safety: skip mesh if layer nr too high (CURA-1134)

makes for a better moveInsideCombBoundary functionality

.gitignore

@@ -1,25 +1,50 @@
 *.tar.bz2
 *.tar.gz
 *.7z
-*.pyc
 *.zip
-*.exe
-.idea
 .DS_Store
-_bin
-_obj
-*.depend
-*.o
-.*.swp
-*.gcode
-CuraEngine
-build/*
 *~
 NUL
+*.gcode
+
+## Building result.
+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
+*kdev*
+*.kate-swp
+nbproject/*
+.idea
+*.depend
+.*.swp
+
+## Documentation.
 documentation/html/*
 documentation/latex/*
 
-*kdev*
-*.kate-swp
+## Test results.
+tests/output.xml
+callgrind.out.*

CMakeLists.txt

@@ -2,7 +2,14 @@ project(CuraEngine)
 
 cmake_minimum_required(VERSION 2.8.12)
 
-find_package(Arcus REQUIRED)
+option (ENABLE_ARCUS
+    "Enable support for ARCUS" ON)
+
+if (ENABLE_ARCUS)
+    message(STATUS "Building with Arcus")
+    find_package(Arcus REQUIRED)
+    add_definitions(-DARCUS)
+endif ()
 
 if(NOT ${CMAKE_VERSION} VERSION_LESS 3.1)
     set(CMAKE_CXX_STANDARD 11)
@@ -10,6 +17,24 @@ else()
     set(CMAKE_CXX_FLAGS "-std=c++11")
 endif()
 
+if(APPLE AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -stdlib=libc++")
+endif()
+
+set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib")
+
+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 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
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
 
@@ -21,46 +46,131 @@ include_directories(${CMAKE_CURRENT_BINARY_DIR} libs)
 
 add_library(clipper STATIC libs/clipper/clipper.cpp)
 
-set(engine_SRCS
+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/inset.cpp
+    src/WallsComputation.cpp
     src/layerPart.cpp
-    src/main.cpp
+    src/LayerPlanBuffer.cpp
+    src/MergeInfillLines.cpp
     src/mesh.cpp
+    src/MeshGroup.cpp
     src/multiVolumes.cpp
     src/pathOrderOptimizer.cpp
-    src/polygonOptimizer.cpp
+    src/Preheat.cpp
+    src/PrimeTower.cpp
     src/raft.cpp
-    src/settingRegistry.cpp
-    src/settings.cpp
     src/skin.cpp
-    src/skirt.cpp
+    src/SkirtBrim.cpp
+    src/sliceDataStorage.cpp
     src/slicer.cpp
     src/support.cpp
     src/timeEstimate.cpp
+    src/WallsComputation.cpp
+    src/wallOverlap.cpp
     src/Weaver.cpp
     src/Wireframe2gcode.cpp
 
-    src/modelFile/modelFile.cpp
+    src/infill/NoZigZagConnectorProcessor.cpp
+    src/infill/ZigzagConnectorProcessorConnectedEndPieces.cpp
+    src/infill/ZigzagConnectorProcessorDisconnectedEndPieces.cpp
+    src/infill/ZigzagConnectorProcessorEndPieces.cpp
+    src/infill/ZigzagConnectorProcessorNoEndPieces.cpp
 
+    src/pathPlanning/Comb.cpp
+    src/pathPlanning/LinePolygonsCrossings.cpp
+
+    src/progress/Progress.cpp
+    src/progress/ProgressStageEstimator.cpp
+
+    src/settings/SettingConfig.cpp
+    src/settings/SettingContainer.cpp
+    src/settings/SettingRegistry.cpp
+    src/settings/settings.cpp
+
+    src/utils/AABB.cpp
+    src/utils/AABB3D.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
 )
 
-protobuf_generate_cpp(engine_PB_SRCS engine_PB_HEADERS Cura.proto)
+# List of tests. For each test there must be a file tests/${NAME}.cpp and a file tests/${NAME}.h.
+set(engine_TEST
+    GCodePlannerTest
+)
+set(engine_TEST_INFILL
+)
+set(engine_TEST_UTILS
+    SparseGridTest
+    LinearAlg2DTest
+    PolygonUtilsTest
+    PolygonTest
+    StringTest
+)
 
-add_executable(CuraEngine ${engine_SRCS} ${engine_PB_SRCS})
-target_link_libraries(CuraEngine clipper Arcus)
+# Generating ProtoBuf protocol
+if (ENABLE_ARCUS)
+protobuf_generate_cpp(engine_PB_SRCS engine_PB_HEADERS Cura.proto)
+endif ()
+
+# Compiling CuraEngine itself.
+add_library(_CuraEngine ${engine_SRCS} ${engine_PB_SRCS}) #First compile all of CuraEngine as library, allowing this to be re-used for tests.
+target_link_libraries(_CuraEngine clipper)
+if (ENABLE_ARCUS)
+    target_link_libraries(_CuraEngine Arcus)
+endif ()
+
+set_target_properties(_CuraEngine PROPERTIES COMPILE_DEFINITIONS "VERSION=\"${CURA_ENGINE_VERSION}\"")
 
 if (UNIX)
-    target_link_libraries(CuraEngine pthread)
+    target_link_libraries(_CuraEngine pthread)
+endif()
+add_executable(CuraEngine src/main.cpp) #Then compile main.cpp as separate executable, and link the library to it.
+target_link_libraries(CuraEngine _CuraEngine)
+
+# Compiling the test environment.
+if (BUILD_TESTS)
+    message(STATUS "Building tests...")
+    enable_testing()
+    foreach (test ${engine_TEST})
+        add_executable(${test} tests/main.cpp tests/${test}.cpp)
+        target_link_libraries(${test} _CuraEngine cppunit)
+        add_test(${test} ${test})
+    endforeach()
+    foreach (test ${engine_TEST_INFILL})
+        add_executable(${test} tests/main.cpp tests/infill/${test}.cpp)
+        target_link_libraries(${test} _CuraEngine cppunit)
+        add_test(${test} ${test})
+    endforeach()
+    foreach (test ${engine_TEST_UTILS})
+        add_executable(${test} tests/main.cpp tests/utils/${test}.cpp)
+        target_link_libraries(${test} _CuraEngine cppunit)
+        add_test(${test} ${test})
+    endforeach()
 endif()
 
+
+add_custom_command(TARGET CuraEngine POST_BUILD
+                   COMMAND ${CMAKE_COMMAND} -E copy_directory
+                       ${CMAKE_SOURCE_DIR}/resources $<TARGET_FILE_DIR:CuraEngine>)
+
+# Installing CuraEngine.
 include(GNUInstallDirs)
 install(TARGETS CuraEngine DESTINATION ${CMAKE_INSTALL_BINDIR})
+include(CPackConfig.cmake)

CPackConfig.cmake

@@ -0,0 +1,20 @@
+set(CPACK_PACKAGE_VENDOR "Ultimaker")
+set(CPACK_PACKAGE_CONTACT "Arjen Hiemstra <a.hiemstra@ultimaker.com>")
+set(CPACK_PACKAGE_DESCRIPTION_SUMMARY "Cura Engine")
+set(CPACK_PACKAGE_VERSION "15.05.90")
+set(CPACK_GENERATOR "DEB")
+if(NOT DEFINED CPACK_DEBIAN_PACKAGE_ARCHITECTURE)
+  execute_process(COMMAND dpkg --print-architecture OUTPUT_VARIABLE CPACK_DEBIAN_PACKAGE_ARCHITECTURE OUTPUT_STRIP_TRAILING_WHITESPACE)
+endif()
+set(CPACK_PACKAGE_FILE_NAME "${CMAKE_PROJECT_NAME}-${CPACK_PACKAGE_VERSION}_${CPACK_DEBIAN_PACKAGE_ARCHITECTURE}")
+
+set(DEB_DEPENDS
+    "arcus (>= 15.05.90)"
+    "protobuf (>= 3.0.0)"
+    "libstdc++6 (>= 4.9.0)"
+    "libgcc1 (>= 4.9.0)"
+)
+string(REPLACE ";" ", " DEB_DEPENDS "${DEB_DEPENDS}")
+set(CPACK_DEBIAN_PACKAGE_DEPENDS ${DEB_DEPENDS})
+
+include(CPack)

Changelog.md

@@ -0,0 +1,14 @@
+Changelog CuraEngine
+====================
+
+
+
+
+- Feature: infill_wipe_dist. Add a travel move after an infill line in order to let it stick better to the walls.
+- Feature: Draft Protection Screen. A shell similar to the ooze shield providing protection from gusts of wind and acting similar to a heated chamber
+
+
+Release 15.06.01
+-----
+
+- [Not documented]

Cura.proto

@@ -1,13 +1,29 @@
 syntax = "proto3";
 
-package Cura;
+package cura.proto;
 
-// typeid 1
-message ObjectList {
+message ObjectList
+{
     repeated Object objects = 1;
+    repeated Setting settings = 2; // meshgroup settings (for one-at-a-time printing)
 }
 
-message Object {
+message Slice
+{
+    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
+{
     int64 id = 1;
     bytes vertices = 2; //An array of 3 floats.
     bytes normals = 3; //An array of 3 floats.
@@ -15,29 +31,17 @@ message Object {
     repeated Setting settings = 5; // Setting override per object, overruling the global settings.
 }
 
-// typeid 3
-message Progress {
+message Progress
+{
     float amount = 1;
 }
 
-// typeid 2
-message SlicedObjectList {
-    repeated SlicedObject objects = 1;
-}
-
-message SlicedObject {
-    int64 id = 1;
-
-    repeated Layer layers = 2;
-}
-
 message Layer {
     int32 id = 1;
+    float height = 2; // Z position
+    float thickness = 3; // height of a single layer
 
-    float height = 2;
-    float thickness = 3;
-
-    repeated Polygon polygons = 4;
+    repeated Polygon polygons = 4; // layer data
 }
 
 message Polygon {
@@ -50,37 +54,71 @@ message Polygon {
         SkirtType = 5;
         InfillType = 6;
         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
 }
 
-// typeid 4
+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 {
-    int64 id = 1;
     bytes data = 2;
 }
 
-// typeid 5
-message ObjectPrintTime {
-    int64 id = 1;
-    float time = 2;
-    float material_amount = 3;
+
+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 material_amount = 2; // material used in the extruder
 }
 
-// typeid 6
 message SettingList {
     repeated Setting settings = 1;
 }
 
 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.
 }
 
-// typeid 7
 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

@@ -58,7 +58,8 @@ PROJECT_LOGO           =
 # entered, it will be relative to the location where doxygen was started. If
 # left blank the current directory will be used.
 
-OUTPUT_DIRECTORY       = documentation
+#LEAVE THIS DIRECTORY EMPTY IF THIS DOCUMENTATION NEEDS TO BE PUBLISHED AUTOMATICALLY TO GITHUB PAGES!
+OUTPUT_DIRECTORY       = docs
 
 # If the CREATE_SUBDIRS tag is set to YES, then doxygen will create 4096 sub-
 # directories (in 2 levels) under the output directory of each output format and
@@ -177,7 +178,7 @@ JAVADOC_AUTOBRIEF      = NO
 # requiring an explicit \brief command for a brief description.)
 # The default value is: NO.
 
-QT_AUTOBRIEF           = NO
+QT_AUTOBRIEF           = YES
 
 # The MULTILINE_CPP_IS_BRIEF tag can be set to YES to make doxygen treat a
 # multi-line C++ special comment block (i.e. a block of //! or /// comments) as
@@ -831,7 +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
@@ -2049,7 +2050,7 @@ HIDE_UNDOC_RELATIONS   = YES
 # set to NO
 # The default value is: NO.
 
-HAVE_DOT               = NO
+HAVE_DOT               = YES
 
 # The DOT_NUM_THREADS specifies the number of dot invocations doxygen is allowed
 # to run in parallel. When set to 0 doxygen will base this on the number of

README.md

@@ -3,9 +3,9 @@ CuraEngine
 The CuraEngine is a C++ console application for 3D printing GCode generation. It has been made as a better and faster alternative to the old Skeinforge engine.
 
 The CuraEngine is pure C++ and uses Clipper from http://www.angusj.com/delphi/clipper.php
-There are no external dependences and Clipper is included in the source code without modifications.
+Furthermore it depends on libArcus by Ultimaker, which can be found at http://github.com/Ultimaker/libArcus
 
-This is just a console application for GCode generation. For a full graphical application look at https://github.com/daid/Cura which is the graphical frontend for CuraEngine.
+This is just a console application for GCode generation. For a full graphical application look at https://github.com/Ultimaker/Cura which is the graphical frontend for CuraEngine.
 
