_nr = 0; extruder_nr < extruder_count; extruder_nr++)
-        {
-            if (extruder_nr == extruder_max_object_height) { continue; }
-            if (extruder_second_max_object_height == -1 || max_object_height_per_extruder[extruder_nr] > max_object_height_per_extruder[extruder_second_max_object_height])
-            {
-                extruder_second_max_object_height = extruder_nr;
-            }
-        }
-        if (extruder_second_max_object_height < 0)
-        {
-            storage.max_object_height_second_to_last_extruder = -1;
-        }
-        else 
-        {
-            storage.max_object_height_second_to_last_extruder = max_object_height_per_extruder[extruder_second_max_object_height];
-        }
-    }
-       
-}
-
-void PrimeTower::generateGroundpoly(SliceDataStorage& storage) 
-{
-    PolygonRef p = storage.primeTower.ground_poly.newPoly();
-    int tower_size = storage.getSettingInMicrons("prime_tower_size");
+    PolygonRef p = ground_poly.newPoly();
     int tower_distance = 0; 
     int x = storage.getSettingInMicrons("prime_tower_position_x"); // storage.model_max.x
     int y = storage.getSettingInMicrons("prime_tower_position_y"); // storage.model_max.y
@@ -111,195 +45,228 @@ void PrimeTower::generateGroundpoly(SliceDataStorage& storage)
     p.add(Point(x + tower_distance, y + tower_distance + tower_size));
     p.add(Point(x + tower_distance - tower_size, y + tower_distance + tower_size));
     p.add(Point(x + tower_distance - tower_size, y + tower_distance));
+    middle = Point(x - tower_size / 2, y + tower_size / 2);
 
-    storage.wipePoint = Point(x + tower_distance - tower_size / 2, y + tower_distance + tower_size / 2);   
+    if (is_hollow)
+    {
+        ground_poly = ground_poly.difference(ground_poly.offset(-prime_tower_wall_thickness));
+    }
+
+    post_wipe_point = Point(x + tower_distance - tower_size / 2, y + tower_distance + tower_size / 2);
 }
 
-void PrimeTower::generatePaths(SliceDataStorage& storage, unsigned int total_layers)
+void PrimeTower::generatePaths(const SliceDataStorage& storage)
 {
-    if (storage.max_object_height_second_to_last_extruder >= 0 && storage.getSettingBoolean("prime_tower_enable"))
+    enabled &= storage.max_print_height_second_to_last_extruder >= 0; //Maybe it turns out that we don't need a prime tower after all because there are no layer switches.
+    if (enabled)
     {
-        generatePaths3(storage);
+        generatePaths_denseInfill(storage);
+        generateWipeLocations(storage);
     }
 }
-void PrimeTower::generatePaths_OLD(SliceDataStorage& storage, unsigned int total_layers)
-{
-    
-    if (storage.max_object_height_second_to_last_extruder >= 0 && storage.getSettingBoolean("prime_tower_enable"))
-    {
-        PolygonRef p = storage.primeTower.ground_poly.newPoly();
-        int tower_size = storage.getSettingInMicrons("prime_tower_size");
-        int tower_distance = 0; 
-        int x = storage.getSettingInMicrons("prime_tower_position_x"); // storage.model_max.x
-        int y = storage.getSettingInMicrons("prime_tower_position_y"); // storage.model_max.y
-        p.add(Point(x + tower_distance, y + tower_distance));
-        p.add(Point(x + tower_distance, y + tower_distance + tower_size));
-        p.add(Point(x + tower_distance - tower_size, y + tower_distance + tower_size));
-        p.add(Point(x + tower_distance - tower_size, y + tower_distance));
 
-        storage.wipePoint = Point(x + tower_distance - tower_size / 2, y + tower_distance + tower_size / 2);
-    }
-}
-    
-    
-void PrimeTower::generatePaths2(SliceDataStorage& storage) // half baked attempt at spiral shaped prime tower pattern
+void PrimeTower::generatePaths_denseInfill(const SliceDataStorage& storage)
 {
-//     extruder_count = storage.getSettingAsCount("machine_extruder_count");
-//     
-//     int64_t line_dists[extruder_count + 1]; // distance between the lines of different extruders, and half the line dist for beginning and ending
-//     int64_t total_width = 0;
-//     {
-//         int64_t last_line_width = 0;
-//         for (int extr = 0; extr < extruder_count; extr++)
-//         {
-//             int64_t line_width = config_per_extruder[extr].getLineWidth();
-//             line_dists[extr] = (line_width + last_line_width) / 2;
-//             total_width += line_width;
-//             last_line_width = line_width;
-//         }
-//         line_dists[extruder_count] = last_line_width / 2;
-//     }
-//     
-    
-    
-}
-
-void PrimeTower::generatePaths3(SliceDataStorage& storage)
-{
-        
     int n_patterns = 2; // alternating patterns between layers
     int infill_overlap = 60; // so that it can't be zero; EDIT: wtf?
-    
-    generateGroundpoly(storage);
-    
+    int extra_infill_shift = 0;
+
+    int64_t z = 0; // (TODO) because the prime tower stores the paths for each extruder for once instead of generating each layer, we don't know the z position
+
     for (int extruder = 0; extruder < extruder_count; extruder++)
     {
         int line_width = storage.meshgroup->getExtruderTrain(extruder)->getSettingInMicrons("prime_tower_line_width");
         patterns_per_extruder.emplace_back(n_patterns);
-        std::vector<Polygons>& patterns = patterns_per_extruder.back();
+        std::vector<ExtrusionMoves>& patterns = patterns_per_extruder.back();
+        patterns.resize(n_patterns);
         for (int pattern_idx = 0; pattern_idx < n_patterns; pattern_idx++)
         {
-            Polygons result_polygons; // should remain empty, since we generate lines pattern!
-            int outline_offset = -line_width/2;
+            patterns[pattern_idx].polygons = ground_poly.offset(-line_width / 2);
+            Polygons& result_lines = patterns[pattern_idx].lines;
+            int outline_offset = -line_width;
             int line_distance = line_width;
             double fill_angle = 45 + pattern_idx * 90;
-            Polygons& result_lines = patterns[pattern_idx];
-            Infill infill_comp(EFillMethod::LINES, ground_poly, outline_offset, line_width, line_distance, infill_overlap, fill_angle);
+            Polygons result_polygons; // should remain empty, since we generate lines pattern!
+            Infill infill_comp(EFillMethod::LINES, ground_poly, outline_offset, line_width, line_distance, infill_overlap, fill_angle, z, extra_infill_shift);
             infill_comp.generate(result_polygons, result_lines);
         }
     }
 }
 
-    
 
-void PrimeTower::addToGcode(SliceDataStorage& storage, GCodePlanner& gcodeLayer, GCodeExport& gcode, int layer_nr, int prev_extruder, bool prime_tower_dir_outward, bool wipe, int* last_prime_tower_poly_printed)
+void PrimeTower::addToGcode(const SliceDataStorage& storage, GCodePlanner& gcodeLayer, const GCodeExport& gcode, const int layer_nr, const int prev_extruder, const int new_extruder) const
 {
-    if (!( storage.max_object_height_second_to_last_extruder >= 0 && storage.getSettingInMicrons("prime_tower_size") > 0) )
+    if (!enabled)
     {
         return;
     }
-    bool prime_tower_added = false;
-    for (int extruder = 0; extruder <  storage.meshgroup->getExtruderCount() && !prime_tower_added; extruder++)
-    {
-        prime_tower_added = last_prime_tower_poly_printed[extruder] == int(layer_nr);
-    }
-    if (prime_tower_added)
+    if (gcodeLayer.getPrimeTowerIsPlanned())
     { // don't print the prime tower if it has been printed already
         return;
     }
-    
-    if (prev_extruder == gcodeLayer.getExtruder())
-    {
-        wipe = false;
-    }
-    addToGcode3(storage, gcodeLayer, gcode, layer_nr, prev_extruder, prime_tower_dir_outward, wipe, last_prime_tower_poly_printed);
-}
 
-void PrimeTower::addToGcode3(SliceDataStorage& storage, GCodePlanner& gcodeLayer, GCodeExport& gcode, int layer_nr, int prev_extruder, bool prime_tower_dir_outward, bool wipe, int* last_prime_tower_poly_printed)
-{
-    if (layer_nr > storage.max_object_height_second_to_last_extruder + 1)
+    if (layer_nr > storage.max_print_height_second_to_last_extruder + 1)
     {
         return;
     }
-    
-    int new_extruder = gcodeLayer.getExtruder();
 
-    
-    Polygons& pattern = patterns_per_extruder[new_extruder][layer_nr % 2];
+    bool pre_wipe = storage.meshgroup->getExtruderTrain(new_extruder)->getSettingBoolean("dual_pre_wipe");
+    bool post_wipe = storage.meshgroup->getExtruderTrain(prev_extruder)->getSettingBoolean("prime_tower_wipe_enabled");
 
-    
-    GCodePathConfig& config = config_per_extruder[new_extruder];
-    int start_idx = 0; // TODO: figure out which idx is closest to the far right corner
-    gcodeLayer.addPolygon(ground_poly.back(), start_idx, &config);
-    gcodeLayer.addLinesByOptimizer(pattern, &config, SpaceFillType::Lines);
-    
-    last_prime_tower_poly_printed[new_extruder] = layer_nr;
-
-    if (CommandSocket::isInstantiated())
+    if (prev_extruder == new_extruder)
     {
-        CommandSocket::getInstance()->sendPolygons(PrintFeatureType::Support, layer_nr, pattern, config.getLineWidth());
+        pre_wipe = false;
+        post_wipe = false;
+    }
+    // pre-wipe:
+    if (pre_wipe)
+    {
+        preWipe(storage, gcodeLayer, layer_nr, new_extruder);
     }
 
-    if (wipe)
+    addToGcode_denseInfill(gcodeLayer, layer_nr, new_extruder);
+
+    // post-wipe:
+    if (post_wipe)
     { //Make sure we wipe the old extruder on the prime tower.
-        gcodeLayer.addTravel(storage.wipePoint - gcode.getExtruderOffset(prev_extruder) + gcode.getExtruderOffset(new_extruder));
+        gcodeLayer.addTravel(post_wipe_point - gcode.getExtruderOffset(prev_extruder) + gcode.getExtruderOffset(new_extruder));
     }
+
+    gcodeLayer.setPrimeTowerIsPlanned();
 }
 
-void PrimeTower::addToGcode_OLD(SliceDataStorage& storage, GCodePlanner& gcodeLayer, GCodeExport& gcode, int layer_nr, int prev_extruder, bool prime_tower_dir_outward, bool wipe, int* last_prime_tower_poly_printed)
+void PrimeTower::addToGcode_denseInfill(GCodePlanner& gcode_layer, const int layer_nr, const int extruder_nr) const
 {
-    if (layer_nr > storage.max_object_height_second_to_last_extruder + 1)
-    {
-        return;
-    }
-    
-    int new_extruder = gcodeLayer.getExtruder();
+    const ExtrusionMoves& pattern = patterns_per_extruder[extruder_nr][((layer_nr % 2) + 2) % 2]; // +2) %2 to handle negative layer numbers
 
-    int64_t offset = -config_per_extruder[new_extruder].getLineWidth(); 
-    if (layer_nr > 0)
-        offset *= 2;
-    
-    //If we changed extruder, print the wipe/prime tower for this nozzle;
-    std::vector<Polygons> insets;
-    { // generate polygons
-        if ((layer_nr % 2) == 1)
-            insets.push_back(storage.primeTower.ground_poly.offset(offset / 2));
-        else
-            insets.push_back(storage.primeTower.ground_poly);
-        while(true)
+    const GCodePathConfig& config = gcode_layer.configs_storage.prime_tower_config_per_extruder[extruder_nr];
+
+    gcode_layer.addPolygonsByOptimizer(pattern.polygons, &config);
+    gcode_layer.addLinesByOptimizer(pattern.lines, &config, SpaceFillType::Lines);
+}
+
+Point PrimeTower::getLocationBeforePrimeTower(const SliceDataStorage& storage) const
+{
+    Point ret(0, 0);
+    int absolute_starting_points = 0;
+    for (int extruder_nr = 0; extruder_nr < storage.meshgroup->getExtruderCount(); extruder_nr++)
+    {
+        ExtruderTrain& train = *storage.meshgroup->getExtruderTrain(0);
+        if (train.getSettingBoolean("machine_extruder_start_pos_abs"))
         {
-            Polygons new_inset = insets[insets.size() - 1].offset(offset);
-            if (new_inset.size() < 1)
-                break;
-            insets.push_back(new_inset);
+            ret += Point(train.getSettingInMicrons("machine_extruder_start_pos_x"), train.getSettingInMicrons("machine_extruder_start_pos_y"));
+            absolute_starting_points++;
         }
     }
-    
-    
-    for(unsigned int n=0; n<insets.size(); n++)
+    if (absolute_starting_points > 0)
+    { // take the average over all absolute starting positions
+        ret /= absolute_starting_points;
+    }
+    else
+    { // use the middle of the bed
+        if (!storage.getSettingBoolean("machine_center_is_zero"))
+        {
+            ret = Point(storage.getSettingInMicrons("machine_width"), storage.getSettingInMicrons("machine_depth")) / 2;
+        }
+        // otherwise keep (0, 0)
+    }
+    return ret;
+}
+
+void PrimeTower::generateWipeLocations(const SliceDataStorage& storage)
+{
+    wipe_from_middle = is_hollow;
+    // only wipe from the middle of the prime tower if we have a z hop already on the first move after the layer switch
+    for (int extruder_nr = 0; extruder_nr < storage.meshgroup->getExtruderCount(); extruder_nr++)
     {
-        GCodePathConfig& config = config_per_extruder[new_extruder];
-        gcodeLayer.addPolygonsByOptimizer(insets[(prime_tower_dir_outward)? insets.size() - 1 - n : n], &config);
+        const ExtruderTrain& train = *storage.meshgroup->getExtruderTrain(extruder_nr);
+        wipe_from_middle &= train.getSettingBoolean("retraction_hop_enabled") 
+                        && (!train.getSettingBoolean("retraction_hop_only_when_collides") || train.getSettingBoolean("retraction_hop_after_extruder_switch"));
     }
-    last_prime_tower_poly_printed[new_extruder] = layer_nr;
-    
-    if (wipe)
-    { //Make sure we wipe the old extruder on the prime tower.
-        gcodeLayer.addTravel(storage.wipePoint - gcode.getExtruderOffset(prev_extruder) + gcode.getExtruderOffset(new_extruder));
+
+    PolygonsPointIndex segment_start; // from where to start the sequence of wipe points
+    PolygonsPointIndex segment_end; // where to end the sequence of wipe points
+
+    if (wipe_from_middle)
+    {
+        // take the same start as end point so that the whole poly os covered.
+        // find the inner polygon.
+        segment_start = segment_end = PolygonUtils::findNearestVert(middle, ground_poly);
     }
-};
-    
-    
-    
-    
-    
-    
-    
-    
-    
-    
-    
-    
-    
-    
-}//namespace cura
+    else
+    {
+        // take the closer corner of the wipe tower and generate wipe locations on that side only:
+        //
+        //     |
+        //     |
+        //     +-----
+        //  .
+        //  ^ nozzle switch location
+        Point from = getLocationBeforePrimeTower(storage);
+
+        // find the single line segment closest to [from] pointing most toward [from]
+        PolygonsPointIndex closest_vert = PolygonUtils::findNearestVert(from, ground_poly);
+        PolygonsPointIndex prev = closest_vert.prev();
+        PolygonsPointIndex next = closest_vert.next();
+        int64_t prev_dot_score = dot(from - closest_vert.p(), turn90CCW(prev.p() - closest_vert.p()));
+        int64_t next_dot_score = dot(from - closest_vert.p(), turn90CCW(closest_vert.p() - next.p()));
+        if (prev_dot_score > next_dot_score)
+        {
+            segment_start = prev;
+            segment_end = closest_vert;
+        }
+        else
+        {
+            segment_start = closest_vert;
+            segment_end = next;
+        }
+    }
+
+    PolygonUtils::spreadDots(segment_start, segment_end, number_of_pre_wipe_locations, pre_wipe_locations);
+}
+
+void PrimeTower::preWipe(const SliceDataStorage& storage, GCodePlanner& gcode_layer, const int layer_nr, const int extruder_nr) const
+{
+    int current_pre_wipe_location_idx = (pre_wipe_location_skip * layer_nr) % number_of_pre_wipe_locations;
+    const ClosestPolygonPoint wipe_location = pre_wipe_locations[current_pre_wipe_location_idx];
+
+    ExtruderTrain& train = *storage.meshgroup->getExtruderTrain(extruder_nr);
+    const int inward_dist = train.getSettingInMicrons("machine_nozzle_size") * 3 / 2 ;
+    const int start_dist = train.getSettingInMicrons("machine_nozzle_size") * 2;
+    const Point end = PolygonUtils::moveInsideDiagonally(wipe_location, inward_dist);
+    const Point outward_dir = wipe_location.location - end;
+    const Point start = wipe_location.location + normal(outward_dir, start_dist);
+    if (wipe_from_middle)
+    {
+        // for hollow wipe tower:
+        // start from above
+        // go to wipe start
+        // go to the Z height of the previous/current layer
+        // wipe
+        // go to normal layer height (automatically on the next extrusion move)...
+        GCodePath& toward_middle = gcode_layer.addTravel(middle);
+        toward_middle.perform_z_hop = true;
+        gcode_layer.forceNewPathStart();
+        GCodePath& toward_wipe_start = gcode_layer.addTravel_simple(start);
+        toward_wipe_start.perform_z_hop = false;
+        toward_wipe_start.retract = true;
+    }
+    else
+    {
+        gcode_layer.addTravel(start);
+    }
+    float flow = 0.0001; // force this path being interpreted as an extrusion path, so that no Z hop will occur (TODO: really separately handle travel and extrusion moves)
+    gcode_layer.addExtrusionMove(end, &gcode_layer.configs_storage.prime_tower_config_per_extruder[extruder_nr], SpaceFillType::None, flow);
+}
+
+void PrimeTower::subtractFromSupport(SliceDataStorage& storage)
+{
+    const Polygons outside_polygon = ground_poly.getOutsidePolygons();
+    for(size_t layer = 0; layer <= (size_t)storage.max_print_height_second_to_last_extruder + 1 && layer < storage.support.supportLayers.size(); layer++)
+    {
+        storage.support.supportLayers[layer].supportAreas = storage.support.supportLayers[layer].supportAreas.difference(outside_polygon);
+    }
+}
+
+
+}//namespace cura

src/PrimeTower.h

@@ -1,9 +1,15 @@
+//Copyright (c) 2016 Ultimaker B.V.
+//CuraEngine is released under the terms of the AGPLv3 or higher.
+
 #ifndef PRIME_TOWER_H
 #define PRIME_TOWER_H
 
-#include "gcodeExport.h" // GCodePathConfig
+#include <vector>
+
+#include "GCodePathConfig.h"
 #include "MeshGroup.h"
 #include "utils/polygon.h" // Polygons
+#include "utils/polygonUtils.h"
 
 namespace cura 
 {
@@ -13,51 +19,134 @@ class SliceDataStorage;
 class GCodePlanner;
 class GCodeExport;
 
-typedef std::vector<IntPoint> PolyLine;
-
+/*!
+ * Class for everything to do with the prime tower:
+ * - generating the areas
+ * - checking up till which height the prime tower has to be printed
+ * - generating the paths and adding them to the layer plan
+ */
 class PrimeTower
 {
 private:
-    int extruder_count;
-    std::vector<GCodePathConfig> config_per_extruder;
-
-    class WallInfill
+    struct ExtrusionMoves
     {
-        
+        Polygons polygons;
+        Polygons lines;
     };
-public:
-    void initConfigs(MeshGroup* meshgroup, std::vector<RetractionConfig>& retraction_config_per_extruder);
-    void setConfigs(MeshGroup* configs, int layer_thickness);
-    
-    Polygons ground_poly;
-    
-    std::vector<PolyLine> extruder_paths;
-    
-    
-    void generateGroundpoly(SliceDataStorage& storage);
+    int extruder_count; //!< number of extruders
+
+    bool is_hollow; //!< Whether the prime tower is hollow
+
+    bool wipe_from_middle; //!< Whether to wipe on the inside of the hollow prime tower
+    Point middle; //!< The middle of the prime tower
+
+    Point post_wipe_point; //!< location to post-wipe the unused nozzle off on
+
+    std::vector<ClosestPolygonPoint> pre_wipe_locations; //!< The differernt locations where to pre-wipe the active nozzle
+    const unsigned int pre_wipe_location_skip = 13; //!< How big the steps are when stepping through \ref PrimeTower::wipe_locations
+    const unsigned int number_of_pre_wipe_locations = 21; //!< The required size of \ref PrimeTower::wipe_locations
+    // note that the above are two consecutive numbers in the Fibonacci sequence
+
+public:
+    bool enabled; //!< Whether the prime tower is enabled.
+    Polygons ground_poly; //!< The outline of the prime tower to be used for each layer
+
+    std::vector<std::vector<ExtrusionMoves>> patterns_per_extruder; //!< for each extruder a vector of patterns to alternate between, over the layers
+
+    /*!
+     * \brief Creates a prime tower instance that will determine where and how
+     * the prime tower gets printed.
+     *
+     * \param storage A storage where it retrieves the prime tower settings.
+     */
+    PrimeTower(const SliceDataStorage& storage);
+
+    /*!
+     * Generate the prime tower area to be used on each layer
+     * 
+     * Fills \ref PrimeTower::ground_poly and sets \ref PrimeTower::middle
+     * 
+     * \param storage Where to retrieve prime tower settings from
+     */
+    void generateGroundpoly(const SliceDataStorage& storage);
 
-    std::vector<std::vector<Polygons>> patterns_per_extruder; //!< for each extruder a vector of patterns to alternate between, over the layers
-    
-    void generatePaths3(SliceDataStorage& storage);
-    
-    void generatePaths2(SliceDataStorage& storage);
     /*!
      * Generate the area where the prime tower should be.
      * 
-     * \param storage Input and Output parameter: fetches the outline information (see SliceLayerPart::outline) and generates the other reachable field of the \p storage
+     * \param storage where to get settings from
      * \param total_layers The total number of layers 
      */
-    void generatePaths(SliceDataStorage& storage, unsigned int total_layers);
-    void generatePaths_OLD(SliceDataStorage& storage, unsigned int total_layers);
+    void generatePaths(const SliceDataStorage& storage);
 
-    void computePrimeTowerMax(SliceDataStorage& storage);
-    
-    PrimeTower();
+    /*!
+     * Add path plans for the prime tower to the \p gcode_layer
+     * 
+     * \param storage where to get settings from; where to get the maximum height of the prime tower from
+     * \param[in,out] gcode_layer Where to get the current extruder from; where to store the generated layer paths
+     * \param layer_nr The layer for which to generate the prime tower paths
+     * \param prev_extruder The previous extruder with which paths were planned; from which extruder a switch was made
+     * \param new_extruder The switched to extruder with which the prime tower paths should be generated.
+     */
+    void addToGcode(const SliceDataStorage& storage, GCodePlanner& gcode_layer, const GCodeExport& gcode, const int layer_nr, const int prev_extruder, const int new_extruder) const;
 
-    void addToGcode(SliceDataStorage& storage, GCodePlanner& gcodeLayer, GCodeExport& gcode, int layer_nr, int prev_extruder, bool prime_tower_dir_outward, bool wipe, int* last_prime_tower_poly_printed);
-    void addToGcode_OLD(SliceDataStorage& storage, GCodePlanner& gcodeLayer, GCodeExport& gcode, int layer_nr, int prev_extruder, bool prime_tower_dir_outward, bool wipe, int* last_prime_tower_poly_printed);
-    void addToGcode3(SliceDataStorage& storage, GCodePlanner& gcodeLayer, GCodeExport& gcode, int layer_nr, int prev_extruder, bool prime_tower_dir_outward, bool wipe, int* last_prime_tower_poly_printed);
+    /*!
+     * \brief Subtract the prime tower from the support areas in storage.
+     *
+     * \param storage The storage where to find the support from which to
+     * subtract a prime tower.
+     */
+    void subtractFromSupport(SliceDataStorage& storage);
 
+private:
+
+    /*!
+     * Find an approriate representation for the point representing the location before going to the prime tower
+     * 
+     * \warning This is not the actual position each time before the wipe tower
+     * 
+     * \param storage where to get settings from
+     * \return that location
+     */
+    Point getLocationBeforePrimeTower(const SliceDataStorage& storage) const;
+
+    /*!
+     * \param storage where to get settings from
+     * Depends on ground_poly being generated
+     */
+    void generateWipeLocations(const SliceDataStorage& storage);
+
+    /*!
+     * \see WipeTower::generatePaths
+     * 
+     * Generate the extrude paths for each extruder on even and odd layers
+     * Fill the ground poly with dense infill.
+     * 
+     * \param storage where to get settings from
+     * \param total_layers The total number of layers 
+     */
+    void generatePaths_denseInfill(const SliceDataStorage& storage);
+
+    /*!
+     * \see PrimeTower::addToGcode
+     *
+     * Add path plans for the prime tower to the \p gcode_layer
+     *
+     * \param[in,out] gcode_layer Where to get the current extruder from; where to store the generated layer paths
+     * \param layer_nr The layer for which to generate the prime tower paths
+     * \param extruder The extruder we just switched to, with which the prime
+     * tower paths should be drawn.
+     */
+    void addToGcode_denseInfill(GCodePlanner& gcode_layer, const int layer_nr, const int extruder) const;
+
+    /*!
+     * Plan the moves for wiping the current nozzles oozed material before starting to print the prime tower.
+     * 
+     * \param storage where to get settings from
+     * \param[out] gcode_layer where to add the planned paths for wiping
+     * \param layer_nr The layer number of the \p gcode_layer
+     * \param extruder_nr The current extruder
+     */
+    void preWipe(const SliceDataStorage& storage, GCodePlanner& gcode_layer, const int layer_nr, const int extruder_nr) const;
 };
 
 

src/PrintFeature.h

@@ -4,18 +4,19 @@
 namespace cura
 {
 
-enum class PrintFeatureType
+enum class PrintFeatureType: unsigned char
 {
-    NoneType, // unused, but libArcus depends on it
+    NoneType, // used to mark unspecified jumps in polygons. libArcus depends on it
     OuterWall,
     InnerWall,
     Skin,
     Support,
-    Skirt,
+    SkirtBrim,
     Infill,
     SupportInfill,
     MoveCombing,
-    MoveRetraction
+    MoveRetraction,
+    SupportInterface
 };
 
 
@@ -23,4 +24,4 @@ enum class PrintFeatureType
 
 } // namespace cura
 
-#endif // PRINT_FEATURE
+#endif // PRINT_FEATURE

src/RetractionConfig.h

@@ -0,0 +1,28 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef RETRACTION_CONFIG_H
+#define RETRACTION_CONFIG_H
+
+
+namespace cura 
+{
+
+/*!
+ * The retraction configuration used in the GCodePathConfig of each feature (and the travel config)
+ */
+class RetractionConfig
+{
+public:
+    double distance; //!< The distance retracted (in mm)
+    double speed; //!< The speed with which to retract (in mm/s)
+    double primeSpeed; //!< the speed with which to unretract (in mm/s)
+    double prime_volume; //!< the amount of material primed after unretracting (in mm^3)
+    int zHop; //!< the amount with which to lift the head during a retraction-travel
+    int retraction_min_travel_distance; //!< Minimal distance traversed to even consider retracting (in micron)
+    double retraction_extrusion_window; //!< Window of mm extruded filament in which to limit the amount of retractions
+    int retraction_count_max; //!< The maximum amount of retractions allowed to occur in the RetractionConfig::retraction_extrusion_window
+};
+
+
+}//namespace cura
+
+#endif // RETRACTION_CONFIG_H

src/SkirtBrim.cpp

@@ -0,0 +1,198 @@
+//Copyright (C) 2013 David Braam
+//Copyright (c) 2016 Ultimaker B.V.
+//CuraEngine is released under the terms of the AGPLv3 or higher.
+
+#include "SkirtBrim.h"
+#include "support.h"
+
+namespace cura 
+{
+
+void SkirtBrim::getFirstLayerOutline(SliceDataStorage& storage, const unsigned int primary_line_count, const int primary_extruder_skirt_brim_line_width, const bool is_skirt, const bool outside_only, Polygons& first_layer_outline)
+{
+    bool external_only = is_skirt; // whether to include holes or not
+    const int layer_nr = 0;
+    if (is_skirt)
+    {
+        const bool include_helper_parts = true;
+        first_layer_outline = storage.getLayerOutlines(layer_nr, include_helper_parts, external_only);
+        first_layer_outline = first_layer_outline.approxConvexHull();
+    }
+    else
+    { // add brim underneath support by removing support where there's brim around the model
+        const bool include_helper_parts = false; // include manually below
+        first_layer_outline = storage.getLayerOutlines(layer_nr, include_helper_parts, external_only);
+        first_layer_outline = first_layer_outline.unionPolygons(); //To guard against overlapping outlines, which would produce holes according to the even-odd rule.
+        Polygons first_layer_empty_holes;
+        if (outside_only)
+        {
+            first_layer_empty_holes = first_layer_outline.getEmptyHoles();
+            first_layer_outline = first_layer_outline.removeEmptyHoles();
+        }
+        if (storage.support.generated && primary_line_count > 0)
+        { // remove model-brim from support
+            // avoid gap in the middle
+            //    V
+            //  +---+     +----+
+            //  |+-+|     |+--+|
+            //  || ||     ||[]|| > expand to fit an extra brim line
+            //  |+-+|     |+--+|
+            //  +---+     +----+ 
+            Polygons model_brim_covered_area = first_layer_outline.offset(primary_extruder_skirt_brim_line_width * (primary_line_count + primary_line_count % 2), ClipperLib::jtRound); // always leave a gap of an even number of brim lines, so that it fits if it's generating brim from both sides
+            if (outside_only)
+            { // don't remove support within empty holes where no brim is generated.
+                model_brim_covered_area.add(first_layer_empty_holes);
+            }
+            SupportLayer& support_layer = storage.support.supportLayers[0];
+            support_layer.supportAreas = support_layer.supportAreas.difference(model_brim_covered_area);
+            first_layer_outline.add(support_layer.supportAreas);
+            first_layer_outline.add(support_layer.skin);
+        }
+        if (storage.primeTower.enabled)
+        {
+            first_layer_outline.add(storage.primeTower.ground_poly); // don't remove parts of the prime tower, but make a brim for it
+        }
+    }
+    constexpr int join_distance = 20;
+    first_layer_outline = first_layer_outline.offset(join_distance).offset(-join_distance); // merge adjacent models into single polygon
+    constexpr int smallest_line_length = 200;
+    constexpr int largest_error_of_removed_point = 50;
+    first_layer_outline.simplify(smallest_line_length, largest_error_of_removed_point); // simplify for faster processing of the brim lines
+    if (first_layer_outline.size() == 0)
+    {
+        logError("Couldn't generate skirt / brim! No polygons on first layer.");
+    }
+}
+
+int SkirtBrim::generatePrimarySkirtBrimLines(SliceDataStorage& storage, int start_distance, unsigned int primary_line_count, const int primary_extruder_skirt_brim_line_width, const int64_t primary_extruder_minimal_length, const Polygons& first_layer_outline, Polygons& skirt_brim_primary_extruder)
+{
+
+    int offset_distance = start_distance - primary_extruder_skirt_brim_line_width / 2;
+    for (unsigned int skirt_brim_number = 0; skirt_brim_number < primary_line_count; skirt_brim_number++)
+    {
+        offset_distance += primary_extruder_skirt_brim_line_width;
+
+        Polygons outer_skirt_brim_line = first_layer_outline.offset(offset_distance, ClipperLib::jtRound);
+
+        //Remove small inner skirt and brim holes. Holes have a negative area, remove anything smaller then 100x extrusion "area"
+        for (unsigned int n = 0; n < outer_skirt_brim_line.size(); n++)
+        {
+            double area = outer_skirt_brim_line[n].area();
+            if (area < 0 && area > -primary_extruder_skirt_brim_line_width * primary_extruder_skirt_brim_line_width * 100)
+            {
+                outer_skirt_brim_line.remove(n--);
+            }
+        }
+
+        skirt_brim_primary_extruder.add(outer_skirt_brim_line);
+
+        int length = skirt_brim_primary_extruder.polygonLength();
+        if (skirt_brim_number + 1 >= primary_line_count && length > 0 && length < primary_extruder_minimal_length) //Make brim or skirt have more lines when total length is too small.
+        {
+            primary_line_count++;
+        }
+    }
+    return offset_distance;
+}
+
+void SkirtBrim::generate(SliceDataStorage& storage, int start_distance, unsigned int primary_line_count, bool outside_only)
+{
+    const bool is_skirt = start_distance > 0;
+
+    const int adhesion_extruder_nr = storage.getSettingAsIndex("adhesion_extruder_nr");
+    const ExtruderTrain* adhesion_extruder = storage.meshgroup->getExtruderTrain(adhesion_extruder_nr);
+    const int primary_extruder_skirt_brim_line_width = adhesion_extruder->getSettingInMicrons("skirt_brim_line_width");
+    const int64_t primary_extruder_minimal_length = adhesion_extruder->getSettingInMicrons("skirt_brim_minimal_length");
+
+    Polygons& skirt_brim_primary_extruder = storage.skirt_brim[adhesion_extruder_nr];
+
+    Polygons first_layer_outline;
+    getFirstLayerOutline(storage, primary_line_count, primary_extruder_skirt_brim_line_width, is_skirt, outside_only, first_layer_outline);
+
+    const bool has_ooze_shield = storage.oozeShield.size() > 0 && storage.oozeShield[0].size() > 0;
+    const bool has_draft_shield = storage.draft_protection_shield.size() > 0;
+
+    if (is_skirt && (has_ooze_shield || has_draft_shield))
+    { // make sure we don't generate skirt through draft / ooze shield
+        first_layer_outline = first_layer_outline.offset(start_distance - primary_extruder_skirt_brim_line_width / 2, ClipperLib::jtRound).unionPolygons(storage.draft_protection_shield);
+        if (has_ooze_shield)
+        {
+            first_layer_outline = first_layer_outline.unionPolygons(storage.oozeShield[0]);
+        }
+        first_layer_outline = first_layer_outline.approxConvexHull();
+        start_distance = primary_extruder_skirt_brim_line_width / 2;
+    }
+
+    int offset_distance = generatePrimarySkirtBrimLines(storage, start_distance, primary_line_count, primary_extruder_skirt_brim_line_width, primary_extruder_minimal_length, first_layer_outline, skirt_brim_primary_extruder);
+
+
+    // generate brim for ooze shield and draft shield
+    if (!is_skirt && (has_ooze_shield || has_draft_shield))
+    {
+        // generate areas where to make extra brim for the shields
+        // avoid gap in the middle
+        //    V
+        //  +---+     +----+
+        //  |+-+|     |+--+|
+        //  || ||     ||[]|| > expand to fit an extra brim line
+        //  |+-+|     |+--+|
+        //  +---+     +----+ 
+        const int64_t primary_skirt_brim_width = (primary_line_count + primary_line_count % 2) * primary_extruder_skirt_brim_line_width; // always use an even number, because we will fil the area from both sides
+
+        Polygons shield_brim;
+        if (has_ooze_shield)
+        {
+            shield_brim = storage.oozeShield[0].difference(storage.oozeShield[0].offset(-primary_skirt_brim_width - primary_extruder_skirt_brim_line_width));
+        }
+        if (has_draft_shield)
+        {
+            shield_brim = shield_brim.unionPolygons(storage.draft_protection_shield.difference(storage.draft_protection_shield.offset(-primary_skirt_brim_width - primary_extruder_skirt_brim_line_width)));
+        }
+        const Polygons outer_primary_brim = first_layer_outline.offset(offset_distance, ClipperLib::jtRound);
+        shield_brim = shield_brim.difference(outer_primary_brim.offset(primary_extruder_skirt_brim_line_width));
+
+        // generate brim within shield_brim
+        skirt_brim_primary_extruder.add(shield_brim);
+        while (shield_brim.size() > 0)
+        {
+            shield_brim = shield_brim.offset(-primary_extruder_skirt_brim_line_width);
+            skirt_brim_primary_extruder.add(shield_brim);
+        }
+
+        // update parameters to generate secondary skirt around
+        first_layer_outline = outer_primary_brim;
+        if (has_draft_shield)
+        {
+            first_layer_outline = first_layer_outline.unionPolygons(storage.draft_protection_shield);
+        }
+        if (has_ooze_shield)
+        {
+            first_layer_outline = first_layer_outline.unionPolygons(storage.oozeShield[0]);
+        }
+
+        offset_distance = 0;
+    }
+
+    { // process other extruders' brim/skirt (as one brim line around the old brim)
+        int last_width = primary_extruder_skirt_brim_line_width;
+        for (int extruder = 0; extruder < storage.meshgroup->getExtruderCount(); extruder++)
+        {
+            if (extruder == adhesion_extruder_nr || !storage.meshgroup->getExtruderTrain(extruder)->getIsUsed())
+            {
+                continue;
+            }
+            const ExtruderTrain* train = storage.meshgroup->getExtruderTrain(extruder);
+            const int width = train->getSettingInMicrons("skirt_brim_line_width");
+            const int64_t minimal_length = train->getSettingInMicrons("skirt_brim_minimal_length");
+            offset_distance += last_width / 2 + width/2;
+            last_width = width;
+            while (storage.skirt_brim[extruder].polygonLength() < minimal_length)
+            {
+                storage.skirt_brim[extruder].add(first_layer_outline.offset(offset_distance, ClipperLib::jtRound));
+                offset_distance += width;
+            }
+        }
+    }
+}
+
+}//namespace cura

src/SkirtBrim.h

@@ -0,0 +1,59 @@
+/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#ifndef SKIRT_BRIM_H
+#define SKIRT_BRIM_H
+
+#include "sliceDataStorage.h"
+
+namespace cura 
+{
+
+class SkirtBrim
+{
+public:
+    /*!
+     * Generate skirt or brim (depending on parameters).
+     * 
+     * When \p distance > 0 and \p count == 1 a skirt is generated, which has
+     * slightly different configuration. Otherwise, a brim is generated.
+     * 
+     * \param storage Storage containing the parts at the first layer.
+     * \param distance The distance of the first outset from the parts at the first
+     * layer.
+     * \param primary_line_count Number of outsets / brim lines of the primary extruder.
+     * \param outside_only Whether to only generate a brim on the outside, rather than also in holes
+     */
+    static void generate(SliceDataStorage& storage, int distance, unsigned int primary_line_count, bool outside_only);
+
+private:
+    /*!
+     * Get the reference outline of the first layer around which to generate the first brim/skirt line.
+     * 
+     * This function may change the support polygons in the first layer
+     * in order to meet criteria for putting brim around the model as well as around the support.
+     * 
+     * \param storage Storage containing the parts at the first layer.
+     * \param primary_line_count Number of outsets / brim lines of the primary extruder.
+     * \param primary_extruder_skirt_brim_line_width Line widths of the initial skirt/brim lines
+     * \param is_skirt Whether a skirt is being generated vs a brim
+     * \param outside_only Whether to only generate a brim on the outside, rather than also in holes
+     * \param[out] first_layer_outline The resulting reference polygons
+     */
+    static void getFirstLayerOutline(SliceDataStorage& storage, const unsigned int primary_line_count, const int primary_extruder_skirt_brim_line_width, const bool is_skirt, const bool outside_only, Polygons& first_layer_outline);
+
+    /*!
+     * Generate the skirt/brim lines around the model
+     * 
+     * \param storage Storage containing the parts at the first layer.
+     * \param start_distance The distance of the first outset from the parts at the first
+     * \param primary_line_count Number of outsets / brim lines of the primary extruder.
+     * \param primary_extruder_skirt_brim_line_width Line widths of the initial skirt/brim lines
+     * \param primary_extruder_minimal_length The minimal total length of the skirt/brim lines of the primary extruder
+     * \param first_layer_outline The reference polygons from which to offset outward to generate skirt/brim lines
+     * \param[out] skirt_brim_primary_extruder Where to store the resulting brim/skirt lines in
+     * \return The offset of the last brim/skirt line from the reference polygon \p first_layer_outline
+     */
+    static int generatePrimarySkirtBrimLines(SliceDataStorage& storage, int start_distance, unsigned int primary_line_count, const int primary_extruder_skirt_brim_line_width, const int64_t primary_extruder_minimal_length, const Polygons& first_layer_outline, Polygons& skirt_brim_primary_extruder);
+};
+}//namespace cura
+
+#endif //SKIRT_BRIM_H

src/WallsComputation.cpp

@@ -12,6 +12,12 @@ WallsComputation::WallsComputation(int wall_0_inset, int line_width_0, int line_
 {
 }
 
+/*
+ * This function is executed in a parallel region based on layer_nr.
+ * When modifying make sure any changes does not introduce data races.
+ *
+ * generateInsets only reads and writes data for the current layer
+ */
 void WallsComputation::generateInsets(SliceLayerPart* part)
 {
     if (insetCount == 0)
@@ -38,6 +44,7 @@ void WallsComputation::generateInsets(SliceLayerPart* part)
         
         //Finally optimize all the polygons. Every point removed saves time in the long run.
         part->insets[i].simplify();
+        part->insets[i].removeDegenerateVerts();
         if (i == 0)
         {
             if (recompute_outline_based_on_outer_wall)
@@ -57,6 +64,12 @@ void WallsComputation::generateInsets(SliceLayerPart* part)
     }
 }
 
+/*
+ * This function is executed in a parallel region based on layer_nr.
+ * When modifying make sure any changes does not introduce data races.
+ *
+ * generateInsets only reads and writes data for the current layer
+ */
 void WallsComputation::generateInsets(SliceLayer* layer)
 {
     for(unsigned int partNr = 0; partNr < layer->parts.size(); partNr++)

src/WallsComputation.h

@@ -1,6 +1,6 @@
 /** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
-#ifndef INSET_H
-#define INSET_H
+#ifndef WALLS_COMPUTATION_H
+#define WALLS_COMPUTATION_H
 
 #include "sliceDataStorage.h"
 
@@ -66,4 +66,4 @@ private:
 };
 }//namespace cura
 
-#endif//INSET_H
+#endif//WALLS_COMPUTATION_H

src/Weaver.cpp

@@ -19,7 +19,7 @@ void Weaver::weave(MeshGroup* meshgroup)
 
     int layer_count = (maxz - initial_layer_thickness) / connectionHeight + 1;
 
-    DEBUG_SHOW(layer_count);
+    std::cerr << "Layer count: " << layer_count << "\n";
 
     std::vector<cura::Slicer*> slicerList;
 
@@ -42,7 +42,7 @@ void Weaver::weave(MeshGroup* meshgroup)
         }
         if (starting_layer_idx > 0)
         {
-            logError("First %i layers are empty!\n", starting_layer_idx);
+            logWarning("First %i layers are empty!\n", starting_layer_idx);
         }
     }
     
@@ -53,8 +53,7 @@ void Weaver::weave(MeshGroup* meshgroup)
         for (cura::Slicer* slicer : slicerList)
             wireFrame.bottom_outline.add(slicer->layers[starting_layer_idx].polygons);
         
-        if (CommandSocket::isInstantiated())
-            CommandSocket::getInstance()->sendPolygons(PrintFeatureType::OuterWall, 0, wireFrame.bottom_outline, 1);
+        CommandSocket::sendPolygons(PrintFeatureType::OuterWall, /*0,*/ wireFrame.bottom_outline, 1);
         
         if (slicerList.empty()) //Wait, there is nothing to slice.
         {
@@ -85,10 +84,8 @@ void Weaver::weave(MeshGroup* meshgroup)
 
             chainify_polygons(parts1, starting_point_in_layer, chainified, false);
             
-            if (CommandSocket::isInstantiated())
-            {
-                CommandSocket::getInstance()->sendPolygons(PrintFeatureType::OuterWall, layer_idx - starting_layer_idx, chainified, 1);
-            }
+            CommandSocket::sendPolygons(PrintFeatureType::OuterWall, /*layer_idx - starting_layer_idx,*/ chainified, 1);
+
             if (chainified.size() > 0)
             {
                 if (starting_z == -1) starting_z = slicerList[0]->layers[layer_idx-1].z;
@@ -327,7 +324,7 @@ void Weaver::connections2moves(WeaveRoofPart& inset)
             WeaveConnectionSegment& segment = segments[idx];
             assert(segment.segmentType == WeaveSegmentType::UP);
             Point3 from = (idx == 0)? part.connection.from : segments[idx-1].to;
-            bool skipped = (segment.to - from).vSize2() < extrusionWidth * extrusionWidth;
+            bool skipped = (segment.to - from).vSize2() < line_width * line_width;
             if (skipped)
             {
                 unsigned int begin = idx;
@@ -336,9 +333,11 @@ void Weaver::connections2moves(WeaveRoofPart& inset)
                     WeaveConnectionSegment& segment = segments[idx];
                     assert(segments[idx].segmentType == WeaveSegmentType::UP);
                     Point3 from = (idx == 0)? part.connection.from : segments[idx-1].to;
-                    bool skipped = (segment.to - from).vSize2() < extrusionWidth * extrusionWidth;
+                    bool skipped = (segment.to - from).vSize2() < line_width * line_width;
                     if (!skipped) 
+                    {
                         break;
+                    }
                 }
                 int end = idx - ((include_half_of_last_down)? 2 : 1);
                 if (idx >= segments.size())
@@ -388,11 +387,9 @@ void Weaver::connect(Polygons& parts0, int z0, Polygons& parts1, int z1, WeaveCo
 
 void Weaver::chainify_polygons(Polygons& parts1, Point start_close_to, Polygons& result, bool include_last)
 {
-    
-        
     for (unsigned int prt = 0 ; prt < parts1.size(); prt++)
     {
-        const PolygonRef upperPart = parts1[prt];
+        ConstPolygonRef upperPart = parts1[prt];
         
         ClosestPolygonPoint closestInPoly = PolygonUtils::findClosest(start_close_to, upperPart);
 
@@ -403,9 +400,9 @@ void Weaver::chainify_polygons(Polygons& parts1, Point start_close_to, Polygons&
         bool found = true;
         int idx = 0;
         
-        for (Point upper_point = upperPart[closestInPoly.pos]; found; upper_point = next_upper.location)
+        for (Point upper_point = upperPart[closestInPoly.point_idx]; found; upper_point = next_upper.location)
         {
-            found = PolygonUtils::getNextPointWithDistance(upper_point, nozzle_top_diameter, upperPart, idx, closestInPoly.pos, next_upper);
+            found = PolygonUtils::getNextPointWithDistance(upper_point, nozzle_top_diameter, upperPart, idx, closestInPoly.point_idx, next_upper);
 
             
             if (!found) 
@@ -430,7 +427,7 @@ void Weaver::connect_polygons(Polygons& supporting, int z0, Polygons& supported,
  
     if (supporting.size() < 1)
     {
-        DEBUG_PRINTLN("lower layer has zero parts!");
+        std::cerr << "lower layer has zero parts!\n";
         return;
     }
     
@@ -442,7 +439,7 @@ void Weaver::connect_polygons(Polygons& supporting, int z0, Polygons& supported,
     for (unsigned int prt = 0 ; prt < supported.size(); prt++)
     {
         
-        const PolygonRef upperPart = supported[prt];
+        ConstPolygonRef upperPart(supported[prt]);
         
         
         parts.emplace_back(prt);
@@ -476,16 +473,4 @@ void Weaver::connect_polygons(Polygons& supporting, int z0, Polygons& supported,
 }
 
 
-
-
-
-
-
-
-
-
-
-
-
 }//namespace cura
-    

src/Weaver.h

@@ -12,8 +12,6 @@
 #include "utils/polygon.h"
 #include "utils/polygonUtils.h"
 
-#include "debug.h"
-
 namespace cura
 {
 
@@ -30,7 +28,7 @@ private:
     
     int initial_layer_thickness;
     int connectionHeight; 
-    int extrusionWidth;
+    int line_width;
     
     int roof_inset; 
     
@@ -47,7 +45,7 @@ public:
         initial_layer_thickness = getSettingInMicrons("layer_height_0");
         connectionHeight = getSettingInMicrons("wireframe_height"); 
         
-        extrusionWidth = getSettingInMicrons("wall_line_width_x");
+        line_width = getSettingInMicrons("wall_line_width_x");
         
         roof_inset = getSettingInMicrons("wireframe_roof_inset"); 
         nozzle_outer_diameter = getSettingInMicrons("machine_nozzle_tip_outer_diameter");      // ___       ___   .

src/Wireframe2gcode.cpp

@@ -3,10 +3,12 @@
 #include <cmath> // sqrt
 #include <fstream> // debug IO
 
+#include "utils/math.h"
+#include "utils/logoutput.h"
 #include "weaveDataStorage.h"
 #include "progress/Progress.h"
 
-#include "pathOrderOptimizer.h" // for skirt
+#include "pathOrderOptimizer.h" //For skirt/brim.
 
 namespace cura 
 {
@@ -16,8 +18,9 @@ void Wireframe2gcode::writeGCode()
 {
 
     gcode.preSetup(wireFrame.meshgroup);
-    
-    gcode.setInitialTemps(wireFrame.meshgroup);
+
+    const unsigned int start_extruder_nr = getSettingAsIndex("adhesion_extruder_nr"); // TODO: figure out how Wireframe works with dual extrusion
+    gcode.setInitialTemps(*wireFrame.meshgroup, start_extruder_nr);
     
     if (CommandSocket::getInstance())
         CommandSocket::getInstance()->beginGCode();
@@ -33,23 +36,22 @@ void Wireframe2gcode::writeGCode()
     {
         maxObjectHeight = wireFrame.layers.back().z1;
     }
-    
-    processSkirt();
-    
-            
-    unsigned int total_layers = wireFrame.layers.size();
-    gcode.writeLayerComment(0);
-    gcode.writeTypeComment("SKIRT");
 
     gcode.setZ(initial_layer_thickness);
-    
+
+    processSkirt();
+
+    unsigned int total_layers = wireFrame.layers.size();
+    gcode.writeLayerComment(0);
+    gcode.writeTypeComment(PrintFeatureType::SkirtBrim);
+
     for (PolygonRef bottom_part : wireFrame.bottom_infill.roof_outlines)
     {
         if (bottom_part.size() == 0) continue;
         writeMoveWithRetract(bottom_part[bottom_part.size()-1]);
         for (Point& segment_to : bottom_part)
         {
-            gcode.writeMove(segment_to, speedBottom, extrusion_per_mm_flat);
+            gcode.writeMove(segment_to, speedBottom, extrusion_mm3_per_mm_flat);
         }
     }
     
@@ -65,7 +67,7 @@ void Wireframe2gcode::writeGCode()
                         writeMoveWithRetract(segment.to); 
                     } else 
                     {
-                        gcode.writeMove(segment.to, speedBottom, extrusion_per_mm_connection); 
+                        gcode.writeMove(segment.to, speedBottom, extrusion_mm3_per_mm_connection);
                     }
                 }   
             , 
@@ -75,7 +77,7 @@ void Wireframe2gcode::writeGCode()
                     else if (segment.segmentType == WeaveSegmentType::DOWN_AND_FLAT)
                         return; // do nothing
                     else 
-                        gcode.writeMove(segment.to, speedBottom, extrusion_per_mm_flat); 
+                        gcode.writeMove(segment.to, speedBottom, extrusion_mm3_per_mm_flat);
                 }
             );
     Progress::messageProgressStage(Progress::Stage::EXPORT, nullptr);
@@ -98,7 +100,7 @@ void Wireframe2gcode::writeGCode()
        
             if (part.connection.segments.size() == 0) continue;
             
-            gcode.writeTypeComment("SUPPORT"); // connection
+            gcode.writeTypeComment(PrintFeatureType::Support); // connection
             {
                 if (vSize2(gcode.getPositionXY() - part.connection.from) > connectionHeight)
                 {
@@ -114,7 +116,7 @@ void Wireframe2gcode::writeGCode()
             
             
             
-            gcode.writeTypeComment("WALL-OUTER"); // top
+            gcode.writeTypeComment(PrintFeatureType::OuterWall); // top
             {
                 for (unsigned int segment_idx = 0; segment_idx < part.connection.segments.size(); segment_idx++)
                 {
@@ -125,7 +127,7 @@ void Wireframe2gcode::writeGCode()
                         writeMoveWithRetract(segment.to);
                     } else 
                     {
-                        gcode.writeMove(segment.to, speedFlat, extrusion_per_mm_flat);
+                        gcode.writeMove(segment.to, speedFlat, extrusion_mm3_per_mm_flat);
                         gcode.writeDelay(flat_delay);
                     }
                 }
@@ -147,7 +149,7 @@ void Wireframe2gcode::writeGCode()
                         // do nothing
                     } else 
                     {   
-                        gcode.writeMove(segment.to, speedFlat, extrusion_per_mm_flat);
+                        gcode.writeMove(segment.to, speedFlat, extrusion_mm3_per_mm_flat);
                         gcode.writeDelay(flat_delay);
                     }
                 });
@@ -158,7 +160,7 @@ void Wireframe2gcode::writeGCode()
     
     gcode.setZ(maxObjectHeight);
     
-    gcode.writeRetraction(&standard_retraction_config);
+    gcode.writeRetraction(standard_retraction_config);
     
     
     gcode.updateTotalPrintTime();
@@ -179,7 +181,7 @@ void Wireframe2gcode::go_down(WeaveLayer& layer, WeaveConnectionPart& part, unsi
         gcode.writeMove(from, speedDown, 0);
     if (straight_first_when_going_down <= 0)
     {
-        gcode.writeMove(segment.to, speedDown, extrusion_per_mm_connection);
+        gcode.writeMove(segment.to, speedDown, extrusion_mm3_per_mm_connection);
     } else 
     {
         Point3& to = segment.to;
@@ -191,14 +193,14 @@ void Wireframe2gcode::go_down(WeaveLayer& layer, WeaveConnectionPart& part, unsi
         int64_t new_length = (up - from).vSize() + (to - up).vSize() + 5;
         int64_t orr_length = vec.vSize();
         double enlargement = new_length / orr_length;
-        gcode.writeMove(up, speedDown*enlargement, extrusion_per_mm_connection / enlargement);
-        gcode.writeMove(to, speedDown*enlargement, extrusion_per_mm_connection / enlargement);
+        gcode.writeMove(up, speedDown*enlargement, extrusion_mm3_per_mm_connection / enlargement);
+        gcode.writeMove(to, speedDown*enlargement, extrusion_mm3_per_mm_connection / enlargement);
     }
     gcode.writeDelay(bottom_delay);
     if (up_dist_half_speed > 0)
     {
         
-        gcode.writeMove(Point3(0,0,up_dist_half_speed) + gcode.getPosition(), speedUp / 2, extrusion_per_mm_connection * 2);
+        gcode.writeMove(Point3(0,0,up_dist_half_speed) + gcode.getPosition(), speedUp / 2, extrusion_mm3_per_mm_connection * 2);
     }
 }
 
@@ -207,7 +209,7 @@ void Wireframe2gcode::go_down(WeaveLayer& layer, WeaveConnectionPart& part, unsi
 void Wireframe2gcode::strategy_knot(WeaveLayer& layer, WeaveConnectionPart& part, unsigned int segment_idx)
 {
     WeaveConnectionSegment& segment = part.connection.segments[segment_idx];
-    gcode.writeMove(segment.to, speedUp, extrusion_per_mm_connection);
+    gcode.writeMove(segment.to, speedUp, extrusion_mm3_per_mm_connection);
     Point3 next_vector;
     if (segment_idx + 1 < part.connection.segments.size())
     {
@@ -257,8 +259,8 @@ void Wireframe2gcode::strategy_retract(WeaveLayer& layer, WeaveConnectionPart& p
         Point3 vec = to - from;
         Point3 lowering = vec * retract_hop_dist / 2 / vec.vSize();
         Point3 lower = to - lowering;
-        gcode.writeMove(lower, speedUp, extrusion_per_mm_connection);
-        gcode.writeRetraction(&retraction_config);
+        gcode.writeMove(lower, speedUp, extrusion_mm3_per_mm_connection);
+        gcode.writeRetraction(retraction_config);
         gcode.writeMove(to + lowering, speedUp, 0);
         gcode.writeDelay(top_retract_pause);
         if (after_retract_hop)
@@ -266,8 +268,8 @@ void Wireframe2gcode::strategy_retract(WeaveLayer& layer, WeaveConnectionPart& p
         