 The CuraEngine can be used seperately or in other applications. Feel free to add it to your application. But please take note of the License.
 
@@ -19,43 +19,52 @@ 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 PluggableCura, one can run CuraEngine from the command line.
+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
 ```
-./build/CuraEngine -v -j fdmprinter.json -s machine_start_gcode=";FLAVOR:UltiGCode
-;TIME:10000000
-;MATERIAL:2000
-;MATERIAL2:0" -s mesh_position_x=115.0 -s mesh_position_y=112.5 -s mesh_position_z=0 -s material_diameter=1.128 -o "output/test.gcode" "/path/to/model.stl"
+./build/CuraEngine slice -v -j ../Cura/resources/definitions/dual_extrusion_printer.def.json -o "output/test.gcode" -e1 -s infill_line_distance=0 -e0 -l "/model_1.stl" -e1 -l "fully_filled_model.stl" 
+```
+
+Run `CuraEngine help` for a general description of how to use the CuraEngine tool.
+
+[Set the environment variable](https://help.ubuntu.com/community/EnvironmentVariables) CURA_ENGINE_SEARCH_PATH to the appropriate paths, delimited by a colon e.g.
+```
+CURA_ENGINE_SEARCH_PATH=/path/to/Cura/resources/definitions:/user/defined/path
 ```
 
 Internals
@@ -119,4 +128,4 @@ The GCode generation is quite a large bit of code. As a lot is going on here. Im
 * PathOrderOptimizer: This piece of code needs to solve a TravelingSalesmanProblem. Given a list of polygons/lines it tries to find the best order in which to print them. It currently does this by finding the closest next polygon to print.
 * Infill: This code generates a group of lines from an area. This is the code that generates the actuall infill pattern. There is also a concentric infill function, which is currently not used.
 * Comb: The combing code is the code that tries to avoid holes when moving the head around without printing. This code also detects when it fails. The final GCode generator uses the combing code while generating the final GCode. So they interact closely.
-* GCodeExport: The GCode export is a 2 step process. First it collects all the paths for a layer that it needs to print, this includes all moves, prints, extrusion widths. And then it generates the final GCode. This is the only piece of code that has knowledge about GCode keywords and syntax;meshmdhfdhfdhf to generate a different flavor of GCode it will be the only piece that needs adjustment. All volumatric calculations also happen here.
+* GCodeExport: The GCode export is a 2 step process. First it collects all the paths for a layer that it needs to print, this includes all moves, prints, extrusion widths. And then it generates the final GCode. This is the only piece of code that has knowledge about GCode keywords and syntax to generate a different flavor of GCode it will be the only piece that needs adjustment. All volumatric calculations also happen here.

docs/glossary.md

@@ -4,6 +4,7 @@ Glossary
 
 Term/Synonyms | Meaning
 --- | ---
+Extruder Train | The whole of a feeder, bowden tube and a nozzle
 Island/Part | isolated/unconnected part in 2D slice
 Inset | perimeter, the perimeters which are laid down around the infill
 Slicing | The act of extracting the contours of the object at a certain height (not the whole process which would also include gcode generation etc.)

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

documentation/code_conventions.md

@@ -1,126 +0,0 @@
-Code Conventions
-=======
-Note that the code convention described here have not all yet been fully implemented.
-
-Bracketing and indenting
------
-~~~~~~~~~~~~~~~{.cpp}
-if (condition) // brackets always on new lines
-{ // allways a bracket after an if, for, while, etc.
-    // indent always with 4 spaces, never with tabs
-}
-else // else on new line
-{
-    // more code
-}
-~~~~~~~~~~~~~~~
-
-Naming conventions
-------
- * variables: lower_case_with_underscores
- * functions: loweCamelCase
- * classes: UpperCamelCase
- * macros: UPPER_CASE_WITH_UNDERSCORES
-~~~~~~~~~~~~~~~{.cpp}
-#define UPPER_CASE_MACRO 1
-
-class UpperCamelCase
-{
-private:
-    MemberVariableObject with_underscores;
-public:
-    MemberVariableObject with_underscores;
-
-public:
-    UpperCamelCase();
-    ~UpperCamelCase();
-    
-    // start with input variable(s) and end with output variable(s)
-    void lowerCamelCaseFunctions(ParamObject& also_with_underscores)
-    {
-        LocalObject under_scores;
-    }
-private:
-    void putFunctionsAndVariablesInSeperatePublicPrivateBlocks();
-};
-~~~~~~~~~~~~~~~
-
-Ordering
-----
-~~~~~~~~~~~~~~~{.cpp}
-class Example
-{
-    // start with input variable(s) and end with output parameter(s) 
-    void function1(ParamObject& input_variable, int setting_parameter, ParamObject2& return_parameter)
-    {
-        function2();
-        function3();
-    }
-    
-    // place functions called solely by one other function below it chronologically
-    void function2();
-    
-    void function3();
-};
-~~~~~~~~~~~~~~~
-
-Documentation
-----
-We use [Doxygen](www.doxygen.org/) to generate documentation. Try to keep your documentation in doxygen style.
-
-Here's a small example:
-~~~~~~~~~~~~~~~{.cpp}
-/ *!
- * Doxygen style comments!
- *
- * \param param1 explanation may refer to another \p param2
- * /
-void function(int param1, int param2)
-{
-    // non-doxygen style comments on implementation details
-}
-
-int member; //!< inline doxygen comment on the entry to the left
-~~~~~~~~~~~~~~~
-
-Files
---------
-For a file Foo.h (UpperCamelCase):
-~~~~~~~~~~~~~~~{.cpp}
-#ifndef FOO_H
-#define FOO_H
-// [content]
-#endif//FOO_H
-~~~~~~~~~~~~~~~
-
-
-Other
-----
-~~~~~~~~~~~~~~~{.cpp}
-#include <all>
-#include <includes>
-#include <on>
-#include <top>
-
-#include <first_system_includes>
-
-#include <then_library_includes>
-
-#include "finally_local_includes"
-
-enum class EnumExample 
-{
-    ELEM0 = 0,
-    ELEM1 = 1
-}
-~~~~~~~~~~~~~~~
-
-Illegal syntax
-----
-~~~~~~~~~~~~~~~{.cpp}
-void function()
-{
-    if (condition)
-        single_line_outside_code_block(); // always use braces!
-}; // unneccesary semicolon after function definition is not allowed
-~~~~~~~~~~~~~~~

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
@@ -46,9 +46,8 @@
 //use_lines: Enables line clipping. Adds a very minor cost to performance.
 //#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
 };
 //------------------------------------------------------------------------------

libs/rapidjson/license.txt

@@ -0,0 +1,57 @@
+Tencent is pleased to support the open source community by making RapidJSON available. 
+ 
+Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip.  All rights reserved.
+
+If you have downloaded a copy of the RapidJSON binary from Tencent, please note that the RapidJSON binary is licensed under the MIT License.
+If you have downloaded a copy of the RapidJSON source code from Tencent, please note that RapidJSON source code is licensed under the MIT License, except for the third-party components listed below which are subject to different license terms.  Your integration of RapidJSON into your own projects may require compliance with the MIT License, as well as the other licenses applicable to the third-party components included within RapidJSON.
+A copy of the MIT License is included in this file.
+
+Other dependencies and licenses:
+
+Open Source Software Licensed Under the BSD License:
+--------------------------------------------------------------------
+
+The msinttypes r29 
+Copyright (c) 2006-2013 Alexander Chemeris 
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 
+* Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
+* Neither the name of  copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+Open Source Software Licensed Under the JSON License:
+--------------------------------------------------------------------
+
+json.org 
+Copyright (c) 2002 JSON.org
+All Rights Reserved.
+
+JSON_checker
+Copyright (c) 2002 JSON.org
+All Rights Reserved.
+
+	
+Terms of the JSON License:
+---------------------------------------------------
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+The Software shall be used for Good, not Evil.
+
+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 AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+
+Terms of the MIT License:
+--------------------------------------------------------------------
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of 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 AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

meta/15.04_to_2.0.txt

@@ -0,0 +1,203 @@
+This file is a conversion from the ENGINE settings of 15.04 to the ENGINE setting of 2.0
+
+This is NOT a conversion on the frontend internal setting names (15.04 has the dictionary of doom)
+
+
+autoCenter ?        ==> center_object OR machine_center_is_zero ??
+coolHeadLift        ==> cool_lift_head
+downSkinCount       ==> bottom_layers
+enableCombing       ==> retraction_combing
+enableOozeShield    ==> ooze_shield_enabled
+endCode             ==> machine_end_gcode
+extruderOffset[MAX_EXTRUDERS] = (machine_nozzle_offset_x, machine_nozzle_offset_y)
+extrusionWidth      ==> infill_line_width, skirt_line_width, support_line_width
+fanFullOnLayerNr    ==> cool_fan_full_layer
+fanSpeedMax         ==> cool_fan_speed_max
+fanSpeedMin         ==> cool_fan_speed_min
+filamentDiameter    ==> material_diameter
+filamentFlow        ==> material_flow
+fixHorrible         ==> meshfix_union_all AND/OR meshfix_union_all_remove_holes AND/OR meshfix_extensive_stitching AND/OR magic_mesh_surface_mode
+gcodeFlavor         ==> machine_gcode_flavor
+infillOverlap       ==> infill_overlap
+infillPattern       ==> infill_pattern
+infillSpeed         ==> speed_infill
+initialLayerSpeed   ==> speed_layer_0
+initialLayerThickness   ==> layer_height_0
+initialSpeedupLayers    ==> speed_slowdown_layers
+inset0Speed         ==> speed_wall_0
+insetCount          ==> wall_line_count
+insetXSpeed         ==> speed_wall_x
+layer0extrusionWidth    [ Doesn't exist anymore ]
+layerThickness      ==> layer_height
+matrix                  [ Doesn't exist anymore ]
+minimalExtrusionBeforeRetraction
+minimalFeedrate     ==> cool_min_speed
+minimalLayerTime    ==> cool_min_layer_time
+moveSpeed           ==> speed_travel
+multiVolumeOverlap  ==> multiple_mesh_overlap
+nozzleSize          ==> machine_nozzle_size
+objectPosition      ==> mesh_position_x, mesh_position_y, mesh_position_z
+objectSink              [ Doesn't exist in CuraEngine anymore ]
+perimeterBeforeInfill = not(infill_before_walls)
+postSwitchExtruderCode  ==> machine_extruder_start_code
+preSwitchExtruderCode   ==> machine_extruder_end_code
+printSpeed          ==> speed_prime_tower, speed_support_lines, speed_support_roof, skirt_speed
+raftAirGap          ==> raft_airgap
+raftAirGapLayer0        ?!?!?
+raftBaseLinewidth       ==> raft_base_line_width
+raftBaseSpeed           ==> raft_interface_speed, raft_base_speed
+raftBaseThickness       ==> raft_base_thickness
+raftFanSpeed            ==> raft_base_fan_speed, raft_interface_fan_speed, raft_surface_fan_speed
+raftInterfaceLineSpacing==> raft_interface_line_spacing
+raftInterfaceLinewidth  ==> raft_interface_line_width
+raftInterfaceThickness  ==> raft_interface_thickness
+raftLineSpacing         ==> raft_base_line_spacing
+raftMargin              ==> raft_margin
+raftSurfaceLayers       ==> raft_surface_layers
+raftSurfaceLineSpacing  ==> raft_surface_line_spacing
+raftSurfaceLinewidth    ==> raft_surface_line_width
+raftSurfaceSpeed        ==> raft_surface_speed
+raftSurfaceThickness    ==> raft_surface_thickness
+retractionAmount                ==> retraction_amount (set retraction_enable = true)
+retractionAmountExtruderSwitch  ==> switch_extruder_retraction_amount
+retractionAmountPrime           ==> retraction_extra_prime_amount
+retractionMinimalDistance       ==> retraction_extrusion_window ( set retraction_count_max = 1 )
+retractionSpeed                 ==> retraction_retract_speed (, retraction_prime_speed ?), switch_extruder_retraction_speed
+retractionZHop                  ==> retraction_hop
+simpleMode              ??!
+skinSpeed           ==> speed_topbottom
+skirtDistance       ==> skirt_gap
+skirtLineCount      ==> brim_line_count, skirt_line_count
+skirtMinLength      ==> skirt_minimal_length
+sparseInfillLineDistance    ==> infill_line_distance
+spiralizeMode   ==> magic_spiralize
+startCode       ==> machine_start_gcode
+supportAngle        ==> support_angle, support_enable=true if support_angle>0
+supportEverywhere   ==> support_type
+supportExtruder     ==> support_extruder_nr, support_extruder_nr_layer_0
+supportLineDistance ==> support_line_distance
+supportType         ==> support_pattern
+supportXYDistance   ==> support_xy_distance
+supportZDistance    ==> support_z_distance
+upSkinCount         ==> top_layers
+wipeTowerSize       ==> prime_tower_size
+
+
+
+
+
+NEW:
+adhesion_extruder_nr
+adhesion_type
+alternate_extra_perimeter
+coasting_enable
+coasting_min_volume_move
+coasting_min_volume_retract
+coasting_speed_move
+coasting_speed_retract
+coasting_volume_move
+coasting_volume_retract
+cool_min_layer_time_fan_speed_max
+draft_shield_dist
+draft_shield_height
+extruder_nr
+fill_perimeter_gaps
+infill_sparse_thickness
+infill_wipe_dist
+machine_depth
+machine_extruder_count
+machine_extruder_end_pos_abs
+machine_extruder_end_pos_x
+machine_extruder_end_pos_y
+machine_extruder_start_pos_abs
+machine_extruder_start_pos_x
+machine_extruder_start_pos_y
+machine_heated_bed
+machine_nozzle_cool_down_speed
+machine_nozzle_expansion_angle
+machine_nozzle_head_distance
+machine_nozzle_heat_up_speed
+machine_nozzle_tip_outer_diameter
+machine_print_temp_wait
+machine_use_extruder_offset_to_offset_coords
+machine_width
+magic_fuzzy_skin_enabled
+magic_fuzzy_skin_point_dist
+magic_fuzzy_skin_thickness
+material_bed_temperature
+material_bed_temp_prepend
+material_bed_temp_wait
+material_extrusion_cool_down_speed
+material_flow_dependent_temperature
+material_flow_temp_graph
+material_print_temperature
+material_print_temp_prepend
+material_print_temp_wait
+material_standby_temperature
+meshfix_keep_open_polygons
+ooze_shield_angle
+ooze_shield_dist
+prime_tower_dir_outward
+prime_tower_distance
+prime_tower_flow
+prime_tower_line_width
+prime_tower_position_x
+prime_tower_position_y
+prime_tower_wipe_enabled
+remove_overlapping_walls_0_enabled
+remove_overlapping_walls_x_enabled
+retraction_min_travel
+skin_alternate_rotation
+skin_line_width
+skin_no_small_gaps_heuristic
+skin_outline_count
+support_area_smoothing
+support_bottom_distance
+support_bottom_stair_step_height
+support_conical_angle
+support_conical_enabled
+support_conical_min_width
+support_connect_zigzags
+support_join_distance
+support_minimal_diameter
+support_offset
+support_roof_enable
+support_roof_extruder_nr
+support_roof_height
+support_roof_line_distance
+support_roof_line_width
+support_roof_pattern
+support_top_distance
+support_tower_diameter
+support_tower_roof_angle
+switch_extruder_prime_speed
+top_bottom_pattern
+travel_avoid_distance
+travel_avoid_other_parts
+travel_compensate_overlapping_walls_enabled
+wall_line_width_0
+wall_line_width_x
+wireframe_bottom_delay
+wireframe_drag_along
+wireframe_enabled
+wireframe_fall_down
+wireframe_flat_delay
+wireframe_flow_connection
+wireframe_flow_flat
+wireframe_height
+wireframe_nozzle_clearance
+wireframe_printspeed_bottom
+wireframe_printspeed_down
+wireframe_printspeed_flat
+wireframe_printspeed_up
+wireframe_roof_drag_along
+wireframe_roof_fall_down
+wireframe_roof_inset
+wireframe_roof_outer_delay
+wireframe_straight_before_down
+wireframe_strategy
+wireframe_top_delay
+wireframe_top_jump
+wireframe_up_half_speed
+xy_offset
+z_seam_type

meta/HOWTO.txt

@@ -0,0 +1,19 @@
+find engine setting literals
+
+
+cd ~/Development/CuraEngine/output/reflection/
+
+~/bin/substitute.pl y 'while(/getSetting\w+\("(\w+)"\)/gsm) { print "$1\n"; }' ../../src/ | sort | uniq > engineSettingLiterals.txt
+
+
+run setting inheritance reflection
+
+cd ~/Development/CuraEngine
+./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
+
+
+green block = used in engine
+red edge = inherit function only
+black edge = parent-child relation

meta/new settings master

@@ -0,0 +1,130 @@
+[ problem ]
+gantry_height introduced by Jaime while there already was machine_nozzle_gantry_distance
+
+
+[ RENAMES ]
+raft_base_linewidth > raft_base_line_width
+raft_interface_linewidth > raft_interface_line_width
+fill_overlap > infill_overlap
+fill_pattern > infill_pattern
+fill_sparse_combine > infill_sparse_combine
+fill_sparse_density > infill_sparse_density
+fill_sparse_thickness > infill_sparse_thickness
+support_fill_rate > support_infill_rate
+
+
+[ SPLITS ]
+raft_line_spacing > raft_base_line_spacing   (, raft_interface_line_spacing, raft_surface_line_spacing)
+wall_overlap_avoid_enabled > remove_overlapping_walls_enabled (, remove_overlapping_walls_0_enabled, remove_overlapping_walls_x_enabled)
+
+retraction_minimal_extrusion > retraction_extrusion_window (+ retraction_count_max = 1)
+
+magic_mesh_surface_mode : false >> "Normal"
+magic_mesh_surface_mode : true >> "Surface"
+
+
+[ NEW ]
+alternate_extra_perimeter
+
+coasting_enable
+coasting_min_volume
+coasting_min_volume_move
+coasting_min_volume_retract
+coasting_speed
+coasting_speed_move
+coasting_speed_retract
+coasting_volume
+coasting_volume_move
+coasting_volume_retract
+
+fill_perimeter_gaps
+
+draft_shield_dist
+draft_shield_enabled
+draft_shield_height
+draft_shield_height_limitation
+
+infill_wipe_dist
+
+line_width (was wall_line_width)
+
+machine_extruder_count
+
+machine_head_polygon
+machine_head_with_fans_polygon
+machine_heat_zone_length
+
+magic_mesh_surface_mode
+
+meshfix_extensive_stitching
+meshfix_keep_open_polygons
+meshfix_union_all
+meshfix_union_all_remove_holes
+
+print_sequence
+
+raft_base_line_spacing	(from raft_line_spacing)
+raft_base_line_width
+raft_fan_speed
+raft_interface_fan_speed
+raft_interface_line_spacing
+raft_interface_speed
+raft_speed
+raft_surface_fan_speed
+raft_surface_line_spacing
+raft_surface_line_width
+raft_surface_speed
+raft_surface_thickness
+remove_overlapping_walls_0_enabled
+remove_overlapping_walls_enabled
+remove_overlapping_walls_x_enabled
+
+retraction_count_max
+retraction_extrusion_window  (from retraction_minimal_extrusion)
+retraction_extra_prime_amount
+
+skin_alternate_rotation
+
+speed_support_lines
+speed_support_roof
+
+support_conical_angle
+support_conical_enabled
+support_conical_min_width
+support_offset
+support_roof_enable
+support_roof_height
+support_roof_line_width
+
+travel_avoid_distance
+travel_avoid_other_parts
+travel_compensate_overlapping_walls_enabled
+
+z_seam_type
+
+
+[ DUAL EXTRUSION ]
+extruder_nr
+machine_use_extruder_offset_to_offset_coords
+machine_nozzle_offset_x
+machine_nozzle_offset_y
+machine_extruder_start_code
+machine_extruder_start_pos_abs
+machine_extruder_start_pos_x
+machine_extruder_start_pos_y
+machine_extruder_end_pos_abs
+machine_extruder_end_pos_x
+machine_extruder_end_pos_y
+machine_extruder_end_code
+prime_tower_enable
+prime_tower_size
+prime_tower_position_x
+prime_tower_position_y
+prime_tower_flow
+prime_tower_wipe_enabled
+ooze_shield_enabled
+ooze_shield_angle
+ooze_shield_dist
+
+
+

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

@@ -0,0 +1,25 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef EXTRUDER_TRAIN_H
+#define EXTRUDER_TRAIN_H
+
+#include "settings/settings.h"
+
+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();
+
+    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
+#endif // EXTRUDER_TRAIN_H

src/FanSpeedLayerTime.h

@@ -0,0 +1,23 @@
+#ifndef FAN_SPEED_LAYER_TIME_H
+#define FAN_SPEED_LAYER_TIME_H
+
+#include "settings/settings.h"
+
+namespace cura 
+{
+
+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;
+    int cool_fan_full_layer;
+};
+
+} // namespace cura
+
+#endif // FAN_SPEED_LAYER_TIME_H