     } else 
     {
-        gcode.writeMove(to, speedUp, extrusion_per_mm_connection);
-        gcode.writeRetraction(&retraction_config);
+        gcode.writeMove(to, speedUp, extrusion_mm3_per_mm_connection);
+        gcode.writeRetraction(retraction_config);
         gcode.writeMove(to + Point3(0, 0, retract_hop_dist), speedFlat, 0);
         gcode.writeDelay(top_retract_pause);
         if (after_retract_hop)    
@@ -304,7 +306,7 @@ void Wireframe2gcode::strategy_compensate(WeaveLayer& layer, WeaveConnectionPart
     int64_t orrLength = (segment.to - from).vSize() + next_vector.vSize() + 1; // + 1 in order to avoid division by zero
     int64_t newLength = (newTop - from).vSize() + (next_point - newTop).vSize() + 1; // + 1 in order to avoid division by zero
     
-    gcode.writeMove(newTop, speedUp * newLength / orrLength, extrusion_per_mm_connection * orrLength / newLength);
+    gcode.writeMove(newTop, speedUp * newLength / orrLength, extrusion_mm3_per_mm_connection * orrLength / newLength);
 }
 void Wireframe2gcode::handle_segment(WeaveLayer& layer, WeaveConnectionPart& part, unsigned int segment_idx) 
 {
@@ -319,7 +321,7 @@ void Wireframe2gcode::handle_segment(WeaveLayer& layer, WeaveConnectionPart& par
             go_down(layer, part, segment_idx);
             break;
         case WeaveSegmentType::FLAT:
-            DEBUG_SHOW("flat piece in connection?!!?!");
+            logWarning("Warning: flat piece in wire print connection.\n");
             break;
         case WeaveSegmentType::UP:
             if (strategy == STRATEGY_KNOT)
@@ -383,12 +385,12 @@ void Wireframe2gcode::handle_roof_segment(WeaveRoofPart& inset, WeaveConnectionP
                     detoured -= next_dir;
                 }
                 
-                gcode.writeMove(detoured, speedUp, extrusion_per_mm_connection);
+                gcode.writeMove(detoured, speedUp, extrusion_mm3_per_mm_connection);
 
             }
             break;
         case WeaveSegmentType::DOWN:
-            gcode.writeMove(segment.to, speedDown, extrusion_per_mm_connection);
+            gcode.writeMove(segment.to, speedDown, extrusion_mm3_per_mm_connection);
             gcode.writeDelay(roof_outer_delay);
             break;
         case WeaveSegmentType::FLAT:
@@ -406,7 +408,7 @@ void Wireframe2gcode::writeFill(std::vector<WeaveRoofPart>& infill_insets, Polyg
 {
         
     // bottom:
-    gcode.writeTypeComment("FILL");
+    gcode.writeTypeComment(PrintFeatureType::Infill);
     for (unsigned int inset_idx = 0; inset_idx < infill_insets.size(); inset_idx++)
     {
         WeaveRoofPart& inset = infill_insets[inset_idx];
@@ -417,7 +419,7 @@ void Wireframe2gcode::writeFill(std::vector<WeaveRoofPart>& infill_insets, Polyg
             WeaveConnectionPart& inset_part = inset.connections[inset_part_nr];
             std::vector<WeaveConnectionSegment>& segments = inset_part.connection.segments;
             
-            gcode.writeTypeComment("SUPPORT"); // connection
+            gcode.writeTypeComment(PrintFeatureType::Support); // connection
             if (segments.size() == 0) continue;
             Point3 first_extrusion_from = inset_part.connection.from;
             unsigned int first_segment_idx;
@@ -433,7 +435,7 @@ void Wireframe2gcode::writeFill(std::vector<WeaveRoofPart>& infill_insets, Polyg
                 connectionHandler(*this, inset, inset_part, segment_idx);
             }
             
-            gcode.writeTypeComment("WALL-INNER"); // top
+            gcode.writeTypeComment(PrintFeatureType::InnerWall); // top
             for (unsigned int segment_idx = 0; segment_idx < segments.size(); segment_idx++)
             {
                 WeaveConnectionSegment& segment = segments[segment_idx];
@@ -447,7 +449,7 @@ void Wireframe2gcode::writeFill(std::vector<WeaveRoofPart>& infill_insets, Polyg
         
     }
     
-    gcode.writeTypeComment("WALL-OUTER"); // outer perimeter of the flat parts
+    gcode.writeTypeComment(PrintFeatureType::OuterWall); // outer perimeter of the flat parts
     for (PolygonRef poly : roof_outlines)
     {
         writeMoveWithRetract(poly[poly.size() - 1]);
@@ -466,14 +468,14 @@ void Wireframe2gcode::writeFill(std::vector<WeaveRoofPart>& infill_insets, Polyg
 void Wireframe2gcode::writeMoveWithRetract(Point3 to)
 {
     if ((gcode.getPosition() - to).vSize2() >= nozzle_top_diameter * nozzle_top_diameter * 2 * 2)
-        gcode.writeRetraction(&standard_retraction_config);
+        gcode.writeRetraction(standard_retraction_config);
     gcode.writeMove(to, moveSpeed, 0);
 }
 
 void Wireframe2gcode::writeMoveWithRetract(Point to)
 {
     if (vSize2(gcode.getPositionXY() - to) >= nozzle_top_diameter * nozzle_top_diameter * 2 * 2)
-        gcode.writeRetraction(&standard_retraction_config);
+        gcode.writeRetraction(standard_retraction_config);
     gcode.writeMove(to, moveSpeed, 0);
 }
 
@@ -487,16 +489,15 @@ Wireframe2gcode::Wireframe2gcode(Weaver& weaver, GCodeExport& gcode, SettingsBas
     roof_inset = getSettingInMicrons("wireframe_roof_inset"); 
     
     filament_diameter = getSettingInMicrons("material_diameter");
-    extrusionWidth = getSettingInMicrons("wall_line_width_x");
+    line_width = getSettingInMicrons("wall_line_width_x");
     
     flowConnection = getSettingInPercentage("wireframe_flow_connection");
     flowFlat = getSettingInPercentage("wireframe_flow_flat");
-    
-    double filament_area = /* M_PI * */ (INT2MM(filament_diameter) / 2.0) * (INT2MM(filament_diameter) / 2.0);
-    double lineArea = /* M_PI * */ (INT2MM(extrusionWidth) / 2.0) * (INT2MM(extrusionWidth) / 2.0);
-    extrusion_per_mm_connection = lineArea / filament_area * flowConnection / 100.0;
-    extrusion_per_mm_flat = lineArea / filament_area * flowFlat / 100.0;
-    
+
+    const double line_area = M_PI * square(INT2MM(line_width) / 2.0);
+    extrusion_mm3_per_mm_connection = line_area * flowConnection / 100.0;
+    extrusion_mm3_per_mm_flat = line_area * flowFlat / 100.0;
+
     nozzle_outer_diameter = getSettingInMicrons("machine_nozzle_tip_outer_diameter"); // ___       ___   .
     nozzle_head_distance = getSettingInMicrons("machine_nozzle_head_distance");      //    |     |      .
     nozzle_expansion_angle = getSettingInAngleRadians("machine_nozzle_expansion_angle");  //     \_U_/       .
@@ -550,34 +551,44 @@ void Wireframe2gcode::processStartingCode()
 {
     if (!CommandSocket::isInstantiated())
     {
-        gcode.writeCode(gcode.getFileHeader().c_str());
+        std::string prefix = gcode.getFileHeader();
+        gcode.writeCode(prefix.c_str());
     }
-    else 
+
+    int start_extruder_nr = getSettingAsIndex("adhesion_extruder_nr");
+
+    gcode.writeComment("Generated with Cura_SteamEngine " VERSION);
+
+    if (gcode.getFlavor() != EGCodeFlavor::ULTIGCODE && gcode.getFlavor() != EGCodeFlavor::GRIFFIN)
     {
         if (getSettingBoolean("material_bed_temp_prepend"))
         {
-            if (getSettingBoolean("machine_heated_bed") && getSettingInDegreeCelsius("material_bed_temperature") > 0)
+            if (getSettingBoolean("machine_heated_bed") && getSettingInDegreeCelsius("material_bed_temperature") != 0)
             {
                 gcode.writeBedTemperatureCommand(getSettingInDegreeCelsius("material_bed_temperature"), getSettingBoolean("material_bed_temp_wait"));
             }
         }
-        
+
         if (getSettingBoolean("material_print_temp_prepend"))
         {
-            if (getSettingInDegreeCelsius("material_print_temperature") > 0)
+            for (int extruder_nr = 0; extruder_nr < getSettingAsCount("machine_extruder_count"); extruder_nr++)
             {
-                gcode.writeTemperatureCommand(getSettingAsIndex("extruder_nr"), getSettingInDegreeCelsius("material_print_temperature"));
-                if (getSettingBoolean("machine_print_temp_wait"))
+                double print_temp = getSettingInDegreeCelsius("material_print_temperature");
+                gcode.writeTemperatureCommand(extruder_nr, print_temp);
+            }
+            if (getSettingBoolean("material_print_temp_wait"))
+            {
+                for (int extruder_nr = 0; extruder_nr < getSettingAsCount("machine_extruder_count"); extruder_nr++)
                 {
-                    gcode.writeTemperatureCommand(getSettingAsIndex("extruder_nr"), getSettingInDegreeCelsius("material_print_temperature"), true);
+                    double print_temp = getSettingInDegreeCelsius("material_print_temperature");
+                    gcode.writeTemperatureCommand(extruder_nr, print_temp, true);
                 }
             }
         }
-        
     }
+
     gcode.writeCode(getSettingString("machine_start_gcode").c_str());
-    
-    gcode.writeComment("Generated with Cura_SteamEngine " VERSION);
+
     if (gcode.getFlavor() == EGCodeFlavor::BFB)
     {
         gcode.writeComment("enable auto-retraction");
@@ -585,6 +596,16 @@ void Wireframe2gcode::processStartingCode()
         tmp << "M227 S" << (getSettingInMicrons("retraction_amount") * 2560 / 1000) << " P" << (getSettingInMicrons("retraction_amount") * 2560 / 1000);
         gcode.writeLine(tmp.str().c_str());
     }
+    else if (gcode.getFlavor() == EGCodeFlavor::GRIFFIN)
+    { // initialize extruder trains
+        gcode.writeCode("T0"); // Toolhead already assumed to be at T0, but writing it just to be safe...
+        CommandSocket::setSendCurrentPosition(gcode.getPositionXY());
+        gcode.startExtruder(start_extruder_nr);
+        constexpr bool wait = true;
+        gcode.writeTemperatureCommand(start_extruder_nr, getSettingInDegreeCelsius("material_print_temperature"), wait);
+        gcode.writePrimeTrain(getSettingInMillimetersPerSecond("speed_travel"));
+        gcode.writeRetraction(standard_retraction_config);
+    }
 }
 
 
@@ -598,7 +619,7 @@ void Wireframe2gcode::processSkirt()
     PathOrderOptimizer order(Point(INT32_MIN, INT32_MIN));
     order.addPolygons(skirt);
     order.optimize();
-    
+
     for (unsigned int poly_order_idx = 0; poly_order_idx < skirt.size(); poly_order_idx++)
     {
         unsigned int poly_idx = order.polyOrder[poly_order_idx];
@@ -607,7 +628,7 @@ void Wireframe2gcode::processSkirt()
         for (unsigned int point_idx = 0; point_idx < poly.size(); point_idx++)
         {
             Point& p = poly[(point_idx + order.polyStart[poly_idx] + 1) % poly.size()];
-            gcode.writeMove(p, getSettingInMillimetersPerSecond("skirt_speed"), getSettingInMillimetersPerSecond("skirt_line_width"));
+            gcode.writeMove(p, getSettingInMillimetersPerSecond("skirt_brim_speed"), getSettingInMillimeters("skirt_brim_line_width") * INT2MM(initial_layer_thickness));
         }
     }
 }

src/Wireframe2gcode.h

@@ -16,8 +16,6 @@
 #include "utils/polygon.h"
 #include "Weaver.h"
 
-#include "debug.h"
-
 namespace cura
 {
 
@@ -33,11 +31,11 @@ private:
     
     int initial_layer_thickness;
     int filament_diameter;
-    int extrusionWidth;
+    int line_width;
     double flowConnection;
     double flowFlat; 
-    double extrusion_per_mm_connection; 
-    double extrusion_per_mm_flat; 
+    double extrusion_mm3_per_mm_connection;
+    double extrusion_mm3_per_mm_flat;
     int nozzle_outer_diameter;
     int nozzle_head_distance;
     double nozzle_expansion_angle;

src/bridge.cpp

@@ -5,7 +5,7 @@
 
 namespace cura {
 
-int bridgeAngle(Polygons outline, SliceLayer* prevLayer)
+int bridgeAngle(Polygons outline, const SliceLayer* prevLayer)
 {
     AABB boundaryBox(outline);
     //To detect if we have a bridge, first calculate the intersection of the current layer with the previous layer.

src/bridge.h

@@ -6,7 +6,7 @@ namespace cura {
     class Polygons;
     class SliceLayer;
 
-int bridgeAngle(Polygons outline, SliceLayer* prevLayer);
+int bridgeAngle(Polygons outline, const SliceLayer* prevLayer);
 
 }//namespace cura
 

src/comb.cpp

@@ -1,483 +0,0 @@
-/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
-#include "comb.h"
-
-#include <algorithm>
-
-#include "utils/polygonUtils.h"
-#include "sliceDataStorage.h"
-#include "utils/SVG.h"
-
-namespace cura {
-
-
-// boundary_outside is only computed when it's needed!
-Polygons& Comb::getBoundaryOutside()
-{
-    if (!boundary_outside)
-    {
-        boundary_outside = new Polygons();
-        *boundary_outside = storage.getLayerOutlines(layer_nr, false).offset(offset_from_outlines_outside); 
-    }
-    return *boundary_outside;
-}
-
-BucketGrid2D<PolygonsPointIndex>& Comb::getOutsideLocToLine()
-{
-    Polygons& outside = getBoundaryOutside();
-    if (!outside_loc_to_line)
-    {
-        outside_loc_to_line = PolygonUtils::createLocToLineGrid(outside, offset_from_outlines_outside * 3 / 2);
-    }
-    return *outside_loc_to_line;
-}
-
-  
-Comb::Comb(SliceDataStorage& storage, int layer_nr, Polygons& comb_boundary_inside, int64_t comb_boundary_offset, bool travel_avoid_other_parts, int64_t travel_avoid_distance)
-: storage(storage)
-, layer_nr(layer_nr)
-, offset_from_outlines(comb_boundary_offset) // between second wall and infill / other walls
-, max_moveInside_distance2(offset_from_outlines * 2 * offset_from_outlines * 2)
-, offset_from_outlines_outside(travel_avoid_distance)
-, max_crossing_dist2(offset_from_outlines_outside * offset_from_outlines_outside * 3) // so max_crossing_dist = offset_from_outlines_outside * sqrt(3), which is a bit more than sqrt(2) which is necesary for 90* corners
-, avoid_other_parts(travel_avoid_other_parts)
-// , boundary_inside( boundary.offset(-offset_from_outlines) ) // TODO: make inside boundary configurable?
-, boundary_inside( comb_boundary_inside )
-, boundary_outside(nullptr)
-, outside_loc_to_line(nullptr)
-, partsView_inside( boundary_inside.splitIntoPartsView() ) // !! changes the order of boundary_inside !!
-{
-}
-
-Comb::~Comb()
-{
-    if (boundary_outside)
-    {
-        delete boundary_outside;
-    }
-    if (outside_loc_to_line)
-    {
-        delete outside_loc_to_line;
-    }
-}
-
-bool Comb::calc(Point startPoint, Point endPoint, CombPaths& combPaths, bool startInside, bool endInside, int64_t max_comb_distance_ignored)
-{
-    if (shorterThen(endPoint - startPoint, max_comb_distance_ignored))
-    {
-        return true;
-    }
-
-    //Move start and end point inside the comb boundary
-    unsigned int start_inside_poly = NO_INDEX;
-    if (startInside) 
-    {
-        start_inside_poly = PolygonUtils::moveInside(boundary_inside, startPoint, offset_extra_start_end, max_moveInside_distance2);
-        if (!boundary_inside.inside(start_inside_poly) || start_inside_poly == NO_INDEX)
-        {
-            if (start_inside_poly != NO_INDEX)
-            { // if not yet inside because of overshoot, try again
-                start_inside_poly = PolygonUtils::moveInside(boundary_inside, startPoint, offset_extra_start_end, max_moveInside_distance2);
-            }
-            if (start_inside_poly == NO_INDEX)    //If we fail to move the point inside the comb boundary we need to retract.
-            {
-                startInside = false;
-            }
-        }
-    }
-    unsigned int end_inside_poly = NO_INDEX;
-    if (endInside)
-    {
-        end_inside_poly = PolygonUtils::moveInside(boundary_inside, endPoint, offset_extra_start_end, max_moveInside_distance2);
-        if (!boundary_inside.inside(endPoint) || end_inside_poly == NO_INDEX)
-        {
-            if (end_inside_poly != NO_INDEX)
-            { // if not yet inside because of overshoot, try again
-                end_inside_poly = PolygonUtils::moveInside(boundary_inside, endPoint, offset_extra_start_end, max_moveInside_distance2);
-            }
-            if (end_inside_poly == NO_INDEX)    //If we fail to move the point inside the comb boundary we need to retract.
-            {
-                endInside = false;
-            }
-        }
-    }
-
-    
-    unsigned int start_part_boundary_poly_idx;
-    unsigned int end_part_boundary_poly_idx;
-    unsigned int start_part_idx =   (start_inside_poly == NO_INDEX)?    NO_INDEX : partsView_inside.getPartContaining(start_inside_poly, &start_part_boundary_poly_idx);
-    unsigned int end_part_idx =     (end_inside_poly == NO_INDEX)?      NO_INDEX : partsView_inside.getPartContaining(end_inside_poly, &end_part_boundary_poly_idx);
-    
-    if (startInside && endInside && start_part_idx == end_part_idx)
-    { // normal combing within part
-        PolygonsPart part = partsView_inside.assemblePart(start_part_idx);
-        combPaths.emplace_back();
-        LinePolygonsCrossings::comb(part, startPoint, endPoint, combPaths.back(), -offset_dist_to_get_from_on_the_polygon_to_outside, max_comb_distance_ignored);
-        return true;
-    }
-    else 
-    { // comb inside part to edge (if needed) >> move through air avoiding other parts >> comb inside end part upto the endpoint (if needed) 
-        //  INSIDE  |          in_between            |            OUTSIDE     |              in_between         |     INSIDE
-        //        ^crossing_1_in     ^crossing_1_mid  ^crossing_1_out        ^crossing_2_out    ^crossing_2_mid   ^crossing_2_in
-        //
-        // when startPoint is inside crossing_1_in is of interest
-        // when it is in between inside and outside it is equal to crossing_1_mid
-        Point crossing_1_in_or_mid; // the point inside the starting polygon if startPoint is inside or the startPoint itself if it is not inside
-        Point crossing_1_out;
-        Point crossing_2_in_or_mid; // the point inside the ending polygon if endPoint is inside or the endPoint itself if it is not inside
-        Point crossing_2_out;
-        
-        { // find crossing over the in-between area between inside and outside
-            if (startInside)
-            {
-                ClosestPolygonPoint crossing_1_in_cp = PolygonUtils::findClosest(endPoint, boundary_inside[start_part_boundary_poly_idx]);
-                crossing_1_in_or_mid = PolygonUtils::moveInside(crossing_1_in_cp, offset_dist_to_get_from_on_the_polygon_to_outside); // in-case
-            }
-            else 
-            {
-                crossing_1_in_or_mid = startPoint; // mid-case
-            }
-
-            if (endInside)
-            {
-                ClosestPolygonPoint crossing_2_in_cp = PolygonUtils::findClosest(crossing_1_in_or_mid, boundary_inside[end_part_boundary_poly_idx]);
-                crossing_2_in_or_mid = PolygonUtils::moveInside(crossing_2_in_cp, offset_dist_to_get_from_on_the_polygon_to_outside); // in-case
-            }
-            else 
-            {
-                crossing_2_in_or_mid = endPoint; // mid-case
-            }
-        }
-        
-        bool avoid_other_parts_now = avoid_other_parts;
-        if (avoid_other_parts_now && vSize2(crossing_1_in_or_mid - crossing_2_in_or_mid) < offset_from_outlines_outside * offset_from_outlines_outside * 4)
-        { // parts are next to eachother, i.e. the direct crossing will always be smaller than two crossings via outside
-            avoid_other_parts_now = false;
-        }
-        
-        if (avoid_other_parts_now)
-        { // compute the crossing points when moving through air
-            Polygons& outside = getBoundaryOutside(); // comb through all air, since generally the outside consists of a single part
-            
-            
-            crossing_1_out = crossing_1_in_or_mid;
-            if (startInside || outside.inside(crossing_1_in_or_mid, true)) // start in_between
-            { // move outside
-                ClosestPolygonPoint* crossing_1_out_cpp = PolygonUtils::findClose(crossing_1_in_or_mid, outside, getOutsideLocToLine());
-                if (crossing_1_out_cpp)
-                {
-                    crossing_1_out = PolygonUtils::moveOutside(*crossing_1_out_cpp, offset_dist_to_get_from_on_the_polygon_to_outside);
-                }
-                else 
-                {
-                    PolygonUtils::moveOutside(outside, crossing_1_out, offset_dist_to_get_from_on_the_polygon_to_outside);
-                }
-            }
-            int64_t in_out_dist2_1 = vSize2(crossing_1_out - crossing_1_in_or_mid); 
-            if (startInside && in_out_dist2_1 > max_crossing_dist2) // moveInside moved too far
-            { // if move is to far over in_between
-                // find crossing closer by
-                std::shared_ptr<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>> best = findBestCrossing(boundary_inside[start_part_boundary_poly_idx], startPoint, endPoint);
-                if (best)
-                {
-                    crossing_1_in_or_mid = PolygonUtils::moveInside(best->first, offset_dist_to_get_from_on_the_polygon_to_outside);
-                    crossing_1_out = PolygonUtils::moveOutside(best->second, offset_dist_to_get_from_on_the_polygon_to_outside);
-                }
-            }
-
-
-            crossing_2_out = crossing_2_in_or_mid;
-            if (endInside || outside.inside(crossing_2_in_or_mid, true))
-            { // move outside
-                ClosestPolygonPoint* crossing_2_out_cpp = PolygonUtils::findClose(crossing_2_in_or_mid, outside, getOutsideLocToLine());
-                if (crossing_2_out_cpp)
-                {
-                    crossing_2_out = PolygonUtils::moveOutside(*crossing_2_out_cpp, offset_dist_to_get_from_on_the_polygon_to_outside);
-                }
-                else 
-                {
-                    PolygonUtils::moveOutside(outside, crossing_2_out, offset_dist_to_get_from_on_the_polygon_to_outside);
-                }
-            }
-            int64_t in_out_dist2_2 = vSize2(crossing_2_out - crossing_2_in_or_mid); 
-            if (endInside && in_out_dist2_2 > max_crossing_dist2) // moveInside moved too far
-            { // if move is to far over in_between
-                // find crossing closer by
-                std::shared_ptr<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>> best = findBestCrossing(boundary_inside[end_part_boundary_poly_idx], endPoint, crossing_1_out);
-                if (best)
-                {
-                    crossing_2_in_or_mid = PolygonUtils::moveInside(best->first, offset_dist_to_get_from_on_the_polygon_to_outside);
-                    crossing_2_out = PolygonUtils::moveOutside(best->second, offset_dist_to_get_from_on_the_polygon_to_outside);
-                }
-            }
-        }
-
-        if (startInside)
-        {
-            // start to boundary
-            PolygonsPart part_begin = partsView_inside.assemblePart(start_part_idx); // comb through the starting part only
-            combPaths.emplace_back();
-            LinePolygonsCrossings::comb(part_begin, startPoint, crossing_1_in_or_mid, combPaths.back(), -offset_dist_to_get_from_on_the_polygon_to_outside, max_comb_distance_ignored);
-        }
-        
-        // throught air from boundary to boundary
-        if (avoid_other_parts_now)
-        {
-            combPaths.emplace_back();
-            combPaths.throughAir = true;
-            if ( vSize(crossing_1_in_or_mid - crossing_2_in_or_mid) < vSize(crossing_1_in_or_mid - crossing_1_out) + vSize(crossing_2_in_or_mid - crossing_2_out) )
-            { // via outside is moving more over the in-between zone
-                combPaths.back().push_back(crossing_1_in_or_mid);
-                combPaths.back().push_back(crossing_2_in_or_mid);
-            }
-            else
-            {
-                LinePolygonsCrossings::comb(getBoundaryOutside(), crossing_1_out, crossing_2_out, combPaths.back(), offset_dist_to_get_from_on_the_polygon_to_outside, max_comb_distance_ignored);
-            }
-        }
-        else 
-        { // directly through air (not avoiding other parts)
-            combPaths.emplace_back();
-            combPaths.throughAir = true;
-            combPaths.back().cross_boundary = true; // TODO: calculate whether we cross a boundary!
-            combPaths.back().push_back(crossing_1_in_or_mid);
-            combPaths.back().push_back(crossing_2_in_or_mid);
-        }
-        
-        if (endInside)
-        {
-            // boundary to end
-            PolygonsPart part_end = partsView_inside.assemblePart(end_part_idx); // comb through end part only
-            combPaths.emplace_back();
-            LinePolygonsCrossings::comb(part_end, crossing_2_in_or_mid, endPoint, combPaths.back(), -offset_dist_to_get_from_on_the_polygon_to_outside, max_comb_distance_ignored);
-        }
-        
-        return true;
-    }
-}
-
-std::shared_ptr<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>> Comb::findBestCrossing(PolygonRef from, Point estimated_start, Point estimated_end)
-{
-    ClosestPolygonPoint* best_in = nullptr;
-    ClosestPolygonPoint* best_out = nullptr;
-    int64_t best_detour_dist = std::numeric_limits<int64_t>::max();
-    std::vector<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>> crossing_out_candidates = PolygonUtils::findClose(from, getBoundaryOutside(), getOutsideLocToLine());
-    for (std::pair<ClosestPolygonPoint, ClosestPolygonPoint>& crossing_candidate : crossing_out_candidates)
-    {
-        int64_t crossing_dist2 = vSize2(crossing_candidate.first.location - crossing_candidate.second.location);
-        if (crossing_dist2 > max_crossing_dist2)
-        {
-            continue;
-        }
-        
-        int64_t dist_to_start = vSize(crossing_candidate.second.location - estimated_start); // use outside location, so that the crossing direction is taken into account
-        int64_t dist_to_end = vSize(crossing_candidate.second.location - estimated_end);
-        int64_t detour_dist = dist_to_start + dist_to_end;
-        if (detour_dist < best_detour_dist)
-        {
-            best_in = &crossing_candidate.first;
-            best_out = &crossing_candidate.second;
-            best_detour_dist = detour_dist;
-        }
-    }
-    if (best_detour_dist == std::numeric_limits<int64_t>::max())
-    {
-        return std::shared_ptr<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>>();
-    }
-    return std::make_shared<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>>(*best_in, *best_out);
-}
-
-
-void LinePolygonsCrossings::calcScanlineCrossings()
-{
-    
-    min_crossing_idx = NO_INDEX;
-    max_crossing_idx = NO_INDEX;
-        
-    for(unsigned int poly_idx = 0; poly_idx < boundary.size(); poly_idx++)
-    {
-        PolyCrossings minMax(poly_idx); 
-        PolygonRef poly = boundary[poly_idx];
-        Point p0 = transformation_matrix.apply(poly[poly.size() - 1]);
-        for(unsigned int point_idx = 0; point_idx < poly.size(); point_idx++)
-        {
-            Point p1 = transformation_matrix.apply(poly[point_idx]);
-            if((p0.Y >= transformed_startPoint.Y && p1.Y <= transformed_startPoint.Y) || (p1.Y >= transformed_startPoint.Y && p0.Y <= transformed_startPoint.Y))
-            {
-                if(p1.Y == p0.Y) //Line segment is parallel with the scanline. That means that both endpoints lie on the scanline, so they will have intersected with the adjacent line.
-                {
-                    p0 = p1;
-                    continue;
-                }
-                int64_t x = p0.X + (p1.X - p0.X) * (transformed_startPoint.Y - p0.Y) / (p1.Y - p0.Y);
-                
-                if (x >= transformed_startPoint.X && x <= transformed_endPoint.X)
-                {
-                    if(x < minMax.min.x) //For the leftmost intersection, move x left to stay outside of the border.
-                                         //Note: The actual distance from the intersection to the border is almost always less than dist_to_move_boundary_point_outside, since it only moves along the direction of the scanline.
-                    {
-                        minMax.min.x = x;
-                        minMax.min.point_idx = point_idx;
-                    }
-                    if(x > minMax.max.x) //For the rightmost intersection, move x right to stay outside of the border.
-                    {
-                        minMax.max.x = x;
-                        minMax.max.point_idx = point_idx;
-                    }
-                }
-            }
-            p0 = p1;
-        }
-        
-        if (minMax.min.point_idx != NO_INDEX)
-        { // then also max.point_idx != -1
-            if (min_crossing_idx == NO_INDEX || minMax.min.x < crossings[min_crossing_idx].min.x) { min_crossing_idx = crossings.size(); }
-            if (max_crossing_idx == NO_INDEX || minMax.max.x > crossings[max_crossing_idx].max.x) { max_crossing_idx = crossings.size(); }
-            crossings.push_back(minMax);
-        }
-        
-    }
-}
-
-
-bool LinePolygonsCrossings::lineSegmentCollidesWithBoundary()
-{
-    Point diff = endPoint - startPoint;
-
-    transformation_matrix = PointMatrix(diff);
-    transformed_startPoint = transformation_matrix.apply(startPoint);
-    transformed_endPoint = transformation_matrix.apply(endPoint);
-
-    for(PolygonRef poly : boundary)
-    {
-        Point p0 = transformation_matrix.apply(poly.back());
-        for(Point p1_ : poly)
-        {
-            Point p1 = transformation_matrix.apply(p1_);
-            if ((p0.Y > transformed_startPoint.Y && p1.Y < transformed_startPoint.Y) || (p1.Y > transformed_startPoint.Y && p0.Y < transformed_startPoint.Y))
-            {
-                int64_t x = p0.X + (p1.X - p0.X) * (transformed_startPoint.Y - p0.Y) / (p1.Y - p0.Y);
-                
-                if (x > transformed_startPoint.X && x < transformed_endPoint.X)
-                    return true;
-            }
-            p0 = p1;
-        }
-    }
-    
-    return false;
-}
-
-
-void LinePolygonsCrossings::getCombingPath(CombPath& combPath, int64_t max_comb_distance_ignored)
-{
-    if (shorterThen(endPoint - startPoint, max_comb_distance_ignored) || !lineSegmentCollidesWithBoundary())
-    {
-        //We're not crossing any boundaries. So skip the comb generation.
-        combPath.push_back(startPoint); 
-        combPath.push_back(endPoint);
-        return;
-    }
-    
-    calcScanlineCrossings();
-    
-    CombPath basicPath;
-    getBasicCombingPath(basicPath);
-    optimizePath(basicPath, combPath);
-//     combPath = basicPath; // uncomment to disable comb path optimization
-}
-
-
-void LinePolygonsCrossings::getBasicCombingPath(CombPath& combPath) 
-{
-    for (PolyCrossings* crossing = getNextPolygonAlongScanline(transformed_startPoint.X)
-        ; crossing != nullptr
-        ; crossing = getNextPolygonAlongScanline(crossing->max.x))
-    {
-        getBasicCombingPath(*crossing, combPath);
-    }
-    combPath.push_back(endPoint);
-}
-
-void LinePolygonsCrossings::getBasicCombingPath(PolyCrossings& polyCrossings, CombPath& combPath) 
-{
-    PolygonRef poly = boundary[polyCrossings.poly_idx];
-    combPath.push_back(transformation_matrix.unapply(Point(polyCrossings.min.x - dist_to_move_boundary_point_outside, transformed_startPoint.Y)));
-    if ( ( polyCrossings.max.point_idx - polyCrossings.min.point_idx + poly.size() ) % poly.size() 
-        < poly.size() / 2 )
-    { // follow the path in the same direction as the winding order of the boundary polygon
-        for(unsigned int point_idx = polyCrossings.min.point_idx
-            ; point_idx != polyCrossings.max.point_idx
-            ; point_idx = (point_idx < poly.size() - 1) ? (point_idx + 1) : (0))
-        {
-            combPath.push_back(PolygonUtils::getBoundaryPointWithOffset(poly, point_idx, dist_to_move_boundary_point_outside));
-        }
-    }
-    else
-    { // follow the path in the opposite direction of the winding order of the boundary polygon
-        unsigned int min_idx = (polyCrossings.min.point_idx == 0)? poly.size() - 1: polyCrossings.min.point_idx - 1;
-        unsigned int max_idx = (polyCrossings.max.point_idx == 0)? poly.size() - 1: polyCrossings.max.point_idx - 1;
-
-        for(unsigned int point_idx = min_idx; point_idx != max_idx; point_idx = (point_idx > 0) ? (point_idx - 1) : (poly.size() - 1))
-        {
-            combPath.push_back(PolygonUtils::getBoundaryPointWithOffset(poly, point_idx, dist_to_move_boundary_point_outside));
-        }
-    }
-    combPath.push_back(transformation_matrix.unapply(Point(polyCrossings.max.x + dist_to_move_boundary_point_outside, transformed_startPoint.Y))); 
-}
-
-
-
-LinePolygonsCrossings::PolyCrossings* LinePolygonsCrossings::getNextPolygonAlongScanline(int64_t x)
-{
-    PolyCrossings* ret = nullptr;
-    for(PolyCrossings& crossing : crossings)
-    {
-        if (crossing.min.x > x && (ret == nullptr || crossing.min.x < ret->min.x) )
-        {
-            ret = &crossing;
-        }
-    }
-    return ret;
-}
-
-bool LinePolygonsCrossings::optimizePath(CombPath& comb_path, CombPath& optimized_comb_path) 
-{
-    optimized_comb_path.push_back(startPoint);
-    for(unsigned int point_idx = 1; point_idx<comb_path.size(); point_idx++)
-    {
-        if(comb_path[point_idx] == comb_path[point_idx - 1]) //Two points are the same. Skip the second.
-        {
-            continue;
-        }
-        Point& current_point = optimized_comb_path.back();
-        if (PolygonUtils::polygonCollidesWithlineSegment(boundary, current_point, comb_path[point_idx]))
-        {
-            if (PolygonUtils::polygonCollidesWithlineSegment(boundary, current_point, comb_path[point_idx - 1]))
-            {
-                comb_path.cross_boundary = true;
-            }
-            optimized_comb_path.push_back(comb_path[point_idx - 1]);
-        }
-        else 
-        {
-            // : dont add the newest point
-            
-            // TODO: add the below extra optimization? (+/- 7% extra computation time, +/- 2% faster print for Dual_extrusion_support_generation.stl)
-            while (optimized_comb_path.size() > 1)
-            {
-                if (PolygonUtils::polygonCollidesWithlineSegment(boundary, optimized_comb_path[optimized_comb_path.size() - 2], comb_path[point_idx]))
-                {
-                    break;
-                }
-                else 
-                {
-                    optimized_comb_path.pop_back();
-                }
-            }
-        }
-    }
-    optimized_comb_path.push_back(comb_path.back());
-    return true;
-}
-
-}//namespace cura

src/commandSocket.cpp

@@ -18,8 +18,6 @@
 #include <windows.h>
 #endif
 
-#include "settings/SettingRegistry.h" // loadExtruderJSONsettings
-
 #define DEBUG_OUTPUT_OBJECT_STL_THROUGH_CERR(x) 
 
 // std::cerr << x;
@@ -57,45 +55,193 @@ public:
     }
 };
 
+/*!
+ * A template structure used to store data to be sent to the front end.
+ */
+template <typename T>
+class SliceDataStruct
+{
+    SliceDataStruct(const SliceDataStruct&) = delete;
+    SliceDataStruct& operator=(const SliceDataStruct&) = delete;
+public:
+
+    SliceDataStruct()
+        : sliced_objects(0)
+        , current_layer_count(0)
+        , current_layer_offset(0)
+    { }
+
+    //! The number of sliced objects for this sliced object list
+    int sliced_objects;
+
+    int current_layer_count;//!< Number of layers for which data has been buffered in slice_data so far.
+    int current_layer_offset;//!< Offset to add to layer number for the current slice object when slicing one at a time.
+
+    std::unordered_map<int, std::shared_ptr<T>> slice_data;
+};
+
 class CommandSocket::Private
 {
 public:
     Private()
         : socket(nullptr)
         , object_count(0)
-        , sliced_objects(0)
-        , current_layer_count(0)
-        , current_layer_offset(0)
     { }
 
     std::shared_ptr<cura::proto::Layer> getLayerById(int id);
 
+    std::shared_ptr<cura::proto::LayerOptimized> getOptimizedLayerById(int id);
+
     Arcus::Socket* socket;
     
     // Number of objects that need to be sliced
     int object_count;
 
-    // Number of sliced objects for this sliced object list
-    int sliced_objects;
-
-    // Number of layers sent to the front end so far
-    // Used for incrementing the current layer in one at a time mode
-    int current_layer_count;
-    int current_layer_offset;
-
     std::string temp_gcode_file;
     std::ostringstream gcode_output_stream;
     
     // Print object that olds one or more meshes that need to be sliced. 
     std::vector< std::shared_ptr<MeshGroup> > objects_to_slice;
 
-    std::unordered_map<int, std::shared_ptr<cura::proto::Layer>> sliced_layers;
+    SliceDataStruct<cura::proto::Layer> sliced_layers;
+    SliceDataStruct<cura::proto::LayerOptimized> optimized_layers;
+};
+
+/*!
+ * PathCompiler buffers and prepares the sliced data to be sent to the front end and saves them in
+ * appropriate buffers
+ */
+class CommandSocket::PathCompiler
+{
+    typedef cura::proto::PathSegment::PointType PointType;
+    static_assert(sizeof(PrintFeatureType) == 1, "To be compatible with the Cura frontend code PrintFeatureType needs to be of size 1");
+    //! Reference to the private data of the CommandSocket used to send the data to the front end.
+    CommandSocket::Private& _cs_private_data;
+    //! Keeps track of the current layer number being processed. If layer number is set to a different value, the current data is flushed to CommandSocket.
+    int _layer_nr;
+    int extruder;
+    PointType data_point_type;
+
+    std::vector<PrintFeatureType> line_types; //!< Line types for the line segments stored, the size of this vector is N.
+    std::vector<float> line_widths; //!< Line widths for the line segments stored, the size of this vector is N.
+    std::vector<float> points; //!< The points used to define the line segments, the size of this vector is D*(N+1) as each line segment is defined from one point to the next. D is the dimensionality of the point.
+
+    Point last_point;
+
+    PathCompiler(const PathCompiler&) = delete;
+    PathCompiler& operator=(const PathCompiler&) = delete;
+public:
+    PathCompiler(CommandSocket::Private& cs_private_data):
+        _cs_private_data(cs_private_data),
+        _layer_nr(0),
+        extruder(0),
+        data_point_type(cura::proto::PathSegment::Point2D),
+        line_types(),
+        line_widths(),
+        points(),
+        last_point{0,0}
+    {}
+    ~PathCompiler()
+    {
+        if (line_types.size())
+        {
+            flushPathSegments();
+        }
+    }
+
+    /*!
+     * Used to select which layer the following layer data is intended for.
+     */
+    void setLayer(int new_layer_nr)
+    {
+        if (_layer_nr != new_layer_nr)
+        {
+            flushPathSegments();
+            _layer_nr = new_layer_nr;
+        }
+    }
+    /*!
+     * Returns the current layer which data is written to.
+     */
+    int getLayer() const
+    {
+        return _layer_nr;
+    }
+    /*!
+     * Used to set which extruder will be used for printing the following layer data is intended for.
+     */
+    void setExtruder(int new_extruder)
+    {
+        if (extruder != new_extruder)
+        {
+            flushPathSegments();
+            extruder = new_extruder;
+        }
+    }
+
+    /*!
+     * Special handling of the first point in an added line sequence.
+     * If the new sequence of lines does not start at the current end point
+     * of the path this jump is marked as PrintFeatureType::NoneType
+     */
+    void handleInitialPoint(Point from)
+    {
+        if (points.size() == 0)
+        {
+            addPoint2D(from);
+        }
+        else if (from != last_point)
+        {
+            addLineSegment(PrintFeatureType::NoneType, from, 1.0);
+        }
+    }
+
+    /*!
+     * Transfers the currently buffered line segments to the
+     * CommandSocket layer message storage.
+     */
+    void flushPathSegments();
+    /*!
+     * Move the current point of this path to \position.
+     */
+    void setCurrentPosition(Point position)
+    {
+        handleInitialPoint(position);
+    }
+    /*!
+     * Adds a single line segment to the current path. The line segment added is from the current last point to point \p to
+     */
+    void sendLineTo(PrintFeatureType print_feature_type, Point to, int width);
+    /*!
+     * Adds closed polygon to the current path
+     */
+    void sendPolygon(PrintFeatureType print_feature_type, ConstPolygonRef poly, int width);
+private:
+    /*!
+     * Convert and add a point to the points buffer, each point being represented as two consecutive floats. All members adding a 2D point to the data should use this function.
+     */
+    void addPoint2D(Point point)
+    {
+        points.push_back(INT2MM(point.X));
+        points.push_back(INT2MM(point.Y));
+        last_point = point;
+    }
+    /*!
+     * Implements the functionality of adding a single 2D line segment to the path data. All member functions adding a 2D line segment should use this functions.
+     */
+    void addLineSegment(PrintFeatureType print_feature_type, Point point, int line_width)
+    {
+        addPoint2D(point);
+        line_types.push_back(print_feature_type);
+        line_widths.push_back(INT2MM(line_width));
+    }
 };
 #endif
 
 CommandSocket::CommandSocket()
 #ifdef ARCUS
     : private_data(new Private)
+    , path_comp(new PathCompiler(*private_data))
 #endif
 {
 #ifdef ARCUS
@@ -127,12 +273,14 @@ void CommandSocket::connect(const std::string& ip, int port)
     //private_data->socket->registerMessageType(1, &Cura::ObjectList::default_instance());
     private_data->socket->registerMessageType(&cura::proto::Slice::default_instance());
     private_data->socket->registerMessageType(&cura::proto::Layer::default_instance());
+    private_data->socket->registerMessageType(&cura::proto::LayerOptimized::default_instance());
     private_data->socket->registerMessageType(&cura::proto::Progress::default_instance());
     private_data->socket->registerMessageType(&cura::proto::GCodeLayer::default_instance());
-    private_data->socket->registerMessageType(&cura::proto::ObjectPrintTime::default_instance());
+    private_data->socket->registerMessageType(&cura::proto::PrintTimeMaterialEstimates::default_instance());
     private_data->socket->registerMessageType(&cura::proto::SettingList::default_instance());
     private_data->socket->registerMessageType(&cura::proto::GCodePrefix::default_instance());
     private_data->socket->registerMessageType(&cura::proto::SlicingFinished::default_instance());
+    private_data->socket->registerMessageType(&cura::proto::SettingExtruder::default_instance());
 
     private_data->socket->connect(ip, port);
 
@@ -152,44 +300,83 @@ void CommandSocket::connect(const std::string& ip, int port)
     {
         // Actually start handling messages.
         Arcus::MessagePtr message = private_data->socket->takeNextMessage();
+
+        /*
+         * handle a message which consists purely of a SettingList
         cura::proto::SettingList* setting_list = dynamic_cast<cura::proto::SettingList*>(message.get());
         if (setting_list)
         {
             handleSettingList(setting_list);
         }
+        */
 
-        /*cura::proto::ObjectList* object_list = dynamic_cast<cura::proto::ObjectList*>(message.get());
+        /*
+         * handle a message which consists purely of an ObjectList
+        cura::proto::ObjectList* object_list = dynamic_cast<cura::proto::ObjectList*>(message.get());
         if (object_list)
         {
             handleObjectList(object_list);
-        }*/
-        
-        cura::proto::Slice* slice = dynamic_cast<cura::proto::Slice*>(message.get());
+        }
+        */
+
+        // Handle the main Slice message
+        cura::proto::Slice* slice = dynamic_cast<cura::proto::Slice*>(message.get()); // See if the message is of the message type Slice; returns nullptr otherwise
         if (slice)
         {
+            logDebug("Received a Slice message\n");
+            const cura::proto::SettingList& global_settings = slice->global_settings();
+            for (auto setting : global_settings.settings())
+            {
+                FffProcessor::getInstance()->setSetting(setting.name(), setting.value());
+            }
             // Reset object counts
             private_data->object_count = 0;
             for (auto object : slice->object_lists())
             {
-                handleObjectList(&object);
+                handleObjectList(&object, slice->extruders());
             }
+            //For every object, set the extruder fallbacks from the limit_to_extruder.
+            for (const cura::proto::SettingExtruder setting_extruder : slice->limit_to_extruder())
+            {
+                const int32_t extruder_nr = setting_extruder.extruder(); //Implicit cast from Protobuf's int32 to normal int32.
+                for (std::shared_ptr<MeshGroup> meshgroup : private_data->objects_to_slice)
+                {
+                    if (extruder_nr < 0 || extruder_nr >= meshgroup->getExtruderCount()) //We obtained an invalid value from the front-end. Ignore.
+                    {
+                        continue;
+                    }
+                    const ExtruderTrain* settings_base = meshgroup->getExtruderTrain(extruder_nr); //The extruder train that the setting should fall back to.
+                    for (Mesh& mesh : meshgroup->meshes)
+                    {
+                        mesh.setSettingInheritBase(setting_extruder.name(), *settings_base);
+                    }
+                }
+            }
+            logDebug("Done reading Slice message\n");
         }
 
         //If there is an object to slice, do so.
         if (private_data->objects_to_slice.size())
         {
+            int object_count = private_data->objects_to_slice.size();
+            logDebug("Slicing %i objects\n", object_count);
             FffProcessor::getInstance()->resetMeshGroupNumber();
+            int i = 1;
             for (auto object : private_data->objects_to_slice)
             {
+                logDebug("Slicing object %i of %i\n", i, object_count);
                 if (!FffProcessor::getInstance()->processMeshGroup(object.get()))
                 {
                     logError("Slicing mesh group failed!");
                 }
+                i++;
             }
+            logDebug("Done slicing objects\n");
+
             private_data->objects_to_slice.clear();
             FffProcessor::getInstance()->finalize();
             flushGcode();
-            sendPrintTime();
+            sendPrintTimeMaterialEstimates();
             sendFinishedSlicing();
             slice_another_time = false; // TODO: remove this when multiple slicing with CuraEngine is safe
             //TODO: Support all-at-once/one-at-a-time printing
@@ -197,7 +384,7 @@ void CommandSocket::connect(const std::string& ip, int port)
             //private_data->object_to_slice.reset();
             //private_data->processor->resetFileNumber();
 
-            //sendPrintTime();
+            //sendPrintTimeMaterialEstimates();
         }
 
         std::this_thread::sleep_for(std::chrono::milliseconds(250));
@@ -208,7 +395,7 @@ void CommandSocket::connect(const std::string& ip, int port)
 }
 
 #ifdef ARCUS
-void CommandSocket::handleObjectList(cura::proto::ObjectList* list)
+void CommandSocket::handleObjectList(cura::proto::ObjectList* list, const google::protobuf::RepeatedPtrField<cura::proto::Extruder> settings_per_extruder_train)
 {
     if (list->objects_size() <= 0)
     {
@@ -220,18 +407,30 @@ void CommandSocket::handleObjectList(cura::proto::ObjectList* list)
     //private_data->object_ids.clear();
     private_data->objects_to_slice.push_back(std::make_shared<MeshGroup>(FffProcessor::getInstance()));
     MeshGroup* meshgroup = private_data->objects_to_slice.back().get();
-    
+
+    // load meshgroup settings
     for (auto setting : list->settings())
     {
         meshgroup->setSetting(setting.name(), setting.value());
     }
-    
-    for (int extruder_nr = 0; extruder_nr < FffProcessor::getInstance()->getSettingAsCount("machine_extruder_count"); extruder_nr++)
-    { // initialize remaining extruder trains and load the defaults
-        ExtruderTrain* train = meshgroup->createExtruderTrain(extruder_nr); // create new extruder train objects or use already existing ones
-        SettingRegistry::getInstance()->loadExtruderJSONsettings(extruder_nr, train);
+
+    { // load extruder settings
+        for (int extruder_nr = 0; extruder_nr < FffProcessor::getInstance()->getSettingAsCount("machine_extruder_count"); extruder_nr++)
+        { // initialize remaining extruder trains and load the defaults
+            meshgroup->createExtruderTrain(extruder_nr); // create new extruder train objects or use already existing ones
+        }
+
+        for (auto extruder : settings_per_extruder_train)
+        {
+            int extruder_nr = extruder.id();
+            ExtruderTrain* train = meshgroup->getExtruderTrain(extruder_nr);
+            for (auto setting : extruder.settings().settings())
+            {
+                train->setSetting(setting.name(), setting.value());
+            }
+        }
     }
-    
+
     for (auto object : list->objects())
     {
         int bytes_per_face = BYTES_PER_FLOAT * FLOATS_PER_VECTOR * VECTORS_PER_FACE;
@@ -243,7 +442,9 @@ void CommandSocket::handleObjectList(cura::proto::ObjectList* list)
             continue;
         }
         DEBUG_OUTPUT_OBJECT_STL_THROUGH_CERR("solid Cura_out\n");
-        int extruder_train_nr = 0; // TODO: make primary extruder configurable!
+
+        // Check to which extruder train this object belongs
+        int extruder_train_nr = 0; // assume extruder 0 if setting wasn't supplied
         for (auto setting : object.settings())
         {
             if (setting.name() == "extruder_nr")
@@ -278,6 +479,7 @@ void CommandSocket::handleObjectList(cura::proto::ObjectList* list)
             DEBUG_OUTPUT_OBJECT_STL_THROUGH_CERR("  endfacet\n");
         }
         DEBUG_OUTPUT_OBJECT_STL_THROUGH_CERR("endsolid Cura_out\n");
+
         for (auto setting : object.settings())
         {
             mesh.setSetting(setting.name(), setting.value());
@@ -289,51 +491,101 @@ void CommandSocket::handleObjectList(cura::proto::ObjectList* list)
     private_data->object_count++;
     meshgroup->finalize();
 }
-
-void CommandSocket::handleSettingList(cura::proto::SettingList* list)
-{
-    for (auto setting : list->settings())
-    {
-        FffProcessor::getInstance()->setSetting(setting.name(), setting.value());
-    }
-}
 #endif
 
-void CommandSocket::sendLayerInfo(int layer_nr, int32_t z, int32_t height)
+void CommandSocket::sendOptimizedLayerInfo(int layer_nr, int32_t z, int32_t height)
 {
 #ifdef ARCUS
-    std::shared_ptr<cura::proto::Layer> layer = private_data->getLayerById(layer_nr);
+    std::shared_ptr<cura::proto::LayerOptimized> layer = private_data->getOptimizedLayerById(layer_nr);
     layer->set_height(z);
     layer->set_thickness(height);
 #endif
 }
 
-void CommandSocket::sendPolygons(PrintFeatureType type, int layer_nr, Polygons& polygons, int line_width)
+void CommandSocket::sendPolygons(PrintFeatureType type, const Polygons& polygons, int line_width)
 {
 #ifdef ARCUS
     if (polygons.size() == 0)
-        return;
-
-    std::shared_ptr<cura::proto::Layer> proto_layer = private_data->getLayerById(layer_nr);
-
-    for (unsigned int i = 0; i < polygons.size(); ++i)
     {
-        cura::proto::Polygon* p = proto_layer->add_polygons();
-        p->set_type(static_cast<cura::proto::Polygon_Type>(type));
-        std::string polydata;
-        polydata.append(reinterpret_cast<const char*>(polygons[i].data()), polygons[i].size() * sizeof(Point));
-        p->set_points(polydata);
-        p->set_line_width(line_width);
+        return;
+    }
+
+    if (CommandSocket::isInstantiated())
+    {
+        auto& path_comp = CommandSocket::getInstance()->path_comp;
+
+        for (unsigned int i = 0; i < polygons.size(); ++i)
+        {
+            path_comp->sendPolygon(type, polygons[i], line_width);
+        }
     }
 #endif
 }
 
+void CommandSocket::sendPolygon(PrintFeatureType type, ConstPolygonRef polygon, int line_width)
+{
+#ifdef ARCUS
+    if (CommandSocket::isInstantiated())
+    {
+        auto& path_comp = CommandSocket::getInstance()->path_comp;
+
+        path_comp->sendPolygon(type, polygon, line_width);
+    }
+#endif
+}
+
+void CommandSocket::sendLineTo(cura::PrintFeatureType type, Point to, int line_width)
+{
+#ifdef ARCUS
+    if (CommandSocket::isInstantiated())
+    {
+        auto& path_comp = CommandSocket::getInstance()->path_comp;
+
+        path_comp->sendLineTo(type, to, line_width);
+    }
+#endif
+}
+
+void CommandSocket::setSendCurrentPosition(Point position)
+{
+#ifdef ARCUS
+    if (CommandSocket::isInstantiated())
+    {
+        auto& path_comp = CommandSocket::getInstance()->path_comp;
+        path_comp->setCurrentPosition(position);
+    }
+#endif
+}
+
+void CommandSocket::setLayerForSend(int layer_nr)
+{
+#ifdef ARCUS
+    if (CommandSocket::isInstantiated())
+    {
+        auto& path_comp = CommandSocket::getInstance()->path_comp;
+        path_comp->setLayer(layer_nr);
+    }
+#endif
+}
+
+void CommandSocket::setExtruderForSend(int extruder)
+{
+#ifdef ARCUS
+    if (CommandSocket::isInstantiated())
+    {
+        auto& path_comp = CommandSocket::getInstance()->path_comp;
+        path_comp->setExtruder(extruder);
+    }
+#endif
+}
+
+
 void CommandSocket::sendProgress(float amount)
 {
 #ifdef ARCUS
     auto message = std::make_shared<cura::proto::Progress>();
     amount /= private_data->object_count;
-    amount += private_data->sliced_objects * (1. / private_data->object_count);
+    amount += private_data->optimized_layers.sliced_objects * (1. / private_data->object_count);
     message->set_amount(amount);
     private_data->socket->sendMessage(message);
 #endif
@@ -344,13 +596,24 @@ void CommandSocket::sendProgressStage(Progress::Stage stage)
     // TODO
 }
 
-void CommandSocket::sendPrintTime()
+void CommandSocket::sendPrintTimeMaterialEstimates()
 {
 #ifdef ARCUS
-    auto message = std::make_shared<cura::proto::ObjectPrintTime>();
+    logDebug("Sending print time and material estimates.\n");
+    auto message = std::make_shared<cura::proto::PrintTimeMaterialEstimates>();
+
     message->set_time(FffProcessor::getInstance()->getTotalPrintTime());
-    message->set_material_amount(FffProcessor::getInstance()->getTotalFilamentUsed(0));
+    int num_extruders = FffProcessor::getInstance()->getSettingAsCount("machine_extruder_count");
+    for (int extruder_nr (0); extruder_nr < num_extruders; ++extruder_nr)
+    {
+        cura::proto::MaterialEstimates* material_message = message->add_materialestimates();
+
+        material_message->set_id(extruder_nr);
+        material_message->set_material_amount(FffProcessor::getInstance()->getTotalFilamentUsed(extruder_nr));
+    }
+
     private_data->socket->sendMessage(message);
+    logDebug("Done sending print time and material estimates.\n");
 #endif
 }
 
@@ -368,22 +631,50 @@ void CommandSocket::sendLayerData()
 #ifdef ARCUS
 #endif
 #ifdef ARCUS
-    private_data->sliced_objects++;
-    private_data->current_layer_offset = private_data->current_layer_count;
-    log("End sliced object called. Sending ", private_data->current_layer_count, " layers.");
+    auto& data = private_data->sliced_layers;
 