src/FffGcodeWriter.h

@@ -0,0 +1,401 @@
+#ifndef GCODE_WRITER_H
+#define GCODE_WRITER_H
+
+
+#include <fstream>
+#include "utils/gettime.h"
+#include "utils/logoutput.h"
+#include "utils/NoCopy.h"
+#include "utils/polygonUtils.h"
+#include "sliceDataStorage.h"
+#include "raft.h"
+#include "infill.h"
+#include "bridge.h"
+#include "pathOrderOptimizer.h"
+#include "gcodePlanner.h"
+#include "gcodeExport.h"
+#include "commandSocket.h"
+#include "PrimeTower.h"
+#include "FanSpeedLayerTime.h"
+#include "PrintFeature.h"
+
+
+#include "LayerPlanBuffer.h"
+
+
+namespace cura 
+{
+
+/*!
+ * Secondary stage in Fused Filament Fabrication processing: The generated polygons are used in the gcode generation.
+ * Some polygons in the SliceDataStorage signify areas which are to be filled with parallel lines, 
+ * while other polygons signify the contours which should be printed.
+ * 
+ * The main function of this class is FffGcodeWriter::writeGCode().
+ */
+class FffGcodeWriter : public SettingsMessenger, NoCopy
+{
+    friend class FffProcessor; // cause WireFrame2Gcode uses the member [gcode] (TODO)
+private:
+    int max_object_height; //!< The maximal height of all previously sliced meshgroups, used to avoid collision when moving to the next meshgroup to print.
+
+    /*
+     * Buffer for all layer plans (of type GCodePlanner)
+     * 
+     * The layer plans are buffered so that we can start heating up a nozzle several layers before it needs to be used.
+     * Another reason is to perform Auto Temperature.
+     */
+    LayerPlanBuffer layer_plan_buffer; 
+
+    /*!
+     * The class holding the current state of the gcode being written.
+     * 
+     * It holds information such as the last written position etc.
+     */
+    GCodeExport gcode;
+
+    /*!
+     * The gcode file to write to when using CuraEngine as command line tool.
+     */
+    std::ofstream output_file;
+
+    /*!
+     * Whether the skirt or brim polygons have been processed into planned paths
+     * for each extruder train.
+     */
+    bool skirt_brim_is_processed[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.
+
+    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
+public:
+    FffGcodeWriter(SettingsBase* settings_)
+    : SettingsMessenger(settings_)
+    , layer_plan_buffer(this, gcode)
+    , last_position_planned(no_point)
+    , current_extruder_planned(0) // changed somewhere early in FffGcodeWriter::writeGCode
+    {
+        max_object_height = 0;
+    }
+
+    /*!
+     * Set the target to write gcode to: to a file.
+     * 
+     * Used when CuraEngine is used as command line tool.
+     * 
+     * \param filename The filename of the file to which to write the gcode.
+     */
+    bool setTargetFile(const char* filename)
+    {
+        output_file.open(filename);
+        if (output_file.is_open())
+        {
+            gcode.setOutputStream(&output_file);
+            return true;
+        }
+        return false;
+    }
+
+    /*!
+     * Set the target to write gcode to: an output stream.
+     * 
+     * Used when CuraEngine is NOT used as command line tool.
+     * 
+     * \param stream The stream to write gcode to.
+     */
+    void setTargetStream(std::ostream* stream)
+    {
+        gcode.setOutputStream(stream);
+    }
+
+    /*!
+     * Get the total extruded volume for a specific extruder in mm^3
+     * 
+     * Retractions and unretractions don't contribute to this.
+     * 
+     * \param extruder_nr The extruder number for which to get the total netto extruded volume
+     * \return total filament printed in mm^3
+     */
+    double getTotalFilamentUsed(int extruder_nr)
+    {
+        return gcode.getTotalFilamentUsed(extruder_nr);
+    }
+
+    /*!
+     * Get the total estimated print time in seconds
+     * 
+     * \return total print time in seconds
+     */
+    double getTotalPrintTime()
+    {
+        return gcode.getTotalPrintTime();
+    }
+
+    /*!
+     * Write all the gcode for the current meshgroup.
+     * This is the primary function of this class.
+     * 
+     * \param[in] storage The data storage from which to get the polygons to print and the areas to fill.
+     * \param timeKeeper The stop watch to see how long it takes for each of the stages in the slicing process.
+     */
+    void writeGCode(SliceDataStorage& storage, TimeKeeper& timeKeeper);
+
+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(SliceDataStorage& storage);
+
+    /*!
+     * Create and set the SliceDataStorage::coasting_config for each extruder.
+     * 
+     * \param[out] storage The data storage to which to save the configuration
+     */
+    void setConfigCoasting(SliceDataStorage& storage);
+
+    /*!
+     * Set the retraction config globally, per extruder and per mesh.
+     * 
+     * \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.
+     * 
+     * The features are: skirt or brim, support and for each mesh: outer wall,
+     * inner walls, skin, infill (and combined infill).
+     * 
+     * \param[out] storage The data storage to which to save the configurations.
+     */
+    void initConfigs(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.
+     */
+    void processStartingCode(SliceDataStorage& storage);
+
+    /*!
+     * 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);
+    
+    /*!
+     * Add raft layer plans onto the FffGcodeWriter::layer_plan_buffer
+     * 
+     * \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);
+
+    /*!
+     * 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.
+     */
+    void processLayer(SliceDataStorage& storage, int layer_nr, unsigned int total_layers);
+
+    /*!
+     * 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(SliceDataStorage& storage, GCodePlanner& layer_plan, const int layer_nr);
+
+    /*!
+     * 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(SliceDataStorage& storage, GCodePlanner& gcodeLayer, unsigned int extruder_nr);
+    
+    /*!
+     * Adds the ooze shield to the layer plan \p gcodeLayer.
+     * 
+     * \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.
+     */
+    void processOozeShield(SliceDataStorage& storage, GCodePlanner& gcodeLayer, unsigned int layer_nr);
+    
+    /*!
+     * Adds the draft protection screen to the layer plan \p gcodeLayer.
+     * 
+     * \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.
+     */
+    void processDraftShield(SliceDataStorage& storage, GCodePlanner& gcodeLayer, unsigned int layer_nr);
+
+    /*!
+     * 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 pairs of extruder numbers coupled with the mesh indices ordered on print order for that extruder.
+     */
+    std::vector<int> calculateExtruderOrder(SliceDataStorage& storage, int current_extruder);
+
+    /*!
+     * 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(SliceDataStorage& storage, int extruder_nr);
+
+    /*!
+     * 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 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);
+    
+    /*!
+     * 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 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);
+    
+    /*!
+     * Add a single layer from a single mesh-volume to the layer plan \p gcodeLayer.
+     * 
+     * \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 layer_nr The index of the layer to write the gcode of.
+     * 
+     */
+    void addMeshLayerToGCode(SliceDataStorage& storage, SliceMeshStorage* mesh, GCodePlanner& gcodeLayer, int layer_nr);
+    
+    /*!
+     * 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 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.
+     */
+    void processMultiLayerInfill(GCodePlanner& gcodeLayer, SliceMeshStorage* mesh, SliceLayerPart& part, unsigned int layer_nr, int infill_line_distance, int infill_overlap, int fillAngle); 
+    
+    /*!
+     * 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 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.
+     */
+    void processSingleLayerInfill(GCodePlanner& gcodeLayer, SliceMeshStorage* mesh, SliceLayerPart& part, unsigned int layer_nr, int infill_line_distance, int infill_overlap, int fillAngle);
+    
+    /*!
+     * 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 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
+     */
+    void processInsets(GCodePlanner& gcodeLayer, SliceMeshStorage* mesh, SliceLayerPart& part, unsigned int layer_nr, EZSeamType z_seam_type);
+    
+    
+    /*!
+     * Add the gcode of the top/bottom skin of the given 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 part The part for which to create gcode
+     * \param layer_nr The current layer number.
+     * \param skin_overlap The distance by which the skin overlaps with the wall insets.
+     * \param fillAngle The angle in the XY plane at which the infill is generated.
+     */
+    void processSkin(cura::GCodePlanner& gcode_layer, cura::SliceMeshStorage* mesh, cura::SliceLayerPart& part, unsigned int layer_nr, int skin_overlap, int infill_angle);
+
+    /*!
+     * 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.
+     * \return whether any support was added to the layer plan
+     */
+    bool addSupportToGCode(SliceDataStorage& storage, GCodePlanner& gcodeLayer, int layer_nr, int extruder_nr);
+    /*!
+     * 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
+     */
+    bool addSupportInfillToGCode(SliceDataStorage& storage, GCodePlanner& gcodeLayer, int layer_nr);
+    /*!
+     * 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
+     */
+    bool addSupportRoofsToGCode(SliceDataStorage& storage, GCodePlanner& gcodeLayer, int layer_nr);
+    
+    /*!
+     * Change to a new extruder, and add the prime tower instructions if the new extruder is different from the last.
+     * 
+     * On layer 0 this function adds the skirt for the nozzle it switches to, instead of the prime tower.
+     * 
+     * \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 The extruder to which to switch
+     */
+    void setExtruder_addPrime(SliceDataStorage& storage, GCodePlanner& gcode_layer, int layer_nr, int extruder_nr);
+    
+    /*!
+     * Add the prime tower gcode for 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.
+     * \param prev_extruder The current extruder with which we last printed.
+     */
+    void addPrimeTower(SliceDataStorage& storage, GCodePlanner& gcodeLayer, int layer_nr, int prev_extruder);
+    
+    /*!
+     * Add the end gcode and set all temperatures to zero.
+     */
+    void finalize();
+};
+
+}//namespace cura
+
+#endif // GCODE_WRITER_H

src/FffPolygonGenerator.cpp

@@ -0,0 +1,764 @@
+#include "FffPolygonGenerator.h"
+
+#include <algorithm>
+#include <map> // multimap (ordered map allowing duplicate keys)
+
+#include "utils/math.h"
+#include "utils/algorithm.h"
+#include "slicer.h"
+#include "utils/gettime.h"
+#include "utils/logoutput.h"
+#include "MeshGroup.h"
+#include "support.h"
+#include "multiVolumes.h"
+#include "layerPart.h"
+#include "WallsComputation.h"
+#include "SkirtBrim.h"
+#include "skin.h"
+#include "infill.h"
+#include "raft.h"
+#include "progress/Progress.h"
+#include "PrintFeature.h"
+#include "ConicalOverhang.h"
+#include "progress/ProgressEstimator.h"
+#include "progress/ProgressStageEstimator.h"
+#include "progress/ProgressEstimatorLinear.h"
+
+
+namespace cura
+{
+
+
+bool FffPolygonGenerator::generateAreas(SliceDataStorage& storage, MeshGroup* meshgroup, TimeKeeper& timeKeeper)
+{
+    if (!sliceModel(meshgroup, timeKeeper, storage)) 
+    {
+        return false;
+    }
+    
+    slices2polygons(storage, timeKeeper);
+    
+    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(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);
+    
+    storage.model_min = meshgroup->min();
+    storage.model_max = meshgroup->max();
+    storage.model_size = storage.model_max - storage.model_min;
+
+    log("Slicing model...\n");
+    int initial_layer_thickness = getSettingInMicrons("layer_height_0");
+    if(initial_layer_thickness <= 0) //Initial layer height of 0 is not allowed. Negative layer height is nonsense.
+    {
+        logError("Initial layer height %i is disallowed.\n", initial_layer_thickness);
+        return false;
+    }
+    int layer_thickness = getSettingInMicrons("layer_height");
+    if(layer_thickness <= 0) //Layer height of 0 is not allowed. Negative layer height is nonsense.
+    {
+        logError("Layer height %i is disallowed.\n", layer_thickness);
+        return false;
+    }
+    int initial_slice_z = initial_layer_thickness - layer_thickness / 2;
+    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!
+    }
+
+    std::vector<Slicer*> slicerList;
+    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, slice_layer_count, mesh.getSettingBoolean("meshfix_keep_open_polygons"), mesh.getSettingBoolean("meshfix_extensive_stitching"));
+        slicerList.push_back(slicer);
+        /*
+        for(SlicerLayer& layer : slicer->layers)
+        {
+            //Reporting the outline here slows down the engine quite a bit, so only do so when debugging.
+            sendPolygons("outline", layer_nr, layer.z, layer.polygonList);
+            sendPolygons("openoutline", layer_nr, layer.openPolygonList);
+        }
+        */
+        Progress::messageProgress(Progress::Stage::SLICING, mesh_idx + 1, meshgroup->meshes.size());
+    }
+
+    meshgroup->clear();///Clear the mesh face and vertex data, it is no longer needed after this point, and it saves a lot of memory.
+
+
+    for(unsigned int meshIdx=0; meshIdx < slicerList.size(); meshIdx++)
+    {
+        Mesh& mesh = storage.meshgroup->meshes[meshIdx];
+        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);
+            }
+            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);
+            }
+            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;
+        //Add the raft offset to each layer.
+        for(unsigned int layer_nr=0; layer_nr<meshStorage.layers.size(); layer_nr++)
+        {
+            SliceLayer& layer = meshStorage.layers[layer_nr];
+            meshStorage.layers[layer_nr].printZ += 
+                getSettingInMicrons("layer_height_0")
+                - initial_slice_z;
+            if (has_raft)
+            {
+                ExtruderTrain* train = storage.meshgroup->getExtruderTrain(getSettingAsIndex("adhesion_extruder_nr"));
+                layer.printZ += 
+                    Raft::getTotalThickness(storage)
+                    + train->getSettingInMicrons("raft_airgap")
+                    - train->getSettingInMicrons("layer_0_z_overlap"); // shift all layers (except 0) down
+                if (layer_nr == 0)
+                {
+                    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
+            } 
+        }
+
+        Progress::messageProgress(Progress::Stage::PARTS, meshIdx + 1, slicerList.size());
+    }
+    return true;
+}
+
+void FffPolygonGenerator::slices2polygons(SliceDataStorage& storage, TimeKeeper& time_keeper)
+{
+    // compute layer count and remove first empty layers
+    // there is no separate progress stage for removeEmptyFisrtLayer (TODO)
+    unsigned int slice_layer_count = 0;
+    for (SliceMeshStorage& mesh : storage.meshes)
+    {
+        if (!mesh.getSettingBoolean("infill_mesh") && !mesh.getSettingBoolean("anti_overhang_mesh"))
+        {
+            slice_layer_count = std::max<unsigned int>(slice_layer_count, mesh.layers.size());
+        }
+    }
+
+    // handle meshes
+    std::vector<double> mesh_timings;
+    for (unsigned int mesh_idx = 0; mesh_idx < storage.meshes.size(); mesh_idx++)
+    {
+        mesh_timings.push_back(1.0); // TODO: have a more accurate estimate of the relative time it takes per mesh, based on the height and number of polygons
+    }
+    ProgressStageEstimator inset_skin_progress_estimate(mesh_timings);
+
+    Progress::messageProgressStage(Progress::Stage::INSET_SKIN, &time_keeper);
+    std::vector<unsigned int> mesh_order;
+    { // compute mesh order
+        std::multimap<int, unsigned int> order_to_mesh_indices;
+        for (unsigned int mesh_idx = 0; mesh_idx < storage.meshes.size(); mesh_idx++)
+        {
+            order_to_mesh_indices.emplace(storage.meshes[mesh_idx].getSettingAsIndex("infill_mesh_order"), mesh_idx);
+        }
+        for (std::pair<const int, unsigned int>& order_and_mesh_idx : order_to_mesh_indices)
+        {
+            mesh_order.push_back(order_and_mesh_idx.second);
+        }
+    }
+    for (unsigned int mesh_order_idx(0); mesh_order_idx < mesh_order.size(); ++mesh_order_idx)
+    {
+        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
+    // 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;
+    }
+    
+    /*
+    if (storage.support.generated)
+    {
+        for (unsigned int layer_idx = 0; layer_idx < storage.print_layer_count; layer_idx++)
+        {
+            Polygons& support = storage.support.supportLayers[layer_idx].supportAreas;
+            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.generatePaths(storage);
+    
+    logDebug("Processing ooze shield\n");
+    processOozeShield(storage);
+
+    logDebug("Processing draft shield\n");
+    processDraftShield(storage);
+
+    logDebug("Processing platform adhesion\n");
+    processPlatformAdhesion(storage);
+    
+    // meshes post processing
+    for (SliceMeshStorage& mesh : storage.meshes)
+    {
+        processDerivedWallsSkinInfill(mesh);
+    }
+}
+
+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_order_idx, mesh_order);
+    }
+    
+    // TODO: make progress more accurate!!
+    // note: estimated time for     insets : skins = 22.953 : 48.858
+    std::vector<double> walls_vs_skin_timing({22.953, 48.858});
+    ProgressStageEstimator* mesh_inset_skin_progress_estimator = new ProgressStageEstimator(walls_vs_skin_timing);
+    
+    inset_skin_progress_estimate.nextStage(mesh_inset_skin_progress_estimator); // the stage of this function call
+    
+    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 < 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);
+    }
+
+    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;
+    if (mesh.getSettingBoolean("magic_spiralize"))
+    {
+        mesh_max_bottom_layer_count = std::max(mesh_max_bottom_layer_count, mesh.getSettingAsCount("bottom_layers"));
+    }
+    for (unsigned int layer_number = 0; layer_number < mesh.layers.size(); 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);
+        }
+        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_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;
+            }
+
+            SliceLayer& other_layer = other_mesh.layers[layer_idx];
+
+            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 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);
+                        }
+                    }
+                    // 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
+                }
+            }
+        }
+        
+        layer.parts.clear();
+        for (PolygonsPart& part : new_parts)
+        {
+            layer.parts.emplace_back();
+            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)
+{
+    // create gradual infill areas
+    SkinInfillAreaComputation::generateGradualInfill(mesh, mesh.getSettingInMicrons("gradual_infill_step_height"), mesh.getSettingAsCount("gradual_infill_steps"));
+
+    // combine infill
+    unsigned int combined_infill_layers = std::max(1U, round_divide(mesh.getSettingInMicrons("infill_sparse_thickness"), std::max(getSettingInMicrons("layer_height"), 1))); //How many infill layers to combine to obtain the requested sparse thickness.
+    combineInfillLayers(mesh,combined_infill_layers);
+
+    // fuzzy skin
+    if (mesh.getSettingBoolean("magic_fuzzy_skin_enabled"))
+    {
+        processFuzzyWalls(mesh);
+    }
+}
+
+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) + 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) + 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);
+    }
+}
+
+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;
+        if (storage.support.generated && layer_idx < storage.support.supportLayers.size())
+        {
+            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 (layer.parts.size() > 0 || (mesh.getSettingAsSurfaceMode("magic_mesh_surface_mode") != ESurfaceMode::NORMAL && layer.openPolyLines.size() > 0) )
+            {
+                layer_is_empty = false;
+                break;
+            }
+        }
+        
+        if (layer_is_empty) 
+        {
+            n_empty_first_layers++;
+        } else
+        {
+            break;
+        }
+    }
+    
+    if (n_empty_first_layers > 0)
+    {
+        log("Removing %d layers because they are empty\n", n_empty_first_layers);
+        for (SliceMeshStorage& mesh : storage.meshes)
+        {
+            std::vector<SliceLayer>& layers = mesh.layers;
+            layers.erase(layers.begin(), layers.begin() + n_empty_first_layers);
+            for (SliceLayer& layer : layers)
+            {
+                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, bool process_infill) 
+{
+    if (mesh.getSettingAsSurfaceMode("magic_mesh_surface_mode") == ESurfaceMode::SURFACE) 
+    { 
+        return;
+    }
+
+    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 = innermost_wall_line_width / 2;
+        }
+        generateInfill(layer_nr, mesh, innermost_wall_line_width, infill_skin_overlap, wall_line_count);
+    }
+}
+
+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;
+    }
+
+    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, ClipperLib::jtRound));
+    }
+
+    double angle = getSettingInAngleDegrees("ooze_shield_angle");
+    if (angle <= 89)
+    {
+        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));
+        }
+    }
+
+    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].removeSmallAreas(largest_printed_area);
+    }
+}
+
+void FffPolygonGenerator::processDraftShield(SliceDataStorage& storage)
+{
+    const unsigned int draft_shield_layers = getDraftShieldLayerCount(storage.print_layer_count);
+    if (draft_shield_layers <= 0)
+    {
+        return;
+    }
+    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 < storage.print_layer_count && layer_nr < draft_shield_layers; layer_nr += layer_skip)
+    {
+        draft_shield = draft_shield.unionPolygons(storage.getLayerOutlines(layer_nr, true));
+    }
+
+    const int draft_shield_dist = getSettingInMicrons("draft_shield_dist");
+    storage.draft_protection_shield = draft_shield.approxConvexHull(draft_shield_dist);
+}
+
+void FffPolygonGenerator::processPlatformAdhesion(SliceDataStorage& storage)
+{
+    SettingsBaseVirtual* train = storage.meshgroup->getExtruderTrain(getSettingBoolean("adhesion_extruder_nr"));
+    switch(getSettingAsPlatformAdhesion("adhesion_type"))
+    {
+    case EPlatformAdhesion::SKIRT:
+        {
+            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:
+        SkirtBrim::generate(storage, 0, train->getSettingAsCount("brim_line_count"), train->getSettingBoolean("brim_outside_only"));
+        break;
+    case EPlatformAdhesion::RAFT:
+        Raft::generate(storage, train->getSettingInMicrons("raft_margin"));
+        break;
+    case EPlatformAdhesion::NONE:
+        break;
+    }
+}
+
+
+void FffPolygonGenerator::processFuzzyWalls(SliceMeshStorage& mesh)
+{
+    if (mesh.getSettingAsCount("wall_line_count") == 0)
+    {
+        return;
+    }
+    int64_t fuzziness = mesh.getSettingInMicrons("magic_fuzzy_skin_thickness");
+    int64_t avg_dist_between_points = mesh.getSettingInMicrons("magic_fuzzy_skin_point_dist");
+    int64_t min_dist_between_points = avg_dist_between_points * 3 / 4; // hardcoded: the point distance may vary between 3/4 and 5/4 the supplied value
+    int64_t range_random_point_dist = avg_dist_between_points / 2;
+    for (unsigned int layer_nr = 0; layer_nr < mesh.layers.size(); layer_nr++)
+    {
+        SliceLayer& layer = mesh.layers[layer_nr];
+        for (SliceLayerPart& part : layer.parts)
+        {
+            Polygons results;
+            Polygons& skin = (mesh.getSettingAsSurfaceMode("magic_mesh_surface_mode") == ESurfaceMode::SURFACE)? part.outline : part.insets[0];
+            for (PolygonRef poly : skin)
+            {
+                // generate points in between p0 and p1
+                PolygonRef result = results.newPoly();
+                
+                int64_t dist_left_over = rand() % (min_dist_between_points / 2); // the distance to be traversed on the line before making the first new point
+                Point* p0 = &poly.back();
+                for (Point& p1 : poly)
+                { // 'a' is the (next) new point between p0 and p1
+                    Point p0p1 = p1 - *p0;
+                    int64_t p0p1_size = vSize(p0p1);    
+                    int64_t dist_last_point = dist_left_over + p0p1_size * 2; // so that p0p1_size - dist_last_point evaulates to dist_left_over - p0p1_size
+                    for (int64_t p0pa_dist = dist_left_over; p0pa_dist < p0p1_size; p0pa_dist += min_dist_between_points + rand() % range_random_point_dist)
+                    {
+                        int r = rand() % (fuzziness * 2) - fuzziness;
+                        Point perp_to_p0p1 = turn90CCW(p0p1);
+                        Point fuzz = normal(perp_to_p0p1, r);
+                        Point pa = *p0 + normal(p0p1, p0pa_dist) + fuzz;
+                        result.add(pa);
+                        dist_last_point = p0pa_dist;
+                    }
+                    dist_left_over = p0p1_size - dist_last_point;
+                    
+                    p0 = &p1;
+                }
+                while (result.size() < 3 )
+                {
+                    unsigned int point_idx = poly.size() - 2;
+                    result.add(poly[point_idx]);
+                    if (point_idx == 0) { break; }
+                    point_idx--;
+                }
+                if (result.size() < 3)
+                {
+                    result.clear();
+                    for (Point& p : poly)
+                        result.add(p);
+                }
+            }
+            skin = results;
+        }
+    }
+}
+
+
+}//namespace cura

src/FffPolygonGenerator.h

@@ -0,0 +1,174 @@
+#ifndef FFF_AREA_GENERATOR_H
+#define FFF_AREA_GENERATOR_H
+
+
+#include "MeshGroup.h"
+#include "utils/polygonUtils.h"
+#include "utils/NoCopy.h"
+#include "utils/gettime.h"
+#include "settings/settings.h"
+#include "sliceDataStorage.h"
+#include "commandSocket.h"
+#include "PrintFeature.h"
+#include "progress/ProgressEstimator.h"
+#include "progress/ProgressStageEstimator.h"
+
+namespace cura
+{
+
+/*!
+ * Primary stage in Fused Filament Fabrication processing: Polygons are generated.
+ * The model is sliced and each slice consists of polygons representing the outlines: the boundaries between inside and outside the object.
+ * After slicing, the layers are processed; for example the wall insets are generated, and the areas which are to be filled with support and infill, which are all represented by polygons.
+ * In this stage nothing other than areas and circular paths are generated, which are both represented by polygons.
+ * No infill lines or support pattern etc. is generated.
+ * 
+ * The main function of this class is FffPolygonGenerator::generateAreas().
+ */
+class FffPolygonGenerator : public SettingsMessenger, NoCopy
+{
+public:
+    /*!
+     * Basic constructor
+     */
+    FffPolygonGenerator(SettingsBase* settings_)
+    : SettingsMessenger(settings_)
+    {
+    }
+
+    /*!
+     * Slice the \p object, process the outline information into inset perimeter polygons, support area polygons, etc. 
+     * 
+     * \param object The object to slice.
+     * \param timeKeeper Object which keeps track of timings of each stage.
+     * \param storage Output parameter: where the outlines are stored. See SliceLayerPart::outline.
+     */
+    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.
+     * 
+     * \param object The object to slice.
+     * \param timeKeeper Object which keeps track of timings of each stage.
+     * \param storage Output parameter: where the outlines are stored. See SliceLayerPart::outline.
+     * 
+     * \return Whether the process succeeded (always true).
+     */
+    bool sliceModel(MeshGroup* object, TimeKeeper& timeKeeper, SliceDataStorage& storage); /// slices the model
+
+    /*!
+     * Processes the outline information as stored in the \p storage: generates inset perimeter polygons, support area polygons, etc. 
+     * 
+     * \param storage Input and Output parameter: fetches the outline information (see SliceLayerPart::outline) and generates the other reachable field of the \p storage
+     * \param timeKeeper Object which keeps track of timings of each stage.
+     */
+    void slices2polygons(SliceDataStorage& storage, TimeKeeper& timeKeeper);
+    
+    /*!
+     * 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_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 inset_skin_progress_estimate The progress stage estimate calculator
+     */
+    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_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
+     */
+    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
+     */
+    void processDerivedWallsSkinInfill(SliceMeshStorage& mesh);
+    
+    /*!
+     * Remove all bottom layers which are empty.
+     * 
+     * \warning Changes \p total_layers
+     * 
+     * \param storage Input and Ouput parameter: stores all layers
+     * \param layer_height The height of each layer
+     * \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
+     * \param layer_nr The layer for which to generate the insets.
+     */
+    void processInsets(SliceMeshStorage& mesh, unsigned int layer_nr);
+
+    /*!
+     * 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
+     */
+    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, 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
+     */
+    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