-    if (private_data->sliced_objects >= private_data->object_count)
+    data.sliced_objects++;
+    data.current_layer_offset = data.current_layer_count;
+//    log("End sliced object called. Sending %d layers.", data.current_layer_count);
+
+    // Only send the data to the front end when all mesh groups have been processed.
+    if (data.sliced_objects >= private_data->object_count)
     {
-        for (std::pair<const int, std::shared_ptr<cura::proto::Layer>> entry : private_data->sliced_layers) //Note: This is in no particular order!
+        for (std::pair<const int, std::shared_ptr<cura::proto::Layer>> entry : data.slice_data) //Note: This is in no particular order!
         {
+            logDebug("Sending layer data for layer %i of %i.\n", entry.first, data.slice_data.size());
             private_data->socket->sendMessage(entry.second); //Send the actual layers.
         }
-        private_data->sliced_objects = 0;
-        private_data->current_layer_count = 0;
-        private_data->current_layer_offset = 0;
-        private_data->sliced_layers.clear();
-        auto done_message = std::make_shared<cura::proto::SlicingFinished>();
-        private_data->socket->sendMessage(done_message);
+        data.sliced_objects = 0;
+        data.current_layer_count = 0;
+        data.current_layer_offset = 0;
+        data.slice_data.clear();
+    }
+#endif
+}
+
+void CommandSocket::sendOptimizedLayerData()
+{
+#ifdef ARCUS
+    path_comp->flushPathSegments(); // make sure the last path segment has been flushed from the compiler
+
+    auto& data = private_data->optimized_layers;
+
+    data.sliced_objects++;
+    data.current_layer_offset = data.current_layer_count;
+    log("End sliced object called. Sending %d layers.", data.current_layer_count);
+
+    if (data.sliced_objects >= private_data->object_count)
+    {
+        for (std::pair<const int, std::shared_ptr<cura::proto::LayerOptimized>> entry : data.slice_data) //Note: This is in no particular order!
+        {
+            logDebug("Sending layer data for layer %i of %i.\n", entry.first, data.slice_data.size());
+            private_data->socket->sendMessage(entry.second); //Send the actual layers.
+        }
+        data.sliced_objects = 0;
+        data.current_layer_count = 0;
+        data.current_layer_offset = 0;
+        data.slice_data.clear();
     }
 #endif
 }
@@ -391,8 +682,10 @@ void CommandSocket::sendLayerData()
 void CommandSocket::sendFinishedSlicing()
 {
 #ifdef ARCUS
+    logDebug("Sending Slicing Finished message.\n");
     std::shared_ptr<cura::proto::SlicingFinished> done_message = std::make_shared<cura::proto::SlicingFinished>();
     private_data->socket->sendMessage(done_message);
+    logDebug("Done sending Slicing Finished message.\n");
 #endif
 }
 
@@ -426,12 +719,12 @@ void CommandSocket::sendGCodePrefix(std::string prefix)
 #ifdef ARCUS
 std::shared_ptr<cura::proto::Layer> CommandSocket::Private::getLayerById(int id)
 {
-    id += current_layer_offset;
+    id += sliced_layers.current_layer_offset;
 
-    auto itr = sliced_layers.find(id);
+    auto itr = sliced_layers.slice_data.find(id);
 
     std::shared_ptr<cura::proto::Layer> layer;
-    if (itr != sliced_layers.end())
+    if (itr != sliced_layers.slice_data.end())
     {
         layer = itr->second;
     }
@@ -439,12 +732,98 @@ std::shared_ptr<cura::proto::Layer> CommandSocket::Private::getLayerById(int id)
     {
         layer = std::make_shared<cura::proto::Layer>();
         layer->set_id(id);
-        current_layer_count++;
-        sliced_layers[id] = layer;
+        sliced_layers.current_layer_count++;
+        sliced_layers.slice_data[id] = layer;
     }
 
     return layer;
 }
 #endif
 
+#ifdef ARCUS
+std::shared_ptr<cura::proto::LayerOptimized> CommandSocket::Private::getOptimizedLayerById(int id)
+{
+    id += optimized_layers.current_layer_offset;
+
+    auto itr = optimized_layers.slice_data.find(id);
+
+    std::shared_ptr<cura::proto::LayerOptimized> layer;
+    if (itr != optimized_layers.slice_data.end())
+    {
+        layer = itr->second;
+    }
+    else
+    {
+        layer = std::make_shared<cura::proto::LayerOptimized>();
+        layer->set_id(id);
+        optimized_layers.current_layer_count++;
+        optimized_layers.slice_data[id] = layer;
+    }
+
+    return layer;
+}
+#endif
+
+#ifdef ARCUS
+void CommandSocket::PathCompiler::flushPathSegments()
+{
+    if (line_types.size() > 0 && CommandSocket::isInstantiated())
+    {
+        std::shared_ptr<cura::proto::LayerOptimized> proto_layer = _cs_private_data.getOptimizedLayerById(_layer_nr);
+
+        cura::proto::PathSegment* p = proto_layer->add_path_segment();
+        p->set_extruder(extruder);
+        p->set_point_type(data_point_type);
+        std::string line_type_data;
+        line_type_data.append(reinterpret_cast<const char*>(line_types.data()), line_types.size()*sizeof(PrintFeatureType));
+        p->set_line_type(line_type_data);
+        std::string polydata;
+        polydata.append(reinterpret_cast<const char*>(points.data()), points.size() * sizeof(float));
+        p->set_points(polydata);
+        std::string line_width_data;
+        line_width_data.append(reinterpret_cast<const char*>(line_widths.data()), line_widths.size()*sizeof(float));
+        p->set_line_width(line_width_data);
+    }
+    points.clear();
+    line_widths.clear();
+    line_types.clear();
+}
+
+void CommandSocket::PathCompiler::sendLineTo(PrintFeatureType print_feature_type, Point to, int width)
+{
+    assert(points.size() > 0 && "A point must already be in the buffer for sendLineTo(.) to function properly");
+
+    if (to != last_point)
+    {
+        addLineSegment(print_feature_type, to, width);
+    }
+}
+
+void CommandSocket::PathCompiler::sendPolygon(PrintFeatureType print_feature_type, ConstPolygonRef polygon, int width)
+{
+    if (polygon.size() < 2)
+    {
+        return;
+    }
+
+    auto it = polygon.begin();
+    handleInitialPoint(*it);
+
+    const auto it_end = polygon.end();
+    while (++it != it_end)
+    {
+        // Ignore zero-length segments.
+        if (*it != last_point)
+        {
+            addLineSegment(print_feature_type, *it, width);
+        }
+    }
+    // Make sure the polygon is closed
+    if (*polygon.begin() != polygon.back())
+    {
+        addLineSegment(print_feature_type, *polygon.begin(), width);
+    }
+}
+#endif
+
 }//namespace cura

src/commandSocket.h

@@ -42,30 +42,54 @@ public:
     /*! 
      * Handler for ObjectList message. 
      * Loads all objects from the message and starts the slicing process
+     * 
+     * Also handles meshgroup settings and extruder settings.
+     * 
+     * \param[in] list The list of objects to slice
+     * \param[in] settings_per_extruder_train The extruder train settings to load into the meshgroup
      */
-    void handleObjectList(cura::proto::ObjectList* list);
-    
-    /*! 
-     * Handler for SettingList message. 
-     * This simply sets all the settings by using key value pair
-     */
-    void handleSettingList(cura::proto::SettingList* list);
+    void handleObjectList(cura::proto::ObjectList* list, const google::protobuf::RepeatedPtrField<cura::proto::Extruder> settings_per_extruder_train);
 #endif
-    
+
     /*!
-     * Send info on a layer to be displayed by the forntend: set the z and the thickness of the layer.
+     * Send info on an optimized layer to be displayed by the forntend: set the z and the thickness of the layer.
      */
-    void sendLayerInfo(int layer_nr, int32_t z, int32_t height);
-    
-    /*! 
-     * Send a polygon to the engine. This is used for the layerview in the GUI
-     */
-    void sendPolygons(cura::PrintFeatureType type, int layer_nr, cura::Polygons& polygons, int line_width);
+    void sendOptimizedLayerInfo(int layer_nr, int32_t z, int32_t height);
 
     /*! 
-     * Send a polygon to the engine if the command socket is instantiated. This is used for the layerview in the GUI
+     * Send a polygon to the front-end. This is used for the layerview in the GUI
      */
-    static void sendPolygonsToCommandSocket(cura::PrintFeatureType type, int layer_nr, cura::Polygons& polygons, int line_width);
+    static void sendPolygons(cura::PrintFeatureType type, const cura::Polygons& polygons, int line_width);
+
+    /*! 
+     * Send a polygon to the front-end. This is used for the layerview in the GUI
+     */
+    static void sendPolygon(cura::PrintFeatureType type, ConstPolygonRef polygon, int line_width);
+
+    /*!
+     * Send a line to the front-end. This is used for the layerview in the GUI
+     */
+    static void sendLineTo(cura::PrintFeatureType type, Point to, int line_width);
+
+    /*!
+     * Set the current position of the path compiler to \p position. This is used for the layerview in the GUI
+     */
+    static void setSendCurrentPosition(Point position);
+
+    /*!
+    * Set which layer is being used for the following calls to SendPolygons, SendPolygon and SendLineTo.
+    */
+    static void setLayerForSend(int layer_nr);
+
+     /*!
+     * Set which extruder is being used for the following calls to SendPolygons, SendPolygon and SendLineTo.
+     */
+    static void setExtruderForSend(int extruder);
+
+    /*!
+     * Send a polygon to the front-end if the command socket is instantiated. This is used for the layerview in the GUI
+     */
+    static void sendPolygonsToCommandSocket(cura::PrintFeatureType type, int layer_nr, const cura::Polygons& polygons, int line_width);
 
     /*! 
      * Send progress to GUI
@@ -80,7 +104,7 @@ public:
     /*!
      * Send time estimate of how long print would take.
      */
-    void sendPrintTime();
+    void sendPrintTimeMaterialEstimates();
     
     /*!
      * Does nothing at the moment
@@ -88,13 +112,22 @@ public:
     void sendPrintMaterialForObject(int index, int extruder_nr, float material_amount);
     
     /*!
-     * Send the sliced layer data to the GUI.
+     * Send the slices of the model as polygons to the GUI.
      *
-     * The GUI may use this to visualise the g-code, so that the user can
-     * inspect the result of slicing.
+     * The GUI may use this to visualize the early result of the slicing
+     * process.
      */
     void sendLayerData();
 
+    /*!
+     * Send the sliced layer data to the GUI after the optimization is done and
+     * the actual order in which to print has been set.
+     *
+     * The GUI may use this to visualize the g-code, so that the user can
+     * inspect the result of slicing.
+     */
+    void sendOptimizedLayerData();
+
     /*!
      * \brief Sends a message to indicate that all the slicing is done.
      *
@@ -115,6 +148,8 @@ public:
 private:
     class Private;
     const std::unique_ptr<Private> private_data;
+    class PathCompiler;
+    const std::unique_ptr<PathCompiler> path_comp;
 #endif
 };
 

src/debug.h

@@ -1,61 +0,0 @@
-#ifndef DEBUG_H
-#define DEBUG_H
-
-#include <string.h>
-
-#define __FILE_NAME__ (strrchr(__FILE__, '/') ? strrchr(__FILE__, '/') + 1 : __FILE__)
-
-
-#define DEBUG_HERE std::cerr << __FILE_NAME__ << " : " << __LINE__ << std::endl
-
-
-
-
-
-#define DEBUG 1
-
-#define DEBUG_SHOW_LINE 1
-
-#if DEBUG_SHOW_LINE == 1
-#define DEBUG_FILE_LINE __FILE_NAME__ << "." << __LINE__ << ": "
-#else
-#define DEBUG_FILE_LINE  ""
-#endif
-
-#if DEBUG == 1
-#   define DEBUG_DO(x) do { x } while (0)
-#   define DEBUG_SHOW(x) do {       std::cerr << DEBUG_FILE_LINE << #x << " = " << x << std::endl; } while (0)
-#   define DEBUG_PRINTLN(x) do {    std::cerr << DEBUG_FILE_LINE << x << std::endl; } while (0)
-#else
-#   define DEBUG_DO(x)
-#   define DEBUG_SHOW(x)
-#   define DEBUG_PRINTLN(x)
-#endif
-
-
-
-#include <sstream>
-
-#if 0==1
-#define ENUM(name, ...) enum class name { __VA_ARGS__, __COUNT};
-#endif
-#define ENUM(name, ...) enum class name { __VA_ARGS__}; \
-inline std::ostream& operator<<(std::ostream& os, name value) { \
-std::string enumName = #name; \
-std::string str = #__VA_ARGS__; \
-int len = str.length(); \
-std::vector<std::string> strings; \
-std::ostringstream temp; \
-for(int i = 0; i < len; i ++) { \
-if(isspace(str[i])) continue; \
-        else if(str[i] == ',') { \
-        strings.push_back(temp.str()); \
-        temp.str(std::string());\
-        } \
-        else temp<< str[i]; \
-} \
-strings.push_back(temp.str()); \
-os << enumName << "::" << strings[static_cast<int>(value)]; \
-return os;}
-
-#endif // DEBUG_H

src/gcodeExport.cpp

@@ -7,14 +7,19 @@
 #include "utils/logoutput.h"
 #include "PrintFeature.h"
 #include "utils/Date.h"
+#include "utils/string.h" // MMtoStream, PrecisionedDouble
 
 namespace cura {
 
+double layer_height; //!< report basic layer height in RepRap gcode file.
+
 GCodeExport::GCodeExport()
 : output_stream(&std::cout)
 , currentPosition(0,0,MM2INT(20))
 , layer_nr(0)
 {
+    *output_stream << std::fixed;
+
     current_e_value = 0;
     current_extruder = 0;
     currentFanSpeed = -1;
@@ -22,51 +27,79 @@ GCodeExport::GCodeExport()
     totalPrintTime = 0.0;
 
     currentSpeed = 1;
+    current_acceleration = -1;
+    current_jerk = -1;
+    current_max_z_feedrate = -1;
+
     isZHopped = 0;
     setFlavor(EGCodeFlavor::REPRAP);
     initial_bed_temp = 0;
 
     extruder_count = 0;
+
+    total_bounding_box = AABB3D();
 }
 
 GCodeExport::~GCodeExport()
 {
 }
 
-void GCodeExport::preSetup(MeshGroup* settings)
+void GCodeExport::preSetup(const MeshGroup* meshgroup)
 {
-    setFlavor(settings->getSettingAsGCodeFlavor("machine_gcode_flavor"));
-    use_extruder_offset_to_offset_coords = settings->getSettingBoolean("machine_use_extruder_offset_to_offset_coords");
+    setFlavor(meshgroup->getSettingAsGCodeFlavor("machine_gcode_flavor"));
+    use_extruder_offset_to_offset_coords = meshgroup->getSettingBoolean("machine_use_extruder_offset_to_offset_coords");
 
-    extruder_count = settings->getSettingAsCount("machine_extruder_count");
+    extruder_count = meshgroup->getSettingAsCount("machine_extruder_count");
 
-    for (unsigned int n = 0; n < extruder_count; n++)
+    for (const Mesh& mesh : meshgroup->meshes)
     {
-        ExtruderTrain* train = settings->getExtruderTrain(n);
-        setFilamentDiameter(n, train->getSettingInMicrons("material_diameter")); 
-
-        extruder_attr[n].nozzle_size = train->getSettingInMicrons("machine_nozzle_size");
-        extruder_attr[n].nozzle_offset = Point(train->getSettingInMicrons("machine_nozzle_offset_x"), train->getSettingInMicrons("machine_nozzle_offset_y"));
-
-        extruder_attr[n].start_code = train->getSettingString("machine_extruder_start_code");
-        extruder_attr[n].end_code = train->getSettingString("machine_extruder_end_code");
-
-        extruder_attr[n].extruder_switch_retraction_config.distance = train->getSettingInMillimeters("switch_extruder_retraction_amount"); 
-        extruder_attr[n].extruder_switch_retraction_config.prime_volume = 0.0;
-        extruder_attr[n].extruder_switch_retraction_config.speed = train->getSettingInMillimetersPerSecond("switch_extruder_retraction_speed");
-        extruder_attr[n].extruder_switch_retraction_config.primeSpeed = train->getSettingInMillimetersPerSecond("switch_extruder_prime_speed");
-        extruder_attr[n].extruder_switch_retraction_config.zHop = train->getSettingInMicrons("switch_extruder_retraction_hop");
-        extruder_attr[n].extruder_switch_retraction_config.retraction_count_max = 9999999; // extruder switch retraction is never limited
-        extruder_attr[n].extruder_switch_retraction_config.retraction_extrusion_window = 99999.9; // so that extruder switch retractions won't affect the retraction buffer (extruded_volume_at_previous_n_retractions)
-        extruder_attr[n].extruder_switch_retraction_config.retraction_min_travel_distance = 0; // no limitation on travel distance for an extruder switch retract
-
-        extruder_attr[n].last_retraction_prime_speed = train->getSettingInMillimetersPerSecond("retraction_prime_speed"); // the alternative would be switch_extruder_prime_speed, but dual extrusion might not even be configured...
+        if (!mesh.getSettingBoolean("anti_overhang_mesh")
+            && !mesh.getSettingBoolean("support_mesh")
+        )
+        {
+            extruder_attr[mesh.getSettingAsIndex("extruder_nr")].is_used = true;
+        }
     }
-    machine_dimensions.x = settings->getSettingInMicrons("machine_width");
-    machine_dimensions.y = settings->getSettingInMicrons("machine_depth");
-    machine_dimensions.z = settings->getSettingInMicrons("machine_height");
 
-    machine_name = settings->getSettingString("machine_name");
+    for (unsigned int extruder_nr = 0; extruder_nr < extruder_count; extruder_nr++)
+    {
+        const ExtruderTrain* train = meshgroup->getExtruderTrain(extruder_nr);
+
+        if (meshgroup->getSettingAsIndex("adhesion_extruder_nr") == int(extruder_nr) && meshgroup->getSettingAsPlatformAdhesion("adhesion_type") != EPlatformAdhesion::NONE)
+        {
+            extruder_attr[extruder_nr].is_used = true;
+        }
+        for (const Mesh& mesh : meshgroup->meshes)
+        {
+            if ((mesh.getSettingBoolean("support_enable") && mesh.getSettingBoolean("support_interface_enable") && meshgroup->getSettingAsIndex("support_interface_extruder_nr") == int(extruder_nr))
+                || (mesh.getSettingBoolean("support_enable") && meshgroup->getSettingAsIndex("support_infill_extruder_nr") == int(extruder_nr))
+                || (mesh.getSettingBoolean("support_enable") && meshgroup->getSettingAsIndex("support_extruder_nr_layer_0") == int(extruder_nr))
+                )
+            {
+                extruder_attr[extruder_nr].is_used = true;
+            }
+        }
+        setFilamentDiameter(extruder_nr, train->getSettingInMicrons("material_diameter")); 
+
+        extruder_attr[extruder_nr].prime_pos = Point3(train->getSettingInMicrons("extruder_prime_pos_x"), train->getSettingInMicrons("extruder_prime_pos_y"), train->getSettingInMicrons("extruder_prime_pos_z"));
+        extruder_attr[extruder_nr].prime_pos_is_abs = train->getSettingBoolean("extruder_prime_pos_abs");
+
+        extruder_attr[extruder_nr].nozzle_size = train->getSettingInMicrons("machine_nozzle_size");
+        extruder_attr[extruder_nr].nozzle_offset = Point(train->getSettingInMicrons("machine_nozzle_offset_x"), train->getSettingInMicrons("machine_nozzle_offset_y"));
+        extruder_attr[extruder_nr].material_guid = train->getSettingString("material_guid");
+
+        extruder_attr[extruder_nr].start_code = train->getSettingString("machine_extruder_start_code");
+        extruder_attr[extruder_nr].end_code = train->getSettingString("machine_extruder_end_code");
+
+        extruder_attr[extruder_nr].last_retraction_prime_speed = train->getSettingInMillimetersPerSecond("retraction_prime_speed"); // the alternative would be switch_extruder_prime_speed, but dual extrusion might not even be configured...
+    }
+    machine_dimensions.x = meshgroup->getSettingInMicrons("machine_width");
+    machine_dimensions.y = meshgroup->getSettingInMicrons("machine_depth");
+    machine_dimensions.z = meshgroup->getSettingInMicrons("machine_height");
+
+    machine_name = meshgroup->getSettingString("machine_name");
+
+    layer_height = meshgroup->getSettingInMillimeters("layer_height");
 
     if (flavor == EGCodeFlavor::BFB)
     {
@@ -76,19 +109,23 @@ void GCodeExport::preSetup(MeshGroup* settings)
     {
         new_line = "\n";
     }
+
+    estimateCalculator.setFirmwareDefaults(meshgroup);
 }
 
-void GCodeExport::setInitialTemps(const MeshGroup& settings)
+void GCodeExport::setInitialTemps(const MeshGroup& settings, const unsigned int start_extruder_nr)
 {
     for (unsigned int extr_nr = 0; extr_nr < extruder_count; extr_nr++)
     {
-        const ExtruderTrain* extr_train = settings.getExtruderTrain(extr_nr);
-        assert(extr_train);
-        double temp = extr_train->getSettingInDegreeCelsius((extr_nr == 0)? "material_print_temperature" : "material_standby_temperature");
+        const ExtruderTrain& train = *settings.getExtruderTrain(extr_nr);
+        
+        double print_temp_0 = train.getSettingInDegreeCelsius("material_print_temperature_layer_0");
+        double print_temp_here = (print_temp_0 != 0)? print_temp_0 : train.getSettingInDegreeCelsius("material_print_temperature");
+        double temp = (extr_nr == start_extruder_nr)? print_temp_here : train.getSettingInDegreeCelsius("material_standby_temperature");
         setInitialTemp(extr_nr, temp);
     }
 
-    initial_bed_temp = settings.getSettingInDegreeCelsius("material_bed_temperature");
+    initial_bed_temp = settings.getSettingInDegreeCelsius("material_bed_temperature_layer_0");
 }
 
 void GCodeExport::setInitialTemp(int extruder_nr, double temp)
@@ -101,7 +138,7 @@ void GCodeExport::setInitialTemp(int extruder_nr, double temp)
 }
 
 
-std::string GCodeExport::getFileHeader(const double* print_time, const std::vector<double>& filament_used, const std::vector<int16_t>& mat_ids)
+std::string GCodeExport::getFileHeader(const double* print_time, const std::vector<double>& filament_used, const std::vector<std::string>& mat_ids)
 {
     std::ostringstream prefix;
     switch (flavor)
@@ -117,14 +154,18 @@ std::string GCodeExport::getFileHeader(const double* print_time, const std::vect
 
         for (unsigned int extr_nr = 0; extr_nr < extruder_count; extr_nr++)
         {
+            if (!extruder_attr[extr_nr].is_used)
+            {
+                continue;
+            }
             prefix << ";EXTRUDER_TRAIN." << extr_nr << ".INITIAL_TEMPERATURE:" << extruder_attr[extr_nr].initial_temp << new_line;
             if (filament_used.size() == extruder_count)
             {
                 prefix << ";EXTRUDER_TRAIN." << extr_nr << ".MATERIAL.VOLUME_USED:" << static_cast<int>(filament_used[extr_nr]) << new_line;
             }
-            if (mat_ids.size() == extruder_count)
+            if (mat_ids.size() == extruder_count && mat_ids[extr_nr] != "")
             {
-                prefix << ";EXTRUDER_TRAIN." << extr_nr << ".MATERIAL.GUID:" << mat_ids[extr_nr] << new_line; // TODO: convert to hexadecimal format
+                prefix << ";EXTRUDER_TRAIN." << extr_nr << ".MATERIAL.GUID:" << mat_ids[extr_nr] << new_line;
             }
             prefix << ";EXTRUDER_TRAIN." << extr_nr << ".NOZZLE.DIAMETER:" << float(INT2MM(getNozzleSize(extr_nr))) << new_line;
         }
@@ -135,12 +176,12 @@ std::string GCodeExport::getFileHeader(const double* print_time, const std::vect
             prefix << ";PRINT.TIME:" << static_cast<int>(*print_time) << new_line;
         }
 
-        prefix << ";PRINT.SIZE.MIN.X:0" << new_line;
-        prefix << ";PRINT.SIZE.MIN.Y:0" << new_line;
-        prefix << ";PRINT.SIZE.MIN.Z:0" << new_line;
-        prefix << ";PRINT.SIZE.MAX.X:" << INT2MM(machine_dimensions.x) << new_line;
-        prefix << ";PRINT.SIZE.MAX.Y:" << INT2MM(machine_dimensions.y) << new_line;
-        prefix << ";PRINT.SIZE.MAX.Z:" << INT2MM(machine_dimensions.z) << new_line;
+        prefix << ";PRINT.SIZE.MIN.X:" << INT2MM(total_bounding_box.min.x) << new_line;
+        prefix << ";PRINT.SIZE.MIN.Y:" << INT2MM(total_bounding_box.min.y) << new_line;
+        prefix << ";PRINT.SIZE.MIN.Z:" << INT2MM(total_bounding_box.min.z) << new_line;
+        prefix << ";PRINT.SIZE.MAX.X:" << INT2MM(total_bounding_box.max.x) << new_line;
+        prefix << ";PRINT.SIZE.MAX.Y:" << INT2MM(total_bounding_box.max.y) << new_line;
+        prefix << ";PRINT.SIZE.MAX.Z:" << INT2MM(total_bounding_box.max.z) << new_line;
         prefix << ";END_OF_HEADER" << new_line;
         return prefix.str();
     default:
@@ -154,6 +195,11 @@ std::string GCodeExport::getFileHeader(const double* print_time, const std::vect
             prefix << ";NOZZLE_DIAMETER:" << float(INT2MM(getNozzleSize(0))) << new_line;
             // TODO: the second nozzle size isn't always initiated! ";NOZZLE_DIAMETER2:"
         }
+        else if (flavor == EGCodeFlavor::REPRAP)
+        {
+            prefix << ";Filament used: " << ((filament_used.size() >= 1)? filament_used[0] / (1000 * extruder_attr[0].filament_area) : 0) << "m" << new_line;
+            prefix << ";Layer height: " << layer_height << new_line;
+        }
         return prefix.str();
     }
 }
@@ -169,17 +215,27 @@ void GCodeExport::setOutputStream(std::ostream* stream)
     *output_stream << std::fixed;
 }
 
-int GCodeExport::getNozzleSize(int extruder_idx)
+bool GCodeExport::getExtruderIsUsed(const int extruder_nr) const
 {
-    return extruder_attr[extruder_idx].nozzle_size;
+    return extruder_attr[extruder_nr].is_used;
 }
 
-Point GCodeExport::getExtruderOffset(int id)
+int GCodeExport::getNozzleSize(const int extruder_nr) const
+{
+    return extruder_attr[extruder_nr].nozzle_size;
+}
+
+Point GCodeExport::getExtruderOffset(const int id) const
 {
     return extruder_attr[id].nozzle_offset;
 }
 
-Point GCodeExport::getGcodePos(int64_t x, int64_t y, int extruder_train)
+std::string GCodeExport::getMaterialGUID(const int extruder_nr) const
+{
+    return extruder_attr[extruder_nr].material_guid;
+}
+
+Point GCodeExport::getGcodePos(const int64_t x, const int64_t y, const int extruder_train) const
 {
     if (use_extruder_offset_to_offset_coords) { return Point(x,y) - getExtruderOffset(extruder_train); }
     else { return Point(x,y); }
@@ -214,14 +270,14 @@ void GCodeExport::setFlavor(EGCodeFlavor flavor)
     }
 }
 
-EGCodeFlavor GCodeExport::getFlavor()
+EGCodeFlavor GCodeExport::getFlavor() const
 {
     return this->flavor;
 }
 
 void GCodeExport::setZ(int z)
 {
-    this->zPos = z;
+    this->current_layer_z = z;
 }
 
 Point3 GCodeExport::getPosition()
@@ -333,6 +389,7 @@ void GCodeExport::updateTotalPrintTime()
 {
     totalPrintTime += estimateCalculator.calculate();
     estimateCalculator.reset();
+    writeTimeComment(totalPrintTime);
 }
 
 void GCodeExport::writeComment(std::string comment)
@@ -350,9 +407,9 @@ void GCodeExport::writeComment(std::string comment)
     *output_stream << new_line;
 }
 
-void GCodeExport::writeTypeComment(const char* type)
+void GCodeExport::writeTimeComment(const double time)
 {
-    *output_stream << ";TYPE:" << type << new_line;
+    *output_stream << ";TIME_ELAPSED:" << time << new_line;
 }
 
 void GCodeExport::writeTypeComment(PrintFeatureType type)
@@ -371,7 +428,7 @@ void GCodeExport::writeTypeComment(PrintFeatureType type)
         case PrintFeatureType::Support:
             *output_stream << ";TYPE:SUPPORT" << new_line;
             break;
-        case PrintFeatureType::Skirt:
+        case PrintFeatureType::SkirtBrim:
             *output_stream << ";TYPE:SKIRT" << new_line;
             break;
         case PrintFeatureType::Infill:
@@ -428,7 +485,7 @@ void GCodeExport::writeDelay(double timeAmount)
 
 void GCodeExport::writeMove(Point p, double speed, double extrusion_mm3_per_mm)
 {
-    writeMove(p.X, p.Y, zPos, speed, extrusion_mm3_per_mm);
+    writeMove(p.X, p.Y, current_layer_z, speed, extrusion_mm3_per_mm);
 }
 
 void GCodeExport::writeMove(Point3 p, double speed, double extrusion_mm3_per_mm)
@@ -455,7 +512,7 @@ void GCodeExport::writeMoveBFB(int x, int y, int z, double speed, double extrusi
             {
                 //fprintf(f, "; %f e-per-mm %d mm-width %d mm/s\n", extrusion_per_mm, lineWidth, speed);
                 //fprintf(f, "M108 S%0.1f\r\n", rpm);
-                *output_stream << "M108 S" << std::setprecision(1) << rpm << new_line;
+                *output_stream << "M108 S" << PrecisionedDouble{1, rpm} << new_line;
                 currentSpeed = double(rpm);
             }
             //Add M101 or M201 to enable the proper extruder.
@@ -480,10 +537,8 @@ void GCodeExport::writeMoveBFB(int x, int y, int z, double speed, double extrusi
             extruder_attr[current_extruder].retraction_e_amount_current = 1.0; // 1.0 used as stub; BFB doesn't use the actual retraction amount; it performs retraction on the firmware automatically
         }
     }
-    *output_stream << std::setprecision(3) << 
-        "G1 X" << INT2MM(gcode_pos.X) << 
-        " Y" << INT2MM(gcode_pos.Y) << 
-        " Z" << INT2MM(z) << std::setprecision(1) << " F" << fspeed << new_line;
+    *output_stream << "G1 X" << MMtoStream{gcode_pos.X} << " Y" << MMtoStream{gcode_pos.Y} << " Z" << MMtoStream{z};
+    *output_stream << " F" << PrecisionedDouble{1, fspeed} << new_line;
     
     currentPosition = Point3(x, y, z);
     estimateCalculator.plan(TimeEstimateCalculator::Position(INT2MM(currentPosition.x), INT2MM(currentPosition.y), INT2MM(currentPosition.z), eToMm(current_e_value)), speed);
@@ -495,8 +550,9 @@ void GCodeExport::writeMove(int x, int y, int z, double speed, double extrusion_
         return;
 
 #ifdef ASSERT_INSANE_OUTPUT
-    assert(speed < 200 && speed > 1); // normal F values occurring in UM2 gcode (this code should not be compiled for release)
+    assert(speed < 400 && speed > 1); // normal F values occurring in UM2 gcode (this code should not be compiled for release)
     assert(currentPosition != no_point3);
+    assert(Point3(x, y, z) != no_point3);
     assert((Point3(x,y,z) - currentPosition).vSize() < MM2INT(300)); // no crazy positions (this code should not be compiled for release)
 #endif //ASSERT_INSANE_OUTPUT
 
@@ -512,13 +568,14 @@ void GCodeExport::writeMove(int x, int y, int z, double speed, double extrusion_
     double extrusion_per_mm = mm3ToE(extrusion_mm3_per_mm);
 
     Point gcode_pos = getGcodePos(x,y, current_extruder);
+    total_bounding_box.include(Point3(gcode_pos.X, gcode_pos.Y, z));
 
     if (extrusion_mm3_per_mm > 0.000001)
     {
         Point3 diff = Point3(x,y,z) - getPosition();
         if (isZHopped > 0)
         {
-            *output_stream << std::setprecision(3) << "G1 Z" << INT2MM(currentPosition.z) << new_line;
+            *output_stream << "G1 Z" << MMtoStream{currentPosition.z} << new_line;
             isZHopped = 0;
         }
         double prime_volume = extruder_attr[current_extruder].prime_volume;
@@ -531,7 +588,7 @@ void GCodeExport::writeMove(int x, int y, int z, double speed, double extrusion_
                 //Assume default UM2 retraction settings.
                 if (prime_volume > 0)
                 {
-                    *output_stream << "G1 F" << (extruder_attr[current_extruder].last_retraction_prime_speed * 60) << " " << extruder_attr[current_extruder].extruderCharacter << std::setprecision(5) << current_e_value << new_line;
+                    *output_stream << "G1 F" << PrecisionedDouble{1, extruder_attr[current_extruder].last_retraction_prime_speed * 60} << " " << extruder_attr[current_extruder].extruderCharacter << PrecisionedDouble{5, current_e_value} << new_line;
                     currentSpeed = extruder_attr[current_extruder].last_retraction_prime_speed;
                 }
                 estimateCalculator.plan(TimeEstimateCalculator::Position(INT2MM(currentPosition.x), INT2MM(currentPosition.y), INT2MM(currentPosition.z), eToMm(current_e_value)), 25.0);
@@ -539,7 +596,7 @@ void GCodeExport::writeMove(int x, int y, int z, double speed, double extrusion_
             else
             {
                 current_e_value += extruder_attr[current_extruder].retraction_e_amount_current;
-                *output_stream << "G1 F" << (extruder_attr[current_extruder].last_retraction_prime_speed * 60) << " " << extruder_attr[current_extruder].extruderCharacter << std::setprecision(5) << current_e_value << new_line;
+                *output_stream << "G1 F" << PrecisionedDouble{1, extruder_attr[current_extruder].last_retraction_prime_speed * 60} << " " << extruder_attr[current_extruder].extruderCharacter << PrecisionedDouble{5, current_e_value} << new_line;
                 currentSpeed = extruder_attr[current_extruder].last_retraction_prime_speed;
                 estimateCalculator.plan(TimeEstimateCalculator::Position(INT2MM(currentPosition.x), INT2MM(currentPosition.y), INT2MM(currentPosition.z), eToMm(current_e_value)), currentSpeed);
             }
@@ -551,7 +608,7 @@ void GCodeExport::writeMove(int x, int y, int z, double speed, double extrusion_
         }
         else if (prime_volume > 0.0)
         {
-            *output_stream << "G1 F" << (extruder_attr[current_extruder].last_retraction_prime_speed * 60) << " " << extruder_attr[current_extruder].extruderCharacter << std::setprecision(5) << current_e_value << new_line;
+            *output_stream << "G1 F" << PrecisionedDouble{1, extruder_attr[current_extruder].last_retraction_prime_speed * 60} << " " << extruder_attr[current_extruder].extruderCharacter << PrecisionedDouble{5, current_e_value} << new_line;
             currentSpeed = extruder_attr[current_extruder].last_retraction_prime_speed;
             estimateCalculator.plan(TimeEstimateCalculator::Position(INT2MM(currentPosition.x), INT2MM(currentPosition.y), INT2MM(currentPosition.z), eToMm(current_e_value)), currentSpeed);
         }
@@ -563,37 +620,29 @@ void GCodeExport::writeMove(int x, int y, int z, double speed, double extrusion_
     {
         *output_stream << "G0";
 
-        if (CommandSocket::isInstantiated()) 
-        {
-            // we should send this travel as a non-retraction move
-            cura::Polygons travelPoly;
-            PolygonRef travel = travelPoly.newPoly();
-            travel.add(Point(currentPosition.x, currentPosition.y));
-            travel.add(Point(x, y));
-            CommandSocket::getInstance()->sendPolygons(extruder_attr[current_extruder].retraction_e_amount_current ? PrintFeatureType::MoveRetraction : PrintFeatureType::MoveCombing, layer_nr, travelPoly, extruder_attr[current_extruder].retraction_e_amount_current ? MM2INT(0.2) : MM2INT(0.1));
-        }
+        CommandSocket::sendLineTo(extruder_attr[current_extruder].retraction_e_amount_current ? PrintFeatureType::MoveRetraction : PrintFeatureType::MoveCombing, Point(x, y), extruder_attr[current_extruder].retraction_e_amount_current ? MM2INT(0.2) : MM2INT(0.1));
     }
 
     if (currentSpeed != speed)
     {
-        *output_stream << " F" << (speed * 60);
+        *output_stream << " F" << PrecisionedDouble{1, speed * 60};
         currentSpeed = speed;
     }
 
-    *output_stream << std::setprecision(3) << 
-        " X" << INT2MM(gcode_pos.X) << 
-        " Y" << INT2MM(gcode_pos.Y);
+    *output_stream << " X" << MMtoStream{gcode_pos.X} << " Y" << MMtoStream{gcode_pos.Y};
     if (z != currentPosition.z + isZHopped)
-        *output_stream << " Z" << INT2MM(z + isZHopped);
+    {
+        *output_stream << " Z" << MMtoStream{z + isZHopped};
+    }
     if (extrusion_mm3_per_mm > 0.000001)
-        *output_stream << " " << extruder_attr[current_extruder].extruderCharacter << std::setprecision(5) << current_e_value;
+        *output_stream << " " << extruder_attr[current_extruder].extruderCharacter << PrecisionedDouble{5, current_e_value};
     *output_stream << new_line;
     
     currentPosition = Point3(x, y, z);
     estimateCalculator.plan(TimeEstimateCalculator::Position(INT2MM(currentPosition.x), INT2MM(currentPosition.y), INT2MM(currentPosition.z), eToMm(current_e_value)), speed);
 }
 
-void GCodeExport::writeRetraction(RetractionConfig* config, bool force, bool extruder_switch)
+void GCodeExport::writeRetraction(const RetractionConfig& config, bool force, bool extruder_switch)
 {
     ExtruderTrainAttributes& extr_attr = extruder_attr[current_extruder];
 
@@ -610,7 +659,7 @@ void GCodeExport::writeRetraction(RetractionConfig* config, bool force, bool ext
     }
 
     double old_retraction_e_amount = extr_attr.retraction_e_amount_current;
-    double new_retraction_e_amount = mmToE(config->distance);
+    double new_retraction_e_amount = mmToE(config.distance);
     double retraction_diff_e_amount = old_retraction_e_amount - new_retraction_e_amount;
     if (std::abs(retraction_diff_e_amount) < 0.000001)
     {
@@ -620,23 +669,23 @@ void GCodeExport::writeRetraction(RetractionConfig* config, bool force, bool ext
     { // handle retraction limitation
         double current_extruded_volume = getCurrentExtrudedVolume();
         std::deque<double>& extruded_volume_at_previous_n_retractions = extr_attr.extruded_volume_at_previous_n_retractions;
-        while (int(extruded_volume_at_previous_n_retractions.size()) > config->retraction_count_max && !extruded_volume_at_previous_n_retractions.empty()) 
+        while (int(extruded_volume_at_previous_n_retractions.size()) > config.retraction_count_max && !extruded_volume_at_previous_n_retractions.empty()) 
         {
             // extruder switch could have introduced data which falls outside the retraction window
             // also the retraction_count_max could have changed between the last retraction and this
             extruded_volume_at_previous_n_retractions.pop_back();
         }
-        if (!force && config->retraction_count_max <= 0)
+        if (!force && config.retraction_count_max <= 0)
         {
             return;
         }
-        if (!force && int(extruded_volume_at_previous_n_retractions.size()) == config->retraction_count_max
-            && current_extruded_volume < extruded_volume_at_previous_n_retractions.back() + config->retraction_extrusion_window * extr_attr.filament_area) 
+        if (!force && int(extruded_volume_at_previous_n_retractions.size()) == config.retraction_count_max
+            && current_extruded_volume < extruded_volume_at_previous_n_retractions.back() + config.retraction_extrusion_window * extr_attr.filament_area) 
         {
             return;
         }
         extruded_volume_at_previous_n_retractions.push_front(current_extruded_volume);
-        if (int(extruded_volume_at_previous_n_retractions.size()) == config->retraction_count_max + 1) 
+        if (int(extruded_volume_at_previous_n_retractions.size()) == config.retraction_count_max + 1) 
         {
             extruded_volume_at_previous_n_retractions.pop_back();
         }
@@ -659,61 +708,82 @@ void GCodeExport::writeRetraction(RetractionConfig* config, bool force, bool ext
     }
     else
     {
-        double speed = ((retraction_diff_e_amount < 0.0)? config->speed : extr_attr.last_retraction_prime_speed) * 60;
+        double speed = ((retraction_diff_e_amount < 0.0)? config.speed : extr_attr.last_retraction_prime_speed) * 60;
         current_e_value += retraction_diff_e_amount;
-        *output_stream << "G1 F" << speed << " "
-            << extr_attr.extruderCharacter << std::setprecision(5) << current_e_value << new_line;
+        *output_stream << "G1 F" << PrecisionedDouble{1, speed} << " "
+            << extr_attr.extruderCharacter << PrecisionedDouble{5, current_e_value} << new_line;
         currentSpeed = speed;
         estimateCalculator.plan(TimeEstimateCalculator::Position(INT2MM(currentPosition.x), INT2MM(currentPosition.y), INT2MM(currentPosition.z), eToMm(current_e_value)), currentSpeed);
-        extr_attr.last_retraction_prime_speed = config->primeSpeed;
+        extr_attr.last_retraction_prime_speed = config.primeSpeed;
     }
 
     extr_attr.retraction_e_amount_current = new_retraction_e_amount; // suppose that for UM2 the retraction amount in the firmware is equal to the provided amount
-    extr_attr.prime_volume += config->prime_volume;
+    extr_attr.prime_volume += config.prime_volume;
 
-    if (config->zHop > 0)
+}
+
+void GCodeExport::writeZhopStart(int hop_height)
+{
+    if (hop_height > 0)
     {
-        isZHopped = config->zHop;
-        *output_stream << std::setprecision(3) << "G1 Z" << INT2MM(currentPosition.z + isZHopped) << new_line;
+        isZHopped = hop_height;
+        *output_stream << "G1 Z" << MMtoStream{currentPosition.z + isZHopped} << new_line;
+        total_bounding_box.includeZ(currentPosition.z + isZHopped);
     }
 }
 
-void GCodeExport::writeRetraction_extruderSwitch()
+void GCodeExport::writeZhopEnd()
 {
-    ExtruderTrainAttributes& extr_attr = extruder_attr[current_extruder];
-    RetractionConfig* config = &extr_attr.extruder_switch_retraction_config;
-
-    writeRetraction(config, true, true);
+    if (isZHopped)
+    {
+        isZHopped = 0;
+        *output_stream << "G1 Z" << MMtoStream{currentPosition.z} << new_line;
+    }
 }
 
-void GCodeExport::switchExtruder(int new_extruder)
+void GCodeExport::startExtruder(int new_extruder)
+{
+    if (new_extruder != current_extruder) // wouldn't be the case on the very first extruder start if it's extruder 0
+    {
+        if (flavor == EGCodeFlavor::MAKERBOT)
+        {
+            *output_stream << "M135 T" << new_extruder << new_line;
+        }
+        else
+        {
+            *output_stream << "T" << new_extruder << new_line;
+        }
+    }
+
+    current_extruder = new_extruder;
+
+    assert(getCurrentExtrudedVolume() == 0.0 && "Just after an extruder switch we haven't extruded anything yet!");
+    resetExtrusionValue(); // zero the E value on the new extruder, just to be sure
+
+    writeCode(extruder_attr[new_extruder].start_code.c_str());
+    CommandSocket::setExtruderForSend(new_extruder);
+    CommandSocket::setSendCurrentPosition( getPositionXY() );
+
+    //Change the Z position so it gets re-writting again. We do not know if the switch code modified the Z position.
+    currentPosition.z += 1;
+}
+
+void GCodeExport::switchExtruder(int new_extruder, const RetractionConfig& retraction_config_old_extruder)
 {
     if (current_extruder == new_extruder)
         return;
 
-    writeRetraction_extruderSwitch();
+    bool force = true;
+    bool extruder_switch = true;
+    writeRetraction(retraction_config_old_extruder, force, extruder_switch);
 
     resetExtrusionValue(); // zero the E value on the old extruder, so that the current_e_value is registered on the old extruder
 
     int old_extruder = current_extruder;
-    current_extruder = new_extruder;
 
     writeCode(extruder_attr[old_extruder].end_code.c_str());
-    if (flavor == EGCodeFlavor::MAKERBOT)
-    {
-        *output_stream << "M135 T" << current_extruder << new_line;
-    }
-    else
-    {
-        *output_stream << "T" << current_extruder << new_line;
-    }
 
-    resetExtrusionValue(); // zero the E value on the new extruder, because a firmware bug in Griffin adjusted the E-value when performing a toolswitch (should be fixed as of 9 may 2016)
-
-    writeCode(extruder_attr[new_extruder].start_code.c_str());
-
-    //Change the Z position so it gets re-writting again. We do not know if the switch code modified the Z position.
-    currentPosition.z += 1;
+    startExtruder(new_extruder);
 }
 
 void GCodeExport::writeCode(const char* str)
@@ -721,9 +791,29 @@ void GCodeExport::writeCode(const char* str)
     *output_stream << str << new_line;
 }
 
-void GCodeExport::writePrimeTrain()
+void GCodeExport::writePrimeTrain(double travel_speed)
 {
-    *output_stream << "G280" << new_line;
+    if (extruder_attr[current_extruder].is_primed)
+    { // extruder is already primed once!
+        return;
+    }
+    Point3 prime_pos = extruder_attr[current_extruder].prime_pos;
+    if (!extruder_attr[current_extruder].prime_pos_is_abs)
+    {
+        prime_pos += currentPosition;
+    }
+    writeMove(prime_pos, travel_speed, 0.0);
+
+    if (flavor == EGCodeFlavor::GRIFFIN)
+    {
+        *output_stream << "G280" << new_line;
+    }
+    else
+    {
+        // there is no prime gcode for other firmware versions...
+    }
+
+    extruder_attr[current_extruder].is_primed = true;
 }
 
 
@@ -736,7 +826,7 @@ void GCodeExport::writeFanCommand(double speed)
         if (flavor == EGCodeFlavor::MAKERBOT)
             *output_stream << "M126 T0" << new_line; //value = speed * 255 / 100 // Makerbot cannot set fan speed...;
         else
-            *output_stream << "M106 S" << (speed * 255 / 100) << new_line;
+            *output_stream << "M106 S" << PrecisionedDouble{1, speed * 255 / 100} << new_line;
     }
     else
     {
@@ -752,31 +842,87 @@ void GCodeExport::writeTemperatureCommand(int extruder, double temperature, bool
 {
     if (!wait && extruder_attr[extruder].currentTemperature == temperature)
         return;
-    
+
+    if (flavor == EGCodeFlavor::ULTIGCODE)
+    { // The UM2 family doesn't support temperature commands (they are fixed in the firmware)
+        return;
+    }
+
     if (wait)
         *output_stream << "M109";
     else
         *output_stream << "M104";
     if (extruder != current_extruder)
         *output_stream << " T" << extruder;
-    *output_stream << " S" << temperature << new_line;
+#ifdef ASSERT_INSANE_OUTPUT
+    assert(temperature >= 0);
+#endif // ASSERT_INSANE_OUTPUT
+    *output_stream << " S" << PrecisionedDouble{1, temperature} << new_line;
     extruder_attr[extruder].currentTemperature = temperature;
 }
 
 void GCodeExport::writeBedTemperatureCommand(double temperature, bool wait)
 {
+    if (flavor == EGCodeFlavor::ULTIGCODE)
+    { // The UM2 family doesn't support temperature commands (they are fixed in the firmware)
+        return;
+    }
+
     if (wait)
         *output_stream << "M190 S";
     else
         *output_stream << "M140 S";
-    *output_stream << temperature << new_line;
+    *output_stream << PrecisionedDouble{1, temperature} << new_line;
+}
+
+void GCodeExport::writeAcceleration(double acceleration)
+{
+    if (current_acceleration != acceleration)
+    {
+        *output_stream << "M204 S" << PrecisionedDouble{0, acceleration} << new_line; // Print and Travel acceleration
+        current_acceleration = acceleration;
+        estimateCalculator.setAcceleration(acceleration);
+    }
+}
+
+void GCodeExport::writeJerk(double jerk)
+{
+    if (current_jerk != jerk)
+    {
+        if (getFlavor() == EGCodeFlavor::REPETIER)
+        {
+            *output_stream << "M207 X";
+        }
+        else
+        {
+            *output_stream << "M205 X";
+        }
+        *output_stream << PrecisionedDouble{2, jerk} << new_line;
+        current_jerk = jerk;
+        estimateCalculator.setMaxXyJerk(jerk);
+    }
+}
+
+void GCodeExport::writeMaxZFeedrate(double max_z_feedrate)
+{
+    if (current_max_z_feedrate != max_z_feedrate)
+    {
+        *output_stream << "M203 Z" << PrecisionedDouble{2, max_z_feedrate} << new_line;
+        current_max_z_feedrate = max_z_feedrate;
+        estimateCalculator.setMaxZFeedrate(max_z_feedrate);
+    }
+}
+
+double GCodeExport::getCurrentMaxZFeedrate()
+{
+    return current_max_z_feedrate;
 }
 
 void GCodeExport::finalize(const char* endCode)
 {
     writeFanCommand(0);
     writeCode(endCode);
-    long print_time = getTotalPrintTime();
+    int64_t print_time = getTotalPrintTime();
     int mat_0 = getTotalFilamentUsed(0);
     log("Print time: %d\n", print_time);
     log("Print time (readable): %dh %dm %ds\n", print_time / 60 / 60, (print_time / 60) % 60, print_time % 60);

src/gcodeExport.h

@@ -12,6 +12,7 @@
 #include "timeEstimate.h"
 #include "MeshGroup.h"
 #include "commandSocket.h"
+#include "RetractionConfig.h"
 
 namespace cura {
 
@@ -29,133 +30,6 @@ struct CoastingConfig
     double coasting_min_volume;  //!< The minimal volume printed to build up enough pressure to leek the coasting_volume
 };
 
-/*!
- * The retraction configuration used in the GCodePathConfig of each feature (and the travel config)
- */
-class RetractionConfig
-{
-public:
-    double distance; //!< The distance retracted (in mm)
-    double speed; //!< The speed with which to retract (in mm/s)
-    double primeSpeed; //!< the speed with which to unretract (in mm/s)
-    double prime_volume; //!< the amount of material primed after unretracting (in mm^3)
-    int zHop; //!< the amount with which to lift the head during a retraction-travel
-    int retraction_min_travel_distance; //!< Minimal distance traversed to even consider retracting (in micron)
-    double retraction_extrusion_window; //!< Window of mm extruded filament in which to limit the amount of retractions
-    int retraction_count_max; //!< The maximum amount of retractions allowed to occur in the RetractionConfig::retraction_extrusion_window
-};
-
-/*!
- * The GCodePathConfig is the configuration for moves/extrusion actions. This defines at which width the line is printed and at which speed.
- */
-class GCodePathConfig
-{
-private:
-    double speed_iconic; //!< movement speed (mm/s) specific to this print feature
-    double speed; //!< current movement speed (mm/s) (modified by layer_nr etc.)
-    int line_width; //!< width of the line extruded
-    double flow; //!< extrusion flow modifier in %
-    int layer_thickness; //!< layer height in micron
-    double extrusion_mm3_per_mm;//!< mm^3 filament moved per mm line traversed
-public:
-    PrintFeatureType type; //!< name of the feature type
-    RetractionConfig *const retraction_config; //!< The retraction configuration to use when retracting after a part of this feature has been printed.
-
-    GCodePathConfig(RetractionConfig* retraction_config, PrintFeatureType type)
-    : speed_iconic(0)
-    , speed(0)
-    , line_width(0)
-    , extrusion_mm3_per_mm(0.0)
-    , type(type)
-    , retraction_config(retraction_config)
-    {
-    }
-    
-    /*!
-     * Initialize some of the member variables.
-     * 
-     * \warning GCodePathConfig::setLayerHeight still has to be called before this object can be used.
-     * 
-     * \param speed The regular speed with which to print this feature
-     * \param line_width The line width for this feature
-     * \param flow The flow modifier to apply to the extruded filament when printing this feature
-     */
-    void init(double speed, int line_width, double flow)
-    {
-        speed_iconic = speed;
-        this->speed = speed;
-        this->line_width = line_width;
-        this->flow = flow;
-    }
-
-    /*!
-     * Set the layer height and (re)compute the extrusion_per_mm
-     */
-    void setLayerHeight(int layer_height)
-    {
-        this->layer_thickness = layer_height;
-        calculateExtrusion();
-    }
-    
-    /*!
-     * Set the speed to somewhere between the @p min_speed and the speed_iconic.
-     * 
-     * This functions should not be called with @p layer_nr > @p max_speed_layer !
-     * 
-     * \param min_speed The speed at layer zero
-     * \param layer_nr The layer number 
-     * \param max_speed_layer The layer number for which the speed_iconic should be used.
-     */
-    void smoothSpeed(double min_speed, int layer_nr, double max_speed_layer) 
-    {
-        speed = (speed_iconic*layer_nr)/max_speed_layer + (min_speed*(max_speed_layer-layer_nr)/max_speed_layer);
-    }
-
-    /*!
-     * Set the speed to the iconic speed, i.e. the normal speed of the feature type for which this is a config.
-     */
-    void setSpeedIconic()
-    {
-        speed = speed_iconic;
-    }
-
-    /*!
-     * Can only be called after the layer height has been set (which is done while writing the gcode!)
-     */
-    double getExtrusionMM3perMM()
-    {
-        return extrusion_mm3_per_mm;
-    }
-    
-    /*!
-     * Get the movement speed in mm/s
-     */
-    double getSpeed()
-    {
-        return speed;
-    }
-    
-    int getLineWidth()
-    {
-        return line_width;
-    }
-    
-    bool isTravelPath()
-    {
-        return line_width == 0;
-    }
-    
-    double getFlowPercentage()
-    {
-        return flow;
-    }
-    
-private:
-    void calculateExtrusion()
-    {
-        extrusion_mm3_per_mm = INT2MM(line_width) * INT2MM(layer_thickness) * double(flow) / 100.0;
-    }
-};
 
 //The GCodeExport class writes the actual GCode. This is the only class that knows how GCode looks and feels.
 //  Any customizations on GCodes flavors are done in this class.
@@ -164,15 +38,20 @@ class GCodeExport : public NoCopy
 private:
     struct ExtruderTrainAttributes
     {
+        Point3 prime_pos; //!< The location this nozzle is primed before printing
+        bool prime_pos_is_abs; //!< Whether the prime position is absolute, rather than relative to the last given position
+        bool is_primed; //!< Whether this extruder has currently already been primed in this print
+
+        bool is_used; //!< Whether this extruder train is actually used during the printing of all meshgroups
         int nozzle_size; //!< The nozzle size label of the nozzle (e.g. 0.4mm; irrespective of tolerances)
         Point nozzle_offset;
         char extruderCharacter;
+        std::string material_guid; //!< The GUID for the material used by this extruder
+
         std::string start_code;
         std::string end_code;
         double filament_area; //!< in mm^2 for non-volumetric, cylindrical filament
 
-        RetractionConfig extruder_switch_retraction_config; //!< Retraction configuration used when performing extruder switches
-
         double totalFilament; //!< total filament used per extruder in mm^3
         int currentTemperature;
         int initial_temp; //!< Temperature this nozzle needs to be at the start of the print.
@@ -186,7 +65,11 @@ private:
         std::deque<double> extruded_volume_at_previous_n_retractions; // in mm^3
 
         ExtruderTrainAttributes()
-        : nozzle_offset(0,0)
+        : prime_pos(0, 0, 0)
+        , prime_pos_is_abs(false)
+        , is_primed(false)
+        , is_used(false)
+        , nozzle_offset(0,0)
         , extruderCharacter(0)
         , start_code("")
         , end_code("")
@@ -212,7 +95,20 @@ private:
     double current_e_value; //!< The last E value written to gcode (in mm or mm^3)
     Point3 currentPosition;
     double currentSpeed; //!< The current speed (F values / 60) in mm/s
-    int zPos; // TODO: why is this different from currentPosition.z ? zPos is set every layer, while currentPosition.z is set every move. However, the z position is generally not changed within a layer!
+    double current_acceleration; //!< The current acceleration in the XY direction (in mm/s^2)
+    double current_jerk; //!< The current jerk in the XY direction (in mm/s^3)
+    double current_max_z_feedrate; //!< The current max z speed
+
+    AABB3D total_bounding_box; //!< The bounding box of all g-code.
+
+    /*!
+     * The z position to be used on the next xy move, if the head wasn't in the correct z position yet.
+     * 
+     * \see GCodeExport::writeMove(Point, double, double)
+     * 
+     * \note After GCodeExport::writeMove(Point, double, double) has been called currentPosition.z coincides with this value
+     */
+    int current_layer_z;
     int isZHopped; //!< The amount by which the print head is currently z hopped, or zero if it is not z hopped. (A z hop is used during travel moves to avoid collision with other layer parts)
 
     int current_extruder;
@@ -272,23 +168,27 @@ public:
      * 
      * \param print_time The total print time in seconds of the whole gcode (if known)
      * \param filament_used The total mm^3 filament used for each extruder or a vector of the wrong size of unknown
-     * \param mat_ids The material ids for each material.
+     * \param mat_ids The material GUIDs for each material.
      * \return The string representing the file header
      */
-    std::string getFileHeader(const double* print_time = nullptr, const std::vector<double>& filament_used = std::vector<double>(), const std::vector<int16_t>& mat_ids = std::vector<int16_t>());
+    std::string getFileHeader(const double* print_time = nullptr, const std::vector<double>& filament_used = std::vector<double>(), const std::vector<std::string>& mat_ids = std::vector<std::string>());
 
     void setLayerNr(unsigned int layer_nr);
     
     void setOutputStream(std::ostream* stream);
 