@@ -0,0 +1,119 @@
+#include "FffProcessor.h" 
+
+namespace cura 
+{
+
+FffProcessor FffProcessor::instance; // definition must be in cpp
+
+FffProcessor::FffProcessor()
+: polygon_generator(this)
+, gcode_writer(this)
+, meshgroup_number(0)
+{
+}
+
+int FffProcessor::getMeshgroupNr()
+{
+    return meshgroup_number;
+}
+
+
+std::string FffProcessor::getAllSettingsString(MeshGroup& meshgroup, bool first_meshgroup)
+{
+    std::stringstream sstream;
+    if (first_meshgroup)
+    {
+        sstream << getAllLocalSettingsString(); // global settings
+        sstream << " -g";
+    }
+    else 
+    {
+        sstream << " --next";
+    }
+    sstream << meshgroup.getAllLocalSettingsString();
+    for (int extruder_nr = 0; extruder_nr < meshgroup.getExtruderCount(); extruder_nr++)
+    {
+        ExtruderTrain* train = meshgroup.getExtruderTrain(extruder_nr);
+        sstream << " -e" << extruder_nr << train->getAllLocalSettingsString();
+    }
+    for (unsigned int mesh_idx = 0; mesh_idx < meshgroup.meshes.size(); mesh_idx++)
+    {
+        Mesh& mesh = meshgroup.meshes[mesh_idx];
+        sstream << " -e" << mesh.getSettingAsIndex("extruder_nr") << " -l \"" << mesh_idx << "\"" << mesh.getAllLocalSettingsString();
+    }
+    sstream << "\n";
+    return sstream.str();
+}
+
+bool FffProcessor::processMeshGroup(MeshGroup* meshgroup)
+{
+    if (SHOW_ALL_SETTINGS) { logWarning(getAllSettingsString(*meshgroup, meshgroup_number == 0).c_str()); }
+    time_keeper.restart();
+    if (!meshgroup)
+        return false;
+
+    TimeKeeper time_keeper_total;
+
+    polygon_generator.setParent(meshgroup);
+    gcode_writer.setParent(meshgroup);
+
+    bool empty = true;
+    for (Mesh& mesh : meshgroup->meshes)
+    {
+        if (!mesh.getSettingBoolean("infill_mesh") && !mesh.getSettingBoolean("anti_overhang_mesh"))
+        {
+            empty = false;
+        }
+    }
+    if (empty)
+    {
+        Progress::messageProgress(Progress::Stage::FINISH, 1, 1); // 100% on this meshgroup
+        log("Total time elapsed %5.2fs.\n", time_keeper_total.restart());
+
+        profile_string += getAllSettingsString(*meshgroup, meshgroup_number == 0);
+        return true;
+    }
+    
+    if (meshgroup->getSettingBoolean("wireframe_enabled"))
+    {
+        log("starting Neith Weaver...\n");
+                    
+        Weaver w(this);
+        w.weave(meshgroup);
+        
+        log("starting Neith Gcode generation...\n");
+        Wireframe2gcode gcoder(w, gcode_writer.gcode, this);
+        gcoder.writeGCode();
+        log("finished Neith Gcode generation...\n");
+        
+    } else 
+    {
+        SliceDataStorage storage(meshgroup);
+
+        if (!polygon_generator.generateAreas(storage, meshgroup, time_keeper))
+        {
+            return false;
+        }
+        
+        Progress::messageProgressStage(Progress::Stage::EXPORT, &time_keeper);
+        gcode_writer.writeGCode(storage, time_keeper);
+    }
+
+    Progress::messageProgress(Progress::Stage::FINISH, 1, 1); // 100% on this meshgroup
+    if (CommandSocket::isInstantiated())
+    {
+        CommandSocket::getInstance()->flushGcode();
+        CommandSocket::getInstance()->sendOptimizedLayerData();
+    }
+    log("Total time elapsed %5.2fs.\n", time_keeper_total.restart());
+
+    profile_string += getAllSettingsString(*meshgroup, meshgroup_number == 0);
+    meshgroup_number++;
+
+    polygon_generator.setParent(this); // otherwise consequent getSetting calls (e.g. for finalize) will refer to non-existent meshgroup
+    gcode_writer.setParent(this); // otherwise consequent getSetting calls (e.g. for finalize) will refer to non-existent meshgroup
+
+    return true;
+}
+
+} // namespace cura 

src/FffProcessor.h

@@ -0,0 +1,166 @@
+#ifndef FFF_PROCESSOR_H
+#define FFF_PROCESSOR_H
+
+#include "settings/settings.h"
+#include "FffGcodeWriter.h"
+#include "FffPolygonGenerator.h"
+#include "commandSocket.h"
+#include "Weaver.h"
+#include "Wireframe2gcode.h"
+#include "progress/Progress.h"
+#include "utils/gettime.h"
+#include "utils/NoCopy.h"
+
+#define SHOW_ALL_SETTINGS true
+
+namespace cura {
+
+//FusedFilamentFabrication processor. Singleton class
+class FffProcessor : public SettingsBase , NoCopy
+{
+private:
+    /*!
+     * The FffProcessor used for the (current) slicing (The instance of this singleton)
+     */
+    static FffProcessor instance; 
+    
+    FffProcessor();
+public:
+    /*!
+     * Get the instance
+     * \return The instance
+     */
+    static FffProcessor* getInstance() 
+    { 
+        return &instance; 
+    }
+
+    /*!
+     * Get the index of the meshgroup currently being processed, starting at zero.
+     */
+    int getMeshgroupNr();
+
+private:
+    /*!
+     * The polygon generator, which slices the models and generates all polygons to be printed and areas to be filled.
+     */
+    FffPolygonGenerator polygon_generator;
+
+    /*!
+     * The gcode writer, which generates paths in layer plans in a buffer, which converts these paths into gcode commands.
+     */
+    FffGcodeWriter gcode_writer;
+
+    /*!
+     * The index of the meshgroup currently being processed, starting at zero.
+     */
+    int meshgroup_number;
+
+    /*!
+     * A string containing all setting values passed to the engine in the format by which CuraEngine is called via the command line.
+     * 
+     * Used in debugging.
+     */
+    std::string profile_string = "";
+
+    /*!
+     * Get all settings for the current meshgroup in the format by which CuraEngine is called via the command line.
+     * 
+     * Also includes all global settings if this is the first meshgroup.
+     * 
+     * Used in debugging.
+     * 
+     * \param meshgroup The meshgroup for which to stringify all settings
+     * \param first_meshgroup Whether this is the first meshgroup and all global settigns should be included as well
+     */
+    std::string getAllSettingsString(MeshGroup& meshgroup, bool first_meshgroup);
+
+public:
+    /*!
+     * Get a string containing all setting values passed to the engine in the format by which CuraEngine is called via the command line.
+     * 
+     * \return A string containing all setting values passed to the engine in the format by which CuraEngine is called via the command line.
+     */
+    std::string getProfileString() { return profile_string; }
+
+    /*!
+     * The stop watch used to time how long the different stages take to compute.
+     */
+    TimeKeeper time_keeper; // TODO: use singleton time keeper
+
+    /*!
+     * Reset the meshgroup number to the first meshgroup to start a new slicing.
+     */
+    void resetMeshGroupNumber()
+    {
+        meshgroup_number = 0;
+    }
+
+    /*!
+     * Set the target to write gcode to: to a file.
+     * 
+     * Used when CuraEngine is used as command line tool.
+     * 
+     * \param filename The filename of the file to which to write the gcode.
+     */
+    bool setTargetFile(const char* filename)
+    {
+        return gcode_writer.setTargetFile(filename);
+    }
+
+    /*!
+     * Set the target to write gcode to: an output stream.
+     * 
+     * Used when CuraEngine is NOT used as command line tool.
+     * 
+     * \param stream The stream to write gcode to.
+     */
+    void setTargetStream(std::ostream* stream)
+    {
+        return gcode_writer.setTargetStream(stream);
+    }
+
+    /*!
+     * Get the total extruded volume for a specific extruder in mm^3
+     * 
+     * Retractions and unretractions don't contribute to this.
+     * 
+     * \param extruder_nr The extruder number for which to get the total netto extruded volume
+     * \return total filament printed in mm^3
+     */
+    double getTotalFilamentUsed(int extruder_nr)
+    {
+        return gcode_writer.getTotalFilamentUsed(extruder_nr);
+    }
+
+    /*!
+     * Get the total estimated print time in seconds
+     * 
+     * \return total print time in seconds
+     */
+    double getTotalPrintTime()
+    {
+        return gcode_writer.getTotalPrintTime();
+    }
+
+    /*!
+     * Add the end gcode and set all temperatures to zero.
+     */
+    void finalize()
+    {
+        gcode_writer.finalize();
+    }
+
+    /*!
+     * Generate gcode for a given \p meshgroup
+     * The primary function of this class.
+     * 
+     * \param meshgroup The meshgroup for which to generate gcode
+     * \return Whether this function succeeded
+     */
+    bool processMeshGroup(MeshGroup* meshgroup);
+};
+
+}//namespace cura
+
+#endif//FFF_PROCESSOR_H

src/FlowTempGraph.h

@@ -0,0 +1,77 @@
+#ifndef FLOW_TEMP_GRAPH
+#define FLOW_TEMP_GRAPH
+
+#include <cassert>
+
+#include "utils/logoutput.h"
+
+namespace cura
+{
+
+/*!
+ * Class representing a graph matching a flow to a temperature.
+ * The graph generally consists of several linear line segments between points at which the temperature and flow are matched.
+ */
+class FlowTempGraph
+{
+public:
+    struct Datum
+    {
+        double flow; //!< The flow in mm^3/s
+        double temp; //!< The temperature in *C
+        Datum(double flow, double temp)
+        : flow(flow)
+        , temp(temp)
+        {}
+    };
+    std::vector<Datum> data; //!< The points of the graph between which the graph is linearly interpolated
+
+    FlowTempGraph()
+    {}
+    
+    /*!
+     * Get the temperature corresponding to a specific flow.
+     * 
+     * For flows outside of the chart, the temperature at the minimal or maximal flow is returned.
+     * When the graph is empty, the @p material_print_temperature is returned.
+     * 
+     * \param flow the flow in mm^3/s
+     * \param material_print_temperature The default printing temp (backward compatibility for when the graph fails)
+     * \return the corresponding temp
+     */
+    double getTemp(double flow, double material_print_temperature, bool flow_dependent_temperature)
+    {
+        if (!flow_dependent_temperature || data.size() == 0)
+        {
+            return material_print_temperature;
+        }
+        if (data.size() == 1)
+        {
+            return data.front().temp;
+        }
+        if (flow < data.front().flow)
+        {
+            logWarning("Warning! Flow too low!\n"); // TODO
+            return data.front().temp;
+        }
+        Datum* last_datum = &data.front();
+        for (unsigned int datum_idx = 1; datum_idx < data.size(); datum_idx++)
+        {
+            Datum& datum = data[datum_idx];
+            if (datum.flow >= flow)
+            {
+                return last_datum->temp + (datum.temp - last_datum->temp) * (flow - last_datum->flow) / (datum.flow - last_datum->flow);
+            }
+            last_datum = &datum;
+        }
+        
+        logWarning("Warning! Flow too high!\n"); // TODO
+        return data.back().temp;
+    };
+};
+
+
+
+} // namespace cura
+
+#endif // FLOW_TEMP_GRAPH

src/GCodePathConfig.cpp

@@ -0,0 +1,111 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+
+#include "utils/intpoint.h" // INT2MM
+#include "GCodePathConfig.h"
+
+namespace cura 
+{
+
+GCodePathConfig::BasicConfig::BasicConfig()
+: speed(0)
+, acceleration(0)
+, jerk(0)
+, line_width(0)
+, flow(100)
+{
+}
+
+
+GCodePathConfig::BasicConfig::BasicConfig(double speed, double acceleration, double jerk, int line_width, double flow)
+: speed(speed)
+, acceleration(acceleration)
+, jerk(jerk)
+, line_width(line_width)
+, flow(flow)
+{
+}
+
+void GCodePathConfig::BasicConfig::set(double speed, double acceleration, double jerk, int line_width, double flow)
+{
+    this->speed = speed;
+    this->acceleration = acceleration;
+    this->jerk = jerk;
+    this->line_width = line_width;
+    this->flow = flow;
+}
+
+
+GCodePathConfig::GCodePathConfig(PrintFeatureType type)
+: extrusion_mm3_per_mm(0.0)
+, type(type)
+{
+}
+
+void GCodePathConfig::init(double speed, double acceleration, double jerk, int line_width, double flow)
+{
+    iconic_config.set(speed, acceleration, jerk, line_width, flow);
+    current_config = iconic_config;
+}
+
+void GCodePathConfig::setLayerHeight(int layer_height)
+{
+    this->layer_thickness = layer_height;
+    calculateExtrusion();
+}
+
+void GCodePathConfig::smoothSpeed(GCodePathConfig::BasicConfig first_layer_config, int layer_nr, double max_speed_layer) 
+{
+    current_config.speed = (iconic_config.speed * layer_nr) / max_speed_layer + (first_layer_config.speed * (max_speed_layer - layer_nr) / max_speed_layer);
+    current_config.acceleration = (iconic_config.acceleration * layer_nr) / max_speed_layer + (first_layer_config.acceleration * (max_speed_layer - layer_nr) / max_speed_layer);
+    current_config.jerk = (iconic_config.jerk * layer_nr) / max_speed_layer + (first_layer_config.jerk * (max_speed_layer - layer_nr) / max_speed_layer);
+}
+
+void GCodePathConfig::setSpeedIconic()
+{
+    current_config.speed = iconic_config.speed;
+    current_config.acceleration = iconic_config.acceleration;
+    current_config.jerk = iconic_config.jerk;
+}
+
+double GCodePathConfig::getExtrusionMM3perMM()
+{
+    return extrusion_mm3_per_mm;
+}
+
+double GCodePathConfig::getSpeed()
+{
+    return current_config.speed;
+}
+
+double GCodePathConfig::getAcceleration()
+{
+    return current_config.acceleration;
+}
+
+double GCodePathConfig::getJerk()
+{
+    return current_config.jerk;
+}
+
+int GCodePathConfig::getLineWidth()
+{
+    return current_config.line_width;
+}
+
+bool GCodePathConfig::isTravelPath()
+{
+    return current_config.line_width == 0;
+}
+
+double GCodePathConfig::getFlowPercentage()
+{
+    return current_config.flow;
+}
+
+void GCodePathConfig::calculateExtrusion()
+{
+    extrusion_mm3_per_mm = INT2MM(current_config.line_width) * INT2MM(layer_thickness) * double(current_config.flow) / 100.0;
+}
+
+
+}//namespace cura

src/GCodePathConfig.h

@@ -0,0 +1,112 @@
+/** 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:
+    /*!
+     * The path config settings which may change from layer to layer
+     */
+    struct BasicConfig
+    {
+        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) (mm/s^3)
+        int line_width; //!< width of the line extruded
+        double flow; //!< extrusion flow modifier in %
+        BasicConfig(); //!< basic contructor initializing with inaccurate values
+        BasicConfig(double speed, double acceleration, double jerk, int line_width, double flow); //!< basic contructor initializing all values
+        void set(double speed, double acceleration, double jerk, int line_width, double flow); //!< Set all config values
+    };
+private:
+    BasicConfig iconic_config; //!< The basic path configuration iconic to this print feature type
+    BasicConfig current_config; //!< The current path configuration for the current layer
+    int layer_thickness; //!< current layer height in micron
+    double extrusion_mm3_per_mm;//!< current mm^3 filament moved per mm line traversed
+public:
+    const PrintFeatureType type; //!< name of the feature type
+
+    /*!
+     * Basic constructor.
+     */
+    GCodePathConfig(PrintFeatureType type);
+    
+    /*!
+     * 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, double acceleration, double jerk, int line_width, double flow);
+
+    /*!
+     * Set the layer height and (re)compute the extrusion_per_mm
+     */
+    void setLayerHeight(int layer_height);
+
+    /*!
+     * 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 !
+     * 
+     * \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(BasicConfig first_layer_config, int layer_nr, double max_speed_layer);
+
+    /*!
+     * Set the speed config to the iconic speed config, i.e. the normal speed of the feature type for which this is a config.
+     * 
+     * Does the same for acceleration and jerk.
+     */
+    void setSpeedIconic();
+
+    /*!
+     * Can only be called after the layer height has been set (which is done while writing the gcode!)
+     */
+    double getExtrusionMM3perMM();
+
+    /*!
+     * Get the movement speed in mm/s
+     */
+    double getSpeed();
+
+    /*!
+     * Get the current acceleration of this config
+     */
+    double getAcceleration();
+
+    /*!
+     * Get the current jerk of this config
+     */
+    double getJerk();
+
+    int getLineWidth();
+
+    bool isTravelPath();
+
+    double getFlowPercentage();
+
+private:
+    void calculateExtrusion();
+};
+
+
+}//namespace cura
+
+#endif // G_CODE_PATH_CONFIG_H

src/LayerPlanBuffer.cpp

@@ -0,0 +1,406 @@
+/** Copyright (C) 2015 Ultimaker - Released under terms of the AGPLv3 License */
+
+#include "LayerPlanBuffer.h"
+#include "gcodeExport.h"
+#include "utils/logoutput.h"
+#include "FffProcessor.h"
+
+namespace cura {
+
+
+
+void LayerPlanBuffer::flush()
+{
+    if (buffer.size() > 0)
+    {
+        insertTempCommands(); // insert preheat commands of the very last layer
+    }
+    while (!buffer.empty())
+    {
+        buffer.front().writeGCode(gcode);
+        if (CommandSocket::isInstantiated())
+        {
+            CommandSocket::getInstance()->flushGcode();
+        }
+        buffer.pop_front();
+    }
+    
+}
+
+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 = extruder_plan_before.paths.size() - 1; int(path_idx) != -1 ; path_idx--)
+    {
+        GCodePath& path = extruder_plan_before.paths[path_idx];
+        const double time_this_path = path.estimates.getTotalTime();
+        acc_time += time_this_path;
+        if (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;
+        }
+    }
+    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
+}
+
+Preheat::WarmUpResult LayerPlanBuffer::timeBeforeExtruderPlanToInsert(std::vector<ExtruderPlan*>& extruder_plans, unsigned int extruder_plan_idx)
+{
+    ExtruderPlan& extruder_plan = *extruder_plans[extruder_plan_idx];
+    int extruder = extruder_plan.extruder;
+    double initial_print_temp = extruder_plan.initial_printing_temperature;
+
+    double in_between_time = 0.0;
+    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)
+        {
+            double temp_before = preheat_config.getFinalPrintTemp(extruder);
+            if (temp_before == 0)
+            {
+                temp_before = extruder_plan_before.printing_temperature;
+            }
+            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;
+        }
+        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.
+    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
+    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::handleStandbyTemp(std::vector<ExtruderPlan*>& extruder_plans, unsigned int extruder_plan_idx, double standby_temp)
+{
+    ExtruderPlan& extruder_plan = *extruder_plans[extruder_plan_idx];
+    int extruder = extruder_plan.extruder;
+    for (unsigned int extruder_plan_before_idx = extruder_plan_idx - 2; int(extruder_plan_before_idx) >= 0; extruder_plan_before_idx--)
+    {
+        if (extruder_plans[extruder_plan_before_idx]->extruder == extruder)
+        {
+            extruder_plans[extruder_plan_before_idx + 1]->prev_extruder_standby_temp = standby_temp;
+            return;
+        }
+    }
+    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_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 initial_print_temp = extruder_plan.initial_printing_temperature;
+    
+    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))
+    {
+        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 && prev_extruder_plan.estimates.getMaterial() > 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 
+            || 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;
+        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)
+                {
+                    // override values from GCodeExport::setInitialTemps
+                    // the first used extruder should be set to the required temp in the start gcode
+                    // see  FffGcodeWriter::processStartingCode
+                    if (extruder_idx == extruder)
+                    {
+                        gcode.setInitialTemp(extruder_idx, extruder_plan.printing_temperature);
+                    }
+                    else 
+                    {
+                        gcode.setInitialTemp(extruder_idx, preheat_config.getStandbyTemp(extruder_idx));
+                    }
+                }
+                else
+                {
+                    if (extruder_idx != extruder)
+                    { // TODO: do we need to do this?
+                        extruder_plan.prev_extruder_standby_temp = preheat_config.getStandbyTemp(extruder_idx);
+                    }
+                }
+            }
+            continue;
+        }
+
+        insertTempCommands(extruder_plans, overall_extruder_plan_idx);
+    }
+}
+
+} // namespace cura

src/LayerPlanBuffer.h

@@ -0,0 +1,181 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef LAYER_PLAN_BUFFER_H
+#define LAYER_PLAN_BUFFER_H
+
+#include <list>
+
+#include "settings/settings.h"
+#include "commandSocket.h"
+
+#include "gcodeExport.h"
+#include "gcodePlanner.h"
+#include "MeshGroup.h"
+
+#include "Preheat.h"
+
+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;
+    
+    Preheat preheat_config; //!< the nozzle and material temperature settings for each extruder train.
+    
+    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.
+    
+    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.
+     */
+    template<typename... Args>
+    GCodePlanner& emplace_back(Args&&... constructor_args)
+    {
+        if (buffer.size() > 0)
+        {
+            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);
+            if (CommandSocket::isInstantiated())
+            {
+                CommandSocket::getInstance()->flushGcode();
+            }
+            buffer.pop_front();
+        }
+        return buffer.back();
+    }
+    
+    /*!
+     * 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_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_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 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
+     */
+    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), 
+     * preheat the extruder to the temperature corresponding to the average flow of the second extruder plan.
+     * 
+     * The preheat commands are inserted such that the middle of the temperature change coincides with the start of the next layer.
+     * 
+     * \param prev_extruder_plan The former extruder plan (of the former layer)
+     * \param extruder The extruder for which too set the temperature
+     * \param required_temp The required temperature for the second extruder plan
+     */
+    void insertPreheatCommand_singleExtrusion(ExtruderPlan& prev_extruder_plan, int extruder, double required_temp);
+    
+    /*!
+     * Insert the preheat command for an extruder plan which is preceded by an extruder plan with a different extruder.
+     * Find the time window in which this extruder hasn't been used
+     * and compute at what time the preheat command needs to be inserted.
+     * Then insert the preheat command in the right 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 for which to find the preheat time needed
+     */
+    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 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 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 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);
+};
+
+
+
+} // namespace cura
+
+#endif // LAYER_PLAN_BUFFER_H