-    int getNozzleSize(int extruder_idx);
+    bool getExtruderIsUsed(const int extruder_nr) const; //!< Returns whether the extruder with the given index is used up until the current meshgroup
 
-    Point getExtruderOffset(int id);
-    
-    Point getGcodePos(int64_t x, int64_t y, int extruder_train);
+    int getNozzleSize(const int extruder_nr) const;
+
+    Point getExtruderOffset(const int id) const;
+
+    std::string getMaterialGUID(const int extruder_nr) const; //!< returns the GUID of the material used for the nozzle with id \p extruder_nr
+
+    Point getGcodePos(const int64_t x, const int64_t y, const int extruder_train) const;
     
     void setFlavor(EGCodeFlavor flavor);
-    EGCodeFlavor getFlavor();
+    EGCodeFlavor getFlavor() const;
     
     void setZ(int z);
     
@@ -329,8 +229,14 @@ public:
     void resetTotalPrintTimeAndFilament();
     
     void writeComment(std::string comment);
-    void writeTypeComment(const char* type);
     void writeTypeComment(PrintFeatureType type);
+
+    /*!
+     * Write a comment saying what (estimated) time has passed up to this point
+     * 
+     * \param time The time passed up till this point
+     */
+    void writeTimeComment(const double time);
     void writeLayerComment(int layer_nr);
     void writeLayerCountComment(int layer_count);
     
@@ -345,40 +251,96 @@ public:
     
     void writeDelay(double timeAmount);
     
-    void writeMove(Point p, double speed, double extrusion_per_mm);
+    void writeMove(Point p, double speed, double extrusion_mm3_per_mm);
     
-    void writeMove(Point3 p, double speed, double extrusion_per_mm);
+    void writeMove(Point3 p, double speed, double extrusion_mm3_per_mm);
 private:
-    void writeMove(int x, int y, int z, double speed, double extrusion_per_mm);
+    void writeMove(int x, int y, int z, double speed, double extrusion_mm3_per_mm);
     /*!
      * The writeMove when flavor == BFB
      */
-    void writeMoveBFB(int x, int y, int z, double speed, double extrusion_per_mm);
+    void writeMoveBFB(int x, int y, int z, double speed, double extrusion_mm3_per_mm);
 public:
-    void writeRetraction(RetractionConfig* config, bool force = false, bool extruder_switch = false);
-    
-    void writeRetraction_extruderSwitch();
-    
-    void switchExtruder(int newExtruder);
-    
+    void writeRetraction(const RetractionConfig& config, bool force = false, bool extruder_switch = false);
+
+    /*!
+     * Start a z hop with the given \p hop_height
+     * 
+     * \param hop_height The height to move above the current layer
+     */
+    void writeZhopStart(int hop_height);
+
+    /*!
+     * End a z hop: go back to the layer height
+     * 
+     */
+    void writeZhopEnd();
+
+    /*!
+     * Start the new_extruder: 
+     * - set new extruder
+     * - zero E value
+     * - write extruder start gcode
+     * 
+     * \param new_extruder The extruder to start with
+     */
+    void startExtruder(int new_extruder);
+
+    /*!
+     * Switch to the new_extruder: 
+     * - perform neccesary retractions
+     * - fiddle with E-values
+     * - write extruder end gcode
+     * - set new extruder
+     * - write extruder start gcode
+     * 
+     * \param new_extruder The extruder to switch to
+     * \param retraction_config_old_extruder The extruder switch retraction config of the old extruder, to perform the extruder switch retraction with.
+     */
+    void switchExtruder(int new_extruder, const RetractionConfig& retraction_config_old_extruder);
+
     void writeCode(const char* str);
     
     /*!
      * Write the gcode for priming the current extruder train so that it can be used.
+     * 
+     * \param travel_speed The travel speed when priming involves a movement
      */
-    void writePrimeTrain();
+    void writePrimeTrain(double travel_speed);
     
     void writeFanCommand(double speed);
     
     void writeTemperatureCommand(int extruder, double temperature, bool wait = false);
     void writeBedTemperatureCommand(double temperature, bool wait = false);
 
+    /*!
+     * Write the command for setting the acceleration to a specific value
+     */
+    void writeAcceleration(double acceleration);
+
+    /*!
+     * Write the command for setting the jerk to a specific value
+     */
+    void writeJerk(double jerk);
+
+    /*!
+     * Write the command for setting the maximum z feedrate to a specific value
+     */
+    void writeMaxZFeedrate(double max_z_feedrate);
+
+    /*!
+     * Get the last set max z feedrate value sent in the gcode.
+     * 
+     * Returns a value <= 0 when no value is set.
+     */
+    double getCurrentMaxZFeedrate();
+
     /*!
      * Set member variables using the settings in \p settings
      * 
      * \param settings The meshgroup to get the global bed temp from and to get the extruder trains from which to get the nozzle temperatures
      */
-    void preSetup(MeshGroup* settings);
+    void preSetup(const MeshGroup* settings);
 
     /*!
      * Handle the initial (bed/nozzle) temperatures before any gcode is processed.
@@ -387,13 +349,17 @@ public:
      * See FffGcodeWriter::processStartingCode
      * 
      * \param settings The meshgroup to get the global bed temp from and to get the extruder trains from which to get the nozzle temperatures
+     * \param start_extruder_nr The extruder with which to start this print
      */
-    void setInitialTemps(const MeshGroup& settings);
+    void setInitialTemps(const MeshGroup& settings, const unsigned int start_extruder_nr);
 
     /*!
      * Override or set an initial nozzle temperature as written by GCodeExport::setInitialTemps
      * This is used primarily during better specification of temperatures in LayerPlanBuffer::insertPreheatCommand
      * 
+     * \warning This function must be called before any of the layers in the meshgroup are written to file!
+     * That's because it sets the current temperature in the gcode!
+     * 
      * \param extruder_nr The extruder number for which to better specify the temp
      * \param temp The temp at which the nozzle should be at startup
      */

src/gcodePlanner.h

@@ -1,263 +1,32 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
 #ifndef GCODE_PLANNER_H
 #define GCODE_PLANNER_H
 
 #include <vector>
 
 #include "gcodeExport.h"
-#include "comb.h"
+#include "pathPlanning/Comb.h"
+#include "pathPlanning/GCodePath.h"
+#include "pathPlanning/NozzleTempInsert.h"
+#include "pathPlanning/TimeMaterialEstimates.h"
 #include "utils/polygon.h"
 #include "utils/logoutput.h"
 #include "wallOverlap.h"
 #include "commandSocket.h"
 #include "FanSpeedLayerTime.h"
 #include "SpaceFillType.h"
+#include "GCodePathConfig.h"
+#include "settings/PathConfigStorage.h"
 
+#include "utils/optional.h"
 
 namespace cura 
 {
 
 class SliceDataStorage;
 
-/*!
- * A gcode command to insert before a specific path.
- * 
- * Currently only used for preheat commands
- */
-struct NozzleTempInsert
-{
-    const unsigned int path_idx; //!< The path before which to insert this command
-    double time_after_path_start; //!< The time after the start of the path, before which to insert the command // TODO: use this to insert command in between moves in a path!
-    int extruder; //!< The extruder for which to set the temp
-    double temperature; //!< The temperature of the temperature command to insert
-    bool wait; //!< Whether to wait for the temperature to be reached
-    NozzleTempInsert(unsigned int path_idx, int extruder, double temperature, bool wait, double time_after_path_start = 0.0)
-    : path_idx(path_idx)
-    , time_after_path_start(time_after_path_start)
-    , extruder(extruder)
-    , temperature(temperature)
-    , wait(wait)
-    {}
-    
-    /*!
-     * Write the temperature command at the current position in the gcode.
-     * \param gcode The actual gcode writer
-     */
-    void write(GCodeExport& gcode)
-    {
-        gcode.writeTemperatureCommand(extruder, temperature, wait);
-    }
-};
-
-class GCodePlanner; // forward declaration so that TimeMaterialEstimates can be a friend
-
-/*!
- * Time and material estimates for a portion of paths, e.g. layer, extruder plan, path.
- */
-class TimeMaterialEstimates
-{
-    friend class GCodePlanner;
-private:
-    double extrude_time; //!< Time in seconds occupied by extrusion
-    double unretracted_travel_time; //!< Time in seconds occupied by non-retracted travel (non-extrusion)
-    double retracted_travel_time; //!< Time in seconds occupied by retracted travel (non-extrusion)
-    double material; //!< Material used (in mm^3)
-public:
-    /*!
-     * Basic contructor
-     * 
-     * \param extrude_time Time in seconds occupied by extrusion
-     * \param unretracted_travel_time Time in seconds occupied by non-retracted travel (non-extrusion)
-     * \param retracted_travel_time Time in seconds occupied by retracted travel (non-extrusion)
-     * \param material Material used (in mm^3)
-     */
-    TimeMaterialEstimates(double extrude_time, double unretracted_travel_time, double retracted_travel_time, double material)
-    : extrude_time(extrude_time)
-    , unretracted_travel_time(unretracted_travel_time)
-    , retracted_travel_time(retracted_travel_time)
-    , material(material)
-    {
-    }
-
-    /*!
-     * Basic constructor initializing all estimates to zero.
-     */
-    TimeMaterialEstimates()
-    : extrude_time(0.0)
-    , unretracted_travel_time(0.0)
-    , retracted_travel_time(0.0)
-    , material(0.0)
-    {
-    }
-
-    /*!
-     * Set all estimates to zero.
-     */
-    void reset() 
-    {
-        extrude_time = 0.0;
-        unretracted_travel_time = 0.0;
-        retracted_travel_time = 0.0;
-        material = 0.0;
-    }
-
-    /*!
-     * Pointwise addition of estimate stats
-     * 
-     * \param other The estimates to add to these estimates.
-     * \return The resulting estimates
-     */
-    TimeMaterialEstimates operator+(const TimeMaterialEstimates& other)
-    {
-        return TimeMaterialEstimates(extrude_time+other.extrude_time, unretracted_travel_time+other.unretracted_travel_time, retracted_travel_time+other.retracted_travel_time, material+other.material);
-    }
-
-    /*!
-     * In place pointwise addition of estimate stats
-     * 
-     * \param other The estimates to add to these estimates.
-     * \return These estimates
-     */
-    TimeMaterialEstimates& operator+=(const TimeMaterialEstimates& other)
-    {
-        extrude_time += other.extrude_time;
-        unretracted_travel_time += other.unretracted_travel_time;
-        retracted_travel_time += other.retracted_travel_time;
-        material += other.material;
-        return *this;
-    }
-
-    /*!
-     * \brief Subtracts the specified estimates from these estimates and returns
-     * the result.
-     * 
-     * Each of the estimates in this class are individually subtracted.
-     * 
-     * \param other The estimates to subtract from these estimates.
-     * \return These estimates with the specified estimates subtracted.
-     */
-    TimeMaterialEstimates operator-(const TimeMaterialEstimates& other);
-
-    /*!
-     * \brief Subtracts the specified elements from these estimates.
-     * 
-     * This causes the estimates in this instance to change. Each of the
-     * estimates in this class are individually subtracted.
-     * 
-     * \param other The estimates to subtract from these estimates.
-     * \return A reference to this instance.
-     */
-    TimeMaterialEstimates& operator-=(const TimeMaterialEstimates& other);
-
-    /*!
-     * Get total time estimate. The different time estimate member values added together.
-     * 
-     * \return the total of all different time estimate values 
-     */
-    double getTotalTime() const
-    {
-        return extrude_time + unretracted_travel_time + retracted_travel_time;
-    }
-
-    /*!
-     * Get the total time during which the head is not retracted.
-     * 
-     * This includes extrusion time and non-retracted travel time
-     * 
-     * \return the total time during which the head is not retracted.
-     */
-    double getTotalUnretractedTime() const
-    {
-        return extrude_time + unretracted_travel_time;
-    }
-
-    /*!
-     * Get the total travel time.
-     * 
-     * This includes the retracted travel time as well as the unretracted travel time.
-     * 
-     * \return the total travel time.
-     */
-    double getTravelTime() const
-    {
-        return retracted_travel_time + unretracted_travel_time;
-    }
-
-    /*!
-     * Get the extrusion time.
-     * 
-     * \return extrusion time.
-     */
-    double getExtrudeTime() const
-    {
-        return extrude_time;
-    }
-
-    /*!
-     * Get the amount of material used in mm^3.
-     * 
-     * \return amount of material
-     */
-    double getMaterial() const
-    {
-        return material;
-    }
-};
-
-/*!
- * A class for representing a planned path.
- * 
- * A path consists of several segments of the same type of movement: retracted travel, infill extrusion, etc.
- * 
- * This is a compact premature representation in which are line segments have the same config, i.e. the config of this path.
- * 
- * In the final representation (gcode) each line segment may have different properties, 
- * which are added when the generated GCodePaths are processed.
- */
-class GCodePath
-{
-public:
-    GCodePathConfig* config; //!< The configuration settings of the path.
-    SpaceFillType space_fill_type; //!< The type of space filling of which this path is a part
-    float flow; //!< A type-independent flow configuration (used for wall overlap compensation)
-    bool retract; //!< Whether the path is a move path preceded by a retraction move; whether the path is a retracted move path. 
-    std::vector<Point> points; //!< The points constituting this path.
-    bool done;//!< Path is finished, no more moves should be added, and a new path should be started instead of any appending done to this one.
-
-    bool spiralize; //!< Whether to gradually increment the z position during the printing of this path. A sequence of spiralized paths should start at the given layer height and end in one layer higher.
-
-    TimeMaterialEstimates estimates; //!< Naive time and material estimates
-
-    /*!
-     * Whether this config is the config of a travel path.
-     * 
-     * \return Whether this config is the config of a travel path.
-     */
-    bool isTravelPath()
-    {
-        return config->isTravelPath();
-    }
-
-    /*!
-     * Get the material flow in mm^3 per mm traversed.
-     * 
-     * \warning Can only be called after the layer height has been set (which is done while writing the gcode!)
-     * 
-     * \return The flow
-     */
-    double getExtrusionMM3perMM()
-    {
-        return flow * config->getExtrusionMM3perMM();
-    }
-    
-    /*!
-     * Get the actual line width (modulated by the flow)
-     * \return the actual line width as shown in layer view
-     */
-    int getLineWidth()
-    {
-        return flow * config->getLineWidth() * config->getFlowPercentage() / 100.0;
-    }
-};
+class GCodePlanner; // forward declaration so that ExtruderPlan can be a friend
+class LayerPlanBuffer; // forward declaration so that ExtruderPlan can be a friend
 
 /*!
  * An extruder plan contains all planned paths (GCodePath) pertaining to a single extruder train.
@@ -266,27 +35,30 @@ public:
  */
 class ExtruderPlan
 {
-public:
+    friend class GCodePlanner; // TODO: GCodePlanner still does a lot which should actually be handled in this class.
+    friend class LayerPlanBuffer; // TODO: LayerPlanBuffer handles paths directly
+protected:
     std::vector<GCodePath> paths; //!< The paths planned for this extruder
     std::list<NozzleTempInsert> inserts; //!< The nozzle temperature command inserts, to be inserted in between paths
 
     int extruder; //!< The extruder used for this paths in the current plan.
-    double required_temp; //!< The required temperature at the start of this extruder plan.
+    double heated_pre_travel_time; //!< The time at the start of this ExtruderPlan during which the head travels and has a temperature of initial_print_temperature
+    double initial_printing_temperature; //!< The required temperature at the start of this extruder plan.
+    double printing_temperature; //!< The normal temperature for printing this extruder plan. That start and end of this extruder plan may deviate because of the initial and final print temp
+    std::optional<std::list<NozzleTempInsert>::iterator> printing_temperature_command; //!< The command to heat from the printing temperature of this extruder plan to the printing temperature of the next extruder plan (if it has the same extruder).
+    std::optional<double> prev_extruder_standby_temp; //!< The temperature to which to set the previous extruder. Not used if the previous extruder plan was the same extruder.
 
     TimeMaterialEstimates estimates; //!< Accumulated time and material estimates for all planned paths within this extruder plan.
-
+public:
     /*!
      * Simple contructor.
      * 
      * \warning Doesn't set the required temperature yet.
      * 
      * \param extruder The extruder number for which this object is a plan.
+     * \param start_position The position the head is when this extruder plan starts
      */
-    ExtruderPlan(int extruder)
-    : extruder(extruder)
-    , required_temp(-1)
-    {
-    }
+    ExtruderPlan(int extruder, Point start_position, int layer_nr, bool is_initial_layer, int layer_thickness, const FanSpeedLayerTimeSettings& fan_speed_layer_time_settings, const RetractionConfig& retraction_config);
 
     /*!
      * Add a new Insert, constructed with the given arguments
@@ -335,6 +107,97 @@ public:
             inserts.pop_front();
         }
     }
+
+    /*!
+     * Applying speed corrections for minimal layer times and determine the fanSpeed. 
+     * 
+     * \param force_minimal_layer_time Whether we should apply speed changes and perhaps a head lift in order to meet the minimal layer time
+     */
+    void processFanSpeedAndMinimalLayerTime(bool force_minimal_layer_time);
+
+    /*!
+     * Set the extrude speed factor. This is used for printing slower than normal.
+     * 
+     * Leaves the extrusion speed as is for values of 1.0
+     * 
+     * \param speedFactor The factor by which to alter the extrusion move speed
+     */
+    void setExtrudeSpeedFactor(double speedFactor);
+
+    /*!
+     * Get the extrude speed factor. This is used for printing slower than normal.
+     * 
+     * \return The factor by which to alter the extrusion move speed
+     */
+    double getExtrudeSpeedFactor();
+
+    /*!
+     * Set the travel speed factor. This is used for performing non-extrusion travel moves slower than normal.
+     * 
+     * Leaves the extrusion speed as is for values of 1.0
+     * 
+     * \param speedFactor The factor by which to alter the non-extrusion move speed
+     */
+    void setTravelSpeedFactor(double speedFactor);
+
+    /*!
+     * Get the travel speed factor. This is used for travelling slower than normal.
+     * 
+     * Limited to at most 1.0
+     * 
+     * \return The factor by which to alter the non-extrusion move speed
+     */
+    double getTravelSpeedFactor();
+
+    /*!
+     * Get the fan speed computed for this extruder plan
+     * 
+     * \warning assumes ExtruderPlan::processFanSpeedAndMinimalLayerTime has already been called
+     * 
+     * \return The fan speed computed in processFanSpeedAndMinimalLayerTime
+     */
+    double getFanSpeed();
+protected:
+
+    Point start_position; //!< The position the print head was at at the start of this extruder plan
+
+    int layer_nr; //!< The layer number at which we are currently printing.
+    bool is_initial_layer; //!< Whether this extruder plan is printed on the very first layer (which might be raft)
+
+    int layer_thickness; //!< The thickness of this layer in Z-direction
+
+    const FanSpeedLayerTimeSettings& fan_speed_layer_time_settings; //!< The fan speed and layer time settings used to limit this extruder plan
+
+    const RetractionConfig& retraction_config; //!< The retraction settings for the extruder of this plan
+
+    double extrudeSpeedFactor; //!< The factor by which to alter the extrusion move speed
+    double travelSpeedFactor; //!< The factor by which to alter the non-extrusion move speed
+
+    double extraTime; //!< Extra waiting time at the and of this extruder plan, so that the filament can cool
+    double totalPrintTime; //!< The total naive time estimate for this extruder plan
+
+    double fan_speed; //!< The fan speed to be used during this extruder plan
+
+    /*!
+     * Set the fan speed to be used while printing this extruder plan
+     * 
+     * \param fan_speed The speed for the fan
+     */
+    void setFanSpeed(double fan_speed);
+
+    /*!
+     * Force the minimal layer time to hold by slowing down and lifting the head if required.
+     * 
+     */
+    void forceMinimalLayerTime(double minTime, double minimalSpeed, double travelTime, double extrusionTime);
+
+    /*!
+     * Compute naive time estimates (without accounting for slow down at corners etc.) and naive material estimates (without accounting for MergeInfillLines)
+     * and store them in each ExtruderPlan and each GCodePath.
+     * 
+     * \return the total estimates of this layer
+     */
+    TimeMaterialEstimates computeNaiveTimeEstimates();
 };
 
 class LayerPlanBuffer; // forward declaration to prevent circular dependency
@@ -352,10 +215,28 @@ class LayerPlanBuffer; // forward declaration to prevent circular dependency
 class GCodePlanner : public NoCopy
 {
     friend class LayerPlanBuffer;
+    friend class GCodePlannerTest;
+public:
+    /*!
+     * The state which is passed along between layer plans.
+     * This is what a \ref GCodePlanner delivers to further computation in \ref FffGcodeWriter
+     * This is the state which is currently planned, not which is written to gcode.
+     */
+    struct PlanningState
+    {
+        Point last_position; //!< The position of the head before planning the next layer
+        int current_extruder; //!< The extruder train in use before planning the next layer
+        bool is_inside_mesh_layer_part; //!< Whether the last position was inside a layer part (used in combing)
+    };
 private:
-    SliceDataStorage& storage; //!< The polygon data obtained from FffPolygonProcessor
+    const SliceDataStorage& storage; //!< The polygon data obtained from FffPolygonProcessor
 
+public:
+    const PathConfigStorage configs_storage; //!< The line configs for this layer for each feature type
+
+private:
     int layer_nr; //!< The layer number of this layer plan
+    int is_initial_layer; //!< Whether this is the first layer (which might be raft)
     
     int z; 
     
@@ -363,25 +244,20 @@ private:
     
     Point start_position;
     Point lastPosition;
-    
+
+    bool has_prime_tower_planned;
+
     std::vector<ExtruderPlan> extruder_plans; //!< should always contain at least one ExtruderPlan
-    
+
+    int last_extruder_previous_layer; //!< The last id of the extruder with which was printed in the previous layer
+    SettingsBaseVirtual* last_planned_extruder_setting_base; //!< The setting base of the last planned extruder.
     bool was_inside; //!< Whether the last planned (extrusion) move was inside a layer part
     bool is_inside; //!< Whether the destination of the next planned travel move is inside a layer part
     Polygons comb_boundary_inside; //!< The boundary within which to comb, or to move into when performing a retraction.
     Comb* comb;
 
-    RetractionConfig* last_retraction_config;
-    
-    FanSpeedLayerTimeSettings& fan_speed_layer_time_settings;
 
-    double extrudeSpeedFactor;
-    double travelSpeedFactor;
-    
-    double fan_speed;
-    
-    double extraTime;
-    double totalPrintTime;
+    const std::vector<FanSpeedLayerTimeSettings>& fan_speed_layer_time_settings_per_extruder;
     
 private:
     /*!
@@ -394,8 +270,9 @@ private:
      * \param spiralize Whether to gradually increase the z while printing. (Note that this path may be part of a sequence of spiralized paths, forming one polygon)
      * \return A path with the given config which is now the last path in GCodePlanner::paths
      */
-    GCodePath* getLatestPathWithConfig(GCodePathConfig* config, SpaceFillType space_fill_type, float flow = 1.0, bool spiralize = false);
-    
+    GCodePath* getLatestPathWithConfig(const GCodePathConfig* config, SpaceFillType space_fill_type, float flow = 1.0, bool spiralize = false);
+
+public:
     /*!
      * Force GCodePlanner::getLatestPathWithConfig to return a new path.
      * 
@@ -407,17 +284,24 @@ private:
      * - when changing extruder, the same travel config is used, but its extruder field is changed.
      */
     void forceNewPathStart();
-public:
+
     /*!
      * 
+     * \param fan_speed_layer_time_settings_per_extruder The fan speed and layer time settings for each extruder.
      * \param travel_avoid_other_parts Whether to avoid other layer parts when travaeling through air.
      * \param travel_avoid_distance The distance by which to avoid other layer parts when traveling through air.
      * \param last_position The position of the head at the start of this gcode layer
      * \param combing_mode Whether combing is enabled and full or within infill only.
      */
-    GCodePlanner(SliceDataStorage& storage, unsigned int layer_nr, int z, int layer_height, Point last_position, int current_extruder, bool is_inside_mesh, FanSpeedLayerTimeSettings& fan_speed_layer_time_settings, CombingMode combing_mode, int64_t comb_boundary_offset, bool travel_avoid_other_parts, int64_t travel_avoid_distance);
+    GCodePlanner(const SliceDataStorage& storage, int layer_nr, int z, int layer_height, PlanningState last_planned_state, const std::vector<FanSpeedLayerTimeSettings>& fan_speed_layer_time_settings_per_extruder, CombingMode combing_mode, int64_t comb_boundary_offset, bool travel_avoid_other_parts, int64_t travel_avoid_distance);
     ~GCodePlanner();
 
+    void overrideFanSpeeds(double speed);
+    /*!
+     * Get the settings base of the last extruder planned.
+     * \return the settings base of the last extruder planned.
+     */
+    SettingsBaseVirtual* getLastPlannedExtruderTrainSettings();
 private:
     /*!
      * Compute the boundary within which to comb, or to move into when performing a retraction.
@@ -427,12 +311,21 @@ private:
     Polygons computeCombBoundaryInside(CombingMode combing_mode);
 
 public:
-    int getLayerNr()
+    int getLayerNr() const
     {
         return layer_nr;
     }
-    
-    Point getLastPosition()
+
+    PlanningState getPlanningState() const
+    {
+        PlanningState ret;
+        ret.last_position = lastPosition;
+        ret.current_extruder = getExtruder();
+        ret.is_inside_mesh_layer_part = was_inside;
+        return ret;
+    }
+
+    Point getLastPosition() const
     {
         return lastPosition;
     }
@@ -440,24 +333,27 @@ public:
     /*!
      * return whether the last position planned was inside the mesh (used in combing)
      */
-    bool getIsInsideMesh()
+    bool getIsInsideMesh() const
     {
         return was_inside;
     }
-    /*!
-     * send a polygon through the command socket from the previous point to the given point
-     */
-    void sendPolygon(PrintFeatureType print_feature_type, Point from, Point to, int line_width)
+
+    bool getPrimeTowerIsPlanned() const
     {
-        if (CommandSocket::isInstantiated()) 
-        {
-            // we should send this travel as a non-retraction move
-            cura::Polygons pathPoly;
-            PolygonRef path = pathPoly.newPoly();
-            path.add(from);
-            path.add(to);
-            CommandSocket::getInstance()->sendPolygons(print_feature_type, layer_nr, pathPoly, line_width);
-        }
+        return has_prime_tower_planned;
+    }
+
+    void setPrimeTowerIsPlanned()
+    {
+        has_prime_tower_planned = true;
+    }
+
+    /*!
+     * send a line segment through the command socket from the previous point to the given point \p to
+     */
+    void sendLineTo(PrintFeatureType print_feature_type, Point to, int line_width) const
+    {
+        CommandSocket::sendLineTo(print_feature_type, to, line_width);
     }
 
     /*!
@@ -467,39 +363,24 @@ public:
     * Features like prime tower and support are considered outside.
     */
     void setIsInside(bool going_to_comb);
-    
+
+    /*!
+     * Plan a switch to a new extruder
+     * 
+     * \param extruder The extruder number to which to switch
+     * \return whether the extruder has changed
+     */
     bool setExtruder(int extruder);
 
     /*!
      * Get the last planned extruder.
      */
-    int getExtruder()
+    int getExtruder() const
     {
         return extruder_plans.back().extruder;
     }
 
-    void setExtrudeSpeedFactor(double speedFactor)
-    {
-        this->extrudeSpeedFactor = speedFactor;
-    }
-    double getExtrudeSpeedFactor()
-    {
-        return this->extrudeSpeedFactor;
-    }
-    void setTravelSpeedFactor(double speedFactor)
-    {
-        if (speedFactor < 1) speedFactor = 1.0;
-        this->travelSpeedFactor = speedFactor;
-    }
-    double getTravelSpeedFactor()
-    {
-        return this->travelSpeedFactor;
-    }
-    
-    void setFanSpeed(double _fan_speed)
-    {
-        fan_speed = _fan_speed;
-    }
+
     
     /*!
      * Add a travel path to a certain point, retract if needed and when avoiding boundary crossings:
@@ -507,7 +388,7 @@ public:
      * 
      * \param p The point to travel to
      */
-    void addTravel(Point p);
+    GCodePath& addTravel(Point p);
     
     /*!
      * Add a travel path to a certain point and retract if needed.
@@ -517,7 +398,14 @@ public:
      * \param p The point to travel to
      * \param path (optional) The travel path to which to add the point \p p
      */
-    void addTravel_simple(Point p, GCodePath* path = nullptr);
+    GCodePath& addTravel_simple(Point p, GCodePath* path = nullptr);
+
+    /*!
+     * Plan a prime poop at the current location.
+     * 
+     * \warning A nonretracted move is introduced so that the LayerPlanBuffer classifies this move as an extrusion move.
+     */
+    void planPrime();
 
     /*!
      * Add an extrusion move to a certain point, optionally with a different flow than the one in the \p config.
@@ -528,7 +416,7 @@ public:
      * \param flow A modifier of the extrusion width which would follow from the \p config
      * \param spiralize Whether to gradually increase the z while printing. (Note that this path may be part of a sequence of spiralized paths, forming one polygon)
      */
-    void addExtrusionMove(Point p, GCodePathConfig* config, SpaceFillType space_fill_type, float flow = 1.0, bool spiralize = false);
+    void addExtrusionMove(Point p, const GCodePathConfig* config, SpaceFillType space_fill_type, float flow = 1.0, bool spiralize = false);
 
     /*!
      * Add polygon to the gcode starting at vertex \p startIdx
@@ -536,9 +424,10 @@ public:
      * \param startIdx The index of the starting vertex of the \p polygon
      * \param config The config with which to print the polygon lines
      * \param wall_overlap_computation The wall overlap compensation calculator for each given segment (optionally nullptr)
+     * \param wall_0_wipe_dist The distance to travel along the polygon after it has been laid down, in order to wipe the start and end of the wall together
      * \param spiralize Whether to gradually increase the z height from the normal layer height to the height of the next layer over this polygon
      */
-    void addPolygon(PolygonRef polygon, int startIdx, GCodePathConfig* config, WallOverlapComputation* wall_overlap_computation = nullptr, bool spiralize = false);
+    void addPolygon(ConstPolygonRef polygon, int startIdx, const GCodePathConfig* config, WallOverlapComputation* wall_overlap_computation = nullptr, coord_t wall_0_wipe_dist = 0, bool spiralize = false);
 
     /*!
      * Add polygons to the gcode with optimized order.
@@ -553,9 +442,11 @@ public:
      * \param config The config with which to print the polygon lines
      * \param wall_overlap_computation The wall overlap compensation calculator for each given segment (optionally nullptr)
      * \param z_seam_type The seam type / poly start optimizer
+     * \param z_seam_pos The location near where to start each part in case \p z_seam_type is 'back'
+     * \param wall_0_wipe_dist The distance to travel along each polygon after it has been laid down, in order to wipe the start and end of the wall together
      * \param spiralize Whether to gradually increase the z height from the normal layer height to the height of the next layer over each polygon printed
      */
-    void addPolygonsByOptimizer(Polygons& polygons, GCodePathConfig* config, WallOverlapComputation* wall_overlap_computation = nullptr, EZSeamType z_seam_type = EZSeamType::SHORTEST, bool spiralize = false);
+    void addPolygonsByOptimizer(const Polygons& polygons, const GCodePathConfig* config, WallOverlapComputation* wall_overlap_computation = nullptr, EZSeamType z_seam_type = EZSeamType::SHORTEST, Point z_seam_pos = Point(0, 0), coord_t wall_0_wipe_dist = 0, bool spiralize = false);
 
     /*!
      * Add lines to the gcode with optimized order.
@@ -564,37 +455,25 @@ public:
      * \param space_fill_type The type of space filling used to generate the line segments (should be either Lines or PolyLines!)
      * \param wipe_dist (optional) the distance wiped without extruding after laying down a line.
      */
-    void addLinesByOptimizer(Polygons& polygons, GCodePathConfig* config, SpaceFillType space_fill_type, int wipe_dist = 0);
+    void addLinesByOptimizer(const Polygons& polygons, const GCodePathConfig* config, SpaceFillType space_fill_type, int wipe_dist = 0);
 
     /*!
-     * Compute naive time estimates (without accountign for slow down at corners etc.) and naive material estimates (without accounting for MergeInfillLines)
+     * Compute naive time estimates (without accounting for slow down at corners etc.) and naive material estimates (without accounting for MergeInfillLines)
      * and store them in each ExtruderPlan and each GCodePath.
      * 
+     * \warning This function recomputes values which are already computed if you've called processFanSpeedAndMinimalLayerTime
+     * 
      * \return the total estimates of this layer
      */
     TimeMaterialEstimates computeNaiveTimeEstimates();
     
-    void forceMinimalLayerTime(double minTime, double minimalSpeed, double travelTime, double extrusionTime);
-    
     /*!
      * Write the planned paths to gcode
      * 
      * \param gcode The gcode to write the planned paths to
      */
     void writeGCode(GCodeExport& gcode);
-    
-    /*!
-     * Complete all GcodePathConfig s by 
-     * - altering speed to conform to speed_layer_0
-     * - setting the layer_height (and thereby computing the extrusionMM3perMM)
-     */
-    void completeConfigs();
-    
-    /*!
-     * Interpolate between the initial layer speeds and the eventual speeds.
-     */
-    void processInitialLayersSpeedup();
-    
+
     /*!
      * Whether the current retracted path is to be an extruder switch retraction.
      * This function is used to avoid a G10 S1 after a G10.
@@ -622,22 +501,6 @@ public:
      */
     bool writePathWithCoasting(GCodeExport& gcode, unsigned int extruder_plan_idx, unsigned int path_idx, int64_t layerThickness, double coasting_volume, double coasting_speed, double coasting_min_volume);
 
-    /*!
-     * Write a retraction: either an extruder switch retraction or a normal retraction based on the last extrusion paths retraction config.
-     * \param gcode The gcode to write the planned paths to
-     * \param extruder_plan_idx The index of the current extruder plan
-     * \param path_idx_travel_after Index in GCodePlanner::paths to the travel move before which to do the retraction
-     */
-    void writeRetraction(GCodeExport& gcode, unsigned int extruder_plan_idx, unsigned int path_idx_travel_after);
-    
-    /*!
-     * Write a retraction: either an extruder switch retraction or a normal retraction based on the given retraction config.
-     * \param gcode The gcode to write the planned paths to
-     * \param extruder_switch_retract Whether to write an extruder switch retract
-     * \param retraction_config The config used.
-     */
-    void writeRetraction(GCodeExport& gcode, bool extruder_switch_retract, RetractionConfig* retraction_config);
-    
     /*!
      * Applying speed corrections for minimal layer times and determine the fanSpeed. 
      */

src/infill.cpp

@@ -6,11 +6,21 @@
 
 namespace cura {
 
-void Infill::generate(Polygons& result_polygons, Polygons& result_lines)
+int Infill::computeScanSegmentIdx(int x, int line_width)
+{
+    if (x < 0)
+    {
+        return (x + 1) / line_width - 1;
+        // - 1 because -1 belongs to scansegment -1
+        // + 1 because -line_width belongs to scansegment -1
+    }
+    return x / line_width;
+}
+
+void Infill::generate(Polygons& result_polygons, Polygons& result_lines, const SliceMeshStorage* mesh)
 {
     if (in_outline.size() == 0) return;
     if (line_distance == 0) return;
-    const Polygons* outline = &in_outline;
     Polygons outline_offsetted;
     switch(pattern)
     {
@@ -18,57 +28,142 @@ void Infill::generate(Polygons& result_polygons, Polygons& result_lines)
         generateGridInfill(result_lines);
         break;
     case EFillMethod::LINES:
-        generateLineInfill(result_lines, line_distance, fill_angle);
+        generateLineInfill(result_lines, line_distance, fill_angle, 0);
+        break;
+    case EFillMethod::CUBIC:
+        generateCubicInfill(result_lines);
+        break;
+    case EFillMethod::TETRAHEDRAL:
+        generateTetrahedralInfill(result_lines);
         break;
     case EFillMethod::TRIANGLES:
         generateTriangleInfill(result_lines);
         break;
     case EFillMethod::CONCENTRIC:
-        outline_offsetted = in_outline.offset(outline_offset - infill_line_width / 2); // - infill_line_width / 2 cause generateConcentricInfill expects [outline] to be the outer most polygon instead of the outer outline 
-        outline = &outline_offsetted;
-        generateConcentricInfill(*outline, result_polygons, line_distance);
+        generateConcentricInfill(result_polygons, line_distance);
+        break;
+    case EFillMethod::CONCENTRIC_3D:
+        generateConcentric3DInfill(result_polygons);
         break;
     case EFillMethod::ZIG_ZAG:
         generateZigZagInfill(result_lines, line_distance, fill_angle, connected_zigzags, use_endpieces);
         break;
+    case EFillMethod::CUBICSUBDIV:
+        if (!mesh)
+        {
+            logError("Cannot generate Cubic Subdivision infill without a mesh!\n");
+            break;
+        }
+        generateCubicSubDivInfill(result_lines, *mesh);
+        break;
     default:
         logError("Fill pattern has unknown value.\n");
         break;
     }
 }
 
-void Infill::generateConcentricInfill(Polygons outline, Polygons& result, int inset_value)
+void Infill::generateConcentricInfill(Polygons& result, int inset_value)
 {
-    while(outline.size() > 0)
+    Polygons first_concentric_wall = in_outline.offset(outline_offset - line_distance + infill_line_width / 2); // - infill_line_width / 2 cause generateConcentricInfill expects [outline] to be the outer most polygon instead of the outer outline
+
+    if (perimeter_gaps)
     {
-        result.add(outline);
-        outline = outline.offset(-inset_value);
-    } 
+        const Polygons inner = first_concentric_wall.offset(infill_line_width / 2 + perimeter_gaps_extra_offset);
+        const Polygons gaps_here = in_outline.difference(inner);
+        perimeter_gaps->add(gaps_here);
+    }
+    generateConcentricInfill(first_concentric_wall, result, inset_value);
 }
 
+void Infill::generateConcentricInfill(Polygons& first_concentric_wall, Polygons& result, int inset_value)
+{
+    result.add(first_concentric_wall);
+    Polygons* prev_inset = &first_concentric_wall;
+    Polygons next_inset;
+    while (prev_inset->size() > 0)
+    {
+        next_inset = prev_inset->offset(-inset_value);
+        result.add(next_inset);
+        if (perimeter_gaps)
+        {
+            const Polygons outer = prev_inset->offset(-infill_line_width / 2 - perimeter_gaps_extra_offset);
+            const Polygons inner = next_inset.offset(infill_line_width / 2);
+            const Polygons gaps_here = outer.difference(inner);
+            perimeter_gaps->add(gaps_here);
+        }
+        prev_inset = &next_inset;
+    }
+}
+
+void Infill::generateConcentric3DInfill(Polygons& result)
+{
+    int period = line_distance * 2;
+    int shift = int64_t(one_over_sqrt_2 * z) % period;
+    shift = std::min(shift, period - shift); // symmetry due to the fact that we are applying the shift in both directions
+    shift = std::min(shift, period / 2 - infill_line_width / 2); // don't put lines too close to each other
+    shift = std::max(shift, infill_line_width / 2); // don't put lines too close to each other
+    Polygons first_wall;
+    // in contrast to concentric infill we dont do "- infill_line_width / 2" cause this is already handled by the max two lines above
+    first_wall = in_outline.offset(outline_offset - shift);
+    generateConcentricInfill(first_wall, result, period);
+    first_wall = in_outline.offset(outline_offset - period + shift);
+    generateConcentricInfill(first_wall, result, period);
+}
 
 void Infill::generateGridInfill(Polygons& result)
 {
-    generateLineInfill(result, line_distance, fill_angle);
-    generateLineInfill(result, line_distance, fill_angle + 90);
+    generateLineInfill(result, line_distance, fill_angle, 0);
+    generateLineInfill(result, line_distance, fill_angle + 90, 0);
+}
+
+void Infill::generateCubicInfill(Polygons& result)
+{
+    int64_t shift = one_over_sqrt_2 * z;
+    generateLineInfill(result, line_distance, fill_angle, shift);
+    generateLineInfill(result, line_distance, fill_angle + 120, shift);
+    generateLineInfill(result, line_distance, fill_angle + 240, shift);
+}
+
+void Infill::generateTetrahedralInfill(Polygons& result)
+{
+    int period = line_distance * 2;
+    int shift = int64_t(one_over_sqrt_2 * z) % period;
+    shift = std::min(shift, period - shift); // symmetry due to the fact that we are applying the shift in both directions
+    shift = std::min(shift, period / 2 - infill_line_width / 2); // don't put lines too close to each other
+    shift = std::max(shift, infill_line_width / 2); // don't put lines too close to each other
+    generateLineInfill(result, period, fill_angle, shift);
+    generateLineInfill(result, period, fill_angle, -shift);
+    generateLineInfill(result, period, fill_angle + 90, shift);
+    generateLineInfill(result, period, fill_angle + 90, -shift);
 }
 
 void Infill::generateTriangleInfill(Polygons& result)
 {
-    generateLineInfill(result, line_distance, fill_angle);
-    generateLineInfill(result, line_distance, fill_angle + 60);
-    generateLineInfill(result, line_distance, fill_angle + 120);
+    generateLineInfill(result, line_distance, fill_angle, 0);
+    generateLineInfill(result, line_distance, fill_angle + 60, 0);
+    generateLineInfill(result, line_distance, fill_angle + 120, 0);
 }
 
-void Infill::addLineInfill(Polygons& result, const PointMatrix& rotation_matrix, const int scanline_min_idx, const int line_distance, const AABB boundary, std::vector<std::vector<int64_t>>& cut_list)
+void Infill::generateCubicSubDivInfill(Polygons& result, const SliceMeshStorage& mesh)
 {
-    auto addLine = [&](Point from, Point to)
-    {
-        PolygonRef p = result.newPoly();
-        p.add(rotation_matrix.unapply(from));
-        p.add(rotation_matrix.unapply(to));
-    };
+    Polygons uncropped;
+    mesh.base_subdiv_cube->generateSubdivisionLines(z, uncropped);
+    addLineSegmentsInfill(result, uncropped);
+}
 
+void Infill::addLineSegmentsInfill(Polygons& result, Polygons& input)
+{
+    ClipperLib::PolyTree interior_segments_tree = in_outline.lineSegmentIntersection(input);
+    ClipperLib::Paths interior_segments;
+    ClipperLib::OpenPathsFromPolyTree(interior_segments_tree, interior_segments);
+    for (uint64_t idx = 0; idx < interior_segments.size(); idx++)
+    {
+        result.addLine(interior_segments[idx][0], interior_segments[idx][1]);
+    }
+}
+
+void Infill::addLineInfill(Polygons& result, const PointMatrix& rotation_matrix, const int scanline_min_idx, const int line_distance, const AABB boundary, std::vector<std::vector<int64_t>>& cut_list, int64_t shift)
+{
     auto compare_int64_t = [](const void* a, const void* b)
     {
         int64_t n = (*(int64_t*)a) - (*(int64_t*)b);
@@ -84,7 +179,7 @@ void Infill::addLineInfill(Polygons& result, const PointMatrix& rotation_matrix,
     };
 
     int scanline_idx = 0;
-    for(int64_t x = scanline_min_idx * line_distance; x < boundary.max.X; x += line_distance)
+    for(int64_t x = scanline_min_idx * line_distance + shift; x < boundary.max.X; x += line_distance)
     {
         std::vector<int64_t>& crossings = cut_list[scanline_idx];
         qsort(crossings.data(), crossings.size(), sizeof(int64_t), compare_int64_t);
@@ -94,25 +189,23 @@ void Infill::addLineInfill(Polygons& result, const PointMatrix& rotation_matrix,
             { // segment is too short to create infill
                 continue;
             }
-            addLine(Point(x, crossings[crossing_idx]), Point(x, crossings[crossing_idx + 1]));
+            result.addLine(rotation_matrix.unapply(Point(x, crossings[crossing_idx])), rotation_matrix.unapply(Point(x, crossings[crossing_idx + 1])));
         }
         scanline_idx += 1;
     }
 }
 
-void Infill::generateLineInfill(Polygons& result, int line_distance, const double& fill_angle)
+void Infill::generateLineInfill(Polygons& result, int line_distance, const double& fill_angle, int64_t shift)
 {
     PointMatrix rotation_matrix(fill_angle);
     NoZigZagConnectorProcessor lines_processor(rotation_matrix, result);
     bool connected_zigzags = false;
-    bool safe_outline_offset = false;
-    generateLinearBasedInfill(outline_offset, safe_outline_offset, result, line_distance, rotation_matrix, lines_processor, connected_zigzags);
+    generateLinearBasedInfill(outline_offset, result, line_distance, rotation_matrix, lines_processor, connected_zigzags, shift);
 }
 
 
 void Infill::generateZigZagInfill(Polygons& result, const int line_distance, const double& fill_angle, const bool connected_zigzags, const bool use_endpieces)
 {
-    bool safe_outline_offset = true;
 
     PointMatrix rotation_matrix(fill_angle);
     if (use_endpieces)
@@ -120,18 +213,18 @@ void Infill::generateZigZagInfill(Polygons& result, const int line_distance, con
         if (connected_zigzags)
         {
             ZigzagConnectorProcessorConnectedEndPieces zigzag_processor(rotation_matrix, result);
-            generateLinearBasedInfill(outline_offset - infill_line_width / 2, safe_outline_offset, result, line_distance, rotation_matrix, zigzag_processor, connected_zigzags);
+            generateLinearBasedInfill(outline_offset - infill_line_width / 2, result, line_distance, rotation_matrix, zigzag_processor, connected_zigzags, 0);
         }
         else
         {
             ZigzagConnectorProcessorDisconnectedEndPieces zigzag_processor(rotation_matrix, result);
-            generateLinearBasedInfill(outline_offset - infill_line_width / 2, safe_outline_offset, result, line_distance, rotation_matrix, zigzag_processor, connected_zigzags);
+            generateLinearBasedInfill(outline_offset - infill_line_width / 2, result, line_distance, rotation_matrix, zigzag_processor, connected_zigzags, 0);
         }
     }
     else 
     {
         ZigzagConnectorProcessorNoEndPieces zigzag_processor(rotation_matrix, result);
-        generateLinearBasedInfill(outline_offset - infill_line_width / 2, safe_outline_offset, result, line_distance, rotation_matrix, zigzag_processor, connected_zigzags);
+        generateLinearBasedInfill(outline_offset - infill_line_width / 2, result, line_distance, rotation_matrix, zigzag_processor, connected_zigzags, 0);
     }
 }
 
@@ -158,7 +251,7 @@ void Infill::generateZigZagInfill(Polygons& result, const int line_distance, con
  * Edit: the term scansegment is wrong, since I call a boundary segment leaving from an even scanline to the left as belonging to an even scansegment, 
  *  while I also call a boundary segment leaving from an even scanline toward the right as belonging to an even scansegment.
  */
-void Infill::generateLinearBasedInfill(const int outline_offset, bool safe_outline_offset, Polygons& result, const int line_distance, const PointMatrix& rotation_matrix, ZigzagConnectorProcessor& zigzag_connector_processor, const bool connected_zigzags)
+void Infill::generateLinearBasedInfill(const int outline_offset, Polygons& result, const int line_distance, const PointMatrix& rotation_matrix, ZigzagConnectorProcessor& zigzag_connector_processor, const bool connected_zigzags, int64_t extra_shift)
 {
     if (line_distance == 0)
     {
@@ -168,19 +261,25 @@ void Infill::generateLinearBasedInfill(const int outline_offset, bool safe_outli
     {
         return;
     }
-    
+
+    int shift = extra_shift + this->shift;
+
     Polygons outline;
     if (outline_offset != 0)
     {
         outline = in_outline.offset(outline_offset);
+        if (perimeter_gaps)
+        {
+            perimeter_gaps->add(in_outline.difference(outline.offset(infill_line_width / 2 + perimeter_gaps_extra_offset)));
+        }
     }
     else
     {
         outline = in_outline;
     }
-    
-        outline = outline.offset(infill_overlap);
-    
+
+    outline = outline.offset(infill_overlap);
+
     if (outline.size() == 0)
     {
         return;
@@ -188,10 +287,19 @@ void Infill::generateLinearBasedInfill(const int outline_offset, bool safe_outli
 
     outline.applyMatrix(rotation_matrix);
 
+    if (shift < 0)
+    {
+        shift = line_distance - (-shift) % line_distance;
+    }
+    else
+    {
+        shift = shift % line_distance;
+    }
+
     AABB boundary(outline);
 
-    int scanline_min_idx = boundary.min.X / line_distance;
-    int line_count = (boundary.max.X + (line_distance - 1)) / line_distance - scanline_min_idx;
+    int scanline_min_idx = computeScanSegmentIdx(boundary.min.X - shift, line_distance);
+    int line_count = computeScanSegmentIdx(boundary.max.X - shift, line_distance) + 1 - scanline_min_idx;
 
     std::vector<std::vector<int64_t> > cut_list; // mapping from scanline to all intersections with polygon segments
 
@@ -217,26 +325,29 @@ void Infill::generateLinearBasedInfill(const int outline_offset, bool safe_outli
                 continue; 
             }
 
-            int scanline_idx0 = (p0.X + ((p0.X > 0)? -1 : -line_distance)) / line_distance; // -1 cause a linesegment on scanline x counts as belonging to scansegment x-1   ...
-            int scanline_idx1 = (p1.X + ((p1.X > 0)? -1 : -line_distance)) / line_distance; // -linespacing because a line between scanline -n and -n-1 belongs to scansegment -n-1 (for n=positive natural number)
+            int scanline_idx0;
+            int scanline_idx1;
             // this way of handling the indices takes care of the case where a boundary line segment ends exactly on a scanline:
             // in case the next segment moves back from that scanline either 2 or 0 scanline-boundary intersections are created
             // otherwise only 1 will be created, counting as an actual intersection
             int direction = 1;
-            if (p0.X > p1.X) 
+            if (p0.X < p1.X) 
             { 
-                direction = -1; 
-                scanline_idx1 += 1; // only consider the scanlines in between the scansegments
+                scanline_idx0 = computeScanSegmentIdx(p0.X - shift, line_distance) + 1; // + 1 cause we don't cross the scanline of the first scan segment
+                scanline_idx1 = computeScanSegmentIdx(p1.X - shift, line_distance); // -1 cause the vertex point is handled in the next segment (or not in the case which looks like >)
             }
             else
             {
-                scanline_idx0 += 1; // only consider the scanlines in between the scansegments
+                direction = -1; 
+                scanline_idx0 = computeScanSegmentIdx(p0.X - shift, line_distance); // -1 cause the vertex point is handled in the previous segment (or not in the case which looks like >)
+                scanline_idx1 = computeScanSegmentIdx(p1.X - shift, line_distance) + 1; // + 1 cause we don't cross the scanline of the first scan segment
             }
 
             for(int scanline_idx = scanline_idx0; scanline_idx != scanline_idx1 + direction; scanline_idx += direction)
             {
-                int x = scanline_idx * line_distance;
+                int x = scanline_idx * line_distance + shift;
                 int y = p1.Y + (p0.Y - p1.Y) * (x - p1.X) / (p0.X - p1.X);
+                assert(scanline_idx - scanline_min_idx >= 0 && scanline_idx - scanline_min_idx < int(cut_list.size()) && "reading infill cutlist index out of bounds!");
                 cut_list[scanline_idx - scanline_min_idx].push_back(y);
                 Point scanline_linesegment_intersection(x, y);
                 zigzag_connector_processor.registerScanlineSegmentIntersection(scanline_linesegment_intersection, scanline_idx % 2 == 0);
@@ -256,7 +367,7 @@ void Infill::generateLinearBasedInfill(const int outline_offset, bool safe_outli
         return;  // don't add connection if boundary already contains whole outline!
     }
 
-    addLineInfill(result, rotation_matrix, scanline_min_idx, line_distance, boundary, cut_list);
+    addLineInfill(result, rotation_matrix, scanline_min_idx, line_distance, boundary, cut_list, shift);
 }
 
 }//namespace cura

src/infill.h

@@ -12,6 +12,7 @@
 #include "infill/ZigzagConnectorProcessorEndPieces.h"
 #include "infill/ZigzagConnectorProcessorConnectedEndPieces.h"
 #include "infill/ZigzagConnectorProcessorDisconnectedEndPieces.h"
+#include "infill/SubDivCube.h"
 #include "utils/intpoint.h"
 #include "utils/AABB.h"
 
@@ -20,6 +21,8 @@ namespace cura
 
 class Infill 
 {
+    static constexpr int perimeter_gaps_extra_offset = 15; // extra offset so that the perimeter gaps aren't created everywhere due to rounding errors
+
     EFillMethod pattern; //!< the space filling pattern of the infill to generate
     const Polygons& in_outline; //!< a reference polygon for getting the actual area within which to generate infill (see outline_offset)
     int outline_offset; //!< Offset from Infill::in_outline to get the actual area within which to generate infill
@@ -27,11 +30,35 @@ class Infill
     int line_distance; //!< The distance between two infill lines / polygons
     int infill_overlap; //!< the distance by which to overlap with the actual area within which to generate infill
     double fill_angle; //!< for linear infill types: the angle of the infill lines (or the angle of the grid)
+    int64_t z; //!< height of the layer for which we generate infill
+    int64_t shift; //!< shift of the scanlines in the direction perpendicular to the fill_angle
+    Polygons* perimeter_gaps; //!< (optional output) The areas in between consecutive insets when Concentric infill is used.
     bool connected_zigzags; //!< (ZigZag) Whether endpieces of zigzag infill should be connected to the nearest infill line on both sides of the zigzag connector
     bool use_endpieces; //!< (ZigZag) Whether to include endpieces: zigzag connector segments from one infill line to itself
 
+    static constexpr double one_over_sqrt_2 = 0.7071067811865475244008443621048490392848359376884740; //!< 1.0 / sqrt(2.0)
 public:
-    Infill(EFillMethod pattern, const Polygons& in_outline, int outline_offset, int infill_line_width, int line_distance, int infill_overlap, double fill_angle, bool connected_zigzags = false, bool use_endpieces = false)
+    /*!
+     * \warning If \p perimeter_gaps is given, then the difference between the \p in_outline
+     * and the polygons which result from offsetting it by the \p outline_offset
+     * and then expanding it again by half the \p infill_line_width
+     * is added to the \p perimeter_gaps
+     * 
+     * \param[out] perimeter_gaps (optional output) The areas in between consecutive insets when Concentric infill is used.
+     */
+    Infill(EFillMethod pattern
+        , const Polygons& in_outline
+        , int outline_offset
+        , int infill_line_width
+        , int line_distance
+        , int infill_overlap
+        , double fill_angle
+        , int64_t z
+        , int64_t shift
+        , Polygons* perimeter_gaps = nullptr
+        , bool connected_zigzags = false
+        , bool use_endpieces = false
+    )
     : pattern(pattern)
     , in_outline(in_outline)
     , outline_offset(outline_offset)
@@ -39,6 +66,9 @@ public:
     , line_distance(line_distance)
     , infill_overlap(infill_overlap)
     , fill_angle(fill_angle)
+    , z(z)
+    , shift(shift)
+    , perimeter_gaps(perimeter_gaps)
     , connected_zigzags(connected_zigzags)
     , use_endpieces(use_endpieces)
     {
@@ -48,18 +78,46 @@ public:
      * 
      * \param result_polygons (output) The resulting polygons (from concentric infill)
      * \param result_lines (output) The resulting line segments (from linear infill types)
+     * \param mesh The mesh for which to geenrate infill (should only be used for non-helper objects)
      */
-    void generate(Polygons& result_polygons, Polygons& result_lines);
+    void generate(Polygons& result_polygons, Polygons& result_lines, const SliceMeshStorage* mesh = nullptr);
 
 private:
+    /*!
+     * Function which returns the scanline_idx for a given x coordinate
+     * 
+     * For negative \p x this is different from simple division.
+     * 
+     * \warning \p line_distance is assumed to be positive
+     * 
+     * \param x the point to get the scansegment index for
+     * \param line_distance the width of the scan segments
+     */
+    static inline int computeScanSegmentIdx(int x, int line_distance);
 
     /*!
-     * Generate sparse concentric infill 
-     * \param outline The actual outline of the area within which to generate infill
+     * Generate sparse concentric infill
+     * 
+     * Also adds \ref Inifll::perimeter_gaps between \ref Infill::in_outline and the first wall
+     * 
      * \param result (output) The resulting polygons
      * \param inset_value The offset between each consecutive two polygons
      */
-    void generateConcentricInfill(Polygons outline, Polygons& result, int inset_value);
+    void generateConcentricInfill(Polygons& result, int inset_value);
+
+    /*!
+     * Generate sparse concentric infill starting from a specific outer wall
+     * \param first_wall The outer wall from which to start
+     * \param result (output) The resulting polygons
+     * \param inset_value The offset between each consecutive two polygons
+     */
+    void generateConcentricInfill(Polygons& first_wall, Polygons& result, int inset_value);
+
+    /*!
+     * Generate sparse concentric infill 
+     * \param result (output) The resulting polygons
+     */
+    void generateConcentric3DInfill(Polygons& result);
 
     /*!
      * Generate a rectangular grid of infill lines
@@ -67,12 +125,31 @@ private:
      */
     void generateGridInfill(Polygons& result);
 
+    /*!
+     * Generate a shifting triangular grid of infill lines, which combine with consecutive layers into a cubic pattern
+     * \param result (output) The resulting lines
+     */
+    void generateCubicInfill(Polygons& result);
+
+    /*!
+     * Generate a double shifting square grid of infill lines, which combine with consecutive layers into a tetrahedral pattern
+     * \param result (output) The resulting lines
+     */
+    void generateTetrahedralInfill(Polygons& result);
+
     /*!
      * Generate a triangular grid of infill lines
      * \param result (output) The resulting lines
      */
     void generateTriangleInfill(Polygons& result);
-    
+
+    /*!
+     * Generate a 3d pattern of subdivided cubes on their points
+     * \param[out] result The resulting lines
+     * \param[in] mesh Where the Cubic Subdivision Infill precomputation is stored
+     */
+    void generateCubicSubDivInfill(Polygons& result, const SliceMeshStorage& mesh);
+
     /*!
      * Convert a mapping from scanline to line_segment-scanline-intersections (\p cut_list) into line segments, using the even-odd rule
      * \param result (output) The resulting lines
@@ -81,8 +158,16 @@ private:
      * \param line_distance The distance between two lines which are in the same direction
      * \param boundary The axis aligned boundary box within which the polygon is
      * \param cut_list A mapping of each scanline to all y-coordinates (in the space transformed by rotation_matrix) where the polygons are crossing the scanline
+     * \param total_shift total shift of the scanlines in the direction perpendicular to the fill_angle.
      */
-    void addLineInfill(Polygons& result, const PointMatrix& rotation_matrix, const int scanline_min_idx, const int line_distance, const AABB boundary, std::vector<std::vector<int64_t>>& cut_list);
+    void addLineInfill(Polygons& result, const PointMatrix& rotation_matrix, const int scanline_min_idx, const int line_distance, const AABB boundary, std::vector<std::vector<int64_t>>& cut_list, int64_t total_shift);
+
+    /*!
+     * Crop line segments by the infill polygon using Clipper
+     * \param result (output) The resulting lines
+     * \param input The line segments to be cropped
+     */
+    void addLineSegmentsInfill(Polygons& result, Polygons& input);
 
     /*!
      * generate lines within the area of \p in_outline, at regular intervals of \p line_distance
@@ -93,8 +178,9 @@ private:
      * \param result (output) The resulting lines
      * \param line_distance The distance between two lines which are in the same direction
      * \param fill_angle The angle of the generated lines
+     * \param extra_shift extra shift of the scanlines in the direction perpendicular to the fill_angle
      */
-    void generateLineInfill(Polygons& result, int line_distance, const double& fill_angle);
+    void generateLineInfill(Polygons& result, int line_distance, const double& fill_angle, int64_t extra_shift);
     
     /*!
      * Function for creating linear based infill types (Lines, ZigZag).
@@ -105,14 +191,14 @@ private:
      * It is called only from Infill::generateLineinfill and Infill::generateZigZagInfill.
      * 
      * \param outline_offset An offset from the reference polygon (Infill::in_outline) to get the actual outline within which to generate infill
-     * \param safe_outline_offset Whether to consider removing overlapping wall parts (not so for normal line infill)
      * \param result (output) The resulting lines
      * \param line_distance The distance between two lines which are in the same direction
      * \param rotation_matrix The rotation matrix (un)applied to enforce the angle of the infill 
      * \param zigzag_connector_processor The processor used to generate zigzag connectors
      * \param connected_zigzags Whether to connect the endpiece zigzag segments on both sides to the same infill line
+     * \param extra_shift extra shift of the scanlines in the direction perpendicular to the fill_angle
      */
-    void generateLinearBasedInfill(const int outline_offset, bool safe_outline_offset, Polygons& result, const int line_distance, const PointMatrix& rotation_matrix, ZigzagConnectorProcessor& zigzag_connector_processor, const bool connected_zigzags);
+    void generateLinearBasedInfill(const int outline_offset, Polygons& result, const int line_distance, const PointMatrix& rotation_matrix, ZigzagConnectorProcessor& zigzag_connector_processor, const bool connected_zigzags, int64_t extra_shift);
 
     /*!
      * 

src/infill/SubDivCube.cpp

@@ -0,0 +1,282 @@
+#include "SubDivCube.h"
+
+#include <functional>
+
+#include "../utils/polygonUtils.h"
+#include "../sliceDataStorage.h"
+#include "../utils/math.h"
+
+#define ONE_OVER_SQRT_2 0.7071067811865475244008443621048490392848359376884740 //1 / sqrt(2)
+#define ONE_OVER_SQRT_3 0.577350269189625764509148780501957455647601751270126876018 //1 / sqrt(3)
+#define ONE_OVER_SQRT_6 0.408248290463863016366214012450981898660991246776111688072 //1 / sqrt(6)
+#define SQRT_TWO_THIRD 0.816496580927726032732428024901963797321982493552223376144 //sqrt(2 / 3)
+
+namespace cura
+{
+
+std::vector<SubDivCube::CubeProperties> SubDivCube::cube_properties_per_recursion_step;
+double SubDivCube::radius_multiplier = 1;
+int32_t SubDivCube::radius_addition = 0;
+Point3Matrix SubDivCube::rotation_matrix;
+PointMatrix SubDivCube::infill_rotation_matrix;
+
+SubDivCube::~SubDivCube()
+{
+    for (int child_idx = 0; child_idx < 8; child_idx++)
+    {
+        if (children[child_idx])
+        {
+            delete children[child_idx];
+        }
+    }
+}
+
+void SubDivCube::precomputeOctree(SliceMeshStorage& mesh)
+{
+    radius_multiplier = mesh.getSettingAsRatio("sub_div_rad_mult");
+    radius_addition = mesh.getSettingInMicrons("sub_div_rad_add");
+    double infill_angle = M_PI / 4.0;
+
+    coord_t furthest_dist_from_origin = std::sqrt(square(mesh.getSettingInMicrons("machine_height")) + square(mesh.getSettingInMicrons("machine_depth") / 2) + square(mesh.getSettingInMicrons("machine_width") / 2));
+    coord_t max_side_length = furthest_dist_from_origin * 2;
+
+    int curr_recursion_depth = 0;
+    const int64_t infill_line_distance = mesh.getSettingInMicrons("infill_line_distance");
+    if (infill_line_distance > 0)
+    {
+        for (int64_t curr_side_length = infill_line_distance * 2; curr_side_length < max_side_length * 2; curr_side_length *= 2)
+        {
+            cube_properties_per_recursion_step.emplace_back();
+            CubeProperties& cube_properties_here = cube_properties_per_recursion_step.back();
+            cube_properties_here.side_length = curr_side_length;
+            cube_properties_here.height = sqrt(3) * curr_side_length;
+            cube_properties_here.square_height = sqrt(2) * curr_side_length;
+            cube_properties_here.max_draw_z_diff = ONE_OVER_SQRT_3 * curr_side_length;
+            cube_properties_here.max_line_offset = ONE_OVER_SQRT_6 * curr_side_length;
+            curr_recursion_depth++;
+        }
+    }
+    Point3 center(0, 0, 0);
+
+    Point3Matrix tilt; // rotation matrix to get from axis aligned cubes to cubes standing on their tip
+    // The Z axis is transformed to go in positive Y direction
+    //
+    //  cross section in a horizontal plane      horizontal plane showing
+    //  looking down at the origin O             positive X and positive Y
+    //                 Z                                                        .
+    //                /:\                              Y                        .
+    //               / : \                             ^                        .
+    //              /  :  \                            |                        .
+    //             /  .O.  \                           |                        .
+    //            /.~'   '~.\                          O---->X                  .
+    //          X """"""""""" Y                                                 .
+    tilt.matrix[0] = -ONE_OVER_SQRT_2;  tilt.matrix[1] = ONE_OVER_SQRT_2; tilt.matrix[2] = 0;
+    tilt.matrix[3] = -ONE_OVER_SQRT_6; tilt.matrix[4] = -ONE_OVER_SQRT_6; tilt.matrix[5] = SQRT_TWO_THIRD ;
+    tilt.matrix[6] = ONE_OVER_SQRT_3;  tilt.matrix[7] = ONE_OVER_SQRT_3;  tilt.matrix[8] = ONE_OVER_SQRT_3;
+
+    infill_rotation_matrix = PointMatrix(infill_angle);
+    Point3Matrix infill_angle_mat(infill_rotation_matrix);
+
+    rotation_matrix = infill_angle_mat.compose(tilt);
+
+    mesh.base_subdiv_cube = new SubDivCube(mesh, center, curr_recursion_depth - 1);
+}
+
+void SubDivCube::generateSubdivisionLines(int64_t z, Polygons& result)
+{
+    if (cube_properties_per_recursion_step.empty()) //Infill is set to 0%.
+    {
+        return;
+    }
+    Polygons directional_line_groups[3];
+
+    generateSubdivisionLines(z, result, directional_line_groups);
+
+    for (int dir_idx = 0; dir_idx < 3; dir_idx++)
+    {
+        Polygons& line_group = directional_line_groups[dir_idx];
+        for (unsigned int line_idx = 0; line_idx < line_group.size(); line_idx++)
+        {
+            result.addLine(line_group[line_idx][0], line_group[line_idx][1]);
+        }
+    }
+}
+
+void SubDivCube::generateSubdivisionLines(int64_t z, Polygons& result, Polygons (&directional_line_groups)[3])
+{
+    CubeProperties cube_properties = cube_properties_per_recursion_step[depth];
+
+    int32_t z_diff = std::abs(z - center.z); //!< the difference between the cube center and the target layer.
+    if (z_diff > cube_properties.height / 2) //!< this cube does not touch the target layer. Early exit.
+    {
+        return;
+    }
+    if (z_diff < cube_properties.max_draw_z_diff) //!< this cube has lines that need to be drawn.
+    {
+        Point relative_a, relative_b; //!< relative coordinates of line endpoints around cube center
+        Point a, b; //!< absolute coordinates of line endpoints
+        relative_a.X = (cube_properties.square_height / 2) * (cube_properties.max_draw_z_diff - z_diff) / cube_properties.max_draw_z_diff;
+        relative_b.X = -relative_a.X;
+        relative_a.Y = cube_properties.max_line_offset - ((z - (center.z - cube_properties.max_draw_z_diff)) * ONE_OVER_SQRT_2);
+        relative_b.Y = relative_a.Y;
+        rotatePointInitial(relative_a);
+        rotatePointInitial(relative_b);
+        for (int dir_idx = 0; dir_idx < 3; dir_idx++)//!< draw the line, then rotate 120 degrees.
+        {
+            a.X = center.x + relative_a.X;
+            a.Y = center.y + relative_a.Y;
+            b.X = center.x + relative_b.X;
+            b.Y = center.y + relative_b.Y;
+            addLineAndCombine(directional_line_groups[dir_idx], a, b);
+            if (dir_idx < 2)
+            {
+                rotatePoint120(relative_a);
+                rotatePoint120(relative_b);
+            }
+        }
+    }
+    for (int idx = 0; idx < 8; idx++) //!< draws the eight children
+    {
+        if (children[idx] != nullptr)
+        {
+            children[idx]->generateSubdivisionLines(z, result, directional_line_groups);
+        }
+    }
+}
+
+SubDivCube::SubDivCube(SliceMeshStorage& mesh, Point3& center, unsigned int depth)
+{
+    this->depth = depth;
+    this->center = center;
+
+    if (depth == 0) // lowest layer, no need for subdivision, exit.
+    {
+        return;
+    }
+    if (depth >= cube_properties_per_recursion_step.size()) //Depth is out of bounds of what we pre-computed.
+    {
+        return;
+    }
+
+    CubeProperties cube_properties = cube_properties_per_recursion_step[depth];
+    Point3 child_center;
+    coord_t radius = double(radius_multiplier * double(cube_properties.height)) / 4.0 + radius_addition;
+
+    int child_nr = 0;
+    std::vector<Point3> rel_child_centers;
+    rel_child_centers.emplace_back(1, 1, 1); // top
+    rel_child_centers.emplace_back(-1, 1, 1); // top three
+    rel_child_centers.emplace_back(1, -1, 1);
+    rel_child_centers.emplace_back(1, 1, -1);
+    rel_child_centers.emplace_back(-1, -1, -1); // bottom
+    rel_child_centers.emplace_back(1, -1, -1); // bottom three
+    rel_child_centers.emplace_back(-1, 1, -1);
+    rel_child_centers.emplace_back(-1, -1, 1);
+    for (Point3 rel_child_center : rel_child_centers)
+    {
+        child_center = center + rotation_matrix.apply(rel_child_center * int32_t(cube_properties.side_length / 4));
+        if (isValidSubdivision(mesh, child_center, radius))
+        {
+            children[child_nr] = new SubDivCube(mesh, child_center, depth - 1);
+            child_nr++;
+        }
+    }
+}
+
+bool SubDivCube::isValidSubdivision(SliceMeshStorage& mesh, Point3& center, int64_t radius)
+{
+    int64_t distance2;
+    coord_t sphere_slice_radius2;//!< squared radius of bounding sphere slice on target layer
+    bool inside_somewhere = false;
+    bool outside_somewhere = false;
+    int inside;
+    double part_dist;//what percentage of the radius the target layer is away from the center along the z axis. 0 - 1
+    const coord_t layer_height = mesh.getSettingInMicrons("layer_height");
+    int bottom_layer = (center.z - radius) / layer_height;
+    int top_layer = (center.z + radius) / layer_height;
+    for (int test_layer = bottom_layer; test_layer <= top_layer; test_layer += 3) // steps of three. Low-hanging speed gain.
+    {
+        part_dist = (double)(test_layer * layer_height - center.z) / radius;
+        sphere_slice_radius2 = radius * radius * (1.0 - (part_dist * part_dist));
+        Point loc(center.x, center.y);
+
+        inside = distanceFromPointToMesh(mesh, test_layer, loc, &distance2);
+        if (inside == 1)
+        {
+            inside_somewhere = true;
+        }
+        else
+        {
+            outside_somewhere = true;
+        }
+        if (outside_somewhere && inside_somewhere)
+        {
+            return true;
+        }
+        if ((inside != 2) && distance2 < sphere_slice_radius2)
+        {
+            return true;
+        }
+    }
+    return false;
+}
+
+int SubDivCube::distanceFromPointToMesh(SliceMeshStorage& mesh, int layer_nr, Point& location, int64_t* distance2)
+{
+    if (layer_nr < 0 || (unsigned int)layer_nr >= mesh.layers.size()) //!< this layer is outside of valid range
+    {
+        return 2;
+    }
+    Polygons collide;
+    mesh.layers[layer_nr].getSecondOrInnermostWalls(collide);
+    Point centerpoint = location;
+    bool inside = collide.inside(centerpoint);
+    ClosestPolygonPoint border_point = PolygonUtils::moveInside2(collide, centerpoint);
+    Point diff = border_point.location - location;
+    *distance2 = vSize2(diff);
+    if (inside)
+    {
+        return 1;
+    }
+    return 0;
+}
+
+
+void SubDivCube::rotatePointInitial(Point& target)
+{
+    target = infill_rotation_matrix.apply(target);
+}
+
+void SubDivCube::rotatePoint120(Point& target)
+{
+    constexpr double sqrt_three_fourths = 0.8660254037844386467637231707529361834714026269051903; //!< sqrt(3.0 / 4.0) = sqrt(3) / 2
+    int64_t x;
+    x = (-0.5) * target.X - sqrt_three_fourths * target.Y;
+    target.Y = (-0.5)*target.Y + sqrt_three_fourths * target.X;
+    target.X = x;
+}
+
+void SubDivCube::addLineAndCombine(Polygons& group, Point from, Point to)
+{
+    int epsilon = 10; // the smallest distance of two points which are viewed as coincident (dist > 0 due to rounding errors)
+    for (unsigned int idx = 0; idx < group.size(); idx++)
+    {
+        if (std::abs(from.X - group[idx][1].X) < epsilon && std::abs(from.Y - group[idx][1].Y) < epsilon)
+        {
+            from = group[idx][0];
+            group.remove(idx);
+            idx--;
+            continue;
+        }
+        if (std::abs(to.X - group[idx][0].X) < epsilon && std::abs(to.Y - group[idx][0].Y) < epsilon)
+        {
+            to = group[idx][1];
+            group.remove(idx);
+            idx--;
+            continue;
+        }
+    }
+    group.addLine(from, to);
+}
+
+}//namespace cura

src/infill/SubDivCube.h

@@ -0,0 +1,98 @@
+#ifndef INFILL_SUBDIVCUBE_H
+#define INFILL_SUBDIVCUBE_H
+
+#include "../sliceDataStorage.h"
+
+namespace cura
+{
+
+class Infill;
+
+class SubDivCube
+{
+public:
+    /*!
+     * Constructor for SubDivCube. Recursively calls itself eight times to flesh out the octree.
+     * \param mesh contains infill layer data and settings
+     * \param my_center the center of the cube
+     * \param depth the recursion depth of the cube (0 is most recursed)
+     */
+    SubDivCube(SliceMeshStorage& mesh, Point3& center, unsigned int depth);
+
+    ~SubDivCube(); //!< destructor (also destroys children
+
+    /*!
+     * Precompute the octree of subdivided cubes
+     * \param mesh contains infill layer data and settings
+     */
+    static void precomputeOctree(SliceMeshStorage& mesh);
+    /*!
+     * Generates the lines of subdivision of the specific cube at the specific layer. It recursively calls itself, so it ends up drawing all the subdivision lines of sub-cubes too.
+     * \param z the specified layer height
+     * \param result (output) The resulting lines
+     */
+    void generateSubdivisionLines(int64_t z, Polygons& result);
+private:
+    /*!
+     * Generates the lines of subdivision of the specific cube at the specific layer. It recursively calls itself, so it ends up drawing all the subdivision lines of sub-cubes too.
+     * \param z the specified layer height
+     * \param result (output) The resulting lines
+     * \param directional_line_groups Array of 3 times a polylines. Used to keep track of line segments that are all pointing the same direction for line segment combining
+     */
+    void generateSubdivisionLines(int64_t z, Polygons& result, Polygons (&directional_line_groups)[3]);
+    struct CubeProperties
+    {
+        int64_t side_length; //!< side length of cubes
+        int64_t height; //!< height of cubes based. This is the distance from one point of a cube to its 3d opposite.
+        int64_t square_height; //!< square cut across lengths. This is the diagonal distance across a face of the cube.
+        int64_t max_draw_z_diff; //!< maximum draw z differences. This is the maximum difference in z at which lines need to be drawn.
+        int64_t max_line_offset; //!< maximum line offsets. This is the maximum distance at which subdivision lines should be drawn from the 2d cube center.
+    };
+    /*!
+     * Rotates a point 120 degrees about the origin.
+     * \param target the point to rotate.
+     */
+    static void rotatePoint120(Point& target);
+    /*!
+     * Rotates a point to align it with the orientation of the infill.
+     * \param target the point to rotate.
+     */
+    static void rotatePointInitial(Point& target);
+    /*!
+     * Determines if a described theoretical cube should be subdivided based on if a sphere that encloses the cube touches the infill mesh.
+     * \param mesh contains infill layer data and settings
+     * \param center the center of the described cube
+     * \param radius the radius of the enclosing sphere
+     * \return the described cube should be subdivided
+     */
+    static bool isValidSubdivision(SliceMeshStorage& mesh, Point3& center, int64_t radius);
+    /*!
+     * Finds the distance to the infill border at the specified layer from the specified point.
+     * \param mesh contains infill layer data and settings
+     * \param layer_nr the number of the specified layer
+     * \param location the location of the specified point
+     * \param[out] distance2 the squared distance to the infill border
+     * \return Code 0: outside, 1: inside, 2: boundary does not exist at specified layer
+     */
+    static int distanceFromPointToMesh(SliceMeshStorage& mesh, int layer_nr, Point& location, int64_t* distance2);
+
+    /*!
+     * Adds the defined line to the specified polygons. It assumes that the specified polygons are all parallel lines. Combines line segments with touching ends closer than epsilon.
+     * \param[out] group the polygons to add the line to
+     * \param from the first endpoint of the line
+     * \param to the second endpoint of the line
+     */
+    void addLineAndCombine(Polygons& group, Point from, Point to);
+
+    unsigned int depth; //!< the recursion depth of the cube (0 is most recursed)
+    Point3 center; //!< center location of the cube in absolute coordinates
+    SubDivCube* children[8] = {nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr}; //!< pointers to this cube's eight octree children
+    static std::vector<CubeProperties> cube_properties_per_recursion_step; //!< precomputed array of basic properties of cubes based on recursion depth.
+    static double radius_multiplier; //!< multiplier for the bounding radius when determining if a cube should be subdivided
+    static Point3Matrix rotation_matrix; //!< The rotation matrix to get from axis aligned cubes to cubes standing on a corner point aligned with the infill_angle
+    static PointMatrix infill_rotation_matrix; //!< Horizontal rotation applied to infill
+    static int32_t radius_addition; //!< addition to the bounding radius when determining if a cube should be subdivided
+};
+
+}
+#endif //INFILL_SUBDIVCUBE_H

src/infill/ZigzagConnectorProcessor.h

@@ -109,9 +109,7 @@ protected:
      */
     void addLine(Point from, Point to)
     {
-        PolygonRef line_poly = result.newPoly();
-        line_poly.add(rotation_matrix.unapply(from));
-        line_poly.add(rotation_matrix.unapply(to));
+        result.addLine(rotation_matrix.unapply(from), rotation_matrix.unapply(to));
     }
 
     /*!

src/layerPart.cpp

@@ -44,9 +44,11 @@ void createLayerWithParts(SliceLayer& storageLayer, SlicerLayer* layer, bool uni
 }
 void createLayerParts(SliceMeshStorage& mesh, Slicer* slicer, bool union_layers, bool union_all_remove_holes)
 {
-    for(unsigned int layer_nr = 0; layer_nr < slicer->layers.size(); layer_nr++)
+    const auto total_layers = slicer->layers.size();
+    assert(mesh.layers.size() == total_layers);
+#pragma omp parallel for default(none) shared(mesh,slicer) firstprivate(union_layers,union_all_remove_holes) schedule(dynamic)
+    for(unsigned int layer_nr = 0; layer_nr < total_layers; layer_nr++)
     {
-        mesh.layers.push_back(SliceLayer());
         mesh.layers[layer_nr].sliceZ = slicer->layers[layer_nr].z;
         mesh.layers[layer_nr].printZ = slicer->layers[layer_nr].z;
         createLayerWithParts(mesh.layers[layer_nr], &slicer->layers[layer_nr], union_layers, union_all_remove_holes);

src/main.cpp

@@ -20,36 +20,39 @@
 
 #include "settings/SettingsToGV.h"
 
+#include <omp.h> // omp_get_num_threads
+
 namespace cura
 {
     
 void print_usage()
 {
-    cura::logError("\n");
-    cura::logError("usage:\n");
-    cura::logError("CuraEngine help\n");
-    cura::logError("\tShow this help message\n");
-    cura::logError("\n");
-    cura::logError("CuraEngine connect <host>[:<port>] [-j <settings.def.json>]\n");
-    cura::logError("  --connect <host>[:<port>]\n\tConnect to <host> via a command socket, \n\tinstead of passing information via the command line\n");
-    cura::logError("  -j<settings.def.json>\n\tLoad settings.json file to register all settings and their defaults\n");
-    cura::logError("\n");
-    cura::logError("CuraEngine slice [-v] [-p] [-j <settings.json>] [-s <settingkey>=<value>] [-g] [-e<extruder_nr>] [-o <output.gcode>] [-l <model.stl>] [--next]\n");
-    cura::logError("  -v\n\tIncrease the verbose level (show log messages).\n");
-    cura::logError("  -p\n\tLog progress information.\n");
-    cura::logError("  -j\n\tLoad settings.def.json file to register all settings and their defaults.\n");
-    cura::logError("  -s <setting>=<value>\n\tSet a setting to a value for the last supplied object, \n\textruder train, or general settings.\n");
-    cura::logError("  -l <model_file>\n\tLoad an STL model. \n");
-    cura::logError("  -g\n\tSwitch setting focus to the current mesh group only.\n\tUsed for one-at-a-time printing.\n");
-    cura::logError("  -e<extruder_nr>\n\tSwitch setting focus to the extruder train with the given number.\n");
-    cura::logError("  --next\n\tGenerate gcode for the previously supplied mesh group and append that to \n\tthe gcode of further models for one-at-a-time printing.\n");
-    cura::logError("  -o <output_file>\n\tSpecify a file to which to write the generated gcode.\n");
-    cura::logError("\n");
-    cura::logError("The settings are appended to the last supplied object:\n");
-    cura::logError("CuraEngine slice [general settings] \n\t-g [current group settings] \n\t-e0 [extruder train 0 settings] \n\t-l obj_inheriting_from_last_extruder_train.stl [object settings] \n\t--next [next group settings]\n\t... etc.\n");
-    cura::logError("\n");
-    cura::logError("In order to load machine definitions from custom locations, you need to create the environment variable CURA_ENGINE_SEARCH_PATH, which should contain all search paths delimited by a (semi-)colon.\n");
-    cura::logError("\n");
+    logAlways("\n");
+    logAlways("usage:\n");
+    logAlways("CuraEngine help\n");
+    logAlways("\tShow this help message\n");
+    logAlways("\n");
+    logAlways("CuraEngine connect <host>[:<port>] [-j <settings.def.json>]\n");
+    logAlways("  --connect <host>[:<port>]\n\tConnect to <host> via a command socket, \n\tinstead of passing information via the command line\n");
+    logAlways("  -j<settings.def.json>\n\tLoad settings.json file to register all settings and their defaults\n");
+    logAlways("  -v\n\tIncrease the verbose level (show log messages).\n");
+    logAlways("\n");
+    logAlways("CuraEngine slice [-v] [-p] [-j <settings.json>] [-s <settingkey>=<value>] [-g] [-e<extruder_nr>] [-o <output.gcode>] [-l <model.stl>] [--next]\n");
+    logAlways("  -v\n\tIncrease the verbose level (show log messages).\n");
+    logAlways("  -p\n\tLog progress information.\n");
+    logAlways("  -j\n\tLoad settings.def.json file to register all settings and their defaults.\n");
+    logAlways("  -s <setting>=<value>\n\tSet a setting to a value for the last supplied object, \n\textruder train, or general settings.\n");
+    logAlways("  -l <model_file>\n\tLoad an STL model. \n");
+    logAlways("  -g\n\tSwitch setting focus to the current mesh group only.\n\tUsed for one-at-a-time printing.\n");
+    logAlways("  -e<extruder_nr>\n\tSwitch setting focus to the extruder train with the given number.\n");
+    logAlways("  --next\n\tGenerate gcode for the previously supplied mesh group and append that to \n\tthe gcode of further models for one-at-a-time printing.\n");
+    logAlways("  -o <output_file>\n\tSpecify a file to which to write the generated gcode.\n");
+    logAlways("\n");
+    logAlways("The settings are appended to the last supplied object:\n");
+    logAlways("CuraEngine slice [general settings] \n\t-g [current group settings] \n\t-e0 [extruder train 0 settings] \n\t-l obj_inheriting_from_last_extruder_train.stl [object settings] \n\t--next [next group settings]\n\t... etc.\n");
+    logAlways("\n");
+    logAlways("In order to load machine definitions from custom locations, you need to create the environment variable CURA_ENGINE_SEARCH_PATH, which should contain all search paths delimited by a (semi-)colon.\n");
+    logAlways("\n");
 }
 
 //Signal handler for a "floating point exception", which can also be integer division by zero errors.
@@ -70,10 +73,10 @@ void print_call(int argc, char **argv)
 
 void connect(int argc, char **argv)
 {
-    CommandSocket::instantiate();
     std::string ip;
     int port = 49674;
-    
+
+    // parse ip port
     std::string ip_port(argv[2]);
     if (ip_port.find(':') != std::string::npos)
     {
@@ -97,7 +100,8 @@ void connect(int argc, char **argv)
                     argn++;
                     if (SettingRegistry::getInstance()->loadJSONsettings(argv[argn], FffProcessor::getInstance()))
                     {
-                        cura::logError("ERROR: Failed to load json file: %s\n", argv[argn]);
+                        cura::logError("Failed to load json file: %s\n", argv[argn]);
+                        std::exit(1);
                     }
                     break;
                 default:
@@ -109,7 +113,8 @@ void connect(int argc, char **argv)
             }
         }
     }
-    
+
+    CommandSocket::instantiate();
     CommandSocket::getInstance()->connect(ip, port);
 }
 
@@ -123,7 +128,7 @@ void slice(int argc, char **argv)
     
     int extruder_train_nr = 0;
 
-    SettingsBase* last_extruder_train = meshgroup->createExtruderTrain(0);
+    SettingsBase* last_extruder_train = nullptr;
     // extruder defaults cannot be loaded yet cause no json has been parsed
     SettingsBase* last_settings_object = FffProcessor::getInstance();
     for(int argn = 2; argn < argc; argn++)
@@ -138,14 +143,15 @@ void slice(int argc, char **argv)
                     try {
                         //Catch all exceptions, this prevents the "something went wrong" dialog on windows to pop up on a thrown exception.
                         // Only ClipperLib currently throws exceptions. And only in case that it makes an internal error.
-                        meshgroup->finalize();
                         log("Loaded from disk in %5.3fs\n", FffProcessor::getInstance()->time_keeper.restart());
                         
                         for (int extruder_nr = 0; extruder_nr < FffProcessor::getInstance()->getSettingAsCount("machine_extruder_count"); extruder_nr++)
                         { // initialize remaining extruder trains and load the defaults
-                            ExtruderTrain* train = meshgroup->createExtruderTrain(extruder_nr); // create new extruder train objects or use already existing ones
-                            SettingRegistry::getInstance()->loadExtruderJSONsettings(extruder_nr, train);
+                            meshgroup->createExtruderTrain(extruder_nr); // create new extruder train objects or use already existing ones
                         }
+
+                        meshgroup->finalize();
+
                         //start slicing
                         FffProcessor::getInstance()->processMeshGroup(meshgroup);
                         
@@ -155,7 +161,6 @@ void slice(int argc, char **argv)
                         meshgroup = new MeshGroup(FffProcessor::getInstance());
                         last_extruder_train = meshgroup->createExtruderTrain(0); 
                         last_settings_object = meshgroup;
-                        SettingRegistry::getInstance()->loadExtruderJSONsettings(0, last_extruder_train);
                         
                     }catch(...){
                         cura::logError("Unknown exception\n");
@@ -179,7 +184,8 @@ void slice(int argc, char **argv)
                         argn++;
                         if (SettingRegistry::getInstance()->loadJSONsettings(argv[argn], last_settings_object))
                         {
-                            cura::logError("ERROR: Failed to load json file: %s\n", argv[argn]);
+                            cura::logError("Failed to load json file: %s\n", argv[argn]);
+                            std::exit(1);
                         }
                         break;
                     case 'e':
@@ -187,17 +193,22 @@ void slice(int argc, char **argv)
                         extruder_train_nr = int(*str - '0'); // TODO: parse int instead (now "-e10"="-e:" , "-e11"="-e;" , "-e12"="-e<" .. etc) 
                         last_settings_object = meshgroup->createExtruderTrain(extruder_train_nr);
                         last_extruder_train = last_settings_object;
-                        SettingRegistry::getInstance()->loadExtruderJSONsettings(extruder_train_nr, last_extruder_train);
                         break;
                     case 'l':
                         argn++;
                         
                         log("Loading %s from disk...\n", argv[argn]);
-                        // transformation = // TODO: get a transformation from somewhere
-                        
+
+                        transformation = last_settings_object->getSettingAsPointMatrix("mesh_rotation_matrix"); // the transformation applied to a model when loaded
+
+                        if (!last_extruder_train)
+                        {
+                            last_extruder_train = meshgroup->createExtruderTrain(0); // assume a json has already been provided on the command line
+                        }
                         if (!loadMeshIntoMeshGroup(meshgroup, argv[argn], transformation, last_extruder_train))
                         {
                             logError("Failed to load model: %s\n", argv[argn]);
+                            std::exit(1);
                         }
                         else 
                         {
@@ -250,8 +261,7 @@ void slice(int argc, char **argv)
     int extruder_count = FffProcessor::getInstance()->getSettingAsCount("machine_extruder_count");
     for (extruder_train_nr = 0; extruder_train_nr < extruder_count; extruder_train_nr++)
     { // initialize remaining extruder trains and load the defaults
-        ExtruderTrain* train = meshgroup->createExtruderTrain(extruder_train_nr); // create new extruder train objects or use already existing ones
-        SettingRegistry::getInstance()->loadExtruderJSONsettings(extruder_train_nr, train);
+        meshgroup->createExtruderTrain(extruder_train_nr); // create new extruder train objects or use already existing ones
     }
     
     
@@ -296,23 +306,23 @@ int main(int argc, char **argv)
 
     Progress::init();
     
-    
-    logCopyright("\n");
-    logCopyright("Cura_SteamEngine version %s\n", VERSION);
-    logCopyright("Copyright (C) 2014 David Braam\n");
-    logCopyright("\n");
-    logCopyright("This program is free software: you can redistribute it and/or modify\n");
-    logCopyright("it under the terms of the GNU Affero General Public License as published by\n");
-    logCopyright("the Free Software Foundation, either version 3 of the License, or\n");
-    logCopyright("(at your option) any later version.\n");
-    logCopyright("\n");
-    logCopyright("This program is distributed in the hope that it will be useful,\n");
-    logCopyright("but WITHOUT ANY WARRANTY; without even the implied warranty of\n");
-    logCopyright("MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n");
-    logCopyright("GNU Affero General Public License for more details.\n");
-    logCopyright("\n");
-    logCopyright("You should have received a copy of the GNU Affero General Public License\n");
-    logCopyright("along with this program.  If not, see <http://www.gnu.org/licenses/>.\n");
+    std::cerr << std::boolalpha;
+    logAlways("\n");
+    logAlways("Cura_SteamEngine version %s\n", VERSION);
+    logAlways("Copyright (C) 2014 David Braam\n");
+    logAlways("\n");
+    logAlways("This program is free software: you can redistribute it and/or modify\n");
+    logAlways("it under the terms of the GNU Affero General Public License as published by\n");
+    logAlways("the Free Software Foundation, either version 3 of the License, or\n");
+    logAlways("(at your option) any later version.\n");
+    logAlways("\n");
+    logAlways("This program is distributed in the hope that it will be useful,\n");
+    logAlways("but WITHOUT ANY WARRANTY; without even the implied warranty of\n");
+    logAlways("MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n");
+    logAlways("GNU Affero General Public License for more details.\n");
+    logAlways("\n");
+    logAlways("You should have received a copy of the GNU Affero General Public License\n");
+    logAlways("along with this program.  If not, see <http://www.gnu.org/licenses/>.\n");
 
 
     if (argc < 2)
@@ -320,7 +330,19 @@ int main(int argc, char **argv)
         print_usage();
         exit(1);
     }
-    
+
+#pragma omp parallel
+    {
+#pragma omp master
+        {
+#ifdef _OPENMP
+            log("OpenMP multithreading enabled, likely number of threads to be used: %u\n", omp_get_num_threads());
+#else
+            log("OpenMP multithreading disabled\n");
+#endif
+        }
+    }
+
     if (stringcasecompare(argv[1], "connect") == 0)
     {
         connect(argc, argv);
@@ -347,6 +369,7 @@ int main(int argc, char **argv)
         bool inherit_viz = false;
         bool warning_viz = false;
         bool error_viz = false;
+        bool global_only_viz = false;
         if (argc >= 6)
         {
             char* str = argv[5];
@@ -368,6 +391,9 @@ int main(int argc, char **argv)
                     case 'w':
                         warning_viz = true;
                         break;
+                    case 'g':
+                        global_only_viz = true;
+                        break;
                     default:
                         cura::logError("Unknown option: %c\n", *str);
                         print_call(argc, argv);
@@ -379,26 +405,26 @@ int main(int argc, char **argv)
         }
         else
         {
-            cura::logError("\n");
-            cura::logError("usage:\n");
-            cura::logError("CuraEngine analyse <fdmPrinter.def.json> <output.gv> <engine_settings_list> -[p|i|e|w]\n");
-            cura::logError("\tGenerate a grpah to visualize the setting inheritance structure.\n");
-            cura::logError("\t<fdmPrinter.def.json>\n\tThe base seting definitions file.\n");
-            cura::logError("\t<output.gv>\n\tThe output file.\n");
-            cura::logError("\t<engine_settings_list>\n\tA text file with all setting keys used in the engine, separated by newlines.\n");
-            cura::logError("\t-[p|i|e|w]\n\tOptions for what to include in the visualization\n");
-            cura::logError("\t\tp\tVisualize the parent-child relationship.\n");
-            cura::logError("\t\ti\tVisualize inheritance function relationships.\n");
-            cura::logError("\t\te\tVisualize (max/min) error function relationships.\n");
-            cura::logError("\t\tw\tVisualize (max/min) warning function relationships.\n");
-            cura::logError("\n");
+            cura::log("\n");
+            cura::log("usage:\n");
+            cura::log("CuraEngine analyse <fdmPrinter.def.json> <output.gv> <engine_settings_list> -[p|i|e|w]\n");
+            cura::log("\tGenerate a grpah to visualize the setting inheritance structure.\n");
+            cura::log("\t<fdmPrinter.def.json>\n\tThe base seting definitions file.\n");
+            cura::log("\t<output.gv>\n\tThe output file.\n");
+            cura::log("\t<engine_settings_list>\n\tA text file with all setting keys used in the engine, separated by newlines.\n");
+            cura::log("\t-[p|i|e|w]\n\tOptions for what to include in the visualization\n");
+            cura::log("\t\tp\tVisualize the parent-child relationship.\n");
+            cura::log("\t\ti\tVisualize inheritance function relationships.\n");
+            cura::log("\t\te\tVisualize (max/min) error function relationships.\n");
+            cura::log("\t\tw\tVisualize (max/min) warning function relationships.\n");
+            cura::log("\n");
     
         }
         
-        SettingsToGv gv_out(argv[3], argv[4], parent_child_viz, inherit_viz, error_viz, warning_viz);
+        SettingsToGv gv_out(argv[3], argv[4], parent_child_viz, inherit_viz, error_viz, warning_viz, global_only_viz);
         if (gv_out.generate(std::string(argv[2])))
         {
-            cura::logError("ERROR: Failed to analyse json file: %s\n", argv[2]);
+            cura::logError("Failed to analyse json file: %s\n", argv[2]);
         }
         exit(0);
     }

src/mesh.cpp

@@ -53,9 +53,10 @@ void Mesh::finish()
     for(unsigned int i=0; i<faces.size(); i++)
     {
         MeshFace& face = faces[i];
-        face.connected_face_index[0] = getFaceIdxWithPoints(face.vertex_index[0], face.vertex_index[1], i); // faces are connected via the outside
-        face.connected_face_index[1] = getFaceIdxWithPoints(face.vertex_index[1], face.vertex_index[2], i);
-        face.connected_face_index[2] = getFaceIdxWithPoints(face.vertex_index[2], face.vertex_index[0], i);
+        // faces are connected via the outside
+        face.connected_face_index[0] = getFaceIdxWithPoints(face.vertex_index[0], face.vertex_index[1], i, face.vertex_index[2]);
+        face.connected_face_index[1] = getFaceIdxWithPoints(face.vertex_index[1], face.vertex_index[2], i, face.vertex_index[0]);
+        face.connected_face_index[2] = getFaceIdxWithPoints(face.vertex_index[2], face.vertex_index[0], i, face.vertex_index[1]);
     }
 }
 
@@ -71,6 +72,13 @@ AABB3D Mesh::getAABB() const
 {
     return aabb;
 }
+void Mesh::expandXY(int64_t offset)
+{
+    if (offset)
+    {
+        aabb.expandXY(offset);
+    }
+}
 
 
 int Mesh::findIndexOfVertex(const Point3& v)
@@ -116,17 +124,13 @@ See <a href="http://stackoverflow.com/questions/14066933/direct-way-of-computing
 
 
 */
-int Mesh::getFaceIdxWithPoints(int idx0, int idx1, int notFaceIdx) const
+int Mesh::getFaceIdxWithPoints(int idx0, int idx1, int notFaceIdx, int notFaceVertexIdx) const
 {
     std::vector<int> candidateFaces; // in case more than two faces meet at an edge, multiple candidates are generated
-    int notFaceVertexIdx = -1; // index of the third vertex of the face corresponding to notFaceIdx
     for(int f : vertices[idx0].connected_faces) // search through all faces connected to the first vertex and find those that are also connected to the second
     {
         if (f == notFaceIdx)
         {
-            for (int i = 0; i<3; i++) // find the vertex which is not idx0 or idx1
-                if (faces[f].vertex_index[i] != idx0 && faces[f].vertex_index[i] != idx1)
-                    notFaceVertexIdx = faces[f].vertex_index[i];
             continue;
         }
         if ( faces[f].vertex_index[0] == idx1 // && faces[f].vertex_index[1] == idx0 // next face should have the right direction!
@@ -136,12 +140,10 @@ int Mesh::getFaceIdxWithPoints(int idx0, int idx1, int notFaceIdx) const
 
     }
 
-    if (candidateFaces.size() == 0) { cura::logError("Couldn't find face connected to face %i.\n", notFaceIdx); return -1; }
+    if (candidateFaces.size() == 0) { cura::logWarning("Couldn't find face connected to face %i.\n", notFaceIdx); return -1; }
     if (candidateFaces.size() == 1) { return candidateFaces[0]; }
 
 
-    if (notFaceVertexIdx < 0) { cura::logError("Couldn't find third point on face %i.\n", notFaceIdx); return -1; }
-
     if (candidateFaces.size() % 2 == 0) cura::log("Warning! Edge with uneven number of faces connecting it!(%i)\n", candidateFaces.size()+1);
 
     FPoint3 vn = vertices[idx1].p - vertices[idx0].p;
@@ -176,7 +178,6 @@ int Mesh::getFaceIdxWithPoints(int idx0, int idx1, int notFaceIdx) const
         if (angle == 0)
         {
             cura::log("Warning! Overlapping faces: face %i and face %i.\n", notFaceIdx, candidateFace);
-            std::cerr<< n.vSize() <<"; "<<n1.vSize()<<";"<<n0.vSize() <<std::endl;
         }
         if (angle < smallestAngle)
         {
@@ -184,7 +185,7 @@ int Mesh::getFaceIdxWithPoints(int idx0, int idx1, int notFaceIdx) const
             bestIdx = candidateFace;
         }
     }
-    if (bestIdx < 0) cura::logError("Couldn't find face connected to face %i.\n", notFaceIdx);
+    if (bestIdx < 0) cura::logWarning("Couldn't find face connected to face %i.\n", notFaceIdx);
     return bestIdx;
 }
 

src/mesh.h

@@ -72,6 +72,7 @@ public:
     Point3 min() const; //!< min (in x,y and z) vertex of the bounding box
     Point3 max() const; //!< max (in x,y and z) vertex of the bounding box
     AABB3D getAABB() const; //!< Get the axis aligned bounding box
+    void expandXY(int64_t offset); //!< Register applied horizontal expansion in the AABB
     
     /*!
      * Offset the whole mesh (all vertices and the bounding box).
@@ -87,11 +88,19 @@ public:
 
 private:
     int findIndexOfVertex(const Point3& v); //!< find index of vertex close to the given point, or create a new vertex and return its index.
+
     /*!
-    Get the index of the face connected to the face with index \p notFaceIdx, via vertices \p idx0 and \p idx1.
-    In case multiple faces connect with the same edge, return the next counter-clockwise face when viewing from \p idx1 to \p idx0.
+     * Get the index of the face connected to the face with index \p notFaceIdx, via vertices \p idx0 and \p idx1.
+     * 
+     * In case multiple faces connect with the same edge, return the next counter-clockwise face when viewing from \p idx1 to \p idx0.
+     * 
+     * \param idx0 the first vertex index
+     * \param idx1 the second vertex index
+     * \param notFaceIdx the index of a face which shouldn't be returned
+     * \param notFaceVertexIdx should be the third vertex of face \p notFaceIdx.
+     * \return the face index of a face sharing the edge from \p idx0 to \p idx1
     */
-    int getFaceIdxWithPoints(int idx0, int idx1, int notFaceIdx) const;
+    int getFaceIdxWithPoints(int idx0, int idx1, int notFaceIdx, int notFaceVertexIdx) const;
 };
 
 }//namespace cura

src/multiVolumes.cpp

@@ -3,20 +3,26 @@
 namespace cura 
 {
  
-void carveMultipleVolumes(std::vector<Slicer*> &volumes)
+void carveMultipleVolumes(std::vector<Slicer*> &volumes, bool alternate_carve_order)
 {
     //Go trough all the volumes, and remove the previous volume outlines from our own outline, so we never have overlapped areas.
-    for (unsigned int volume_1_idx = 0; volume_1_idx < volumes.size(); volume_1_idx++)
+    for (unsigned int volume_1_idx = 1; volume_1_idx < volumes.size(); volume_1_idx++)
     {
         Slicer& volume_1 = *volumes[volume_1_idx];
-        if (volume_1.mesh->getSettingBoolean("infill_mesh"))
+        if (volume_1.mesh->getSettingBoolean("infill_mesh") 
+            || volume_1.mesh->getSettingBoolean("anti_overhang_mesh")
+            || volume_1.mesh->getSettingBoolean("support_mesh")
+            )
         {
             continue;
         }
         for (unsigned int volume_2_idx = 0; volume_2_idx < volume_1_idx; volume_2_idx++)
         {
             Slicer& volume_2 = *volumes[volume_2_idx];
-            if (volume_2.mesh->getSettingBoolean("infill_mesh"))
+            if (volume_2.mesh->getSettingBoolean("infill_mesh")
+                || volume_2.mesh->getSettingBoolean("anti_overhang_mesh")
+                || volume_2.mesh->getSettingBoolean("support_mesh")
+                )
             {
                 continue;
             }
@@ -28,7 +34,14 @@ void carveMultipleVolumes(std::vector<Slicer*> &volumes)
             {
                 SlicerLayer& layer1 = volume_1.layers[layerNr];
                 SlicerLayer& layer2 = volume_2.layers[layerNr];
-                layer1.polygons = layer1.polygons.difference(layer2.polygons);
+                if (alternate_carve_order && layerNr % 2 == 0)
+                {
+                    layer2.polygons = layer2.polygons.difference(layer1.polygons);
+                }
+                else
+                {
+                    layer1.polygons = layer1.polygons.difference(layer2.polygons);
+                }
             }
         }
     }
@@ -48,17 +61,24 @@ void generateMultipleVolumesOverlap(std::vector<Slicer*> &volumes)
     {
         int overlap = volume->mesh->getSettingInMicrons("multiple_mesh_overlap");
         if (volume->mesh->getSettingBoolean("infill_mesh")
+            || volume->mesh->getSettingBoolean("anti_overhang_mesh")
+            || volume->mesh->getSettingBoolean("support_mesh")
             || overlap == 0)
         {
             continue;
         }
+        AABB3D aabb(volume->mesh->getAABB());
+        aabb.expandXY(overlap); // expand to account for the case where two models and their bounding boxes are adjacent along the X or Y-direction
         for (unsigned int layer_nr = 0; layer_nr < volume->layers.size(); layer_nr++)
         {
             Polygons all_other_volumes;
             for (Slicer* other_volume : volumes)
             {
                 if (other_volume->mesh->getSettingBoolean("infill_mesh")
-                    || !other_volume->mesh->getAABB().hit(volume->mesh->getAABB())
+                    || other_volume->mesh->getSettingBoolean("anti_overhang_mesh")
+                    || other_volume->mesh->getSettingBoolean("support_mesh")
+                    || !other_volume->mesh->getAABB().hit(aabb)
+                    || other_volume == volume
                 )
                 {
                     continue;
@@ -66,10 +86,9 @@ void generateMultipleVolumesOverlap(std::vector<Slicer*> &volumes)
                 SlicerLayer& other_volume_layer = other_volume->layers[layer_nr];
                 all_other_volumes = all_other_volumes.unionPolygons(other_volume_layer.polygons.offset(offset_to_merge_other_merged_volumes));
             }
-            all_other_volumes = all_other_volumes.offset(-offset_to_merge_other_merged_volumes);
 
             SlicerLayer& volume_layer = volume->layers[layer_nr];
-            volume_layer.polygons.unionPolygons(all_other_volumes.intersection(volume_layer.polygons.offset(overlap / 2)));
+            volume_layer.polygons = volume_layer.polygons.unionPolygons(all_other_volumes.intersection(volume_layer.polygons.offset(overlap / 2)));
         }
     }
 }

src/multiVolumes.h

@@ -7,7 +7,11 @@
 /* This file contains code to help fixing up and changing layers that are build from multiple volumes. */
 namespace cura {
 
-void carveMultipleVolumes(std::vector<Slicer*> &meshes);
+/*!
+ * 
+ * \param alternate_carve_order Whether to switch which model carves out of which with every layer
+ */
+void carveMultipleVolumes(std::vector<Slicer*> &meshes, bool alternate_carve_order);
 
 /*!
  * Expand each layer a bit and then keep the extra overlapping parts that overlap with other volumes.

src/pathOrderOptimizer.cpp

@@ -1,7 +1,7 @@
 /** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
 #include "pathOrderOptimizer.h"
 #include "utils/logoutput.h"
-#include "utils/BucketGrid2D.h"
+#include "utils/SparsePointGridInclusive.h"
 #include "utils/linearAlg2D.h"
 
 #define INLINE static inline
@@ -16,7 +16,7 @@ void PathOrderOptimizer::optimize()
     bool picked[polygons.size()];
     memset(picked, false, sizeof(bool) * polygons.size());/// initialized as falses
     
-    for (PolygonRef poly : polygons) /// find closest point to initial starting point within each polygon +initialize picked
+    for (ConstPolygonRef poly : polygons) /// find closest point to initial starting point within each polygon +initialize picked
     {
         int best = -1;
         float bestDist = std::numeric_limits<float>::infinity();
@@ -92,7 +92,7 @@ int PathOrderOptimizer::getPolyStart(Point prev_point, int poly_idx)
 {
     switch (type)
     {
-        case EZSeamType::BACK:      return getFarthestPointInPolygon(poly_idx); 
+        case EZSeamType::BACK:      return getClosestPointInPolygon(z_seam_pos, poly_idx); 
         case EZSeamType::RANDOM:    return getRandomPointInPolygon(poly_idx); 
         case EZSeamType::SHORTEST:  return getClosestPointInPolygon(prev_point, poly_idx);
         default:                    return getClosestPointInPolygon(prev_point, poly_idx);
@@ -102,15 +102,15 @@ int PathOrderOptimizer::getPolyStart(Point prev_point, int poly_idx)
 
 int PathOrderOptimizer::getClosestPointInPolygon(Point prev_point, int poly_idx)
 {
-    PolygonRef poly = polygons[poly_idx];
+    ConstPolygonRef poly = polygons[poly_idx];
 
     int best_point_idx = -1;
     float best_point_score = std::numeric_limits<float>::infinity();
     Point p0 = poly.back();
     for (unsigned int point_idx = 0; point_idx < poly.size(); point_idx++)
     {
-        Point& p1 = poly[point_idx];
-        Point& p2 = poly[(point_idx + 1) % poly.size()];
+        const Point& p1 = poly[point_idx];
+        const Point& p2 = poly[(point_idx + 1) % poly.size()];
         int64_t dist = vSize2(p1 - prev_point);
         float is_on_inside_corner_score = -LinearAlg2D::getAngleLeft(p0, p1, p2) / M_PI * 5000 * 5000; // prefer inside corners
         // this score is in the order of 5 mm
@@ -129,31 +129,13 @@ int PathOrderOptimizer::getRandomPointInPolygon(int poly_idx)
     return rand() % polygons[poly_idx].size();
 }
 
-
-int PathOrderOptimizer::getFarthestPointInPolygon(int poly_idx)
-{
-    PolygonRef poly = polygons[poly_idx];
-    int best_point_idx = -1;
-    float best_y = std::numeric_limits<float>::min();
-    for(unsigned int point_idx=0 ; point_idx<poly.size() ; point_idx++)
-    {
-        if (poly[point_idx].Y > best_y)
-        {
-            best_point_idx = point_idx;
-            best_y = poly[point_idx].Y;
-        }
-    }
-    return best_point_idx;
-}
-
-
 /**
 *
 */
 void LineOrderOptimizer::optimize()
 {
     int gridSize = 5000; // the size of the cells in the hash grid. TODO
-    BucketGrid2D<unsigned int> line_bucket_grid(gridSize);
+    SparsePointGridInclusive<unsigned int> line_bucket_grid(gridSize);
     bool picked[polygons.size()];
     memset(picked, false, sizeof(bool) * polygons.size());/// initialized as falses
     
@@ -161,7 +143,7 @@ void LineOrderOptimizer::optimize()
     {
         int best_point_idx = -1;
         float best_point_dist = std::numeric_limits<float>::infinity();
-        PolygonRef poly = polygons[poly_idx];
+        ConstPolygonRef poly = polygons[poly_idx];
         for (unsigned int point_idx = 0; point_idx < poly.size(); point_idx++) /// get closest point from polygon
         {
             float dist = vSize2f(poly[point_idx] - startPoint);
@@ -188,14 +170,16 @@ void LineOrderOptimizer::optimize()
         int best_line_idx = -1;
         float best_score = std::numeric_limits<float>::infinity(); // distance score for the best next line
 
-        for(unsigned int close_line_poly_idx :  line_bucket_grid.findNearbyObjects(prev_point)) /// check if single-line-polygon is close to last point
+        /// check if single-line-polygon is close to last point
+        for(unsigned int close_line_idx :
+                line_bucket_grid.getNearbyVals(prev_point, gridSize))
         {
-            if (picked[close_line_poly_idx] || polygons[close_line_poly_idx].size() < 1)
+            if (picked[close_line_idx] || polygons[close_line_idx].size() < 1)
             {
                 continue;
             }
 
-            updateBestLine(close_line_poly_idx, best_line_idx, best_score, prev_point, incoming_perpundicular_normal);
+            updateBestLine(close_line_idx, best_line_idx, best_score, prev_point, incoming_perpundicular_normal);
         }
 
         if (best_line_idx == -1) /// if single-line-polygon hasn't been found yet
@@ -215,13 +199,13 @@ void LineOrderOptimizer::optimize()
 
         if (best_line_idx > -1) /// should always be true; we should have been able to identify the best next polygon
         {
-            PolygonRef best_line = polygons[best_line_idx];
+            ConstPolygonRef best_line = polygons[best_line_idx];
             assert(best_line.size() == 2);
 
             int line_start_point_idx = polyStart[best_line_idx];
             int line_end_point_idx = line_start_point_idx * -1 + 1; /// 1 -> 0 , 0 -> 1
-            Point& line_start = best_line[line_start_point_idx];
-            Point& line_end = best_line[line_end_point_idx];
+            const Point& line_start = best_line[line_start_point_idx];
+            const Point& line_end = best_line[line_end_point_idx];
             prev_point = line_end;
             incoming_perpundicular_normal = turn90CCW(normal(line_end - line_start, 1000));
 
@@ -237,8 +221,8 @@ void LineOrderOptimizer::optimize()
 
 inline void LineOrderOptimizer::updateBestLine(unsigned int poly_idx, int& best, float& best_score, Point prev_point, Point incoming_perpundicular_normal)
 {
-    Point& p0 = polygons[poly_idx][0];
-    Point& p1 = polygons[poly_idx][1];
+    const Point& p0 = polygons[poly_idx][0];
+    const Point& p1 = polygons[poly_idx][1];
     float dot_score = getAngleScore(incoming_perpundicular_normal, p0, p1);
     { /// check distance to first point on line (0)
         float score = vSize2f(p0 - prev_point) + dot_score; // prefer 90 degree corners

src/pathOrderOptimizer.h

@@ -18,23 +18,30 @@ class PathOrderOptimizer
 {
 public:
     EZSeamType type;
-    Point startPoint; //!< The location of the nozzle before starting to print the current layer
-    std::vector<PolygonRef> polygons; //!< the parts of the layer (in arbitrary order)
+    Point startPoint; //!< A location near the prefered start location
+    Point z_seam_pos; //!< The position near where to create the z_seam (if \ref PathOrderOptimizer::type == 'back')
+    std::vector<ConstPolygonRef> polygons; //!< the parts of the layer (in arbitrary order)
     std::vector<int> polyStart; //!< polygons[i][polyStart[i]] = point of polygon i which is to be the starting point in printing the polygon
     std::vector<int> polyOrder; //!< the optimized order as indices in #polygons
 
-    PathOrderOptimizer(Point startPoint, EZSeamType type = EZSeamType::SHORTEST)
+    PathOrderOptimizer(Point startPoint, Point z_seam_pos = Point(0, 0), EZSeamType type = EZSeamType::SHORTEST)
     : type(type)
     , startPoint(startPoint)
+    , z_seam_pos(z_seam_pos)
     {
     }
 
     void addPolygon(PolygonRef polygon)
     {
-        this->polygons.push_back(polygon);
+        this->polygons.emplace_back(polygon);
     }
 
-    void addPolygons(Polygons& polygons)
+    void addPolygon(ConstPolygonRef polygon)
+    {
+        this->polygons.emplace_back(polygon);
+    }
+
+    void addPolygons(const Polygons& polygons)
     {
         for(unsigned int i=0;i<polygons.size(); i++)
             this->polygons.push_back(polygons[i]);
@@ -43,9 +50,15 @@ public:
     void optimize(); //!< sets #polyStart and #polyOrder
 
 private:
+    /*!
+     * Get the starting vertex of a polygon, depending on the \ref PathOrderOptimizer::type
+     * \param prev_point The previous planned location
+     * \param poly_idx The index of the polygon in \ref PathOrderOptimizer::polygons
+     * \return the index of the starting vertex in \ref PathOrderOptimizer::polygons[\p poly_idx]
+     */
     int getPolyStart(Point prev_point, int poly_idx);
+
     int getClosestPointInPolygon(Point prev, int i_polygon); //!< returns the index of the closest point
-    int getFarthestPointInPolygon(int poly_idx); //!< return the index to the point farthest from the front (highest y)
     int getRandomPointInPolygon(int poly_idx);
 
 
@@ -58,7 +71,7 @@ class LineOrderOptimizer
 {
 public:
     Point startPoint; //!< The location of the nozzle before starting to print the current layer
-    std::vector<PolygonRef> polygons; //!< the parts of the layer (in arbitrary order)
+    std::vector<ConstPolygonRef> polygons; //!< the parts of the layer (in arbitrary order)
     std::vector<int> polyStart; //!< polygons[i][polyStart[i]] = point of polygon i which is to be the starting point in printing the polygon
     std::vector<int> polyOrder; //!< the optimized order as indices in #polygons
 
@@ -72,6 +85,11 @@ public:
         this->polygons.push_back(polygon);
     }
 
+    void addPolygon(ConstPolygonRef polygon)
+    {
+        this->polygons.push_back(polygon);
+    }
+
     void addPolygons(Polygons& polygons)
     {
         for(unsigned int i=0;i<polygons.size(); i++)

src/pathPlanning/Comb.cpp

@@ -0,0 +1,391 @@
+/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#include "Comb.h"
+
+#include <algorithm>
+#include <functional> // function
+#include <unordered_set>
+
+#include "../utils/polygonUtils.h"
+#include "../utils/linearAlg2D.h"
+#include "../utils/PolygonsPointIndex.h"
+#include "../sliceDataStorage.h"
+#include "../utils/SVG.h"
+
+namespace cura {
+
+LocToLineGrid& Comb::getOutsideLocToLine()
+{
+    return *outside_loc_to_line;
+}
+
+Polygons& Comb::getBoundaryOutside()
+{
+    return *boundary_outside;
+}
+  
+Comb::Comb(const SliceDataStorage& storage, int layer_nr, const Polygons& comb_boundary_inside, int64_t comb_boundary_offset, bool travel_avoid_other_parts, int64_t travel_avoid_distance)
+: storage(storage)
+, layer_nr(layer_nr)
+, offset_from_outlines(comb_boundary_offset) // between second wall and infill / other walls
+, max_moveInside_distance2(offset_from_outlines * 2 * offset_from_outlines * 2)
+, offset_from_outlines_outside(travel_avoid_distance)
+, offset_from_inside_to_outside(offset_from_outlines + offset_from_outlines_outside)
+, max_crossing_dist2(offset_from_inside_to_outside * offset_from_inside_to_outside * 2) // so max_crossing_dist = offset_from_inside_to_outside * sqrt(2) =approx 1.5 to allow for slightly diagonal crossings and slightly inaccurate crossing computation
+, avoid_other_parts(travel_avoid_other_parts)
+, boundary_inside( comb_boundary_inside ) // copy the boundary, because the partsView_inside will reorder the polygons
+, partsView_inside( boundary_inside.splitIntoPartsView() ) // WARNING !! changes the order of boundary_inside !!
+, inside_loc_to_line(PolygonUtils::createLocToLineGrid(boundary_inside, comb_boundary_offset))
+, boundary_outside(
+        [&storage, layer_nr, travel_avoid_distance]()
+        {
+            return storage.getLayerOutlines(layer_nr, false).offset(travel_avoid_distance);
+        }
+    )
+, outside_loc_to_line(
+        [](Comb* comber, const int64_t offset_from_inside_to_outside)
+        {
+            return PolygonUtils::createLocToLineGrid(comber->getBoundaryOutside(), offset_from_inside_to_outside * 3 / 2);
+        }
+        , this
+        , offset_from_inside_to_outside
+    )
+{
+}
+
+Comb::~Comb()
+{
+    if (inside_loc_to_line)
+    {
+        delete inside_loc_to_line;
+    }
+}
+
+bool Comb::calc(Point startPoint, Point endPoint, CombPaths& combPaths, bool _startInside, bool _endInside, int64_t max_comb_distance_ignored, bool via_outside_makes_combing_fail, bool fail_on_unavoidable_obstacles)
+{
+    if (shorterThen(endPoint - startPoint, max_comb_distance_ignored))
+    {
+        return true;
+    }
+
+    //Move start and end point inside the comb boundary
+    unsigned int start_inside_poly = NO_INDEX;
+    const bool startInside = moveInside(_startInside, startPoint, start_inside_poly);
+
+    unsigned int end_inside_poly = NO_INDEX;
+    const bool endInside = moveInside(_endInside, endPoint, end_inside_poly);
+
+    unsigned int start_part_boundary_poly_idx;
+    unsigned int end_part_boundary_poly_idx;
+    unsigned int start_part_idx =   (start_inside_poly == NO_INDEX)?    NO_INDEX : partsView_inside.getPartContaining(start_inside_poly, &start_part_boundary_poly_idx);
+    unsigned int end_part_idx =     (end_inside_poly == NO_INDEX)?      NO_INDEX : partsView_inside.getPartContaining(end_inside_poly, &end_part_boundary_poly_idx);
+    
+    if (startInside && endInside && start_part_idx == end_part_idx)
+    { // normal combing within part
+        PolygonsPart part = partsView_inside.assemblePart(start_part_idx);
+        combPaths.emplace_back();
+        return LinePolygonsCrossings::comb(part, *inside_loc_to_line, startPoint, endPoint, combPaths.back(), -offset_dist_to_get_from_on_the_polygon_to_outside, max_comb_distance_ignored, fail_on_unavoidable_obstacles);
+    }
+    else 
+    { // comb inside part to edge (if needed) >> move through air avoiding other parts >> comb inside end part upto the endpoint (if needed) 
+        //  INSIDE  |          in_between            |            OUTSIDE     |              in_between         |     INSIDE
+        //        ^crossing_1_in     ^crossing_1_mid  ^crossing_1_out        ^crossing_2_out    ^crossing_2_mid   ^crossing_2_in
+        //
+        // when startPoint is inside crossing_1_in is of interest
+        // when it is in between inside and outside it is equal to crossing_1_mid
+
+        if (via_outside_makes_combing_fail)
+        {
+            return false;
+        }
+
+        Crossing start_crossing(startPoint, startInside, start_part_idx, start_part_boundary_poly_idx, boundary_inside, inside_loc_to_line);
+        Crossing end_crossing(endPoint, endInside, end_part_idx, end_part_boundary_poly_idx, boundary_inside, inside_loc_to_line);
+
+        { // find crossing over the in-between area between inside and outside
+            start_crossing.findCrossingInOrMid(partsView_inside, endPoint);
+            end_crossing.findCrossingInOrMid(partsView_inside, start_crossing.in_or_mid);
+        }
+
+        bool skip_avoid_other_parts_path = false;
+        if (skip_avoid_other_parts_path && vSize2(start_crossing.in_or_mid - end_crossing.in_or_mid) < offset_from_inside_to_outside * offset_from_inside_to_outside * 4)
+        { // parts are next to eachother, i.e. the direct crossing will always be smaller than two crossings via outside
+            skip_avoid_other_parts_path = true;
+        }
+
+        if (avoid_other_parts && !skip_avoid_other_parts_path)
+        { // compute the crossing points when moving through air
+            // comb through all air, since generally the outside consists of a single part
+
+            bool success = start_crossing.findOutside(*boundary_outside, end_crossing.in_or_mid, fail_on_unavoidable_obstacles, *this);
+            if (!success)
+            {
+                return false;
+            }
+
+            success = end_crossing.findOutside(*boundary_outside, start_crossing.out, fail_on_unavoidable_obstacles, *this);
+            if (!success)
+            {
+                return false;
+            }
+        }
+
+        // generate the actual comb paths
+        if (startInside)
+        {
+            // start to boundary
+            assert(start_crossing.dest_part.size() > 0 && "The part we start inside when combing should have been computed already!");
+            combPaths.emplace_back();
+            bool combing_succeeded = LinePolygonsCrossings::comb(start_crossing.dest_part, *inside_loc_to_line, startPoint, start_crossing.in_or_mid, combPaths.back(), -offset_dist_to_get_from_on_the_polygon_to_outside, max_comb_distance_ignored, fail_on_unavoidable_obstacles);
+            if (!combing_succeeded)
+            { // Couldn't comb between start point and computed crossing from the start part! Happens for very thin parts when the offset_to_get_off_boundary moves points to outside the polygon
+                return false;
+            }
+        }
+        
+        // throught air from boundary to boundary
+        if (avoid_other_parts && !skip_avoid_other_parts_path)
+        {
+            combPaths.emplace_back();
+            combPaths.throughAir = true;
+            if ( vSize(start_crossing.in_or_mid - end_crossing.in_or_mid) < vSize(start_crossing.in_or_mid - start_crossing.out) + vSize(end_crossing.in_or_mid - end_crossing.out) )
+            { // via outside is moving more over the in-between zone
+                combPaths.back().push_back(start_crossing.in_or_mid);
+                combPaths.back().push_back(end_crossing.in_or_mid);
+            }
+            else
+            {
+                bool combing_succeeded = LinePolygonsCrossings::comb(*boundary_outside, *outside_loc_to_line, start_crossing.out, end_crossing.out, combPaths.back(), offset_dist_to_get_from_on_the_polygon_to_outside, max_comb_distance_ignored, fail_on_unavoidable_obstacles);
+                if (!combing_succeeded)
+                {
+                    return false;
+                }
+            }
+        }
+        else 
+        { // directly through air (not avoiding other parts)
+            combPaths.emplace_back();
+            combPaths.throughAir = true;
+            combPaths.back().cross_boundary = true; // note: we don't actually know whether this is cross boundary, but it might very well be
+            combPaths.back().push_back(start_crossing.in_or_mid);
+            combPaths.back().push_back(end_crossing.in_or_mid);
+        }
+        if (skip_avoid_other_parts_path)
+        {
+            if (startInside == endInside && start_part_idx == end_part_idx)
+            {
+                if (startInside)
+                { // both start and end are inside
+                    combPaths.back().cross_boundary = PolygonUtils::polygonCollidesWithLineSegment(startPoint, endPoint, *inside_loc_to_line);
+                }
+                else
+                { // both start and end are outside
+                    combPaths.back().cross_boundary = PolygonUtils::polygonCollidesWithLineSegment(startPoint, endPoint, *outside_loc_to_line);
+                }
+            }
+            else
+            {
+                combPaths.back().cross_boundary = true;
+            }
+        }
+        
+        if (endInside)
+        {
+            // boundary to end
+            assert(end_crossing.dest_part.size() > 0 && "The part we end up inside when combing should have been computed already!");
+            combPaths.emplace_back();
+            
+            bool combing_succeeded = LinePolygonsCrossings::comb(end_crossing.dest_part, *inside_loc_to_line, end_crossing.in_or_mid, endPoint, combPaths.back(), -offset_dist_to_get_from_on_the_polygon_to_outside, max_comb_distance_ignored, fail_on_unavoidable_obstacles);
+            if (!combing_succeeded)
+            { // Couldn't comb between end point and computed crossing to the end part! Happens for very thin parts when the offset_to_get_off_boundary moves points to outside the polygon
+                return false;
+            }
+        }
+        
+        return true;
+    }
+}
+
+Comb::Crossing::Crossing(const Point& dest_point, const bool dest_is_inside, const unsigned int dest_part_idx, const unsigned int dest_part_boundary_crossing_poly_idx, const Polygons& boundary_inside, const LocToLineGrid* inside_loc_to_line)
+: dest_is_inside(dest_is_inside)
+, boundary_inside(boundary_inside)
+, inside_loc_to_line(inside_loc_to_line)
+, dest_point(dest_point)
+, dest_part_idx(dest_part_idx)
+{
+    if (dest_is_inside)
+    {
+        dest_crossing_poly.emplace(boundary_inside[dest_part_boundary_crossing_poly_idx]); // initialize with most obvious poly, cause mostly a combing move will move outside the part, rather than inside a hole in the part
+    }
+}
+
+bool Comb::moveInside(bool is_inside, Point& dest_point, unsigned int& inside_poly)
+{
+    if (is_inside)
+    {
+        ClosestPolygonPoint cpp = PolygonUtils::ensureInsideOrOutside(boundary_inside, dest_point, offset_extra_start_end, max_moveInside_distance2, &boundary_inside, inside_loc_to_line);
+        if (!cpp.isValid())
+        {
+            return false;
+        }
+        else
+        {
+            inside_poly = cpp.poly_idx;
+            return true;
+        }
+    }
+    return false;
+}
+
+void Comb::Crossing::findCrossingInOrMid(const PartsView& partsView_inside, const Point close_to)
+{
+    if (dest_is_inside)
+    { // in-case
+        // find the point on the start inside-polygon closest to the endpoint, but also kind of close to the start point
+        Point _dest_point(dest_point); // copy to local variable for lambda capture
+        std::function<int(Point)> close_towards_start_penalty_function([_dest_point](Point candidate){ return vSize2((candidate - _dest_point) / 10); });
+        dest_part = partsView_inside.assemblePart(dest_part_idx);
+
+        ClosestPolygonPoint boundary_crossing_point;
+        { // set [result] to a point on the destination part closest to close_to (but also a bit close to _dest_point)
+            std::unordered_set<unsigned int> dest_part_poly_indices;
+            for (unsigned int poly_idx : partsView_inside[dest_part_idx])
+            {
+                dest_part_poly_indices.emplace(poly_idx);
+            }
+            coord_t dist2_score = std::numeric_limits<coord_t>::max();
+            std::function<bool (const PolygonsPointIndex&)> line_processor
+                = [close_to, _dest_point, &boundary_crossing_point, &dist2_score, &dest_part_poly_indices](const PolygonsPointIndex& boundary_segment)
+                {
+                    if (dest_part_poly_indices.find(boundary_segment.poly_idx) == dest_part_poly_indices.end())
+                    { // we're not looking at a polygon from the dest_part
+                        return true; // a.k.a. continue;
+                    }
+                    Point closest_here = LinearAlg2D::getClosestOnLineSegment(close_to, boundary_segment.p(), boundary_segment.next().p());
+                    coord_t dist2_score_here = vSize2(close_to - closest_here) + vSize2(_dest_point - closest_here) / 10;
+                    if (dist2_score_here < dist2_score)
+                    {
+                        dist2_score = dist2_score_here;
+                        boundary_crossing_point = ClosestPolygonPoint(closest_here, boundary_segment.point_idx, boundary_segment.getPolygon(), boundary_segment.poly_idx);
+                    }
+                    return true;
+                };
+            inside_loc_to_line->processLine(std::make_pair(dest_point, close_to), line_processor);
+        }
+
+        Point result(boundary_crossing_point.p()); // the inside point of the crossing
+        if (!boundary_crossing_point.isValid())
+        { // no point has been found in the sparse grid
+            result = dest_point;
+        }
+
+        int64_t max_dist2 = std::numeric_limits<int64_t>::max();
+        ClosestPolygonPoint crossing_1_in_cp = PolygonUtils::ensureInsideOrOutside(dest_part, result, boundary_crossing_point, offset_dist_to_get_from_on_the_polygon_to_outside, max_dist2, &boundary_inside, inside_loc_to_line, close_towards_start_penalty_function);
+        if (crossing_1_in_cp.isValid())
+        {
+            dest_crossing_poly = crossing_1_in_cp.poly;
+            in_or_mid = result;
+        }
+        else
+        { // part is too small to be ensuring a point inside with the given distance
+            in_or_mid = dest_point; // just use the startPoint or endPoint itself
+        }
+    }
+    else
+    {
+        in_or_mid = dest_point; // mid-case
+    }
+};
+
+bool Comb::Crossing::findOutside(const Polygons& outside, const Point close_to, const bool fail_on_unavoidable_obstacles, Comb& comber)
+{
+    out = in_or_mid;
+    if (dest_is_inside || outside.inside(in_or_mid, true)) // start in_between
+    { // move outside
+        Point preferred_crossing_1_out = in_or_mid + normal(close_to - in_or_mid, comber.offset_from_inside_to_outside);
+        std::function<int(Point)> close_to_penalty_function([preferred_crossing_1_out](Point candidate){ return vSize2((candidate - preferred_crossing_1_out) / 2); });
+        std::optional<ClosestPolygonPoint> crossing_1_out_cpp = PolygonUtils::findClose(in_or_mid, outside, comber.getOutsideLocToLine(), close_to_penalty_function);
+        if (crossing_1_out_cpp)
+        {
+            out = PolygonUtils::moveOutside(*crossing_1_out_cpp, comber.offset_dist_to_get_from_on_the_polygon_to_outside);
+        }
+        else 
+        {
+            PolygonUtils::moveOutside(outside, out, comber.offset_dist_to_get_from_on_the_polygon_to_outside);
+        }
+    }
+    int64_t in_out_dist2_1 = vSize2(out - in_or_mid); 
+    if (dest_is_inside && in_out_dist2_1 > comber.max_crossing_dist2) // moveInside moved too far
+    { // if move is too far over in_between
+        // find crossing closer by
+        assert(dest_crossing_poly && "destination crossing poly should have been instantiated!");
+        std::shared_ptr<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>> best = findBestCrossing(outside, *dest_crossing_poly, dest_point, close_to, comber);
+        if (best)
+        {
+            in_or_mid = PolygonUtils::moveInside(best->first, comber.offset_dist_to_get_from_on_the_polygon_to_outside);
+            out = PolygonUtils::moveOutside(best->second, comber.offset_dist_to_get_from_on_the_polygon_to_outside);
+        }
+        if (fail_on_unavoidable_obstacles && vSize2(out - in_or_mid) > comber.max_crossing_dist2) // moveInside moved still too far
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+
+std::shared_ptr<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>> Comb::Crossing::findBestCrossing(const Polygons& outside, ConstPolygonRef from, const Point estimated_start, const Point estimated_end, Comb& comber)
+{
+    ClosestPolygonPoint* best_in = nullptr;
+    ClosestPolygonPoint* best_out = nullptr;
+    int64_t best_detour_score = std::numeric_limits<int64_t>::max();
+    int64_t best_crossing_dist2;
+    std::vector<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>> crossing_out_candidates = PolygonUtils::findClose(from, outside, comber.getOutsideLocToLine());
+    bool seen_close_enough_connection = false;
+    for (std::pair<ClosestPolygonPoint, ClosestPolygonPoint>& crossing_candidate : crossing_out_candidates)
+    {
+        int64_t crossing_dist2 = vSize2(crossing_candidate.first.location - crossing_candidate.second.location);
+        if (crossing_dist2 > comber.max_crossing_dist2 * 2)
+        { // preliminary filtering
+            continue;
+        }
+        
+        int64_t dist_to_start = vSize(crossing_candidate.second.location - estimated_start); // use outside location, so that the crossing direction is taken into account
+        int64_t dist_to_end = vSize(crossing_candidate.second.location - estimated_end);
+        int64_t detour_dist = dist_to_start + dist_to_end;
+        int64_t detour_score = crossing_dist2 + detour_dist * detour_dist / 1000; // prefer a closest connection over a detour
+        // The detour distance is generally large compared to the crossing distance.
+        // While the crossing is generally about 1mm across,
+        // the distance between an arbitrary point and the boundary may well be a couple of centimetres.
+        // So the crossing_dist2 is about 1.000.000 while the detour_dist_2 is in the order of 400.000.000
+        // In the end we just want to choose between two points which have the _same_ crossing distance, modulo rounding error.
+        if ((!seen_close_enough_connection && detour_score < best_detour_score) // keep the best as long as we havent seen one close enough (so that we may walk along the polygon to find a closer connection from it in the code below)
+            || (!seen_close_enough_connection && crossing_dist2 <= comber.max_crossing_dist2) // make the one which is close enough the best as soon as we see one close enough
+            || (seen_close_enough_connection && crossing_dist2 <= comber.max_crossing_dist2 && detour_score < best_detour_score)) // update to keep the best crossing which is close enough already
+        {
+            if (!seen_close_enough_connection && crossing_dist2 <= comber.max_crossing_dist2)
+            {
+                seen_close_enough_connection = true;
+            }
+            best_in = &crossing_candidate.first;
+            best_out = &crossing_candidate.second;
+            best_detour_score = detour_score;
+            best_crossing_dist2 = crossing_dist2;
+        }
+    }
+    if (best_detour_score == std::numeric_limits<int64_t>::max())
+    { // i.e. if best_in == nullptr or if best_out == nullptr
+        return std::shared_ptr<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>>();
+    }
+    if (best_crossing_dist2 > comber.max_crossing_dist2)
+    { // find closer point on line segments, rather than moving between vertices of the polygons only
+        PolygonUtils::walkToNearestSmallestConnection(*best_in, *best_out);
+        best_crossing_dist2 = vSize2(best_in->location - best_out->location);
+        if (best_crossing_dist2 > comber.max_crossing_dist2)
+        {
+            return std::shared_ptr<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>>();
+        }
+    }
+    return std::make_shared<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>>(*best_in, *best_out);
+}
+
+}//namespace cura

src/pathPlanning/Comb.h

@@ -0,0 +1,179 @@
+/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#ifndef PATH_PLANNING_COMB_H
+#define PATH_PLANNING_COMB_H
+
+#include <memory> // shared_ptr
+
+#include "../utils/optional.h"
+#include "../utils/polygon.h"
+#include "../utils/SparsePointGridInclusive.h"
+#include "../utils/polygonUtils.h"
+#include "../utils/LazyInitialization.h"
+
+#include "LinePolygonsCrossings.h"
+#include "CombPath.h"
+#include "CombPaths.h"
+
+namespace cura 
+{
+
+class SliceDataStorage;
+
+/*!
+ * Class for generating a full combing actions from a travel move from a start point to an end point.
+ * A single Comb object is used for each layer.
+ * 
+ * Comb::calc is the main function of this class.
+ * 
+ * Typical output: A combing path to the boundary of the polygon + a move through air avoiding other parts in the layer + a combing path from the boundary of the ending polygon to the end point.
+ * Each of these three is a CombPath; the first and last are within Comb::boundary_inside while the middle is outside of Comb::boundary_outside.
+ * Between these there is a little gap where the nozzle crosses the boundary of an object approximately perpendicular to its boundary.
+ * 
+ * As an optimization, the combing paths inside are calculated on specifically those PolygonsParts within which to comb, while the coundary_outside isn't split into outside parts, 
+ * because generally there is only one outside part; encapsulated holes occur less often.
+ */
+class Comb
+{
+    friend class LinePolygonsCrossings;
+private:
+    /*!
+     * A crossing from the inside boundary to the outside boundary.
+     * 
+     * 'dest' is either the startPoint or the endpoint of a whole combing move.
+     */
+    class Crossing
+    {
+    public:
+        bool dest_is_inside; //!< Whether the startPoint or endPoint is inside the inside boundary
+        Point in_or_mid; //!< The point on the inside boundary, or in between the inside and outside boundary if the start/end point isn't inside the inside boudary
+        Point out; //!< The point on the outside boundary
+        PolygonsPart dest_part; //!< The assembled inside-boundary PolygonsPart in which the dest_point lies. (will only be initialized when Crossing::dest_is_inside holds)
+        std::optional<ConstPolygonRef> dest_crossing_poly; //!< The polygon of the part in which dest_point lies, which will be crossed (often will be the outside polygon)
+        const Polygons& boundary_inside; //!< The inside boundary as in \ref Comb::boundary_inside
+        const LocToLineGrid* inside_loc_to_line; //!< The loc to line grid \ref Comb::inside_loc_to_line
+
+        /*!
+         * Simple constructor
+         * 
+         * \param dest_point Either the eventual startPoint or the eventual endPoint of this combing move.
+         * \param dest_is_inside Whether the startPoint or endPoint is inside the inside boundary.
+         * \param dest_part_idx The index into Comb:partsView_inside of the part in which the \p dest_point is.
+         * \param dest_part_boundary_crossing_poly_idx The index in \p boundary_inside of the polygon of the part in which dest_point lies, which will be crossed (often will be the outside polygon).
+         * \param boundary_inside The boundary within which to comb.
+         */
+        Crossing(const Point& dest_point, const bool dest_is_inside, const unsigned int dest_part_idx, const unsigned int dest_part_boundary_crossing_poly_idx, const Polygons& boundary_inside, const LocToLineGrid* inside_loc_to_line);
+
+        /*!
+         * Find the not-outside location (Combing::in_or_mid) of the crossing between to the outside boundary
+         * 
+         * \param partsView_inside Structured indices onto Comb::boundary_inside which shows which polygons belong to which part. 
+         * \param close_to[in] Try to get a crossing close to this point
+         */
+        void findCrossingInOrMid(const PartsView& partsView_inside, const Point close_to);
+
+        /*!
+         * Find the outside location (Combing::out)
+         * 
+         * \param outside The outside boundary polygons
+         * \param close_to A point to get closer to when there are multiple candidates on the outside boundary which are almost equally close to the Crossing::in_or_mid
+         * \param fail_on_unavoidable_obstacles When moving over other parts is inavoidable, stop calculation early and return false.
+         * \param comber[in] The combing calculator which has references to the offsets and boundaries to use in combing.
+         */
+        bool findOutside(const Polygons& outside, const Point close_to, const bool fail_on_unavoidable_obstacles, Comb& comber);
+
+    private:
+        const Point dest_point; //!< Either the eventual startPoint or the eventual endPoint of this combing move
+        unsigned int dest_part_idx; //!< The index into Comb:partsView_inside of the part in which the \p dest_point is.
+
+        /*!
+         * Find the best crossing from some inside polygon to the outside boundary.
+         * 
+         * The detour from \p estimated_start to \p estimated_end is minimized.
+         * 
+         * \param outside The outside boundary polygons
+         * \param from From which inside boundary the crossing to the outside starts or ends
+         * \param estimated_start The one point to which to stay close when evaluating crossings which cross about the same distance
+         * \param estimated_end The other point to which to stay close when evaluating crossings which cross about the same distance
+         * \param comber[in] The combing calculator which has references to the offsets and boundaries to use in combing.
+         * \return A pair of which the first is the crossing point on the inside boundary and the second the crossing point on the outside boundary
+         */
+        std::shared_ptr<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>> findBestCrossing(const Polygons& outside, ConstPolygonRef from, Point estimated_start, Point estimated_end, Comb& comber);
+    };
+
+
+    const SliceDataStorage& storage; //!< The storage from which to compute the outside boundary, when needed.
+    const int layer_nr; //!< The layer number for the layer for which to compute the outside boundary, when needed.
+    
+    const int64_t offset_from_outlines; //!< Offset from the boundary of a part to the comb path. (nozzle width / 2)
+    const int64_t max_moveInside_distance2; //!< Maximal distance of a point to the Comb::boundary_inside which is still to be considered inside. (very sharp corners not allowed :S)
+    const int64_t offset_from_outlines_outside; //!< Offset from the boundary of a part to a travel path which avoids it by this distance.
+    const int64_t offset_from_inside_to_outside; //!< The sum of the offsets for the inside and outside boundary Comb::offset_from_outlines and Comb::offset_from_outlines_outside
+    const int64_t max_crossing_dist2; //!< The maximal distance by which to cross the in_between area between inside and outside
+    static const int64_t max_moveOutside_distance2 = INT64_MAX; //!< Any point which is not inside should be considered outside.
+    static const int64_t offset_dist_to_get_from_on_the_polygon_to_outside = 40; //!< in order to prevent on-boundary vs crossing boundary confusions (precision thing)
+    static const int64_t offset_extra_start_end = 100; //!< Distance to move start point and end point toward eachother to extra avoid collision with the boundaries.
+
+    const bool avoid_other_parts; //!< Whether to perform inverse combing a.k.a. avoid parts.
+    
+    Polygons boundary_inside; //!< The boundary within which to comb. (Will be reordered by the partsView_inside)
+    const PartsView partsView_inside; //!< Structured indices onto boundary_inside which shows which polygons belong to which part. 
+    LocToLineGrid* inside_loc_to_line; //!< The SparsePointGridInclusive mapping locations to line segments of the inner boundary.
+    LazyInitialization<Polygons> boundary_outside; //!< The boundary outside of which to stay to avoid collision with other layer parts. This is a pointer cause we only compute it when we move outside the boundary (so not when there is only a single part in the layer)
+    LazyInitialization<LocToLineGrid, Comb*, const int64_t> outside_loc_to_line; //!< The SparsePointGridInclusive mapping locations to line segments of the outside boundary.
+
+    /*!
+     * Get the SparsePointGridInclusive mapping locations to line segments of the outside boundary. Calculate it when it hasn't been calculated yet.
+     */
+    LocToLineGrid& getOutsideLocToLine();
+
+     /*!
+      * Get the boundary_outside, which is an offset from the outlines of all meshes in the layer. Calculate it when it hasn't been calculated yet.
+      */
+    Polygons& getBoundaryOutside();
+
+    /*!
+     * Move the startPoint or endPoint inside when it should be inside
+     * \param is_inside[in] Whether the \p dest_point should be inside
+     * \param dest_point[in,out] The point to move
+     * \param start_inside_poly[out] The polygon in which the point has been moved
+     * \return Whether we have moved the point inside
+     */
+    bool moveInside(bool is_inside, Point& dest_point, unsigned int& start_inside_poly);
+
+public:
+    /*!
+     * Initializes the combing areas for every mesh in the layer (not support)
+     * 
+     * \warning \ref Comb::calc changes the order of polygons in \p Comb::comb_boundary_inside
+     * 
+     * \param storage Where the layer polygon data is stored
+     * \param layer_nr The number of the layer for which to generate the combing areas.
+     * \param comb_boundary_inside The comb boundary within which to comb within layer parts.
+     * \param offset_from_outlines The offset from the outline polygon, to create the combing boundary in case there is no second wall.
+     * \param travel_avoid_other_parts Whether to avoid other layer parts when traveling through air.
+     * \param travel_avoid_distance The distance by which to avoid other layer parts when traveling through air.
+     */
+    Comb(const SliceDataStorage& storage, int layer_nr, const Polygons& comb_boundary_inside, int64_t offset_from_outlines, bool travel_avoid_other_parts, int64_t travel_avoid_distance);
+
+    ~Comb();
+
+    /*!
+     * Calculate the comb paths (if any) - one for each polygon combed alternated with travel paths
+     * 
+     * \warning Changes the order of polygons in \ref Comb::comb_boundary_inside
+     * 
+     * \param startPoint Where to start moving from
+     * \param endPoint Where to move to
+     * \param combPoints Output parameter: The points along the combing path, excluding the \p startPoint (?) and \p endPoint
+     * \param startInside Whether we want to start inside the comb boundary
+     * \param endInside Whether we want to end up inside the comb boundary
+     * \param via_outside_makes_combing_fail When going through air is inavoidable, stop calculation early and return false.
+     * \param fail_on_unavoidable_obstacles When moving over other parts is inavoidable, stop calculation early and return false.
+     * \return Whether combing has succeeded; otherwise a retraction is needed.
+     */
+    bool calc(Point startPoint, Point endPoint, CombPaths& combPaths, bool startInside, bool endInside, int64_t max_comb_distance_ignored, bool via_outside_makes_combing_fail, bool fail_on_unavoidable_obstacles);
+};
+
+}//namespace cura
+
+#endif//PATH_PLANNING_COMB_H

src/pathPlanning/CombPath.h

@@ -0,0 +1,17 @@
+/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#ifndef PATH_PLANNING_COMB_PATH_H
+#define PATH_PLANNING_COMB_PATH_H
+
+#include "../utils/intpoint.h"
+
+namespace cura 
+{
+
+struct CombPath : public  std::vector<Point> //!< A single path either inside or outise the parts
+{
+    bool cross_boundary = false; //!< Whether the path crosses a boundary.
+};
+
+}//namespace cura
+
+#endif//PATH_PLANNING_COMB_PATH_H

src/pathPlanning/CombPaths.h

@@ -0,0 +1,17 @@
+/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#ifndef PATH_PLANNING_COMB_PATHS_H
+#define PATH_PLANNING_COMB_PATHS_H
+
+#include "CombPath.h"
+
+namespace cura 
+{
+
+struct CombPaths : public  std::vector<CombPath> //!< A list of paths alternating between inside a part and outside a part
+{
+    bool throughAir = false; //!< Whether the path is one which moves through air.
+}; 
+
+}//namespace cura
+
+#endif//PATH_PLANNING_COMB_PATHS_H

src/pathPlanning/GCodePath.cpp

@@ -0,0 +1,24 @@
+//Copyright (C) 2016 Ultimaker
+//Released under terms of the AGPLv3 License
+
+#include "GCodePath.h"
+
+namespace cura
+{
+
+bool GCodePath::isTravelPath()
+{
+    return config->isTravelPath();
+}
+
+double GCodePath::getExtrusionMM3perMM()
+{
+    return flow * config->getExtrusionMM3perMM();
+}
+
+int GCodePath::getLineWidth()
+{
+    return flow * config->getLineWidth() * config->getFlowPercentage() / 100.0;
+}
+
+}

src/pathPlanning/GCodePath.h

@@ -0,0 +1,64 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef PATH_PLANNING_G_CODE_PATH_H
+#define PATH_PLANNING_G_CODE_PATH_H
+
+#include "../SpaceFillType.h"
+#include "../GCodePathConfig.h"
+
+#include "TimeMaterialEstimates.h"
+
+namespace cura 
+{
+
+/*!
+ * A class for representing a planned path.
+ * 
+ * A path consists of several segments of the same type of movement: retracted travel, infill extrusion, etc.
+ * 
+ * This is a compact premature representation in which are line segments have the same config, i.e. the config of this path.
+ * 
+ * In the final representation (gcode) each line segment may have different properties, 
+ * which are added when the generated GCodePaths are processed.
+ */
+class GCodePath
+{
+public:
+    const GCodePathConfig* config; //!< The configuration settings of the path.
+    SpaceFillType space_fill_type; //!< The type of space filling of which this path is a part
+    float flow; //!< A type-independent flow configuration (used for wall overlap compensation)
+    bool retract; //!< Whether the path is a move path preceded by a retraction move; whether the path is a retracted move path. 
+    bool perform_z_hop; //!< Whether to perform a z_hop in this path, which is assumed to be a travel path.
+    bool perform_prime; //!< Whether this path is preceded by a prime (poop)
+    std::vector<Point> points; //!< The points constituting this path.
+    bool done;//!< Path is finished, no more moves should be added, and a new path should be started instead of any appending done to this one.
+
+    bool spiralize; //!< Whether to gradually increment the z position during the printing of this path. A sequence of spiralized paths should start at the given layer height and end in one layer higher.
+
+    TimeMaterialEstimates estimates; //!< Naive time and material estimates
+
+    /*!
+     * Whether this config is the config of a travel path.
+     * 
+     * \return Whether this config is the config of a travel path.
+     */
+    bool isTravelPath();
+
+    /*!
+     * Get the material flow in mm^3 per mm traversed.
+     * 
+     * \warning Can only be called after the layer height has been set (which is done while writing the gcode!)
+     * 
+     * \return The flow
+     */
+    double getExtrusionMM3perMM();
+
+    /*!
+     * Get the actual line width (modulated by the flow)
+     * \return the actual line width as shown in layer view
+     */
+    int getLineWidth();
+};
+
+}//namespace cura
+
+#endif//PATH_PLANNING_G_CODE_PATH_H

src/pathPlanning/LinePolygonsCrossings.cpp

@@ -0,0 +1,227 @@
+/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#include "LinePolygonsCrossings.h"
+
+#include <algorithm>
+
+#include "../utils/polygonUtils.h"
+#include "../sliceDataStorage.h"
+#include "../utils/SVG.h"
+
+namespace cura {
+
+
+bool LinePolygonsCrossings::calcScanlineCrossings(bool fail_on_unavoidable_obstacles)
+{
+    
+    min_crossing_idx = NO_INDEX;
+    max_crossing_idx = NO_INDEX;
+
+    for(unsigned int poly_idx = 0; poly_idx < boundary.size(); poly_idx++)
+    {
+        PolyCrossings minMax(poly_idx); 
+        PolygonRef poly = boundary[poly_idx];
+        Point p0 = transformation_matrix.apply(poly[poly.size() - 1]);
+        for(unsigned int point_idx = 0; point_idx < poly.size(); point_idx++)
+        {
+            Point p1 = transformation_matrix.apply(poly[point_idx]);
+            if ((p0.Y >= transformed_startPoint.Y && p1.Y <= transformed_startPoint.Y) || (p1.Y >= transformed_startPoint.Y && p0.Y <= transformed_startPoint.Y))
+            { // if line segment crosses the line through the transformed start and end point (aka scanline)
+                if (p1.Y == p0.Y) //Line segment is parallel with the scanline. That means that both endpoints lie on the scanline, so they will have intersected with the adjacent line.
+                {
+                    p0 = p1;
+                    continue;
+                }
+                int64_t x = p0.X + (p1.X - p0.X) * (transformed_startPoint.Y - p0.Y) / (p1.Y - p0.Y); // intersection point between line segment and the scanline
+                
+                if (x >= transformed_startPoint.X && x <= transformed_endPoint.X)
+                {
+                    if (!((p1.Y == transformed_startPoint.Y && p1.Y < p0.Y) || (p0.Y == transformed_startPoint.Y && p0.Y < p1.Y)))
+                    { // perform edge case only for line segments on and below the scanline, not for line segments on and above.
+                        // \/ will be no crossings and /\ two, but most importantly | will be one crossing.
+                        minMax.n_crossings++;
+                    }
+                    if(x < minMax.min.x) //For the leftmost intersection, move x left to stay outside of the border.
+                                         //Note: The actual distance from the intersection to the border is almost always less than dist_to_move_boundary_point_outside, since it only moves along the direction of the scanline.
+                    {
+                        minMax.min.x = x;
+                        minMax.min.point_idx = point_idx;
+                    }
+                    if(x > minMax.max.x) //For the rightmost intersection, move x right to stay outside of the border.
+                    {
+                        minMax.max.x = x;
+                        minMax.max.point_idx = point_idx;
+                    }
+                }
+            }
+            p0 = p1;
+        }
+
+        if (fail_on_unavoidable_obstacles && minMax.n_crossings % 2 == 1)
+        { // if start area and end area are not the same
+            return false;
+        }
+        else if (minMax.min.point_idx != NO_INDEX) // then always also max.point_idx != NO_INDEX
+        { // if this polygon crossed the scanline
+            if (min_crossing_idx == NO_INDEX || minMax.min.x < crossings[min_crossing_idx].min.x) { min_crossing_idx = crossings.size(); }
+            if (max_crossing_idx == NO_INDEX || minMax.max.x > crossings[max_crossing_idx].max.x) { max_crossing_idx = crossings.size(); }
+            crossings.push_back(minMax);
+        }
+    }
+    return true;
+}
+
+
+bool LinePolygonsCrossings::lineSegmentCollidesWithBoundary()
+{
+    Point diff = endPoint - startPoint;
+
+    transformation_matrix = PointMatrix(diff);
+    transformed_startPoint = transformation_matrix.apply(startPoint);
+    transformed_endPoint = transformation_matrix.apply(endPoint);
+
+    for(PolygonRef poly : boundary)
+    {
+        Point p0 = transformation_matrix.apply(poly.back());
+        for(Point p1_ : poly)
+        {
+            Point p1 = transformation_matrix.apply(p1_);
+            // when the boundary just touches the line don't disambiguate between the boundary moving on to actually cross the line
+            // and the boundary bouncing back, resulting in not a real collision - to keep the algorithm simple.
+            //
+            // disregard overlapping line segments; probably the next or previous line segment is not overlapping, but will give a collision
+            // when the boundary line segment fully overlaps with the line segment this edge case is not viewed as a collision
+            if (p1.Y != p0.Y && ((p0.Y >= transformed_startPoint.Y && p1.Y <= transformed_startPoint.Y) || (p1.Y >= transformed_startPoint.Y && p0.Y <= transformed_startPoint.Y)))
+            {
+                int64_t x = p0.X + (p1.X - p0.X) * (transformed_startPoint.Y - p0.Y) / (p1.Y - p0.Y);
+
+                if (x > transformed_startPoint.X && x < transformed_endPoint.X)
+                {
+                    return true;
+                }
+            }
+            p0 = p1;
+        }
+    }
+    
+    return false;
+}
+
+
+bool LinePolygonsCrossings::getCombingPath(CombPath& combPath, int64_t max_comb_distance_ignored, bool fail_on_unavoidable_obstacles)
+{
+    if (shorterThen(endPoint - startPoint, max_comb_distance_ignored) || !lineSegmentCollidesWithBoundary())
+    {
+        //We're not crossing any boundaries. So skip the comb generation.
+        combPath.push_back(startPoint); 
+        combPath.push_back(endPoint);
+        return true;
+    }
+    
+    bool success = calcScanlineCrossings(fail_on_unavoidable_obstacles);
+    if (!success)
+    {
+        return false;
+    }
+
+    CombPath basicPath;
+    getBasicCombingPath(basicPath);
+    optimizePath(basicPath, combPath);
+//     combPath = basicPath; // uncomment to disable comb path optimization
+    return true;
+}
+
+
+void LinePolygonsCrossings::getBasicCombingPath(CombPath& combPath) 
+{
+    for (PolyCrossings* crossing = getNextPolygonAlongScanline(transformed_startPoint.X)
+        ; crossing != nullptr
+        ; crossing = getNextPolygonAlongScanline(crossing->max.x))
+    {
+        getBasicCombingPath(*crossing, combPath);
+    }
+    combPath.push_back(endPoint);
+}
+
+void LinePolygonsCrossings::getBasicCombingPath(PolyCrossings& polyCrossings, CombPath& combPath) 
+{
+    PolygonRef poly = boundary[polyCrossings.poly_idx];
+    combPath.push_back(transformation_matrix.unapply(Point(polyCrossings.min.x - std::abs(dist_to_move_boundary_point_outside), transformed_startPoint.Y)));
+    if ( ( polyCrossings.max.point_idx - polyCrossings.min.point_idx + poly.size() ) % poly.size() 
+        < poly.size() / 2 )
+    { // follow the path in the same direction as the winding order of the boundary polygon
+        for(unsigned int point_idx = polyCrossings.min.point_idx
+            ; point_idx != polyCrossings.max.point_idx
+            ; point_idx = (point_idx < poly.size() - 1) ? (point_idx + 1) : (0))
+        {
+            combPath.push_back(PolygonUtils::getBoundaryPointWithOffset(poly, point_idx, dist_to_move_boundary_point_outside));
+        }
+    }
+    else
+    { // follow the path in the opposite direction of the winding order of the boundary polygon
+        unsigned int min_idx = (polyCrossings.min.point_idx == 0)? poly.size() - 1: polyCrossings.min.point_idx - 1;
+        unsigned int max_idx = (polyCrossings.max.point_idx == 0)? poly.size() - 1: polyCrossings.max.point_idx - 1;
+
+        for(unsigned int point_idx = min_idx; point_idx != max_idx; point_idx = (point_idx > 0) ? (point_idx - 1) : (poly.size() - 1))
+        {
+            combPath.push_back(PolygonUtils::getBoundaryPointWithOffset(poly, point_idx, dist_to_move_boundary_point_outside));
+        }
+    }
+    combPath.push_back(transformation_matrix.unapply(Point(polyCrossings.max.x + std::abs(dist_to_move_boundary_point_outside), transformed_startPoint.Y)));
+}
+
+
+
+LinePolygonsCrossings::PolyCrossings* LinePolygonsCrossings::getNextPolygonAlongScanline(int64_t x)
+{
+    PolyCrossings* ret = nullptr;
+    for(PolyCrossings& crossing : crossings)
+    {
+        if (crossing.min.x > x && (ret == nullptr || crossing.min.x < ret->min.x) )
+        {
+            ret = &crossing;
+        }
+    }
+    return ret;
+}
+
+bool LinePolygonsCrossings::optimizePath(CombPath& comb_path, CombPath& optimized_comb_path) 
+{
+    optimized_comb_path.push_back(startPoint);
+    for(unsigned int point_idx = 1; point_idx<comb_path.size(); point_idx++)
+    {
+        if(comb_path[point_idx] == comb_path[point_idx - 1]) //Two points are the same. Skip the second.
+        {
+            continue;
+        }
+        Point& current_point = optimized_comb_path.back();
+        if (PolygonUtils::polygonCollidesWithLineSegment(current_point, comb_path[point_idx], loc_to_line_grid))
+        {
+            if (PolygonUtils::polygonCollidesWithLineSegment(current_point, comb_path[point_idx - 1], loc_to_line_grid))
+            {
+                comb_path.cross_boundary = true;
+            }
+            optimized_comb_path.push_back(comb_path[point_idx - 1]);
+        }
+        else 
+        {
+            // : dont add the newest point
+            
+            // TODO: add the below extra optimization? (+/- 7% extra computation time, +/- 2% faster print for Dual_extrusion_support_generation.stl)
+            while (optimized_comb_path.size() > 1)
+            {
+                if (PolygonUtils::polygonCollidesWithLineSegment(optimized_comb_path[optimized_comb_path.size() - 2], comb_path[point_idx], loc_to_line_grid))
+                {
+                    break;
+                }
+                else 
+                {
+                    optimized_comb_path.pop_back();
+                }
+            }
+        }
+    }
+    optimized_comb_path.push_back(comb_path.back());
+    return true;
+}
+
+}//namespace cura

src/pathPlanning/LinePolygonsCrossings.h

@@ -1,24 +1,15 @@
 /** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
-#ifndef COMB_H
-#define COMB_H
+#ifndef PATH_PLANNING_LINE_POLYGONS_CROSSINGS_H
+#define PATH_PLANNING_LINE_POLYGONS_CROSSINGS_H
 
-#include <memory> // shared_ptr
+#include "../utils/polygon.h"
+#include "../utils/polygonUtils.h"
+#include "../utils/SparseLineGrid.h"
 
-#include "utils/polygon.h"
-#include "utils/BucketGrid2D.h"
-#include "utils/polygonUtils.h"
+#include "CombPath.h"
 
 namespace cura 
 {
-    
-struct CombPath : public  std::vector<Point> //!< A single path either inside or outise the parts
-{
-    bool cross_boundary = false; //!< Whether the path crosses a boundary.
-};
-struct CombPaths : public  std::vector<CombPath> //!< A list of paths alternating between inside a part and outside a part
-{
-    bool throughAir = false; //!< Whether the path is one which moves through air.
-}; 
 
 /*!
  * Class for generating a combing move action from point a to point b and avoiding collision with other parts when moving through air.
@@ -64,6 +55,7 @@ private:
         unsigned int poly_idx; //!< The index of the polygon which crosses the scanline
         Crossing min; //!< The point where the polygon first crosses the scanline.
         Crossing max; //!< The point where the polygon last crosses the scanline.
+        int n_crossings; //!< The number of times the polygon crossed the scanline.
         /*!
          * Create a PolyCrossings with minimal initialization. PolyCrossings::min and PolyCrossings::max are not yet computed.
          * \param poly_idx The index of the polygon in LinePolygonsCrossings::boundary
@@ -71,6 +63,7 @@ private:
         PolyCrossings(unsigned int poly_idx) 
         : poly_idx(poly_idx)
         , min(INT64_MAX, NO_INDEX), max(INT64_MIN, NO_INDEX) 
+        , n_crossings(0)
         { 
         }
     };
@@ -89,14 +82,15 @@ private:
     unsigned int max_crossing_idx; //!< The index into LinePolygonsCrossings::crossings to the crossing with the maximal PolyCrossings::max crossing of all PolyCrossings's.
     
     Polygons& boundary; //!< The boundary not to cross during combing.
+    LocToLineGrid& loc_to_line_grid; //!< Mapping from locations to line segments of \ref LinePolygonsCrossings::boundary
     Point startPoint; //!< The start point of the scanline.
     Point endPoint; //!< The end point of the scanline.
     
     int64_t dist_to_move_boundary_point_outside; //!< The distance used to move outside or inside so that a boundary point doesn't intersect with the boundary anymore. Neccesary due to computational rounding problems. Use negative value for insicde combing.
     
     PointMatrix transformation_matrix; //!< The transformation which rotates everything such that the scanline is aligned with the x-axis.
-    Point transformed_startPoint; //!< The LinePolygonsCrossings::startPoint as transformed by Comb::transformation_matrix
-    Point transformed_endPoint; //!< The LinePolygonsCrossings::endPoint as transformed by Comb::transformation_matrix
+    Point transformed_startPoint; //!< The LinePolygonsCrossings::startPoint as transformed by Comb::transformation_matrix such that it has (roughly) the same Y as transformed_endPoint
+    Point transformed_endPoint; //!< The LinePolygonsCrossings::endPoint as transformed by Comb::transformation_matrix such that it has (roughly) the same Y as transformed_startPoint
 
     
     /*!
@@ -109,15 +103,19 @@ private:
     
     /*!
      * Calculate Comb::crossings, Comb::min_crossing_idx and Comb::max_crossing_idx.
+     * \param fail_on_unavoidable_obstacles When moving over other parts is inavoidable, stop calculation early and return false.
+     * \return Whether combing succeeded, i.e. when fail_on_unavoidable_obstacles: we didn't cross any gaps/other parts
      */
-    void calcScanlineCrossings();
+    bool calcScanlineCrossings(bool fail_on_unavoidable_obstacles);
     
     /*! 
      * Get the basic combing path and optimize it.
      * 
      * \param combPath Output parameter: the points along the combing path.
+     * \param fail_on_unavoidable_obstacles When moving over other parts is inavoidable, stop calculation early and return false.
+     * \return Whether combing succeeded, i.e. we didn't cross any gaps/other parts
      */
-    void getCombingPath(CombPath& combPath, int64_t max_comb_distance_ignored = MM2INT(1.5));
+    bool getCombingPath(CombPath& combPath, int64_t max_comb_distance_ignored, bool fail_on_unavoidable_obstacles);
     
     /*! 
      * Get the basic combing path, without shortcuts. The path goes straight toward the endPoint and follows the boundary when it hits it, until it passes the scanline again.
@@ -168,8 +166,12 @@ private:
      * \param end the end point
      * \param dist_to_move_boundary_point_outside Distance used to move a point from a boundary so that it doesn't intersect with it anymore. (Precision issue)
      */
-    LinePolygonsCrossings(Polygons& boundary, Point& start, Point& end, int64_t dist_to_move_boundary_point_outside)
-    : boundary(boundary), startPoint(start), endPoint(end), dist_to_move_boundary_point_outside(dist_to_move_boundary_point_outside)
+    LinePolygonsCrossings(Polygons& boundary, LocToLineGrid& loc_to_line_grid, Point& start, Point& end, int64_t dist_to_move_boundary_point_outside)
+    : boundary(boundary)
+    , loc_to_line_grid(loc_to_line_grid)
+    , startPoint(start)
+    , endPoint(end)
+    , dist_to_move_boundary_point_outside(dist_to_move_boundary_point_outside)
     {
     }
     
@@ -178,103 +180,20 @@ public:
     /*!
      * The main function of this class: calculate one combing path within the boundary.
      * \param boundary The polygons to follow when calculating the basic combing path
+     * \param loc_to_line_grid A sparse grid mapping cells to all line segments of (at least) \p boundary in those cells
      * \param startPoint From where to start the combing move.
      * \param endPoint Where to end the combing move.
      * \param combPath Output parameter: the combing path generated.
+     * \param fail_on_unavoidable_obstacles When moving over other parts is inavoidable, stop calculation early and return false.
+     * \return Whether combing succeeded, i.e. we didn't cross any gaps/other parts
      */
-    static void comb(Polygons& boundary, Point startPoint, Point endPoint, CombPath& combPath, int64_t dist_to_move_boundary_point_outside, int64_t max_comb_distance_ignored = MM2INT(1.5))
+    static bool comb(Polygons& boundary, LocToLineGrid& loc_to_line_grid, Point startPoint, Point endPoint, CombPath& combPath, int64_t dist_to_move_boundary_point_outside, int64_t max_comb_distance_ignored, bool fail_on_unavoidable_obstacles)
     {
-        LinePolygonsCrossings linePolygonsCrossings(boundary, startPoint, endPoint, dist_to_move_boundary_point_outside);
-        linePolygonsCrossings.getCombingPath(combPath, max_comb_distance_ignored);
+        LinePolygonsCrossings linePolygonsCrossings(boundary, loc_to_line_grid, startPoint, endPoint, dist_to_move_boundary_point_outside);
+        return linePolygonsCrossings.getCombingPath(combPath, max_comb_distance_ignored, fail_on_unavoidable_obstacles);
     };
 };
 
-class SliceDataStorage;
-
-/*!
- * Class for generating a full combing actions from a travel move from a start point to an end point.
- * A single Comb object is used for each layer.
- * 
- * Comb::calc is the main function of this class.
- * 
- * Typical output: A combing path to the boundary of the polygon + a move through air avoiding other parts in the layer + a combing path from the boundary of the ending polygon to the end point.
- * Each of these three is a CombPath; the first and last are within Comb::boundary_inside while the middle is outside of Comb::boundary_outside.
- * Between these there is a little gap where the nozzle crosses the boundary of an object approximately perpendicular to its boundary.
- * 
- * As an optimization, the combing paths inside are calculated on specifically those PolygonsParts within which to comb, while the coundary_outside isn't split into outside parts, 
- * because generally there is only one outside part; encapsulated holes occur less often.
- */
-class Comb 
-{
-    friend class LinePolygonsCrossings;
-private:
-    SliceDataStorage& storage; //!< The storage from which to compute the outside boundary, when needed.
-    const int layer_nr; //!< The layer number for the layer for which to compute the outside boundary, when needed.
-    
-    const int64_t offset_from_outlines; //!< Offset from the boundary of a part to the comb path. (nozzle width / 2)
-    const int64_t max_moveInside_distance2; //!< Maximal distance of a point to the Comb::boundary_inside which is still to be considered inside. (very sharp corners not allowed :S)
-    const int64_t offset_from_outlines_outside; //!< Offset from the boundary of a part to a travel path which avoids it by this distance.
-    const int64_t max_crossing_dist2; //!< The maximal distance by which to cross the in_between area between inside and outside
-    static const int64_t max_moveOutside_distance2 = INT64_MAX; //!< Any point which is not inside should be considered outside.
-    static const int64_t offset_dist_to_get_from_on_the_polygon_to_outside = 40; //!< in order to prevent on-boundary vs crossing boundary confusions (precision thing)
-    static const int64_t offset_extra_start_end = 100; //!< Distance to move start point and end point toward eachother to extra avoid collision with the boundaries.
-
-    const bool avoid_other_parts; //!< Whether to perform inverse combing a.k.a. avoid parts.
-    
-    Polygons& boundary_inside; //!< The boundary within which to comb.
-    Polygons* boundary_outside; //!< The boundary outside of which to stay to avoid collision with other layer parts. This is a pointer cause we only compute it when we move outside the boundary (so not when there is only a single part in the layer)
-    BucketGrid2D<PolygonsPointIndex>* outside_loc_to_line; //!< The BucketGrid mapping locations to line segments of the outside boundary.
-    PartsView partsView_inside; //!< Structured indices onto boundary_inside which shows which polygons belong to which part. 
-
-    /*!
-     * Get the boundary_outside, which is an offset from the outlines of all meshes in the layer. Calculate it when it hasn't been calculated yet.
-     */
-    Polygons& getBoundaryOutside();
-    
-    /*!
-     * Get the BucketGrid mapping locations to line segments of the outside boundary. Calculate it when it hasn't been calculated yet.
-     */
-    BucketGrid2D<PolygonsPointIndex>& getOutsideLocToLine();
-    
-    /*!
-     * Find the best crossing from some inside polygon to the outside boundary.
-     * 
-     * The detour from \p estimated_start to \p estimated_end is minimized.
-     * 
-     * \param from From which inside boundary the crossing to the outside starts or ends
-     * \param estimated_start The one point to which to stay close when evaluating crossings which cross about the same distance
-     * \param estimated_end The other point to which to stay close when evaluating crossings which cross about the same distance
-     * \return A pair of which the first is the crossing point on the inside boundary and the second the crossing point on the outside boundary
-     */
-    std::shared_ptr<std::pair<ClosestPolygonPoint, ClosestPolygonPoint>> findBestCrossing(PolygonRef from, Point estimated_start, Point estimated_end);
-    
-public:
-    /*!
-     * Initializes the combing areas for every mesh in the layer (not support)
-     * \param storage Where the layer polygon data is stored
-     * \param layer_nr The number of the layer for which to generate the combing areas.
-     * \param comb_boundary_inside The comb boundary within which to comb within layer parts.
-     * \param offset_from_outlines The offset from the outline polygon, to create the combing boundary in case there is no second wall.
-     * \param travel_avoid_other_parts Whether to avoid other layer parts when traveling through air.
-     * \param travel_avoid_distance The distance by which to avoid other layer parts when traveling through air.
-     */
-    Comb(SliceDataStorage& storage, int layer_nr, Polygons& comb_boundary_inside, int64_t offset_from_outlines, bool travel_avoid_other_parts, int64_t travel_avoid_distance);
-    
-    ~Comb();
-
-    /*!
-     * Calculate the comb paths (if any) - one for each polygon combed alternated with travel paths
-     * 
-     * \param startPoint Where to start moving from
-     * \param endPoint Where to move to
-     * \param combPoints Output parameter: The points along the combing path, excluding the \p startPoint (?) and \p endPoint
-     * \param startInside Whether we want to start inside the comb boundary
-     * \param endInside Whether we want to end up inside the comb boundary
-     * \return Whether combing has succeeded; otherwise a retraction is needed.
-     */    
-    bool calc(Point startPoint, Point endPoint, CombPaths& combPaths, bool startInside = false, bool endInside = false, int64_t max_comb_distance_ignored = MM2INT(1.5));
-};
-
 }//namespace cura
 
-#endif//COMB_H
+#endif//PATH_PLANNING_LINE_POLYGONS_CROSSINGS_H

src/pathPlanning/NozzleTempInsert.cpp

@@ -0,0 +1,24 @@
+//Copyright (C) 2016 Ultimaker
+//Released under terms of the AGPLv3 License
+
+#include "NozzleTempInsert.h"
+
+namespace cura
+{
+
+NozzleTempInsert::NozzleTempInsert(unsigned int path_idx, int extruder, double temperature, bool wait, double time_after_path_start)
+: path_idx(path_idx)
+, time_after_path_start(time_after_path_start)
+, extruder(extruder)
+, temperature(temperature)
+, wait(wait)
+{
+    assert(temperature != 0 && temperature != -1 && "Temperature command must be set!");
+}
+
+void NozzleTempInsert::write(GCodeExport& gcode)
+{
+    gcode.writeTemperatureCommand(extruder, temperature, wait);
+}
+
+}

src/pathPlanning/NozzleTempInsert.h

@@ -0,0 +1,32 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef PATH_PLANNING_NOZZLE_TEMP_INSERT_H
+#define PATH_PLANNING_NOZZLE_TEMP_INSERT_H
+
+#include "../gcodeExport.h"
+
+namespace cura 
+{
+
+/*!
+ * A gcode command to insert before a specific path.
+ * 
+ * Currently only used for preheat commands
+ */
+struct NozzleTempInsert
+{
+    const unsigned int path_idx; //!< The path before which to insert this command
+    double time_after_path_start; //!< The time after the start of the path, before which to insert the command // TODO: use this to insert command in between moves in a path!
+    int extruder; //!< The extruder for which to set the temp
+    double temperature; //!< The temperature of the temperature command to insert
+    bool wait; //!< Whether to wait for the temperature to be reached
+    NozzleTempInsert(unsigned int path_idx, int extruder, double temperature, bool wait, double time_after_path_start = 0.0);
+
+    /*!
+     * Write the temperature command at the current position in the gcode.
+     * \param gcode The actual gcode writer
+     */
+    void write(GCodeExport& gcode);
+};
+}//namespace cura
+
+#endif//PATH_PLANNING_NOZZLE_TEMP_INSERT_H

src/pathPlanning/TimeMaterialEstimates.cpp

@@ -0,0 +1,84 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#include "TimeMaterialEstimates.h"
+
+namespace cura
+{
+
+TimeMaterialEstimates::TimeMaterialEstimates(double extrude_time, double unretracted_travel_time, double retracted_travel_time, double material)
+: extrude_time(extrude_time)
+, unretracted_travel_time(unretracted_travel_time)
+, retracted_travel_time(retracted_travel_time)
+, material(material)
+{
+}
+
+TimeMaterialEstimates::TimeMaterialEstimates()
+: extrude_time(0.0)
+, unretracted_travel_time(0.0)
+, retracted_travel_time(0.0)
+, material(0.0)
+{
+}
+
+TimeMaterialEstimates TimeMaterialEstimates::operator-(const TimeMaterialEstimates& other)
+{
+    return TimeMaterialEstimates(extrude_time - other.extrude_time,unretracted_travel_time - other.unretracted_travel_time,retracted_travel_time - other.retracted_travel_time,material - other.material);
+}
+
+TimeMaterialEstimates& TimeMaterialEstimates::operator-=(const TimeMaterialEstimates& other)
+{
+    extrude_time -= other.extrude_time;
+    unretracted_travel_time -= other.unretracted_travel_time;
+    retracted_travel_time -= other.retracted_travel_time;
+    material -= other.material;
+    return *this;
+}
+
+TimeMaterialEstimates TimeMaterialEstimates::operator+(const TimeMaterialEstimates& other)
+{
+    return TimeMaterialEstimates(extrude_time+other.extrude_time, unretracted_travel_time+other.unretracted_travel_time, retracted_travel_time+other.retracted_travel_time, material+other.material);
+}
+
+TimeMaterialEstimates& TimeMaterialEstimates::operator+=(const TimeMaterialEstimates& other)
+{
+    extrude_time += other.extrude_time;
+    unretracted_travel_time += other.unretracted_travel_time;
+    retracted_travel_time += other.retracted_travel_time;
+    material += other.material;
+    return *this;
+}
+
+double TimeMaterialEstimates::getExtrudeTime() const
+{
+    return extrude_time;
+}
+
+double TimeMaterialEstimates::getMaterial() const
+{
+    return material;
+}
+
+double TimeMaterialEstimates::getTotalTime() const
+{
+    return extrude_time + unretracted_travel_time + retracted_travel_time;
+}
+
+double TimeMaterialEstimates::getTotalUnretractedTime() const
+{
+    return extrude_time + unretracted_travel_time;
+}
+
+double TimeMaterialEstimates::getTravelTime() const
+{
+    return retracted_travel_time + unretracted_travel_time;
+}
+
+void TimeMaterialEstimates::reset()
+{
+    extrude_time = 0.0;
+    unretracted_travel_time = 0.0;
+    retracted_travel_time = 0.0;
+    material = 0.0;
+}
+
+}//namespace cura

src/pathPlanning/TimeMaterialEstimates.h

@@ -0,0 +1,124 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef PATH_PLANNING_TIME_MATERIAL_ESTIMATES_H
+#define PATH_PLANNING_TIME_MATERIAL_ESTIMATES_H
+
+#include "../gcodeExport.h"
+
+namespace cura 
+{
+
+class ExtruderPlan; // forward declaration so that TimeMaterialEstimates can be a friend
+
+/*!
+ * Time and material estimates for a portion of paths, e.g. layer, extruder plan, path.
+ */
+class TimeMaterialEstimates
+{
+    friend class ExtruderPlan; // cause there the naive estimates are calculated
+private:
+    double extrude_time; //!< Time in seconds occupied by extrusion
+    double unretracted_travel_time; //!< Time in seconds occupied by non-retracted travel (non-extrusion)
+    double retracted_travel_time; //!< Time in seconds occupied by retracted travel (non-extrusion)
+    double material; //!< Material used (in mm^3)
+public:
+    /*!
+     * Basic contructor
+     * 
+     * \param extrude_time Time in seconds occupied by extrusion
+     * \param unretracted_travel_time Time in seconds occupied by non-retracted travel (non-extrusion)
+     * \param retracted_travel_time Time in seconds occupied by retracted travel (non-extrusion)
+     * \param material Material used (in mm^3)
+     */
+    TimeMaterialEstimates(double extrude_time, double unretracted_travel_time, double retracted_travel_time, double material);
+
+    /*!
+     * Basic constructor initializing all estimates to zero.
+     */
+    TimeMaterialEstimates();
+
+    /*!
+     * Set all estimates to zero.
+     */
+    void reset();
+
+    /*!
+     * Pointwise addition of estimate stats
+     * 
+     * \param other The estimates to add to these estimates.
+     * \return The resulting estimates
+     */
+    TimeMaterialEstimates operator+(const TimeMaterialEstimates& other);
+
+    /*!
+     * In place pointwise addition of estimate stats
+     * 
+     * \param other The estimates to add to these estimates.
+     * \return These estimates
+     */
+    TimeMaterialEstimates& operator+=(const TimeMaterialEstimates& other);
+
+    /*!
+     * \brief Subtracts the specified estimates from these estimates and returns
+     * the result.
+     * 
+     * Each of the estimates in this class are individually subtracted.
+     * 
+     * \param other The estimates to subtract from these estimates.
+     * \return These estimates with the specified estimates subtracted.
+     */
+    TimeMaterialEstimates operator-(const TimeMaterialEstimates& other);
+
+    /*!
+     * \brief Subtracts the specified elements from these estimates.
+     * 
+     * This causes the estimates in this instance to change. Each of the
+     * estimates in this class are individually subtracted.
+     * 
+     * \param other The estimates to subtract from these estimates.
+     * \return A reference to this instance.
+     */
+    TimeMaterialEstimates& operator-=(const TimeMaterialEstimates& other);
+
+    /*!
+     * Get total time estimate. The different time estimate member values added together.
+     * 
+     * \return the total of all different time estimate values 
+     */
+    double getTotalTime() const;
+
+    /*!
+     * Get the total time during which the head is not retracted.
+     * 
+     * This includes extrusion time and non-retracted travel time
+     * 
+     * \return the total time during which the head is not retracted.
+     */
+    double getTotalUnretractedTime() const;
+
+    /*!
+     * Get the total travel time.
+     * 
+     * This includes the retracted travel time as well as the unretracted travel time.
+     * 
+     * \return the total travel time.
+     */
+    double getTravelTime() const;
+
+    /*!
+     * Get the extrusion time.
+     * 
+     * \return extrusion time.
+     */
+    double getExtrudeTime() const;
+
+    /*!
+     * Get the amount of material used in mm^3.
+     * 
+     * \return amount of material
+     */
+    double getMaterial() const;
+};
+
+}//namespace cura
+
+#endif//PATH_PLANNING_TIME_MATERIAL_ESTIMATES_H

src/raft.cpp

@@ -1,23 +1,86 @@
 /** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#include <clipper/clipper.hpp>
+
+#include "utils/math.h"
 #include "raft.h"
 #include "support.h"
 
 namespace cura {
 
-void generateRaft(SliceDataStorage& storage, int distance)
+void Raft::generate(SliceDataStorage& storage, int distance)
 {
+    assert(storage.raftOutline.size() == 0 && "Raft polygon isn't generated yet, so should be empty!");
+    storage.raftOutline = storage.getLayerOutlines(0, true).offset(distance, ClipperLib::jtRound);
+    const int shield_line_width = storage.meshgroup->getExtruderTrain(storage.getSettingAsIndex("adhesion_extruder_nr"))->getSettingInMicrons("skirt_brim_line_width");
     if (storage.draft_protection_shield.size() > 0)
     {
-        storage.raftOutline = storage.raftOutline.unionPolygons(storage.draft_protection_shield.offset(distance));
+        Polygons draft_shield_raft = storage.draft_protection_shield.offset(shield_line_width) // start half a line width outside shield
+                                        .difference(storage.draft_protection_shield.offset(-distance - shield_line_width / 2, ClipperLib::jtRound)); // end distance inside shield
+        storage.raftOutline = storage.raftOutline.unionPolygons(draft_shield_raft);
     }
-    else if (storage.oozeShield.size() > 0 && storage.oozeShield[0].size() > 0)
+    if (storage.oozeShield.size() > 0 && storage.oozeShield[0].size() > 0)
     {
-        storage.raftOutline = storage.raftOutline.unionPolygons(storage.oozeShield[0].offset(distance));
-    }
-    else 
-    {
-        storage.raftOutline = storage.getLayerOutlines(0, true).offset(distance);
+        const Polygons& ooze_shield = storage.oozeShield[0];
+        Polygons ooze_shield_raft = ooze_shield.offset(shield_line_width) // start half a line width outside shield
+                                        .difference(ooze_shield.offset(-distance - shield_line_width / 2, ClipperLib::jtRound)); // end distance inside shield
+        storage.raftOutline = storage.raftOutline.unionPolygons(ooze_shield_raft);
     }
+    storage.raftOutline = storage.raftOutline.offset(1000).offset(-1000); // remove small holes
 }
 
+int Raft::getTotalThickness(const SliceDataStorage& storage)
+{
+    const ExtruderTrain& train = *storage.meshgroup->getExtruderTrain(storage.getSettingAsIndex("adhesion_extruder_nr"));
+    return train.getSettingInMicrons("raft_base_thickness")
+        + train.getSettingInMicrons("raft_interface_thickness")
+        + train.getSettingAsCount("raft_surface_layers") * train.getSettingInMicrons("raft_surface_thickness");
+}
+
+int Raft::getZdiffBetweenRaftAndLayer1(const SliceDataStorage& storage)
+{
+    const ExtruderTrain& train = *storage.meshgroup->getExtruderTrain(storage.getSettingAsIndex("adhesion_extruder_nr"));
+    if (storage.getSettingAsPlatformAdhesion("adhesion_type") != EPlatformAdhesion::RAFT)
+    {
+        return 0;
+    }
+    const int64_t airgap = std::max((coord_t)0, train.getSettingInMicrons("raft_airgap"));
+    const int64_t layer_0_overlap = storage.getSettingInMicrons("layer_0_z_overlap");
+
+    const int64_t layer_height_0 = storage.getSettingInMicrons("layer_height_0");
+
+    const int64_t z_diff_raft_to_bottom_of_layer_1 = std::max(int64_t(0), airgap + layer_height_0 - layer_0_overlap);
+    return z_diff_raft_to_bottom_of_layer_1;
+}
+
+
+int Raft::getFillerLayerCount(const SliceDataStorage& storage)
+{
+    const int64_t normal_layer_height = storage.getSettingInMicrons("layer_height");
+    const unsigned int filler_layer_count = round_divide(getZdiffBetweenRaftAndLayer1(storage), normal_layer_height);
+    return filler_layer_count;
+}
+
+int Raft::getFillerLayerHeight(const SliceDataStorage& storage)
+{
+    if (storage.getSettingAsPlatformAdhesion("adhesion_type") != EPlatformAdhesion::RAFT)
+    {
+        const int64_t normal_layer_height = storage.getSettingInMicrons("layer_height");
+        return normal_layer_height;
+    }
+    const unsigned int filler_layer_height = round_divide(getZdiffBetweenRaftAndLayer1(storage), getFillerLayerCount(storage));
+    return filler_layer_height;
+}
+
+
+int Raft::getTotalExtraLayers(const SliceDataStorage& storage)
+{
+    const ExtruderTrain& train = *storage.meshgroup->getExtruderTrain(storage.getSettingAsIndex("adhesion_extruder_nr"));
+    if (train.getSettingAsPlatformAdhesion("adhesion_type") != EPlatformAdhesion::RAFT)
+    {
+        return 0;
+    }
+    return 2 + train.getSettingAsCount("raft_surface_layers") + getFillerLayerCount(storage);
+}
+
+
 }//namespace cura

src/raft.h

@@ -6,7 +6,43 @@
 
 namespace cura {
 
-void generateRaft(SliceDataStorage& storage, int distance);
+class Raft
+{
+public:
+    static void generate(SliceDataStorage& storage, int distance);
+
+    /*!
+     * Get the height difference between the raft and the bottom of layer 1.
+     * 
+     * This is used for the filler layers because they don't use the layer_0_z_overlap
+     */
+    static int getZdiffBetweenRaftAndLayer1(const SliceDataStorage& storage);
+
+    /*!
+     * Get the amount of layers to fill the airgap and initial layer with helper parts (support, prime tower, etc.)
+     * 
+     * The initial layer gets a separate filler layer because we don't want to apply the layer_0_z_overlap to it.
+     */
+    static int getFillerLayerCount(const SliceDataStorage& storage);
+
+    /*!
+     * Get the layer height of the filler layers in between the raft and layer 1
+     */
+    static int getFillerLayerHeight(const SliceDataStorage& storage);
+
+    /*!
+     * Get the total thickness of the raft (without airgap)
+     */
+    static int getTotalThickness(const SliceDataStorage& storage);
+
+    /*!
+     * Get the total amount of extra layers below zero because there is a raft.
+     * 
+     * This includes the filler layers which are introduced in the air gap.
+     */
+    static int getTotalExtraLayers(const SliceDataStorage& storage);
+
+};
 
 }//namespace cura
 

src/settings/PathConfigStorage.cpp

@@ -0,0 +1,235 @@
+/** Copyright (C) 2017 Ultimaker - Released under terms of the AGPLv3 License */
+#include "PathConfigStorage.h"
+
+#include "settings.h" // MAX_INFILL_COMBINE
+#include "../sliceDataStorage.h" // SliceDataStorage
+
+
+namespace cura
+{
+
+GCodePathConfig getPerimeterGapConfig(const SliceMeshStorage& mesh, int layer_thickness)
+{
+    // The perimeter gap config follows the skin config, but has a different line width:
+    // wall_line_width_x divided by two because the gaps are between 0 and 1 times the wall line width
+    const int perimeter_gaps_line_width = mesh.getSettingInMicrons("wall_line_width_x") / 2;
+    double perimeter_gaps_speed = mesh.getSettingInMillimetersPerSecond("speed_topbottom");
+    if (mesh.getSettingBoolean("speed_equalize_flow_enabled"))
+    {
+        perimeter_gaps_speed = perimeter_gaps_speed * mesh.getSettingInMicrons("skin_line_width") / perimeter_gaps_line_width;
+    }
+    return GCodePathConfig(
+            PrintFeatureType::Skin
+            , perimeter_gaps_line_width
+            , layer_thickness
+            , mesh.getSettingInPercentage("material_flow")
+            , GCodePathConfig::SpeedDerivatives{perimeter_gaps_speed, mesh.getSettingInMillimetersPerSecond("acceleration_topbottom"), mesh.getSettingInMillimetersPerSecond("jerk_topbottom")}
+        );
+}
+
+PathConfigStorage::MeshPathConfigs::MeshPathConfigs(const SliceMeshStorage& mesh, int layer_thickness)
+: inset0_config(
+    PrintFeatureType::OuterWall
+    , mesh.getSettingInMicrons("wall_line_width_0")
+    , layer_thickness
+    , mesh.getSettingInPercentage("material_flow")
+    , GCodePathConfig::SpeedDerivatives{mesh.getSettingInMillimetersPerSecond("speed_wall_0"), mesh.getSettingInMillimetersPerSecond("acceleration_wall_0"), mesh.getSettingInMillimetersPerSecond("jerk_wall_0")}
+)
+, insetX_config(
+    PrintFeatureType::InnerWall
+    , mesh.getSettingInMicrons("wall_line_width_x")
+    , layer_thickness
+    , mesh.getSettingInPercentage("material_flow")
+    , GCodePathConfig::SpeedDerivatives{mesh.getSettingInMillimetersPerSecond("speed_wall_x"), mesh.getSettingInMillimetersPerSecond("acceleration_wall_x"), mesh.getSettingInMillimetersPerSecond("jerk_wall_x")}
+)
+, skin_config(
+    PrintFeatureType::Skin
+    , mesh.getSettingInMicrons("skin_line_width")
+    , layer_thickness
+    , mesh.getSettingInPercentage("material_flow")
+    , GCodePathConfig::SpeedDerivatives{mesh.getSettingInMillimetersPerSecond("speed_topbottom"), mesh.getSettingInMillimetersPerSecond("acceleration_topbottom"), mesh.getSettingInMillimetersPerSecond("jerk_topbottom")}
+)
+
+, perimeter_gap_config(getPerimeterGapConfig(mesh, layer_thickness))
+{
+    infill_config.reserve(MAX_INFILL_COMBINE);
+    for (int combine_idx = 0; combine_idx < MAX_INFILL_COMBINE; combine_idx++)
+    {
+        infill_config.emplace_back(
+                PrintFeatureType::Infill
+                , mesh.getSettingInMicrons("infill_line_width") * (combine_idx + 1)
+                , layer_thickness
+                , mesh.getSettingInPercentage("material_flow")
+                , GCodePathConfig::SpeedDerivatives{mesh.getSettingInMillimetersPerSecond("speed_infill"), mesh.getSettingInMillimetersPerSecond("acceleration_infill"), mesh.getSettingInMillimetersPerSecond("jerk_infill")}
+            );
+    }
+}
+
+PathConfigStorage::PathConfigStorage(const SliceDataStorage& storage, int layer_nr, int layer_thickness)
+: adhesion_extruder_train(storage.meshgroup->getExtruderTrain(storage.getSettingAsIndex("adhesion_extruder_nr")))
+, support_infill_train(storage.meshgroup->getExtruderTrain(storage.getSettingAsIndex("support_infill_extruder_nr")))
+, support_interface_train(storage.meshgroup->getExtruderTrain(storage.getSettingAsIndex("support_interface_extruder_nr")))
+, raft_base_config(
+            PrintFeatureType::SupportInterface
+            , adhesion_extruder_train->getSettingInMicrons("raft_base_line_width")
+            , adhesion_extruder_train->getSettingInMicrons("raft_base_thickness")
+            , adhesion_extruder_train->getSettingInPercentage("material_flow")
+            , GCodePathConfig::SpeedDerivatives{adhesion_extruder_train->getSettingInMillimetersPerSecond("raft_base_speed"), adhesion_extruder_train->getSettingInMillimetersPerSecond("raft_base_acceleration"), adhesion_extruder_train->getSettingInMillimetersPerSecond("raft_base_jerk")}
+        )
+, raft_interface_config(
+            PrintFeatureType::Support
+            , adhesion_extruder_train->getSettingInMicrons("raft_interface_line_width")
+            , adhesion_extruder_train->getSettingInMicrons("raft_interface_thickness")
+            , adhesion_extruder_train->getSettingInPercentage("material_flow")
+            , GCodePathConfig::SpeedDerivatives{adhesion_extruder_train->getSettingInMillimetersPerSecond("raft_interface_speed"), adhesion_extruder_train->getSettingInMillimetersPerSecond("raft_interface_acceleration"), adhesion_extruder_train->getSettingInMillimetersPerSecond("raft_interface_jerk")}
+        )
+, raft_surface_config(
+            PrintFeatureType::SupportInterface
+            , adhesion_extruder_train->getSettingInMicrons("raft_surface_line_width")
+            , adhesion_extruder_train->getSettingInMicrons("raft_surface_thickness")
+            , adhesion_extruder_train->getSettingInPercentage("material_flow")
+            , GCodePathConfig::SpeedDerivatives{adhesion_extruder_train->getSettingInMillimetersPerSecond("raft_surface_speed"), adhesion_extruder_train->getSettingInMillimetersPerSecond("raft_surface_acceleration"), adhesion_extruder_train->getSettingInMillimetersPerSecond("raft_surface_jerk")}
+        )
+, support_infill_config(
+            PrintFeatureType::Support
+            , support_infill_train->getSettingInMicrons("support_line_width")
+            , layer_thickness
+            , support_infill_train->getSettingInPercentage("material_flow")
+            , GCodePathConfig::SpeedDerivatives{support_infill_train->getSettingInMillimetersPerSecond("speed_support_infill"), support_infill_train->getSettingInMillimetersPerSecond("acceleration_support_infill"), support_infill_train->getSettingInMillimetersPerSecond("jerk_support_infill")}
+        )
+, support_interface_config(
+            PrintFeatureType::SupportInterface
+            , support_interface_train->getSettingInMicrons("support_interface_line_width")
+            , layer_thickness
+            , support_interface_train->getSettingInPercentage("material_flow")
+            , GCodePathConfig::SpeedDerivatives{support_interface_train->getSettingInMillimetersPerSecond("speed_support_interface"), support_interface_train->getSettingInMillimetersPerSecond("acceleration_support_interface"), support_interface_train->getSettingInMillimetersPerSecond("jerk_support_interface")}
+        )
+{
+    int extruder_count = storage.meshgroup->getExtruderCount();
+    travel_config_per_extruder.reserve(extruder_count);
+    skirt_brim_config.reserve(extruder_count);
+    prime_tower_config_per_extruder.reserve(extruder_count);
+    for (int extruder_nr = 0; extruder_nr < extruder_count; extruder_nr++)
+    {
+        const ExtruderTrain* train = storage.meshgroup->getExtruderTrain(extruder_nr);
+        travel_config_per_extruder.emplace_back(
+                PrintFeatureType::MoveCombing
+                , 0
+                , 0
+                , 0.0
+                , GCodePathConfig::SpeedDerivatives{train->getSettingInMillimetersPerSecond("speed_travel"), train->getSettingInMillimetersPerSecond("acceleration_travel"), train->getSettingInMillimetersPerSecond("jerk_travel")}
+            );
+        skirt_brim_config.emplace_back(
+                PrintFeatureType::SkirtBrim
+                , train->getSettingInMicrons("skirt_brim_line_width")
+                , layer_thickness
+                , train->getSettingInPercentage("material_flow")
+                , GCodePathConfig::SpeedDerivatives{train->getSettingInMillimetersPerSecond("skirt_brim_speed"), train->getSettingInMillimetersPerSecond("acceleration_skirt_brim"), train->getSettingInMillimetersPerSecond("jerk_skirt_brim")}
+            );
+        prime_tower_config_per_extruder.emplace_back(
+                PrintFeatureType::SupportInfill
+                , train->getSettingInMicrons("prime_tower_line_width")
+                , layer_thickness
+                , train->getSettingInPercentage("prime_tower_flow")
+                , GCodePathConfig::SpeedDerivatives{train->getSettingInMillimetersPerSecond("speed_prime_tower"), train->getSettingInMillimetersPerSecond("acceleration_prime_tower"), train->getSettingInMillimetersPerSecond("jerk_prime_tower")}
+            );
+    }
+
+    mesh_configs.reserve(storage.meshes.size());
+    for (const SliceMeshStorage& mesh_storage : storage.meshes)
+    {
+        mesh_configs.emplace_back(mesh_storage, layer_thickness);
+    }
+
+    int initial_speedup_layer_count = storage.getSettingAsCount("speed_slowdown_layers");
+    if (layer_nr < initial_speedup_layer_count)
+    {
+        handleInitialLayerSpeedup(storage, layer_nr, initial_speedup_layer_count);
+    }
+}
+
+void cura::PathConfigStorage::handleInitialLayerSpeedup(const SliceDataStorage& storage, int layer_nr, int initial_speedup_layer_count)
+{
+    std::vector<GCodePathConfig::SpeedDerivatives> global_first_layer_config_per_extruder;
+    global_first_layer_config_per_extruder.reserve(storage.meshgroup->getExtruderCount());
+    for (int extruder_nr = 0; extruder_nr < storage.meshgroup->getExtruderCount(); extruder_nr++)
+    {
+        const ExtruderTrain* extruder = storage.meshgroup->getExtruderTrain(extruder_nr);
+        global_first_layer_config_per_extruder.emplace_back(
+            GCodePathConfig::SpeedDerivatives{
+                extruder->getSettingInMillimetersPerSecond("speed_print_layer_0")
+                , extruder->getSettingInMillimetersPerSecond("acceleration_print_layer_0")
+                , extruder->getSettingInMillimetersPerSecond("jerk_print_layer_0")
+            });
+    }
+
+    { // support
+        if (layer_nr < initial_speedup_layer_count)
+        {
+            int extruder_nr_support_infill = storage.getSettingAsIndex((layer_nr <= 0)? "support_extruder_nr_layer_0" : "support_infill_extruder_nr");
+            GCodePathConfig::SpeedDerivatives& first_layer_config_infill = global_first_layer_config_per_extruder[extruder_nr_support_infill];
+            support_infill_config.smoothSpeed(first_layer_config_infill, std::max(0, layer_nr), initial_speedup_layer_count);
+
+            int extruder_nr_support_interface = storage.getSettingAsIndex("support_interface_extruder_nr");
+            GCodePathConfig::SpeedDerivatives& first_layer_config_interface = global_first_layer_config_per_extruder[extruder_nr_support_interface];
+            support_interface_config.smoothSpeed(first_layer_config_interface, std::max(0, layer_nr), initial_speedup_layer_count);
+        }
+    }
+
+    { // extruder configs: travel, skirt/brim (= shield)
+        for (int extruder_nr = 0; extruder_nr < storage.meshgroup->getExtruderCount(); ++extruder_nr)
+        {
+            const ExtruderTrain* train = storage.meshgroup->getExtruderTrain(extruder_nr);
+            GCodePathConfig::SpeedDerivatives initial_layer_speed_config{
+                    train->getSettingInMillimetersPerSecond("speed_travel_layer_0")
+                    , train->getSettingInMillimetersPerSecond("acceleration_travel_layer_0")
+                    , train->getSettingInMillimetersPerSecond("jerk_travel_layer_0")
+            };
+            GCodePathConfig& travel = travel_config_per_extruder[extruder_nr];
+
+            travel.smoothSpeed(initial_layer_speed_config, std::max(0, layer_nr), initial_speedup_layer_count);
+
+            // don't smooth speed for the skirt/brim!
+            // NOTE: not smoothing skirt/brim means the speeds are also not smoothed for the draft/ooze shield
+
+            GCodePathConfig& prime_tower = prime_tower_config_per_extruder[extruder_nr];
+
+            prime_tower.smoothSpeed(initial_layer_speed_config, std::max(0, layer_nr), initial_speedup_layer_count);
+        }
+
+    }
+
+    { // meshes
+        for (unsigned int mesh_idx = 0; mesh_idx < storage.meshes.size(); mesh_idx++)
+        {
+            const SliceMeshStorage& mesh = storage.meshes[mesh_idx];
+
+
+            GCodePathConfig::SpeedDerivatives initial_layer_speed_config{
+                    mesh.getSettingInMillimetersPerSecond("speed_print_layer_0")
+                    , mesh.getSettingInMillimetersPerSecond("acceleration_print_layer_0")
+                    , mesh.getSettingInMillimetersPerSecond("jerk_print_layer_0")
+            };
+
+            MeshPathConfigs& mesh_config = mesh_configs[mesh_idx];
+            //Outer wall speed (per mesh).
+            mesh_config.inset0_config.smoothSpeed(initial_layer_speed_config, layer_nr, initial_speedup_layer_count);
+
+            //Inner wall speed (per mesh).
+            mesh_config.insetX_config.smoothSpeed(initial_layer_speed_config, layer_nr, initial_speedup_layer_count);
+
+            //Skin speed (per mesh).
+            mesh_config.skin_config.smoothSpeed(initial_layer_speed_config, layer_nr, initial_speedup_layer_count);
+            mesh_config.perimeter_gap_config.smoothSpeed(initial_layer_speed_config, layer_nr, initial_speedup_layer_count);
+
+            for (unsigned int idx = 0; idx < MAX_INFILL_COMBINE; idx++)
+            {
+                //Infill speed (per combine part per mesh).
+                mesh_config.infill_config[idx].smoothSpeed(initial_layer_speed_config, layer_nr, initial_speedup_layer_count);
+            }
+        }
+    }
+}
+
+
+}//namespace cura

src/settings/PathConfigStorage.h

@@ -0,0 +1,63 @@
+/** Copyright (C) 2017 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef SETTINGS_PATH_CONFIGS_H
+#define SETTINGS_PATH_CONFIGS_H
+
+#include <vector>
+
+#include "../utils/intpoint.h" // coord_t
+#include "../GCodePathConfig.h"
+
+namespace cura
+{
+
+class SliceDataStorage; // forward decl for SliceDataStorage
+class SliceMeshStorage; // forward decl for SliceDataStorage
+class ExtruderTrain; // forward decl for SliceDataStorage
+
+/*!
+ * A class to represent all configurations for all features types of printed lines in a meshgroup.
+ */
+class PathConfigStorage
+{
+private:
+    const ExtruderTrain* adhesion_extruder_train;
+    const ExtruderTrain* support_infill_train;
+    const ExtruderTrain* support_interface_train;
+public:
+    class MeshPathConfigs
+    {
+    public:
+        GCodePathConfig inset0_config;
+        GCodePathConfig insetX_config;
+        GCodePathConfig skin_config;
+        GCodePathConfig perimeter_gap_config;
+        std::vector<GCodePathConfig> infill_config;
+
+        MeshPathConfigs(const SliceMeshStorage& mesh, int layer_thickness);
+    };
+    
+    GCodePathConfig raft_base_config;
+    GCodePathConfig raft_interface_config;
+    GCodePathConfig raft_surface_config;
+
+    std::vector<GCodePathConfig> travel_config_per_extruder; //!< The config used for travel moves (only speed is set!)
+    std::vector<GCodePathConfig> skirt_brim_config; //!< Configuration for skirt and brim per extruder.
+    std::vector<GCodePathConfig> prime_tower_config_per_extruder; //!< Configuration for the prime tower per extruder.
+
+    GCodePathConfig support_infill_config; //!< The config used to print the normal support, rather than the support interface
+    GCodePathConfig support_interface_config; //!< The config to use to print the dense roofs and bottoms of support
+
+    std::vector<MeshPathConfigs> mesh_configs; //!< For each meash the config for all its feature types
+    
+    /*!
+     * \warning Note that the layer_nr might be below zero for raft (filler) layers
+     */
+    PathConfigStorage(const SliceDataStorage& storage, int layer_nr, int layer_thickness);
+
+private:
+    void handleInitialLayerSpeedup(const SliceDataStorage& storage, int layer_nr, int initial_speedup_layer_count);
+};
+
+}; // namespace cura
+
+#endif // SETTINGS_PATH_CONFIGS_H

src/settings/SettingRegistry.cpp

@@ -125,15 +125,21 @@ bool SettingRegistry::getDefinitionFile(const std::string machine_id, std::strin
 
 int SettingRegistry::loadExtruderJSONsettings(unsigned int extruder_nr, SettingsBase* settings_base)
 {
-    if (extruder_nr >= extruder_train_ids.size())
+    if (extruder_train_ids.empty())
     {
+        logError("Couldn't find any extruder trains!\n");
         return -1;
     }
-    
+    if (extruder_nr >= extruder_train_ids.size())
+    {
+        logWarning("Couldn't load extruder.def.json file for extruder %i. Index out of bounds.\n Loading first extruder definition instead.\n", extruder_nr);
+        extruder_nr = 0;
+    }
     std::string definition_file;
     bool found = getDefinitionFile(extruder_train_ids[extruder_nr], definition_file);
     if (!found)
     {
+        logError("Couldn't find extruder.def.json file for extruder %i.\n", extruder_nr);
         return -1;
     }
     bool warn_base_file_duplicates = false;
@@ -150,7 +156,7 @@ int SettingRegistry::loadJSONsettings(std::string filename, SettingsBase* settin
     if (err) { return err; }
 
     { // add parent folder to search paths
-        char filename_cstr[500];
+        char filename_cstr[filename.size()];
         std::strcpy(filename_cstr, filename.c_str()); // copy the string because dirname(.) changes the input string!!!
         std::string folder_name = std::string(dirname(filename_cstr));
         search_paths.emplace(folder_name);
@@ -162,6 +168,7 @@ int SettingRegistry::loadJSONsettings(std::string filename, SettingsBase* settin
         bool found = getDefinitionFile(json_document["inherits"].GetString(), child_filename);
         if (!found)
         {
+            cura::logError("Inherited JSON file \"%s\" not found\n", json_document["inherits"].GetString());
             return -1;
         }
         err = loadJSONsettings(child_filename, settings_base, warn_base_file_duplicates); // load child first
@@ -216,26 +223,9 @@ int SettingRegistry::loadJSONsettingsFromDoc(rapidjson::Document& json_document,
         return 3;
     }
 
-    { // handle machine name
-        std::string machine_name = "Unknown";
-        if (json_document.HasMember("name"))
-        {
-            const rapidjson::Value& machine_name_field = json_document["name"];
-            if (machine_name_field.IsString())
-            {
-                machine_name = machine_name_field.GetString();
-            }
-        }
-        SettingConfig& machine_name_setting = addSetting("machine_name", "Machine Name");
-        machine_name_setting.setDefault(machine_name);
-        machine_name_setting.setType("string");
-        settings_base->_setSetting(machine_name_setting.getKey(), machine_name_setting.getDefaultValue());
-    }
-
     if (json_document.HasMember("settings"))
     {
-        std::list<std::string> path;
-        handleChildren(json_document["settings"], path, settings_base, warn_duplicates);
+        handleChildren(json_document["settings"], settings_base, warn_duplicates);
     }
     
     if (json_document.HasMember("overrides"))
@@ -257,21 +247,19 @@ int SettingRegistry::loadJSONsettingsFromDoc(rapidjson::Document& json_document,
     return 0;
 }
 
-void SettingRegistry::handleChildren(const rapidjson::Value& settings_list, std::list<std::string>& path, SettingsBase* settings_base, bool warn_duplicates)
+void SettingRegistry::handleChildren(const rapidjson::Value& settings_list, SettingsBase* settings_base, bool warn_duplicates)
 {
     if (!settings_list.IsObject())
     {
-        logError("ERROR: json settings list is not an object!\n");
+        logError("json settings list is not an object!\n");
         return;
     }
     for (rapidjson::Value::ConstMemberIterator setting_iterator = settings_list.MemberBegin(); setting_iterator != settings_list.MemberEnd(); ++setting_iterator)
     {
-        handleSetting(setting_iterator, path, settings_base, warn_duplicates);
+        handleSetting(setting_iterator, settings_base, warn_duplicates);
         if (setting_iterator->value.HasMember("children"))
         {
-            std::list<std::string> path_here = path;
-            path_here.push_back(setting_iterator->name.GetString());
-            handleChildren(setting_iterator->value["children"], path_here, settings_base, warn_duplicates);
+            handleChildren(setting_iterator->value["children"], settings_base, warn_duplicates);
         }
     }
 }
@@ -289,24 +277,25 @@ bool SettingRegistry::settingIsUsedByEngine(const rapidjson::Value& setting)
 }
 
 
-void SettingRegistry::handleSetting(const rapidjson::Value::ConstMemberIterator& json_setting_it, std::list<std::string>& path, SettingsBase* settings_base, bool warn_duplicates)
+void SettingRegistry::handleSetting(const rapidjson::Value::ConstMemberIterator& json_setting_it, SettingsBase* settings_base, bool warn_duplicates)
 {
     const rapidjson::Value& json_setting = json_setting_it->value;
     if (!json_setting.IsObject())
     {
-        logError("ERROR: json setting is not an object!\n");
+        logError("json setting is not an object!\n");
         return;
     }
     std::string name = json_setting_it->name.GetString();
     if (json_setting.HasMember("type") && json_setting["type"].IsString() && json_setting["type"].GetString() == std::string("category"))
     { // skip category objects
+        setting_key_to_config[name] = nullptr; // add the category name to the mapping, but don't instantiate a setting config for it.
         return;
     }
     if (settingIsUsedByEngine(json_setting))
     {
         if (!json_setting.HasMember("label") || !json_setting["label"].IsString())
         {
-            logError("ERROR: json setting \"%s\" has no label!\n", name.c_str());
+            logError("json setting \"%s\" has no label!\n", name.c_str());
             return;
         }
         std::string label = json_setting["label"].GetString();
@@ -314,7 +303,7 @@ void SettingRegistry::handleSetting(const rapidjson::Value::ConstMemberIterator&
         SettingConfig* setting = getSettingConfig(name);
         if (warn_duplicates && setting)
         {
-            cura::logError("Duplicate definition of setting: %s a.k.a. \"%s\" was already claimed by \"%s\"\n", name.c_str(), label.c_str(), getSettingConfig(name)->getLabel().c_str());
+            cura::logWarning("Duplicate definition of setting: %s a.k.a. \"%s\" was already claimed by \"%s\"\n", name.c_str(), label.c_str(), getSettingConfig(name)->getLabel().c_str());
         }
         if (!setting)
         {
@@ -322,6 +311,10 @@ void SettingRegistry::handleSetting(const rapidjson::Value::ConstMemberIterator&
         }
         _loadSettingValues(setting, json_setting_it, settings_base);
     }
+    else
+    {
+        setting_key_to_config[name] = nullptr; // add the setting name to the mapping, but don't instantiate a setting config for it.
+    }
 }
 
 SettingConfig& SettingRegistry::addSetting(std::string name, std::string label)

src/settings/SettingRegistry.h

@@ -174,17 +174,16 @@ private:
      * \param settings_base The settings base where to store the default values.
      * \param warn_duplicates whether to warn for duplicate setting definitions
      */
-    void handleChildren(const rapidjson::Value& settings_list, std::list<std::string>& path, SettingsBase* settings_base, bool warn_duplicates);
+    void handleChildren(const rapidjson::Value& settings_list, SettingsBase* settings_base, bool warn_duplicates);
     
     /*!
      * Handle a json object for a setting.
      * 
      * \param json_setting_it Iterator for the setting which contains the key (setting name) and attributes info
-     * \param path The path of (internal) setting names traversed to get to this object
      * \param settings_base The settings base where to store the default values.
      * \param warn_duplicates whether to warn for duplicate setting definitions
      */
-    void handleSetting(const rapidjson::Value::ConstMemberIterator& json_setting_it, std::list<std::string>& path, SettingsBase* settings_base, bool warn_duplicates);
+    void handleSetting(const rapidjson::Value::ConstMemberIterator& json_setting_it, SettingsBase* settings_base, bool warn_duplicates);
 };
 
 }//namespace cura

src/settings/SettingsToGV.h

@@ -13,6 +13,7 @@
 #include <cassert>
 #include <fstream>
 #include <set>
+#include <unordered_map>
 
 #include "rapidjson/rapidjson.h"
 #include "rapidjson/document.h"
@@ -36,13 +37,16 @@ class SettingsToGv
     
     FILE* out;
     std::set<std::string> engine_settings;
-    bool parent_child_viz, inherit_viz, error_viz, warning_viz;
+    
+    std::unordered_map<std::string, std::string> setting_to_color;
+    bool parent_child_viz, inherit_viz, error_viz, warning_viz, global_only_viz;
 public: 
-    SettingsToGv(std::string output_filename, std::string engine_settings_filename, bool parent_child_viz, bool inherit_viz, bool error_viz, bool warning_viz)
+    SettingsToGv(std::string output_filename, std::string engine_settings_filename, bool parent_child_viz, bool inherit_viz, bool error_viz, bool warning_viz, bool global_only_viz)
     : parent_child_viz(parent_child_viz)
     , inherit_viz(inherit_viz)
     , error_viz(error_viz)
     , warning_viz(warning_viz)
+    , global_only_viz(global_only_viz)
     {
         out = fopen(output_filename.c_str(), "w");
         fprintf(out, "digraph G {\n");
@@ -60,14 +64,31 @@ public:
 private:
     void generateEdge(const std::string& parent, const std::string& child, RelationType relation_type)
     {
-        if (engine_settings.find(parent) != engine_settings.end())
+        if (global_only_viz)
         {
-            fprintf(out, "%s [color=green];\n", parent.c_str());
+            auto parent_it = setting_to_color.find(parent);
+            if (parent_it != setting_to_color.end())
+            {
+                fprintf(out, "%s [color=%s];\n", parent_it->first.c_str(), parent_it->second.c_str());
+            }
+            auto child_it = setting_to_color.find(child);
+            if (child_it != setting_to_color.end())
+            {
+                fprintf(out, "%s [color=%s];\n", child_it->first.c_str(), child_it->second.c_str());
+            }
         }
-        if (engine_settings.find(child) != engine_settings.end())
+        else
         {
-            fprintf(out, "%s [color=green];\n", child.c_str());
+            if (engine_settings.find(parent) != engine_settings.end())
+            {
+                fprintf(out, "%s [color=green];\n", parent.c_str());
+            }
+            if (engine_settings.find(child) != engine_settings.end())
+            {
+                fprintf(out, "%s [color=green];\n", child.c_str());
+            }
         }
+
         std::string color;
         switch (relation_type)
         {
@@ -126,7 +147,10 @@ private:
                     inherited_setting_string != "if" && inherited_setting_string != "else" && inherited_setting_string != "and" 
                     && inherited_setting_string != "or" && inherited_setting_string != "math" && inherited_setting_string != "ceil" 
                     && inherited_setting_string != "int" && inherited_setting_string != "round" && inherited_setting_string != "max" // exclude operators and functions
+                    && inherited_setting_string != "log" // exclude functions
                     && inherited_setting_string != "grid" && inherited_setting_string != "triangles" // exclude enum values
+                    && inherited_setting_string != "cubic" && inherited_setting_string != "tetrahedral" // exclude enum values
+                    && inherited_setting_string != "raft" // exclude enum values
                     && function.c_str()[regex_match.position() + regex_match.length()] != '\'') // exclude enum terms
                 {
                     if (inherited_setting_string == parent)
@@ -157,12 +181,41 @@ private:
         
         if (data.HasMember("type") && data["type"].IsString() && data["type"].GetString() != std::string("category"))
         {
+            if (global_only_viz)
+            {
+                std::string color;
+                if (!data.HasMember("settable_per_mesh") || data["settable_per_mesh"].GetBool() == true)
+                {
+                    color = "green";
+                }
+                else if (data.HasMember("settable_per_mesh") && data["settable_per_mesh"].GetBool() == false)
+                {
+                    if (!data.HasMember("settable_per_extruder") || data["settable_per_extruder"].GetBool() == true)
+                    {
+                        color = "yellow";
+                    }
+                    else if (data.HasMember("settable_per_extruder") && data["settable_per_extruder"].GetBool() == false)
+                    {
+                        if (!data.HasMember("settable_per_meshgroup") || data["settable_per_meshgroup"].GetBool() == true)
+                        {
+                            color = "orange";
+                        }
+                        else if (data.HasMember("settable_per_meshgroup") && data["settable_per_meshgroup"].GetBool() == false)
+                        {
+                            color = "red";
+                        }
+                    }
+                }
+                setting_to_color.emplace(name, color);
+//                 fprintf(out, "%s [color=%s];\n", name.c_str(), color.c_str());
+            }
             
-            bool generated_edge_inherit = createFunctionEdges(data, "inherit_function", parent, name, RelationType::INHERIT_FUNCTION);
-            bool generated_edge_max = createFunctionEdges(data, "max_value", parent, name, RelationType::ERROR_FUNCTION);
-            bool generated_edge_min = createFunctionEdges(data, "min_value", parent, name, RelationType::ERROR_FUNCTION);
-            bool generated_edge_max_warn = createFunctionEdges(data, "max_value_warning", parent, name, RelationType::WARNING_FUNCTION);
-            bool generated_edge_min_warn = createFunctionEdges(data, "min_value_warning", parent, name, RelationType::WARNING_FUNCTION);
+            
+            bool generated_edge_inherit = createFunctionEdges(data, "value", parent, name, RelationType::INHERIT_FUNCTION);
+            bool generated_edge_max = createFunctionEdges(data, "maximum_value", parent, name, RelationType::ERROR_FUNCTION);
+            bool generated_edge_min = createFunctionEdges(data, "minimum_value", parent, name, RelationType::ERROR_FUNCTION);
+            bool generated_edge_max_warn = createFunctionEdges(data, "maximum_value_warning", parent, name, RelationType::WARNING_FUNCTION);
+            bool generated_edge_min_warn = createFunctionEdges(data, "minimum_value_warning", parent, name, RelationType::WARNING_FUNCTION);
             if (generated_edge_inherit || generated_edge_max_warn || generated_edge_min_warn || generated_edge_max || generated_edge_min)
             {
                 generated_edge = true;

src/settings/settings.cpp

@@ -3,6 +3,8 @@
 #include <fstream>
 #include <stdio.h>
 #include <sstream> // ostringstream
+#include <regex> // regex parsing for temp flow graph
+#include <string> // stod (string to double)
 #include "../utils/logoutput.h"
 
 #include "settings.h"
@@ -31,6 +33,8 @@ std::string toString(EGCodeFlavor flavor)
             return "RepRap(Volumetric)";
         case EGCodeFlavor::GRIFFIN:
             return "Griffin";
+        case EGCodeFlavor::REPETIER:
+            return "Repetier";
         case EGCodeFlavor::REPRAP:
         default:
             return "RepRap";
@@ -38,7 +42,7 @@ std::string toString(EGCodeFlavor flavor)
 }
 
 SettingsBaseVirtual::SettingsBaseVirtual()
-: parent(NULL)
+: parent(nullptr)
 {
 }
 
@@ -48,7 +52,7 @@ SettingsBaseVirtual::SettingsBaseVirtual(SettingsBaseVirtual* parent)
 }
 
 SettingsBase::SettingsBase()
-: SettingsBaseVirtual(NULL)
+: SettingsBaseVirtual(nullptr)
 {
 }
 
@@ -76,24 +80,36 @@ void SettingsBase::setSetting(std::string key, std::string value)
     }
     else
     {
-        cura::logError("Warning: setting an unregistered setting %s\n", key.c_str() );
+        cura::logWarning("Setting an unregistered setting %s to %s\n", key.c_str(), value.c_str());
         _setSetting(key, value); // Handy when programmers are in the process of introducing a new setting
     }
 }
 
+void SettingsBase::setSettingInheritBase(std::string key, const SettingsBaseVirtual& parent)
+{
+    setting_inherit_base.emplace(key, &parent);
+}
+
+
 std::string SettingsBase::getSettingString(std::string key) const
 {
-    if (setting_values.find(key) != setting_values.end())
+    auto value_it = setting_values.find(key);
+    if (value_it != setting_values.end())
     {
-        return setting_values.at(key);
+        return value_it->second;
+    }
+    auto inherit_override_it = setting_inherit_base.find(key);
+    if (inherit_override_it != setting_inherit_base.end())
+    {
+        return inherit_override_it->second->getSettingString(key);
     }
     if (parent)
     {
         return parent->getSettingString(key);
     }
 
-    const_cast<SettingsBase&>(*this).setting_values[key] = "";
-    cura::logError("Unregistered setting %s\n", key.c_str());
+    cura::logError("Trying to retrieve unregistered setting with no value given: '%s'\n", key.c_str());
+    std::exit(-1);
     return "";
 }
 
@@ -102,6 +118,12 @@ void SettingsMessenger::setSetting(std::string key, std::string value)
     parent->setSetting(key, value);
 }
 
+void SettingsMessenger::setSettingInheritBase(std::string key, const SettingsBaseVirtual& new_parent)
+{
+    parent->setSettingInheritBase(key, new_parent);
+}
+
+
 std::string SettingsMessenger::getSettingString(std::string key) const
 {
     return parent->getSettingString(key);
@@ -119,17 +141,34 @@ int SettingsBaseVirtual::getSettingAsCount(std::string key) const
     return atoi(value.c_str());
 }
 
+unsigned int SettingsBaseVirtual::getSettingAsLayerNumber(std::string key) const
+{
+    const unsigned int indicated_layer_number = stoul(getSettingString(key));
+    if (indicated_layer_number < 1) //Input checking: Layer 0 is not allowed.
+    {
+        cura::logWarning("Invalid layer number %i for setting %s.", indicated_layer_number, key.c_str());
+        return 0; //Assume layer 1.
+    }
+    return indicated_layer_number - 1; //Input starts counting at layer 1, but engine code starts counting at layer 0.
+}
+
 double SettingsBaseVirtual::getSettingInMillimeters(std::string key) const
 {
     std::string value = getSettingString(key);
     return atof(value.c_str());
 }
 
-int SettingsBaseVirtual::getSettingInMicrons(std::string key) const
+coord_t SettingsBaseVirtual::getSettingInMicrons(std::string key) const
 {
     return getSettingInMillimeters(key) * 1000.0;
 }
 
+double SettingsBaseVirtual::getSettingInAngleDegrees(std::string key) const
+{
+    std::string value = getSettingString(key);
+    return atof(value.c_str());
+}
+
 double SettingsBaseVirtual::getSettingInAngleRadians(std::string key) const
 {
     std::string value = getSettingString(key);
@@ -158,7 +197,7 @@ double SettingsBaseVirtual::getSettingInDegreeCelsius(std::string key) const
 double SettingsBaseVirtual::getSettingInMillimetersPerSecond(std::string key) const
 {
     std::string value = getSettingString(key);
-    return std::max(1.0, atof(value.c_str()));
+    return std::max(0.0, atof(value.c_str()));
 }
 
 double SettingsBaseVirtual::getSettingInCubicMillimeters(std::string key) const
@@ -173,69 +212,117 @@ double SettingsBaseVirtual::getSettingInPercentage(std::string key) const
     return std::max(0.0, atof(value.c_str()));
 }
 
+double SettingsBaseVirtual::getSettingAsRatio(std::string key) const
+{
+    std::string value = getSettingString(key);
+    return atof(value.c_str()) / 100.0;
+}
+
 double SettingsBaseVirtual::getSettingInSeconds(std::string key) const
 {
     std::string value = getSettingString(key);
     return std::max(0.0, atof(value.c_str()));
 }
 
+DraftShieldHeightLimitation SettingsBaseVirtual::getSettingAsDraftShieldHeightLimitation(const std::string key) const
+{
+    const std::string value = getSettingString(key);
+    if (value == "full")
+    {
+        return DraftShieldHeightLimitation::FULL;
+    }
+    else if (value == "limited")
+    {
+        return DraftShieldHeightLimitation::LIMITED;
+    }
+    return DraftShieldHeightLimitation::FULL; //Default.
+}
+
 FlowTempGraph SettingsBaseVirtual::getSettingAsFlowTempGraph(std::string key) const
 {
     FlowTempGraph ret;
-    const char* c_str = getSettingString(key).c_str();
-    char const* char_p = c_str;
-    while (*char_p != '[')
+    std::string value_string = getSettingString(key);
+    if (value_string.empty())
     {
-        if (*char_p == '\0') //We've reached the end of string without encountering the first opening bracket.
-        {
-            return ret; //Empty at this point.
-        }
-        char_p++;
+        return ret; //Empty at this point.
     }
-    char_p++; // skip the '['
-    for (; *char_p != '\0'; char_p++)
+    std::regex regex("(\\[([^,\\[]*),([^,\\]]*)\\])");
+    // match with:
+    // - the last opening bracket '['
+    // - then a bunch of characters until the first comma
+    // - a comma
+    // - a bunch of cahracters until the first closing bracket ']'
+    // matches with any substring which looks like "[  124.512 , 124.1 ]"
+
+    // default constructor = end-of-sequence:
+    std::regex_token_iterator<std::string::iterator> rend;
+
+    int submatches[] = { 1, 2, 3 }; // match whole pair, first number and second number of a pair
+    std::regex_token_iterator<std::string::iterator> match_iter(value_string.begin(), value_string.end(), regex, submatches);
+    while (match_iter != rend)
     {
-        while (*char_p != '[')
-        {
-            if (*char_p == '\0') //We've reached the end of string without finding the next opening bracket.
-            {
-                return ret; //Don't continue parsing this item then. Just stop and return.
-            }
-            char_p++;
-        }
-        char_p++; // skip the '['
-        char* end;
-        double first = strtod(char_p, &end); //If not a valid number, this becomes zero.
-        char_p = end;
-        while (*char_p != ',')
-        {
-            if (*char_p == '\0') //We've reached the end of string without finding the comma.
-            {
-                return ret; //This entry is incomplete.
-            }
-            char_p++;
-        }
-        char_p++; // skip the ','
-        double second = strtod(char_p, &end); //If not a valid number, this becomes zero.
-        ret.data.emplace_back(first, second);
-        char_p = end;
-        while (*char_p != ']')
-        {
-            if (*char_p == '\0') //We've reached the end of string without finding the closing bracket.
-            {
-                return ret; //This entry is probably complete and has been added, but stop searching.
-            }
-            char_p++;
-        }
-        char_p++; // skip the ']'
-        if (*char_p == ']' || *char_p == '\0')
+        match_iter++; // match the whole pair
+        if (match_iter == rend)
         {
             break;
         }
+        std::string first_substring = *match_iter++;
+        std::string second_substring = *match_iter++;
+        try
+        {
+            double first = std::stod(first_substring);
+            double second = std::stod(second_substring);
+            ret.data.emplace_back(first, second);
+        }
+        catch (const std::invalid_argument& e)
+        {
+            logError("Couldn't read 2D graph element [%s,%s] in setting '%s'. Ignored.\n", first_substring.c_str(), second_substring.c_str(), key.c_str());
+        }
     }
     return ret;
 }
 
+FMatrix3x3 SettingsBaseVirtual::getSettingAsPointMatrix(std::string key) const
+{
+    FMatrix3x3 ret;
+
+    std::string value_string = getSettingString(key);
+    if (value_string.empty())
+    {
+        return ret; // standard matrix ([1,0,0],[0,1,0],[0,0,1])
+    }
+
+    std::string num("([^,\\] ]*)"); // match with anything but the next ',' ']' or space  and capture the match
+    std::ostringstream row; // match with "[num,num,num]" and ignore whitespace
+    row << "\\s*\\[\\s*" << num << "\\s*,\\s*" << num << "\\s*,\\s*" << num << "\\s*\\]\\s*";
+
+    std::ostringstream matrix; // match with "[row,row,row]" and ignore whitespace
+    matrix << "\\s*\\[" << row.str() << "\\s*,\\s*" << row.str() << "\\s*,\\s*" << row.str() << "\\]\\s*";
+
+    std::regex point_matrix_regex(matrix.str());
+    std::cmatch sub_matches;    // same as std::match_results<const char*> cm;
+    std::regex_match(value_string.c_str(), sub_matches, point_matrix_regex);
+
+    if (sub_matches.size() != 10) // one match for the whole string
+    {
+        logWarning("Mesh transformation matrix could not be parsed!\n\tFormat should be [[f,f,f],[f,f,f],[f,f,f]] allowing whitespace anywhere in between.\n\tWhile what was given was \"%s\".\n", value_string.c_str());
+        return ret; // standard matrix ([1,0,0],[0,1,0],[0,0,1])
+    }
+
+    unsigned int sub_match_idx = 1; // skip the first because the first submatch is the whole string
+    for (unsigned int x = 0; x < 3; x++)
+    {
+        for (unsigned int y = 0; y < 3; y++)
+        {
+            std::sub_match<const char*> sub_match = sub_matches[sub_match_idx];
+            ret.m[y][x] = strtod(std::string(sub_match.str()).c_str(), nullptr);
+            sub_match_idx++;
+        }
+    }
+
+    return ret;
+}
+
 
 EGCodeFlavor SettingsBaseVirtual::getSettingAsGCodeFlavor(std::string key) const
 {
@@ -252,6 +339,8 @@ EGCodeFlavor SettingsBaseVirtual::getSettingAsGCodeFlavor(std::string key) const
         return EGCodeFlavor::MACH3;
     else if (value == "RepRap (Volumatric)")
         return EGCodeFlavor::REPRAP_VOLUMATRIC;
+    else if (value == "Repetier")
+        return EGCodeFlavor::REPETIER;
     return EGCodeFlavor::REPRAP;
 }
 
@@ -262,10 +351,18 @@ EFillMethod SettingsBaseVirtual::getSettingAsFillMethod(std::string key) const
         return EFillMethod::LINES;
     if (value == "grid")
         return EFillMethod::GRID;
+    if (value == "cubic")
+        return EFillMethod::CUBIC;
+    if (value == "cubicsubdiv")
+        return EFillMethod::CUBICSUBDIV;
+    if (value == "tetrahedral")
+        return EFillMethod::TETRAHEDRAL;
     if (value == "triangles")
         return EFillMethod::TRIANGLES;
     if (value == "concentric")
         return EFillMethod::CONCENTRIC;
+    if (value == "concentric_3d")
+        return EFillMethod::CONCENTRIC_3D;
     if (value == "zigzag")
         return EFillMethod::ZIG_ZAG;
     return EFillMethod::NONE;
@@ -278,6 +375,8 @@ EPlatformAdhesion SettingsBaseVirtual::getSettingAsPlatformAdhesion(std::string
         return EPlatformAdhesion::BRIM;
     if (value == "raft")
         return EPlatformAdhesion::RAFT;
+    if (value == "none")
+        return EPlatformAdhesion::NONE;
     return EPlatformAdhesion::SKIRT;
 }
 
@@ -315,7 +414,21 @@ ESurfaceMode SettingsBaseVirtual::getSettingAsSurfaceMode(std::string key) const
     return ESurfaceMode::NORMAL;
 }
 
-CombingMode SettingsBaseVirtual::getSettingAsCombingMode(std::string key)
+FillPerimeterGapMode SettingsBaseVirtual::getSettingAsFillPerimeterGapMode(std::string key) const
+{
+    std::string value = getSettingString(key);
+    if (value == "nowhere")
+    {
+        return FillPerimeterGapMode::NOWHERE;
+    }
+    if (value == "everywhere")
+    {
+        return FillPerimeterGapMode::EVERYWHERE;
+    }
+    return FillPerimeterGapMode::NOWHERE;
+}
+
+CombingMode SettingsBaseVirtual::getSettingAsCombingMode(std::string key) const
 {
     std::string value = getSettingString(key);
     if (value == "off")
@@ -333,7 +446,7 @@ CombingMode SettingsBaseVirtual::getSettingAsCombingMode(std::string key)
     return CombingMode::ALL;
 }
 
-SupportDistPriority SettingsBaseVirtual::getSettingAsSupportDistPriority(std::string key)
+SupportDistPriority SettingsBaseVirtual::getSettingAsSupportDistPriority(std::string key) const
 {
     std::string value = getSettingString(key);
     if (value == "xy_overrides_z")

src/settings/settings.h

@@ -86,6 +86,8 @@ enum class EGCodeFlavor
  *  M227 is used to initialize a single extrusion train.
  **/
     GRIFFIN = 6,
+
+    REPETIER = 7,
 };
 
 /*!
@@ -102,20 +104,25 @@ enum class EFillMethod
 {
     LINES,
     GRID,
+    CUBIC,
+    CUBICSUBDIV,
+    TETRAHEDRAL,
     TRIANGLES,
     CONCENTRIC,
+    CONCENTRIC_3D,
     ZIG_ZAG,
     NONE
 };
 
 /*!
- * Type of platform adheasion
+ * Type of platform adhesion.
  */
 enum class EPlatformAdhesion
 {
     SKIRT,
     BRIM,
-    RAFT
+    RAFT,
+    NONE
 };
 
 /*!
@@ -142,6 +149,12 @@ enum class ESurfaceMode
     BOTH
 };
 
+enum class FillPerimeterGapMode
+{
+    NOWHERE,
+    EVERYWHERE
+};
+
 enum class CombingMode
 {
     OFF,
@@ -149,6 +162,15 @@ enum class CombingMode
     NO_SKIN
 };
 
+/*!
+ * How the draft shield height is limited.
+ */
+enum class DraftShieldHeightLimitation
+{
+    FULL, //Draft shield takes full height of the print.
+    LIMITED //Draft shield is limited by draft_shield_height setting.
+};
+
 enum class SupportDistPriority
 {
     XY_OVERRIDES_Z,
@@ -175,7 +197,16 @@ public:
     virtual std::string getSettingString(std::string key) const = 0;
     
     virtual void setSetting(std::string key, std::string value) = 0;
-    
+
+    /*!
+     * Set the parent settings base for inheriting a setting to a specific setting base.
+     * This overrides the use of \ref SettingsBaseVirtual::parent.
+     * 
+     * \param key The setting for which to override the inheritance
+     * \param parent The setting base from which to obtain the setting instead.
+     */
+    virtual void setSettingInheritBase(std::string key, const SettingsBaseVirtual& parent) = 0;
+
     virtual ~SettingsBaseVirtual() {}
     
     SettingsBaseVirtual(); //!< SettingsBaseVirtual without a parent settings object
@@ -186,27 +217,42 @@ public:
     
     int getSettingAsIndex(std::string key) const;
     int getSettingAsCount(std::string key) const;
-    
+
+    /*!
+     * \brief Interprets a setting as a layer number.
+     *
+     * The input of the layer number is one-based. This translates it to
+     * zero-based numbering.
+     *
+     * \return Zero-based numbering of a layer number setting.
+     */
+    unsigned int getSettingAsLayerNumber(std::string key) const;
+
+    double getSettingInAngleDegrees(std::string key) const;
     double getSettingInAngleRadians(std::string key) const;
     double getSettingInMillimeters(std::string key) const;
-    int getSettingInMicrons(std::string key) const;
+    coord_t getSettingInMicrons(std::string key) const;
     bool getSettingBoolean(std::string key) const;
     double getSettingInDegreeCelsius(std::string key) const;
     double getSettingInMillimetersPerSecond(std::string key) const;
     double getSettingInCubicMillimeters(std::string key) const;
     double getSettingInPercentage(std::string key) const;
+    double getSettingAsRatio(std::string key) const; //!< For settings which are provided in percentage
     double getSettingInSeconds(std::string key) const;
-    
+
     FlowTempGraph getSettingAsFlowTempGraph(std::string key) const;
-    
+    FMatrix3x3 getSettingAsPointMatrix(std::string key) const;
+
+    DraftShieldHeightLimitation getSettingAsDraftShieldHeightLimitation(const std::string key) const;
     EGCodeFlavor getSettingAsGCodeFlavor(std::string key) const;
     EFillMethod getSettingAsFillMethod(std::string key) const;
     EPlatformAdhesion getSettingAsPlatformAdhesion(std::string key) const;
     ESupportType getSettingAsSupportType(std::string key) const;
     EZSeamType getSettingAsZSeamType(std::string key) const;
     ESurfaceMode getSettingAsSurfaceMode(std::string key) const;
-    CombingMode getSettingAsCombingMode(std::string key);
-    SupportDistPriority getSettingAsSupportDistPriority(std::string key);
+    FillPerimeterGapMode getSettingAsFillPerimeterGapMode(std::string key) const;
+    CombingMode getSettingAsCombingMode(std::string key) const;
+    SupportDistPriority getSettingAsSupportDistPriority(std::string key) const;
 };
 
 class SettingRegistry;
@@ -222,6 +268,11 @@ class SettingsBase : public SettingsBaseVirtual
     friend class SettingRegistry;
 private:
     std::unordered_map<std::string, std::string> setting_values;
+
+    /*!
+     * Mapping for each setting which must inherit from a different setting base than \ref SettingsBaseVirtual::parent
+     */
+    std::unordered_map<std::string, const SettingsBaseVirtual*> setting_inherit_base;
 public:
     SettingsBase(); //!< SettingsBase without a parent settings object
     SettingsBase(SettingsBaseVirtual* parent); //!< construct a SettingsBase with a parent settings object
@@ -232,6 +283,7 @@ public:
      * \param value the value
      */
     void setSetting(std::string key, std::string value);
+    void setSettingInheritBase(std::string key, const SettingsBaseVirtual& parent); //!< See \ref SettingsBaseVirtual::setSettingInheritBase
     std::string getSettingString(std::string key) const; //!< Get a setting from this SettingsBase (or any ancestral SettingsBase)
     
     std::string getAllLocalSettingsString() const
@@ -272,6 +324,7 @@ public:
     SettingsMessenger(SettingsBaseVirtual* parent); //!< construct a SettingsMessenger with a parent settings object
     
     void setSetting(std::string key, std::string value); //!< Set a setting of the parent SettingsBase to a given value
+    void setSettingInheritBase(std::string key, const SettingsBaseVirtual& parent); //!< See \ref SettingsBaseVirtual::setSettingInheritBase
     std::string getSettingString(std::string key) const; //!< Get a setting from the parent SettingsBase (or any further ancestral SettingsBase)
 };
 

src/skin.cpp

@@ -1,5 +1,8 @@
 /** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#include <cmath> // std::ceil
+
 #include "skin.h"
+#include "utils/math.h"
 #include "utils/polygonUtils.h"
 
 #define MIN_AREA_SIZE (0.4 * 0.4) 
@@ -7,20 +10,35 @@
 namespace cura 
 {
 
-        
-void generateSkins(int layerNr, SliceMeshStorage& mesh, int extrusionWidth, int downSkinCount, int upSkinCount, int wall_line_count, int innermost_wall_extrusion_width, int insetCount, bool no_small_gaps_heuristic)
+
+/*
+ * This function is executed in a parallel region based on layer_nr.
+ * When modifying make sure any changes does not introduce data races.
+ *
+ * generateSkinAreas reads data from mesh.layers.parts[*].insets and writes to mesh.layers[n].parts[*].skin_parts
+ * generateSkinInsets only read/writes the skin_parts from the current layer.
+ *
+ * generateSkins therefore reads (depends on) data from mesh.layers[*].parts[*].insets and writes mesh.layers[n].parts[*].skin_parts
+ */
+void generateSkins(int layerNr, SliceMeshStorage& mesh, int downSkinCount, int upSkinCount, int wall_line_count, int innermost_wall_line_width, int insetCount, bool no_small_gaps_heuristic)
 {
-    generateSkinAreas(layerNr, mesh, innermost_wall_extrusion_width, downSkinCount, upSkinCount, wall_line_count, no_small_gaps_heuristic);
+    generateSkinAreas(layerNr, mesh, innermost_wall_line_width, downSkinCount, upSkinCount, wall_line_count, no_small_gaps_heuristic);
 
     SliceLayer* layer = &mesh.layers[layerNr];
     for(unsigned int partNr=0; partNr<layer->parts.size(); partNr++)
     {
         SliceLayerPart* part = &layer->parts[partNr];
-        generateSkinInsets(part, extrusionWidth, insetCount);
+        generateSkinInsets(part, innermost_wall_line_width, insetCount);
     }
 }
 
-void generateSkinAreas(int layer_nr, SliceMeshStorage& mesh, int innermost_wall_extrusion_width, int downSkinCount, int upSkinCount, int wall_line_count, bool no_small_gaps_heuristic)
+/*
+ * This function is executed in a parallel region based on layer_nr.
+ * When modifying make sure any changes does not introduce data races.
+ *
+ * generateSkinAreas reads data from mesh.layers[*].parts[*].insets and writes to mesh.layers[n].parts[*].skin_parts
+ */
+void generateSkinAreas(int layer_nr, SliceMeshStorage& mesh, const int innermost_wall_line_width, int downSkinCount, int upSkinCount, int wall_line_count, bool no_small_gaps_heuristic)
 {
     SliceLayer& layer = mesh.layers[layer_nr];
     
@@ -28,18 +46,18 @@ void generateSkinAreas(int layer_nr, SliceMeshStorage& mesh, int innermost_wall_
     {
         return;
     }
-    
+    int min_infill_area = mesh.getSettingInMillimeters("min_infill_area");
     for(unsigned int partNr = 0; partNr < layer.parts.size(); partNr++)
     {
         SliceLayerPart& part = layer.parts[partNr];
 
         if (int(part.insets.size()) < wall_line_count)
         {
-            continue; // the last wall is not present, the part should only get inter preimeter gaps, but no skin.
+            continue; // the last wall is not present, the part should only get inter perimeter gaps, but no skin.
         }
 
-        Polygons upskin = part.insets.back().offset(-innermost_wall_extrusion_width/2);
-        Polygons downskin = (downSkinCount == 0)? Polygons() : upskin;
+        Polygons upskin = part.insets.back().offset(-innermost_wall_line_width / 2);
+        Polygons downskin = (downSkinCount == 0) ? Polygons() : upskin;
         if (upSkinCount == 0) upskin = Polygons();
 
         auto getInsidePolygons = [&part, wall_line_count](SliceLayer& layer2)
@@ -49,7 +67,7 @@ void generateSkinAreas(int layer_nr, SliceMeshStorage& mesh, int innermost_wall_
                 {
                     if (part.boundaryBox.hit(part2.boundaryBox))
                     {
-                        unsigned int wall_idx = std::min(wall_line_count, (int) part2.insets.size()) - 1;
+                        unsigned int wall_idx = std::max(0, std::min(wall_line_count, (int) part2.insets.size()) - 1);
                         result.add(part2.insets[wall_idx]);
                     }
                 }
@@ -60,12 +78,22 @@ void generateSkinAreas(int layer_nr, SliceMeshStorage& mesh, int innermost_wall_
         {
             if (static_cast<int>(layer_nr - downSkinCount) >= 0)
             {
-                downskin = downskin.difference(getInsidePolygons(mesh.layers[layer_nr - downSkinCount])); // skin overlaps with the walls
+                Polygons not_air = getInsidePolygons(mesh.layers[layer_nr - downSkinCount]);
+                if (min_infill_area > 0)
+                {
+                    not_air.removeSmallAreas(min_infill_area);
+                }
+                downskin = downskin.difference(not_air); // skin overlaps with the walls
             }
             
             if (static_cast<int>(layer_nr + upSkinCount) < static_cast<int>(mesh.layers.size()))
             {
-                upskin = upskin.difference(getInsidePolygons(mesh.layers[layer_nr + upSkinCount])); // skin overlaps with the walls
+                Polygons not_air = getInsidePolygons(mesh.layers[layer_nr + upSkinCount]);
+                if (min_infill_area > 0)
+                {
+                    not_air.removeSmallAreas(min_infill_area);
+                }
+                upskin = upskin.difference(not_air); // skin overlaps with the walls
             }
         }
         else 
@@ -77,16 +105,24 @@ void generateSkinAreas(int layer_nr, SliceMeshStorage& mesh, int innermost_wall_
                 {
                     not_air = not_air.intersection(getInsidePolygons(mesh.layers[downskin_layer_nr]));
                 }
+                if (min_infill_area > 0)
+                {
+                    not_air.removeSmallAreas(min_infill_area);
+                }
                 downskin = downskin.difference(not_air); // skin overlaps with the walls
             }
             
-            if (layer_nr < static_cast<int>(mesh.layers.size()) - 1 && upSkinCount > 0)
+            if (layer_nr < static_cast<int>(mesh.layers.size()) - 1 - upSkinCount && upSkinCount > 0)
             {
                 Polygons not_air = getInsidePolygons(mesh.layers[layer_nr + 1]);
                 for (int upskin_layer_nr = layer_nr + 2; upskin_layer_nr < layer_nr + upSkinCount + 1; upskin_layer_nr++)
                 {
                     not_air = not_air.intersection(getInsidePolygons(mesh.layers[upskin_layer_nr]));
                 }
+                if (min_infill_area > 0)
+                {
+                    not_air.removeSmallAreas(min_infill_area);
+                }
                 upskin = upskin.difference(not_air); // skin overlaps with the walls
             }
         }
@@ -103,8 +139,13 @@ void generateSkinAreas(int layer_nr, SliceMeshStorage& mesh, int innermost_wall_
     }
 }
 
-
-void generateSkinInsets(SliceLayerPart* part, int extrusionWidth, int insetCount)
+/*
+ * This function is executed in a parallel region based on layer_nr.
+ * When modifying make sure any changes does not introduce data races.
+ *
+ * generateSkinInsets only read/writes the skin_parts from the current layer.
+ */
+void generateSkinInsets(SliceLayerPart* part, const int wall_line_width, int insetCount)
 {
     if (insetCount == 0)
     {
@@ -118,13 +159,14 @@ void generateSkinInsets(SliceLayerPart* part, int extrusionWidth, int insetCount
             skin_part.insets.push_back(Polygons());
             if (i == 0)
             {
-                skin_part.insets[0] = skin_part.outline.offset(- extrusionWidth/2);
-            } else
+                skin_part.insets[0] = skin_part.outline.offset(-wall_line_width / 2);
+            }
+            else
             {
-                skin_part.insets[i] = skin_part.insets[i - 1].offset(-extrusionWidth);
+                skin_part.insets[i] = skin_part.insets[i - 1].offset(-wall_line_width);
             }
             
-            // optimize polygons: remove unnnecesary verts
+            // optimize polygons: remove unnecessary verts
             skin_part.insets[i].simplify();
             if (skin_part.insets[i].size() < 1)
             {
@@ -135,18 +177,33 @@ void generateSkinInsets(SliceLayerPart* part, int extrusionWidth, int insetCount
     }
 }
 
-void generateInfill(int layerNr, SliceMeshStorage& mesh, int innermost_wall_extrusion_width, int infill_skin_overlap, int wall_line_count)
+/*
+ * This function is executed in a parallel region based on layer_nr.
+ * When modifying make sure any changes does not introduce data races.
+ *
+ * generateInfill read mesh.layers[n].parts[*].{insets,skin_parts,boundingBox} and write mesh.layers[n].parts[*].infill_area
+ */
+void generateInfill(int layerNr, SliceMeshStorage& mesh, const int innermost_wall_line_width, int infill_skin_overlap, int wall_line_count)
 {
     SliceLayer& layer = mesh.layers[layerNr];
 
+    int extra_offset = 0;
+    EFillMethod fill_pattern = mesh.getSettingAsFillMethod("infill_pattern");
+    if ((fill_pattern == EFillMethod::CONCENTRIC || fill_pattern == EFillMethod::CONCENTRIC_3D)
+        && mesh.getSettingBoolean("alternate_extra_perimeter")
+        && layerNr % 2 == 0
+        && mesh.getSettingInMicrons("infill_line_distance") > mesh.getSettingInMicrons("infill_line_width") * 2)
+    {
+        extra_offset = -innermost_wall_line_width;
+    }
+
     for(SliceLayerPart& part : layer.parts)
     {
         if (int(part.insets.size()) < wall_line_count)
         {
-            part.infill_area_per_combine.emplace_back(); // put empty polygons as initial infill_per_combine
             continue; // the last wall is not present, the part should only get inter preimeter gaps, but no infill.
         }
-        Polygons infill = part.insets.back().offset(-innermost_wall_extrusion_width / 2 - infill_skin_overlap);
+        Polygons infill = part.insets.back().offset(extra_offset - innermost_wall_line_width / 2 - infill_skin_overlap);
 
         for(SliceLayerPart& part2 : layer.parts)
         {
@@ -159,20 +216,111 @@ void generateInfill(int layerNr, SliceMeshStorage& mesh, int innermost_wall_extr
             }
         }
         infill.removeSmallAreas(MIN_AREA_SIZE);
-        
-        part.infill_area = infill.offset(infill_skin_overlap);
-        part.infill_area_per_combine.push_back(part.infill_area);
+
+        Polygons final_infill = infill.offset(infill_skin_overlap);
+
+        if (mesh.getSettingBoolean("infill_hollow"))
+        {
+            part.print_outline = part.print_outline.difference(final_infill);
+        }
+        else
+        {
+            part.infill_area = final_infill;
+        }
+    }
+}
+
+void SkinInfillAreaComputation::generateGradualInfill(SliceMeshStorage& mesh, unsigned int gradual_infill_step_height, unsigned int max_infill_steps)
+{
+    // no early-out for this function; it needs to initialize the [infill_area_per_combine_per_density]
+    float layer_skip_count = 8; // skip every so many layers as to ignore small gaps in the model making computation more easy
+    if (!mesh.getSettingBoolean("skin_no_small_gaps_heuristic"))
+    {
+        layer_skip_count = 1;
+    }
+    unsigned int gradual_infill_step_layer_count = round_divide(gradual_infill_step_height, mesh.getSettingInMicrons("layer_height")); // The difference in layer count between consecutive density infill areas
+
+    // make gradual_infill_step_height divisable by layer_skip_count
+    float n_skip_steps_per_gradual_step = std::max(1.0f, std::ceil(gradual_infill_step_layer_count / layer_skip_count)); // only decrease layer_skip_count to make it a divisor of gradual_infill_step_layer_count
+    layer_skip_count = gradual_infill_step_layer_count / n_skip_steps_per_gradual_step;
+
+
+    size_t min_layer = mesh.getSettingAsCount("bottom_layers");
+    size_t max_layer = mesh.layers.size() - 1 - mesh.getSettingAsCount("top_layers");
+
+    for (size_t layer_idx = 0; layer_idx < mesh.layers.size(); layer_idx++)
+    { // loop also over layers which don't contain infill cause of bottom_ and top_layer to initialize their infill_area_per_combine_per_density
+        SliceLayer& layer = mesh.layers[layer_idx];
+
+        for (SliceLayerPart& part : layer.parts)
+        {
+            assert(part.infill_area_per_combine_per_density.size() == 0 && "infill_area_per_combine_per_density is supposed to be uninitialized");
+
+            const Polygons& infill_area = part.getOwnInfillArea();
+
+            if (infill_area.size() == 0 || layer_idx < min_layer || layer_idx > max_layer)
+            { // initialize infill_area_per_combine_per_density empty
+                part.infill_area_per_combine_per_density.emplace_back(); // create a new infill_area_per_combine
+                part.infill_area_per_combine_per_density.back().emplace_back(); // put empty infill area in the newly constructed infill_area_per_combine
+                // note: no need to copy part.infill_area, cause it's the empty vector anyway
+                continue;
+            }
+            Polygons less_dense_infill = infill_area; // one step less dense with each infill_step
+            for (unsigned int infill_step = 0; infill_step < max_infill_steps; infill_step++)
+            {
+                size_t min_layer = layer_idx + infill_step * gradual_infill_step_layer_count + layer_skip_count;
+                size_t max_layer = layer_idx + (infill_step + 1) * gradual_infill_step_layer_count;
+
+                for (float upper_layer_idx = min_layer; static_cast<unsigned int>(upper_layer_idx) <= max_layer; upper_layer_idx += layer_skip_count)
+                {
+                    if (static_cast<unsigned int>(upper_layer_idx) >= mesh.layers.size())
+                    {
+                        less_dense_infill.clear();
+                        break;
+                    }
+                    SliceLayer& upper_layer = mesh.layers[static_cast<unsigned int>(upper_layer_idx)];
+                    Polygons relevent_upper_polygons;
+                    for (SliceLayerPart& upper_layer_part : upper_layer.parts)
+                    {
+                        if (!upper_layer_part.boundaryBox.hit(part.boundaryBox))
+                        {
+                            continue;
+                        }
+                        relevent_upper_polygons.add(upper_layer_part.getOwnInfillArea());
+                    }
+                    less_dense_infill = less_dense_infill.intersection(relevent_upper_polygons);
+                }
+                if (less_dense_infill.size() == 0)
+                {
+                    break;
+                }
+                // add new infill_area_per_combine for the current density
+                part.infill_area_per_combine_per_density.emplace_back();
+                std::vector<Polygons>& infill_area_per_combine_current_density = part.infill_area_per_combine_per_density.back();
+                const Polygons more_dense_infill = infill_area.difference(less_dense_infill);
+                infill_area_per_combine_current_density.push_back(more_dense_infill);
+
+                if (less_dense_infill.size() == 0)
+                {
+                    break;
+                }
+            }
+            part.infill_area_per_combine_per_density.emplace_back();
+            std::vector<Polygons>& infill_area_per_combine_current_density = part.infill_area_per_combine_per_density.back();
+            infill_area_per_combine_current_density.push_back(infill_area);
+            part.infill_area_own = nullptr; // clear infill_area_own, it's not needed any more.
+            assert(part.infill_area_per_combine_per_density.size() != 0 && "infill_area_per_combine_per_density is now initialized");
+        }
     }
 }
 
 void combineInfillLayers(SliceMeshStorage& mesh, unsigned int amount)
 {
-    // Note that *all* parts should have an [infill_area_per_combine] with one element in it, which up till now only contains the exact same polygons as [infill].
-    if(amount <= 1) //If we must combine 1 layer, nothing needs to be combined. Combining 0 layers is invalid.
+    if (mesh.layers.empty() || mesh.layers.size() - 1 < static_cast<size_t>(mesh.getSettingAsCount("top_layers")) || mesh.getSettingAsCount("infill_line_distance") <= 0) //No infill is even generated.
     {
         return;
     }
-    if (mesh.layers.empty() || mesh.layers.size() - 1 < static_cast<size_t>(mesh.getSettingAsCount("top_layers")) || mesh.getSettingAsCount("infill_line_distance") <= 0) //No infill is even generated.
+    if(amount <= 1) //If we must combine 1 layer, nothing needs to be combined. Combining 0 layers is invalid.
     {
         return;
     }
@@ -187,30 +335,46 @@ void combineInfillLayers(SliceMeshStorage& mesh, unsigned int amount)
     for(size_t layer_idx = min_layer;layer_idx <= max_layer;layer_idx += amount) //Skip every few layers, but extrude more.
     {
         SliceLayer* layer = &mesh.layers[layer_idx];
-
-        for(unsigned int n = 1;n < amount;n++)
+        for(unsigned int combine_count_here = 1; combine_count_here < amount; combine_count_here++)
         {
-            if(layer_idx < n)
+            if(layer_idx < combine_count_here)
             {
                 break;
             }
 
-            SliceLayer* layer2 = &mesh.layers[layer_idx - n];
-            for(SliceLayerPart& part : layer->parts)
+            size_t lower_layer_idx = layer_idx - combine_count_here;
+            if (lower_layer_idx < min_layer)
             {
-                Polygons result;
-                for(SliceLayerPart& part2 : layer2->parts)
-                {
-                    if(part.boundaryBox.hit(part2.boundaryBox))
+                break;
+            }
+            SliceLayer* lower_layer = &mesh.layers[lower_layer_idx];
+            for (SliceLayerPart& part : layer->parts)
+            {
+                for (unsigned int density_idx = 0; density_idx < part.infill_area_per_combine_per_density.size(); density_idx++)
+                { // go over each density of gradual infill (these density areas overlap!)
+                    std::vector<Polygons>& infill_area_per_combine = part.infill_area_per_combine_per_density[density_idx];
+                    Polygons result;
+                    for (SliceLayerPart& lower_layer_part : lower_layer->parts)
                     {
-                        Polygons intersection = part.infill_area_per_combine[n - 1].intersection(part2.infill_area_per_combine[0]).offset(-200).offset(200);
-                        result.add(intersection);
-                        part.infill_area_per_combine[n - 1] = part.infill_area_per_combine[n - 1].difference(intersection);
-                        part2.infill_area_per_combine[0] = part2.infill_area_per_combine[0].difference(intersection);
-                    }
-                }
+                        if (part.boundaryBox.hit(lower_layer_part.boundaryBox))
+                        {
 
-                part.infill_area_per_combine.push_back(result);
+                            Polygons intersection = infill_area_per_combine[combine_count_here - 1].intersection(lower_layer_part.infill_area).offset(-200).offset(200);
+                            result.add(intersection); // add area to be thickened
+                            infill_area_per_combine[combine_count_here - 1] = infill_area_per_combine[combine_count_here - 1].difference(intersection); // remove thickened area from less thick layer here
+                            if (density_idx < lower_layer_part.infill_area_per_combine_per_density.size())
+                            { // only remove from *same density* areas on layer below
+                                // If there are no same density areas, then it's ok to print them anyway
+                                // Don't remove other density areas
+                                unsigned int lower_density_idx = density_idx;
+                                std::vector<Polygons>& lower_infill_area_per_combine = lower_layer_part.infill_area_per_combine_per_density[lower_density_idx];
+                                lower_infill_area_per_combine[0] = lower_infill_area_per_combine[0].difference(intersection); // remove thickened area from lower (thickened) layer
+                            }
+                        }
+                    }
+
+                    infill_area_per_combine.push_back(result);
+                }
             }
         }
     }

src/skin.h

@@ -11,38 +11,43 @@ namespace cura
  * 
  * \param layerNr The index of the layer for which to generate the skins.
  * \param mesh The storage where the layer outline information (input) is stored and where the skin insets and fill areas (output) are stored.
- * \param extrusionWidth extrusionWidth
  * \param downSkinCount The number of layers of bottom skin
  * \param upSkinCount The number of layers of top skin
  * \param wall_line_count The number of walls, i.e. the number of the wall from which to offset.
- * \param innermost_wall_extrusion_width The line width of the inner most wall
+ * \param innermost_wall_line_width The line width of the inner most wall
  * \param insetCount The number of perimeters to surround the skin
  * \param no_small_gaps_heuristic A heuristic which assumes there will be no small gaps between bottom and top skin with a z size smaller than the skin size itself
  */
-void generateSkins(int layerNr, SliceMeshStorage& mesh, int extrusionWidth, int downSkinCount, int upSkinCount, int wall_line_count, int innermost_wall_extrusion_width, int insetCount, bool no_small_gaps_heuristic);
+void generateSkins(int layerNr, SliceMeshStorage& mesh, int downSkinCount, int upSkinCount, int wall_line_count, int innermost_wall_line_width, int insetCount, bool no_small_gaps_heuristic);
 
 /*!
  * Generate the skin areas (outlines)
  * 
  * \param layerNr The index of the layer for which to generate the skins.
- * \param mesh The storage where the layer outline information (input) is stored and where the skin outline (output) is stored.
- * \param extrusionWidth extrusionWidth
- * \param downSkinCount The number of layers of bottom skin
- * \param upSkinCount The number of layers of top skin
- * \param wall_line_count The number of walls, i.e. the number of the wall from which to offset.
- * \param no_small_gaps_heuristic A heuristic which assumes there will be no small gaps between bottom and top skin with a z size smaller than the skin size itself
+ * \param mesh The storage where the layer outline information (input) is stored
+ * and where the skin outline (output) is stored.
+ * \param innermost_wall_line_width The line width of the walls around the skin, by which
+ * we must inset for each wall.
+ * \param downSkinCount The number of layers of bottom skin.
+ * \param upSkinCount The number of layers of top skin.
+ * \param wall_line_count The number of walls, i.e. the number of the wall from
+ * which to offset.
+ * \param no_small_gaps_heuristic A heuristic which assumes there will be no
+ * small gaps between bottom and top skin with a z size smaller than the skin
+ * size itself.
  */
-void generateSkinAreas(int layerNr, SliceMeshStorage& mesh, int extrusionWidth, int downSkinCount, int upSkinCount, int wall_line_count, bool no_small_gaps_heuristic);
+void generateSkinAreas(int layerNr, SliceMeshStorage& mesh, const int innermost_wall_line_width, int downSkinCount, int upSkinCount, int wall_line_count, bool no_small_gaps_heuristic);
 
 /*!
  * Generate the skin insets.
  * 
  * \param layerNr The index of the layer for which to generate the skins.
- * \param part The part where the skin outline information (input) is stored and where the skin insets (output) are stored.
- * \param extrusionWidth extrusionWidth
- * \param insetCount The number of perimeters to surround the skin
+ * \param part The part where the skin outline information (input) is stored and
+ * where the skin insets (output) are stored.
+ * \param wall_line_width The width of the perimeters around the skin.
+ * \param insetCount The number of perimeters to surround the skin.
  */
-void generateSkinInsets(SliceLayerPart* part, int extrusionWidth, int insetCount);
+void generateSkinInsets(SliceLayerPart* part, const int wall_line_width, int insetCount);
 
 /*!
  * Generate Infill by offsetting from the last wall.
@@ -54,11 +59,11 @@ void generateSkinInsets(SliceLayerPart* part, int extrusionWidth, int insetCount
  * \param layerNr The index of the layer for which to generate the infill
  * \param mesh The storage where the layer outline information (input) is stored and where the skin outline (output) is stored.
  * \param part The part where the insets (input) are stored and where the infill (output) is stored.
- * \param innermost_wall_extrusion_width width of the innermost wall lines
+ * \param innermost_wall_line_width width of the innermost wall lines
  * \param infill_skin_overlap overlap distance between infill and skin
  * \param wall_line_count The number of walls, i.e. the number of the wall from which to offset.
  */
-void generateInfill(int layerNr, SliceMeshStorage& mesh, int innermost_wall_extrusion_width, int infill_skin_overlap, int wall_line_count);
+void generateInfill(int layerNr, SliceMeshStorage& mesh, const int innermost_wall_line_width, int infill_skin_overlap, int wall_line_count);
 
 /*!
  * \brief Combines the infill of multiple layers for a specified mesh.
@@ -72,6 +77,28 @@ void generateInfill(int layerNr, SliceMeshStorage& mesh, int innermost_wall_extr
  */
 void combineInfillLayers(SliceMeshStorage& mesh, unsigned int amount);
 
+/*!
+ * Class containing all skin and infill area computation functions
+ */
+class SkinInfillAreaComputation
+{
+public:
+    /*!
+     * Generate infill areas which cause a gradually less dense infill structure from top to bottom.
+     * 
+     * The areas generated overlap, so that more dense infill adds on to less dense infill.
+     * That way you don't have infill lines which are broken when they cross a border between separated infill areas - if they would be as such.
+     * 
+     * This function also guarantees that the SliceLayerPart::infill_area_per_combine_per_density is initialized with at least one item.
+     * The last item in the list will be equal to the infill_area after this function.
+     * 
+     * \param gradual_infill_step_height // The height difference between consecutive density infill areas
+     * \param max_infill_steps the maximum exponent of division of infill density. At 5 the least dense infill will be 2^4 * infill_line_distance i.e. one 16th as dense
+     */
+    static void generateGradualInfill(SliceMeshStorage& mesh, unsigned int gradual_infill_step_height, unsigned int max_infill_steps);
+    
+};
+
 }//namespace cura
 
 #endif//SKIN_H

src/skirt.cpp

@@ -1,89 +0,0 @@
-/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
-#include "skirt.h"
-#include "support.h"
-
-#include <queue> 
-
-namespace cura 
-{
-
-void generateSkirt(SliceDataStorage& storage, int distance, int count, int minLength)
-{
-    if (count == 0) return;
-    
-    bool externalOnly = (distance > 0); // whether to include holes or not
-    
-    int primary_extruder = 0; // TODO allow for other extruder to be primary
-    int primary_extrusion_width = storage.meshgroup->getExtruderTrain(primary_extruder)->getSettingInMicrons("skirt_line_width");
-    
-    Polygons& skirt_primary_extruder = storage.skirt[primary_extruder];
-    
-    bool get_convex_hull = count == 1 && distance > 0;
-    
-    Polygons first_layer_outline = storage.getLayerOutlines(0, true, externalOnly);
-    
-    std::vector<Polygons> skirts;
-    for(int skirtNr=0; skirtNr<count;skirtNr++)
-    {
-        int offsetDistance = distance + primary_extrusion_width * skirtNr + primary_extrusion_width / 2;
-
-        skirts.emplace_back(first_layer_outline.offset(offsetDistance, ClipperLib::jtRound));
-        Polygons& skirt_polygons = skirts.back();
-        
-        //Remove small inner skirt holes. Holes have a negative area, remove anything smaller then 100x extrusion "area"
-        for(unsigned int n=0; n<skirt_polygons.size(); n++)
-        {
-            double area = skirt_polygons[n].area();
-            if (area < 0 && area > -primary_extrusion_width * primary_extrusion_width * 100)
-                skirt_polygons.remove(n--);
-        }
-    
-        if (get_convex_hull)
-        {
-            skirt_polygons = skirt_polygons.convexHull(); 
-        } 
-
-        skirt_primary_extruder.add(skirt_polygons);
-
-        int length = skirt_primary_extruder.polygonLength();
-        if (skirtNr + 1 >= count && length > 0 && length < minLength) // make brim have more lines when total length is too small
-            count++;
-    }
-
-
-    if (false) // the code below is for the old prime tower
-    { //Add a skirt UNDER the prime tower to make it stick better.
-        Polygons prime_tower = storage.primeTower.ground_poly.offset(-primary_extrusion_width / 2);
-        std::queue<Polygons> prime_tower_insets;
-        while(prime_tower.size() > 0)
-        {
-            prime_tower_insets.emplace(prime_tower);
-            prime_tower = prime_tower.offset(-primary_extrusion_width);
-        }
-        while (!prime_tower_insets.empty())
-        {
-            Polygons& inset = prime_tower_insets.back();
-            skirt_primary_extruder.add(inset);
-            prime_tower_insets.pop();
-        }
-    }
-    
-    { // process other extruders' brim/skirt (as one brim line around the old brim)
-        int offset_distance = 0;
-        int last_width = primary_extrusion_width;
-        for (int extruder = 0; extruder < storage.meshgroup->getExtruderCount(); extruder++)
-        {
-            if (extruder == primary_extruder) { continue; }
-            int width = storage.meshgroup->getExtruderTrain(extruder)->getSettingInMicrons("skirt_line_width");
-            offset_distance += last_width / 2 + width/2;
-            last_width = width;
-            while (storage.skirt[extruder].polygonLength() < minLength)
-            {
-                storage.skirt[extruder].add(skirts.back().offset(offset_distance, ClipperLib::jtRound));
-                offset_distance += width;
-            }
-        }
-    }
-}
-
-}//namespace cura

src/skirt.h

@@ -1,22 +0,0 @@
-/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
-#ifndef SKIRT_H
-#define SKIRT_H
-
-#include "sliceDataStorage.h"
-
-namespace cura 
-{
-
-/*!
- * Generate skirt or brim (depending on parameters); when \p distance > 0 and \p count == 1 the skirt is generated, which has slighly different configuration.
- * 
- * \param storage Storage containing the parts at the first layer
- * \param distance The distance of the first outset from the parts at the first layer
- * \param count Number of outsets / brim lines
- * \param minLength The minimum length the skirt should have (enforced by taking more outsets)
- */
-void generateSkirt(SliceDataStorage& storage, int distance, int count, int minLength);
-
-}//namespace cura
-
-#endif//SKIRT_H

src/sliceDataStorage.cpp

@@ -1,10 +1,27 @@
+//Copyright (c) 2016 Ultimaker B.V.
+//CuraEngine is released under the terms of the AGPLv3 or higher.
+
 #include "sliceDataStorage.h"
 
 #include "FffProcessor.h" //To create a mesh group with if none is provided.
+#include "infill/SubDivCube.h" // For the destructor
+
 
 namespace cura
 {
 
+Polygons& SliceLayerPart::getOwnInfillArea()
+{
+    if (infill_area_own)
+    {
+        return *infill_area_own;
+    }
+    else
+    {
+        return infill_area;
+    }
+}
+
 Polygons SliceLayer::getOutlines(bool external_polys_only) const
 {
     Polygons ret;
@@ -18,7 +35,7 @@ void SliceLayer::getOutlines(Polygons& result, bool external_polys_only) const
     {
         if (external_polys_only)
         {
-            result.add(const_cast<SliceLayerPart&>(part).outline.outerPolygon()); // TODO: make a const version of outerPolygon()
+            result.add(part.outline.outerPolygon());
         }
         else 
         {
@@ -40,12 +57,12 @@ void SliceLayer::getSecondOrInnermostWalls(Polygons& layer_walls) const
     {
         // we want the 2nd inner walls
         if (part.insets.size() >= 2) {
-            layer_walls.add(const_cast<SliceLayerPart&>(part).insets[1]); // TODO const cast!
+            layer_walls.add(part.insets[1]);
             continue;
         }
         // but we'll also take the inner wall if the 2nd doesn't exist
         if (part.insets.size() == 1) {
-            layer_walls.add(const_cast<SliceLayerPart&>(part).insets[0]); // TODO const cast!
+            layer_walls.add(part.insets[0]);
             continue;
         }
         // offset_from_outlines was so large that it completely destroyed our isle,
@@ -55,6 +72,13 @@ void SliceLayer::getSecondOrInnermostWalls(Polygons& layer_walls) const
     }
 }
 
+SliceMeshStorage::~SliceMeshStorage()
+{
+    if (base_subdiv_cube)
+    {
+        delete base_subdiv_cube;
+    }
+}
 
 std::vector<RetractionConfig> SliceDataStorage::initializeRetractionConfigs()
 {
@@ -62,43 +86,20 @@ std::vector<RetractionConfig> SliceDataStorage::initializeRetractionConfigs()
     ret.resize(meshgroup->getExtruderCount()); // initializes with constructor RetractionConfig()
     return ret;
 }
-std::vector<GCodePathConfig> SliceDataStorage::initializeTravelConfigs()
-{
-    std::vector<GCodePathConfig> ret;
-    for (int extruder = 0; extruder < meshgroup->getExtruderCount(); extruder++)
-    {
-        RetractionConfig* retraction_config = nullptr;
-        travel_config_per_extruder.emplace_back(retraction_config, PrintFeatureType::MoveCombing);
-    }
-    return ret;
-}
-std::vector<GCodePathConfig> SliceDataStorage::initializeSkirtConfigs()
-{
-    std::vector<GCodePathConfig> ret;
-    for (int extruder = 0; extruder < meshgroup->getExtruderCount(); extruder++)
-    {
-        RetractionConfig* extruder_retraction_config = &retraction_config_per_extruder[extruder];
-        skirt_config.emplace_back(extruder_retraction_config, PrintFeatureType::Skirt);
-    }
-    return ret;
-}
+
 SliceDataStorage::SliceDataStorage(MeshGroup* meshgroup) : SettingsMessenger(meshgroup),
     meshgroup(meshgroup != nullptr ? meshgroup : new MeshGroup(FffProcessor::getInstance())), //If no mesh group is provided, we roll our own.
+    print_layer_count(0),
     retraction_config_per_extruder(initializeRetractionConfigs()),
-    travel_config_per_extruder(initializeTravelConfigs()),
-    skirt_config(initializeSkirtConfigs()),
-    raft_base_config(&retraction_config_per_extruder[getSettingAsIndex("adhesion_extruder_nr")], PrintFeatureType::Support),
-    raft_interface_config(&retraction_config_per_extruder[getSettingAsIndex("adhesion_extruder_nr")], PrintFeatureType::Support),
-    raft_surface_config(&retraction_config_per_extruder[getSettingAsIndex("adhesion_extruder_nr")], PrintFeatureType::Support),
-    support_config(&retraction_config_per_extruder[getSettingAsIndex("support_infill_extruder_nr")], PrintFeatureType::Support),
-    support_roof_config(&retraction_config_per_extruder[getSettingAsIndex("support_roof_extruder_nr")], PrintFeatureType::Skin),
-    max_object_height_second_to_last_extruder(-1)
+    extruder_switch_retraction_config_per_extruder(initializeRetractionConfigs()),
+    max_print_height_second_to_last_extruder(-1),
+    primeTower(*this)
 {
 }
 
 Polygons SliceDataStorage::getLayerOutlines(int layer_nr, bool include_helper_parts, bool external_polys_only) const
 {
-    if (layer_nr < 0)
+    if (layer_nr < 0 && layer_nr < -Raft::getFillerLayerCount(*this))
     { // when processing raft
         if (include_helper_parts)
         {
@@ -125,23 +126,33 @@ Polygons SliceDataStorage::getLayerOutlines(int layer_nr, bool include_helper_pa
     else 
     {
         Polygons total;
-        for (const SliceMeshStorage& mesh : meshes)
+        if (layer_nr >= 0)
         {
-            const SliceLayer& layer = mesh.layers[layer_nr];
-            layer.getOutlines(total, external_polys_only);
-            if (const_cast<SliceMeshStorage&>(mesh).getSettingAsSurfaceMode("magic_mesh_surface_mode") != ESurfaceMode::NORMAL) // TODO: make all getSetting functions const??
+            for (const SliceMeshStorage& mesh : meshes)
             {
-                total = total.unionPolygons(layer.openPolyLines.offsetPolyLine(100));
+                if (mesh.getSettingBoolean("infill_mesh") || mesh.getSettingBoolean("anti_overhang_mesh"))
+                {
+                    continue;
+                }
+                const SliceLayer& layer = mesh.layers[layer_nr];
+                layer.getOutlines(total, external_polys_only);
+                if (mesh.getSettingAsSurfaceMode("magic_mesh_surface_mode") != ESurfaceMode::NORMAL)
+                {
+                    total = total.unionPolygons(layer.openPolyLines.offsetPolyLine(100));
+                }
             }
         }
         if (include_helper_parts)
         {
             if (support.generated) 
             {
-                total.add(support.supportLayers[layer_nr].supportAreas);
-                total.add(support.supportLayers[layer_nr].roofs);
+                total.add(support.supportLayers[std::max(0, layer_nr)].supportAreas);
+                total.add(support.supportLayers[std::max(0, layer_nr)].skin);
+            }
+            if (primeTower.enabled)
+            {
+                total.add(primeTower.ground_poly);
             }
-            total.add(primeTower.ground_poly);
         }
         return total;
     }
@@ -149,7 +160,7 @@ Polygons SliceDataStorage::getLayerOutlines(int layer_nr, bool include_helper_pa
 
 Polygons SliceDataStorage::getLayerSecondOrInnermostWalls(int layer_nr, bool include_helper_parts) const
 {
-    if (layer_nr < 0)
+    if (layer_nr < 0 && layer_nr < -Raft::getFillerLayerCount(*this))
     { // when processing raft
         if (include_helper_parts)
         {
@@ -163,100 +174,54 @@ Polygons SliceDataStorage::getLayerSecondOrInnermostWalls(int layer_nr, bool inc
     else 
     {
         Polygons total;
-        for (const SliceMeshStorage& mesh : meshes)
+        if (layer_nr >= 0)
         {
-            const SliceLayer& layer = mesh.layers[layer_nr];
-            layer.getSecondOrInnermostWalls(total);
-            if (const_cast<SliceMeshStorage&>(mesh).getSettingAsSurfaceMode("magic_mesh_surface_mode") != ESurfaceMode::NORMAL) // TODO: make getSetting const? make settings.setting_values mapping mutable??
+            for (const SliceMeshStorage& mesh : meshes)
             {
-                total = total.unionPolygons(layer.openPolyLines.offsetPolyLine(100));
+                const SliceLayer& layer = mesh.layers[layer_nr];
+                layer.getSecondOrInnermostWalls(total);
+                if (mesh.getSettingAsSurfaceMode("magic_mesh_surface_mode") != ESurfaceMode::NORMAL)
+                {
+                    total = total.unionPolygons(layer.openPolyLines.offsetPolyLine(100));
+                }
             }
         }
         if (include_helper_parts)
         {
             if (support.generated) 
             {
-                total.add(support.supportLayers[layer_nr].supportAreas);
-                total.add(support.supportLayers[layer_nr].roofs);
+                total.add(support.supportLayers[std::max(0, layer_nr)].supportAreas);
+                total.add(support.supportLayers[std::max(0, layer_nr)].skin);
+            }
+            if (primeTower.enabled)
+            {
+                total.add(primeTower.ground_poly);
             }
-            total.add(primeTower.ground_poly);
         }
         return total;
     }
 
 }
 
-
-std::vector<bool> SliceDataStorage::getExtrudersUsed(int layer_nr)
+std::vector<bool> SliceDataStorage::getExtrudersUsed() const
 {
+
     std::vector<bool> ret;
     ret.resize(meshgroup->getExtruderCount(), false);
-    if (layer_nr < 0)
+
+    if (getSettingAsPlatformAdhesion("adhesion_type") != EPlatformAdhesion::NONE)
     {
-        ret[getSettingAsIndex("adhesion_extruder_nr")] = true; // raft
-    }
-    else 
-    {
-        if (layer_nr == 0)
+        ret[getSettingAsIndex("adhesion_extruder_nr")] = true;
         { // process brim/skirt
             for (int extr_nr = 0; extr_nr < meshgroup->getExtruderCount(); extr_nr++)
             {
-                if (skirt[extr_nr].size() > 0)
+                if (skirt_brim[extr_nr].size() > 0)
                 {
                     ret[extr_nr] = true;
                     continue;
                 }
             }
         }
-
-        // TODO: ooze shield, draft shield
-
-        // support
-        if (support.supportLayers[layer_nr].supportAreas.size() > 0)
-        {
-            if (layer_nr == 0)
-            {
-                ret[getSettingAsIndex("support_extruder_nr_layer_0")] = true;
-            }
-            else 
-            {
-                ret[getSettingAsIndex("support_infill_extruder_nr")] = true;
-            }
-        }
-        if (support.supportLayers[layer_nr].roofs.size() > 0)
-        {
-            ret[getSettingAsIndex("support_roof_extruder_nr")] = true;
-        }
-
-        for (SliceMeshStorage& mesh : meshes)
-        {
-            SliceLayer& layer = mesh.layers[layer_nr];
-            int extr_nr = mesh.getSettingAsIndex("extruder_nr");
-            if (layer.parts.size() > 0)
-            {
-                ret[extr_nr] = true;
-            }
-        }
-    }
-    return ret;
-}
-
-std::vector< bool > SliceDataStorage::getExtrudersUsed()
-{
-
-    std::vector<bool> ret;
-    ret.resize(meshgroup->getExtruderCount(), false);
-
-    ret[getSettingAsIndex("adhesion_extruder_nr")] = true; 
-    { // process brim/skirt
-        for (int extr_nr = 0; extr_nr < meshgroup->getExtruderCount(); extr_nr++)
-        {
-            if (skirt[extr_nr].size() > 0)
-            {
-                ret[extr_nr] = true;
-                continue;
-            }
-        }
     }
 
     // TODO: ooze shield, draft shield ..?
@@ -265,12 +230,106 @@ std::vector< bool > SliceDataStorage::getExtrudersUsed()
     // support is presupposed to be present...
     ret[getSettingAsIndex("support_extruder_nr_layer_0")] = true;
     ret[getSettingAsIndex("support_infill_extruder_nr")] = true;
-    ret[getSettingAsIndex("support_roof_extruder_nr")] = true;
+    ret[getSettingAsIndex("support_interface_extruder_nr")] = true;
 
     // all meshes are presupposed to actually have content
-    for (SliceMeshStorage& mesh : meshes)
+    for (const SliceMeshStorage& mesh : meshes)
     {
-        ret[mesh.getSettingAsIndex("extruder_nr")] = true;
+        if (!mesh.getSettingBoolean("anti_overhang_mesh")
+            && !mesh.getSettingBoolean("support_mesh")
+        )
+        {
+            ret[mesh.getSettingAsIndex("extruder_nr")] = true;
+        }
+    }
+    return ret;
+}
+
+std::vector<bool> SliceDataStorage::getExtrudersUsed(int layer_nr) const
+{
+
+    std::vector<bool> ret;
+    ret.resize(meshgroup->getExtruderCount(), false);
+
+    bool include_adhesion = true;
+    bool include_helper_parts = true;
+    bool include_models = true;
+    if (layer_nr < 0)
+    {
+        include_models = false;
+        if (layer_nr < -Raft::getFillerLayerCount(*this))
+        {
+            include_helper_parts = false;
+        }
+        else
+        {
+            layer_nr = 0; // because the helper parts are copied from the initial layer in the filler layer
+            include_adhesion = false;
+        }
+    }
+    else if (layer_nr > 0 || getSettingAsPlatformAdhesion("adhesion_type") == EPlatformAdhesion::RAFT)
+    { // only include adhesion only for layers where platform adhesion actually occurs
+        // i.e. layers < 0 are for raft, layer 0 is for brim/skirt
+        include_adhesion = false;
+    }
+    if (include_adhesion)
+    {
+        ret[getSettingAsIndex("adhesion_extruder_nr")] = true;
+        { // process brim/skirt
+            for (int extr_nr = 0; extr_nr < meshgroup->getExtruderCount(); extr_nr++)
+            {
+                if (skirt_brim[extr_nr].size() > 0)
+                {
+                    ret[extr_nr] = true;
+                    continue;
+                }
+            }
+        }
+    }
+
+    // TODO: ooze shield, draft shield ..?
+
+    if (include_helper_parts)
+    {
+        // support
+        if (layer_nr < int(support.supportLayers.size()))
+        {
+            const SupportLayer& support_layer = support.supportLayers[layer_nr];
+            if (layer_nr == 0)
+            {
+                if (support_layer.supportAreas.size() > 0)
+                {
+                    ret[getSettingAsIndex("support_extruder_nr_layer_0")] = true;
+                }
+            }
+            else
+            {
+                if (support_layer.supportAreas.size() > 0)
+                {
+                    ret[getSettingAsIndex("support_infill_extruder_nr")] = true;
+                }
+            }
+            if (support_layer.skin.size() > 0)
+            {
+                ret[getSettingAsIndex("support_interface_extruder_nr")] = true;
+            }
+        }
+    }
+
+    if (include_models)
+    {
+        for (const SliceMeshStorage& mesh : meshes)
+        {
+            if (layer_nr >= int(mesh.layers.size()))
+            {
+                continue;
+            }
+            const SliceLayer& layer = mesh.layers[layer_nr];
+            if (layer.parts.size() > 0)
+            {
+                ret[mesh.getSettingAsIndex("extruder_nr")] = true;
+            }
+        }
     }
     return ret;
 }