src/MergeInfillLines.cpp

@@ -0,0 +1,234 @@
+#include "MergeInfillLines.h"
+
+#include <algorithm> // min
+
+#include "utils/linearAlg2D.h"
+
+namespace cura
+{
+    
+void MergeInfillLines::writeCompensatedMove(Point& to, double speed, GCodePath& last_path, int64_t new_line_width)
+{
+    double old_line_width = INT2MM(last_path.config->getLineWidth());
+    double new_line_width_mm = INT2MM(new_line_width);
+    double extrusion_mod = new_line_width_mm / old_line_width;
+    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(unsigned int& path_idx)
+{ //Check for lots of small moves and combine them into one large line
+    Point prev_middle;
+    Point last_middle;
+    int64_t line_width;
+
+    if (isConvertible(path_idx, prev_middle, last_middle, line_width, false))
+    {
+        //   path_idx + 3 is the index of the second extrusion move to be converted in combination with the first
+        {
+            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], 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, last_path.config->getSpeed() * extruder_plan.getExtrudeSpeedFactor(), last_path, line_width);
+        }
+        
+        path_idx += 2;
+        extruder_plan.handleInserts(path_idx, gcode);
+        for (; isConvertible(path_idx, prev_middle, last_middle, line_width, true); path_idx += 2)
+        {
+            extruder_plan.handleInserts(path_idx, gcode);
+            GCodePath& last_path = paths[path_idx + 3];
+            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);
+        return true;
+    }
+    return false;
+};
+
+bool MergeInfillLines::isConvertible(unsigned int path_idx_first_move, Point& first_middle, Point& second_middle, int64_t& resulting_line_width, bool use_second_middle_as_first)
+{
+    unsigned int idx = path_idx_first_move;
+    if (idx + 3 > paths.size()-1) 
+    {
+        return false;
+    }
+    if (   paths[idx+0].config != &travelConfig // must be travel
+        || paths[idx+1].points.size() > 1       // extrusion path is single line
+        || paths[idx+1].config == &travelConfig // must be extrusion
+//        || paths[idx+2].points.size() > 1       // travel must be direct
+        || paths[idx+2].config != &travelConfig // must be travel
+        || paths[idx+3].points.size() > 1       // extrusion path is single line
+        || paths[idx+3].config == &travelConfig // must be extrusion
+        || paths[idx+1].config != paths[idx+3].config // both extrusion moves should have the same config
+    )
+    {
+        return false;
+    }
+
+    if (!(paths[idx+1].config->type == PrintFeatureType::Infill || paths[idx+1].config->type == PrintFeatureType::Skin))
+    { // only (skin) infill lines can be merged (note that the second extrusion line config is already checked to be the same as the first in code above)
+        return false;
+    }
+
+    if (paths[idx+1].space_fill_type != SpaceFillType::Lines || paths[idx+3].space_fill_type != SpaceFillType::Lines)
+    { // both extrusion moves must be of lines space filling type!
+        return false;
+    }
+
+    int64_t line_width = paths[idx+1].config->getLineWidth();
+    
+    Point& a = paths[idx+0].points.back(); // first extruded line from
+    Point& b = paths[idx+1].points.back(); // first extruded line to
+    Point& c = paths[idx+2].points.back(); // second extruded line from
+    Point& d = paths[idx+3].points.back(); // second extruded line to
+    
+    return isConvertible(a, b, c, d, line_width, first_middle, second_middle, resulting_line_width, use_second_middle_as_first);
+}
+
+bool MergeInfillLines::isConvertible(const Point& a, const Point& b, const Point& c, const Point& d, int64_t line_width, Point& first_middle, Point& second_middle, int64_t& resulting_line_width, bool use_second_middle_as_first)
+{
+    use_second_middle_as_first = false;
+    int64_t max_line_width = nozzle_size * 3 / 2;
+
+    Point ab = b - a;
+    Point cd = d - c;
+
+    if (b == c)
+    {
+        return false; // the line segments are connected!
+    }
+
+    int64_t ab_size = vSize(ab);
+    int64_t cd_size = vSize(cd);
+
+    if (ab_size > nozzle_size * 5 || cd_size > nozzle_size * 5)
+    {
+        return false; // infill lines are too long; otherwise infill lines might be merged when the next infill line is coincidentally shorter like |, would become \ ...
+    }
+
+    // if the lines are in the same direction then abs( dot(ab,cd) / |ab| / |cd| ) == 1
+    int64_t prod = dot(ab,cd);
+    if (std::abs(prod) + 400 < ab_size * cd_size) // 400 = 20*20, where 20 micron is the allowed inaccuracy in the dot product, introduced by the inaccurate point locations of a,b,c,d
+    {
+        return false; // extrusion moves not in the same or opposite diraction
+    }
+    
+    // make lines in the same direction by flipping one
+    if (prod < 0)
+    {
+        ab = ab * -1;
+    }
+    else if (prod == 0)
+    {
+        return false; // lines are orthogonal!
+    }
+    else if (b == d || a == c)
+    {
+        return false; // the line segments are connected!
+    }
+
+    first_middle = (use_second_middle_as_first)?
+                    second_middle :
+                    (a + b) / 2;
+    second_middle = (c + d) / 2;
+    
+    Point dir_vector_perp = turn90CCW(second_middle - first_middle);
+    int64_t dir_vector_perp_length = vSize(dir_vector_perp); // == dir_vector_length
+    if (dir_vector_perp_length == 0)
+    {
+        return false;
+    }
+    if (dir_vector_perp_length > 5 * nozzle_size)
+    {
+        return false; // infill lines too far apart
+    }
+
+    Point infill_vector = (cd + ab) / 2; // (similar to) average line / direction of the infill
+
+    // compute the resulting line width
+    resulting_line_width = std::abs( dot(dir_vector_perp, infill_vector) / dir_vector_perp_length );
+    if (resulting_line_width > max_line_width)
+    {
+        return false; // combined lines would be too wide
+    }
+    if (resulting_line_width == 0)
+    {
+        return false; // dot is zero, so lines are in each others extension, not next to eachother
+    }
+
+    // check whether two lines are adjacent (note: not 'line segments' but 'lines')
+    Point ac = c - first_middle;
+    Point infill_vector_perp = turn90CCW(infill_vector);
+    int64_t perp_proj = dot(ac, infill_vector_perp);
+    int64_t infill_vector_perp_length = vSize(infill_vector_perp);
+    if (std::abs(std::abs(perp_proj) / infill_vector_perp_length - line_width) > 20) // it should be the case that dot(ac, infill_vector_perp) / |infill_vector_perp| == line_width
+    {
+        return false; // lines are too far apart or too close together
+    }
+    
+    // check whether the two line segments are adjacent.
+    // full infill in a narrow area might result in line segments with arbitrary distance between them
+    // the more the narrow passage in the area gets aligned with the infill direction, the further apart the line segments will be
+    // however, distant line segments might also be due to different narrow passages, so we limit the distance between merged line segments.
+    if (!LinearAlg2D::lineSegmentsAreCloserThan(a, b, c, d, line_width * 2))
+    {
+        return false;
+    }
+
+    return true;
+};
+
+     /*   
+void MergeInfillLines::merge(Point& from, Point& p0, Point& p1)
+{ //Check for lots of small moves and combine them into one large line
+    if (path->points.size() == 1 && path->config != &travelConfig); // && shorterThen(from - path->points[0], path->config->getLineWidth() * 2))
+    {
+        Point p0 = path->points[0];
+        unsigned int path_idx_last = path_idx + 1; // index of the last short move 
+        while(path_idx_last < paths.size() && paths[path_idx_last].points.size() == 1 && shorterThen(p0 - paths[path_idx_last].points[0], path->config->getLineWidth() * 2))
+        {
+            p0 = paths[path_idx_last].points[0];
+            path_idx_last ++;
+        }
+        if (paths[path_idx_last-1].config == &travelConfig)
+            path_idx_last --;
+        
+        if (path_idx_last > path_idx + 2)
+        {
+            p0 = from;
+            for(unsigned int path_idx_short = path_idx; path_idx_short < path_idx_last-1; path_idx_short+=2)
+            {
+                int64_t oldLen = vSize(p0 - paths[path_idx_short].points[0]);
+                Point newPoint = (paths[path_idx_short].points[0] + paths[path_idx_short+1].points[0]) / 2;
+                int64_t newLen = vSize(from - newPoint);
+                if (newLen > 0)
+                {
+                    if (oldLen > 0)
+                        gcode.writeMove(newPoint, speed * oldLen / newLen, path->getExtrusionMM3perMM() * newLen / oldLen);
+                    else 
+                        gcode.writeMove(newPoint, speed, path->getExtrusionMM3perMM());
+                }
+            }
+            gcode.writeMove(paths[path_idx_last-1].points[0], speed, path->getExtrusionMM3perMM());
+            path_idx = path_idx_last - 1;
+            continue;
+        }
+    }
+}*/
+     
+     
+     
+}//namespace cura

src/MergeInfillLines.h

@@ -0,0 +1,93 @@
+#ifndef MERGE_INFILL_LINES_H
+#define MERGE_INFILL_LINES_H
+
+#include "utils/intpoint.h"
+#include "gcodeExport.h"
+#include "gcodePlanner.h"
+#include "GCodePathConfig.h"
+
+namespace cura
+{
+    
+class MergeInfillLines 
+{
+//     void merge(Point& from, Point& p0, Point& p1);
+    GCodeExport& gcode; //!<  Where to write the combined line to
+    int layer_nr; //!< The current layer number
+    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
+    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
+     * \param path_idx_first_move Index into MergeInfillLines::paths to the travel before the two extrusion moves udner consideration
+     * \param first_middle Output parameter: the middle of the first extrusion move
+     * \param second_middle Input/Output parameter: outputs the middle of the second extrusion move; inputs \p first_middle so we don't have to compute it
+     * \param resulting_line_width Output parameter: The width of the resulting combined line (the average length of the lines combined)
+     * \param use_second_middle_as_first Whether to use \p second_middle as input parameter for \p first_middle
+     * \return 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
+     */
+    bool isConvertible(unsigned int path_idx_first_move, Point& first_middle, Point& second_middle, int64_t& resulting_line_width, bool use_second_middle_as_first = false);
+
+    /*!
+     * Whether the two consecutive extrusion paths (ab and cd) are convitrible to a single line segment.
+     * 
+     * Note: as an optimization the \p second_middle from the previous call to isConvertible can be used for \p first_middle, instead of recomputing it. 
+     * 
+     * \param a first from
+     * \param b first to
+     * \param c second from
+     * \param d second to
+     * \param line_width The line width of the moves
+     * \param first_middle Output parameter: the middle of the first extrusion move
+     * \param second_middle Input/Output parameter: outputs the middle of the second extrusion move; inputs \p first_middle so we don't have to compute it
+     * \param resulting_line_width Output parameter: The width of the resulting combined line (the average length of the lines combined)
+     * \param use_second_middle_as_first Whether to use \p second_middle as input parameter for \p first_middle
+     * \return 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
+     */
+    bool isConvertible(const Point& a, const Point& b, const Point& c, const Point& d, int64_t line_width, Point& first_middle, Point& second_middle, int64_t& resulting_line_width, bool use_second_middle_as_first = false);
+
+    /*!
+     * Write an extrusion move with compensated width and compensated speed so that the material flow will be the same.
+     * 
+     * \param to The point to move to
+     * \param speed The original speed
+     * \param old_path The original path
+     * \param new_line_width The width of the convewrted line (approximately the length of the original line)
+     */
+    void writeCompensatedMove(Point& to, double speed, GCodePath& old_path, int64_t new_line_width);
+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, 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.
+     * 
+     * \param gcode Where to write the combined line to
+     * \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 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(unsigned int& path_idx);
+    
+    /*!
+     * 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)
+    {
+        CommandSocket::sendLineTo(print_feature_type, to, line_width);
+    }
+};
+
+}//namespace cura
+#endif // MERGE_INFILL_LINES_H

src/MeshGroup.cpp

@@ -0,0 +1,349 @@
+/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#include <string.h>
+#include <strings.h>
+#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
+{
+
+FILE* binaryMeshBlob = nullptr;
+
+/* Custom fgets function to support Mac line-ends in Ascii STL files. OpenSCAD produces this when used on Mac */
+void* fgets_(char* ptr, size_t len, FILE* f)
+{
+    while(len && fread(ptr, 1, 1, f) > 0)
+    {
+        if (*ptr == '\n' || *ptr == '\r')
+        {
+            *ptr = '\0';
+            return ptr;
+        }
+        ptr++;
+        len--;
+    }
+    return nullptr;
+}
+
+MeshGroup::MeshGroup(SettingsBaseVirtual* settings_base)
+: SettingsBase(settings_base)
+, extruder_count(-1)
+{}
+
+MeshGroup::~MeshGroup()
+{
+    for (unsigned int extruder = 0; extruder < MAX_EXTRUDERS; extruder++)
+    {
+        if (extruders[extruder])
+        {
+            delete extruders[extruder];
+        }
+    }
+}
+
+int MeshGroup::getExtruderCount() const
+{
+    if (extruder_count == -1)
+    {
+        extruder_count = getSettingAsCount("machine_extruder_count");
+    }
+    return extruder_count;
+}
+
+ExtruderTrain* MeshGroup::createExtruderTrain(unsigned int 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)
+        {
+            logError("Couldn't load extruder.def.json for extruder %i\n", extruder_nr);
+            std::exit(1);
+        }
+    }
+    return extruders[extruder_nr];
+}
+
+ExtruderTrain* MeshGroup::getExtruderTrain(unsigned int extruder_nr)
+{
+    assert(extruders[extruder_nr]);
+    return extruders[extruder_nr];
+}
+
+const ExtruderTrain* MeshGroup::getExtruderTrain(unsigned int extruder_nr) const
+{
+    assert(extruders[extruder_nr]);
+    return extruders[extruder_nr];
+}
+
+Point3 MeshGroup::min() const
+{
+    if (meshes.size() < 1)
+    {
+        return Point3(0, 0, 0);
+    }
+    Point3 ret = meshes[0].min();
+    for(unsigned int i=1; i<meshes.size(); i++)
+    {
+        Point3 v = meshes[i].min();
+        ret.x = std::min(ret.x, v.x);
+        ret.y = std::min(ret.y, v.y);
+        ret.z = std::min(ret.z, v.z);
+    }
+    return ret;
+}
+
+Point3 MeshGroup::max() const
+{
+    if (meshes.size() < 1)
+    {
+        return Point3(0, 0, 0);
+    }
+    Point3 ret = meshes[0].max();
+    for(unsigned int i=1; i<meshes.size(); i++)
+    {
+        Point3 v = meshes[i].max();
+        ret.x = std::max(ret.x, v.x);
+        ret.y = std::max(ret.y, v.y);
+        ret.z = std::max(ret.z, v.z);
+    }
+    return ret;
+}
+
+void MeshGroup::clear()
+{
+    for(Mesh& m : meshes)
+    {
+        m.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"))
+    {
+        meshgroup_offset.x = getSettingInMicrons("machine_width") / 2;
+        meshgroup_offset.y = getSettingInMicrons("machine_depth") / 2;
+    }
+    
+    // If a mesh position was given, put the mesh at this position in 3D space. 
+    for(Mesh& mesh : meshes)
+    {
+        Point3 mesh_offset(mesh.getSettingInMicrons("mesh_position_x"), mesh.getSettingInMicrons("mesh_position_y"), mesh.getSettingInMicrons("mesh_position_z"));
+        if (mesh.getSettingBoolean("center_object"))
+        {
+            Point3 object_min = mesh.min();
+            Point3 object_max = mesh.max();
+            Point3 object_size = object_max - object_min;
+            mesh_offset += Point3(-object_min.x - object_size.x / 2, -object_min.y - object_size.y / 2, -object_min.z);
+        }
+        mesh.offset(mesh_offset + meshgroup_offset);
+    }
+}
+
+bool loadMeshSTL_ascii(Mesh* mesh, const char* filename, const FMatrix3x3& matrix)
+{
+    FILE* f = fopen(filename, "rt");
+    char buffer[1024];
+    FPoint3 vertex;
+    int n = 0;
+    Point3 v0(0,0,0), v1(0,0,0), v2(0,0,0);
+    while(fgets_(buffer, sizeof(buffer), f))
+    {
+        if (sscanf(buffer, " vertex %f %f %f", &vertex.x, &vertex.y, &vertex.z) == 3)
+        {
+            n++;
+            switch(n)
+            {
+            case 1:
+                v0 = matrix.apply(vertex);
+                break;
+            case 2:
+                v1 = matrix.apply(vertex);
+                break;
+            case 3:
+                v2 = matrix.apply(vertex);
+                mesh->addFace(v0, v1, v2);
+                n = 0;
+                break;
+            }
+        }
+    }
+    fclose(f);
+    mesh->finish();
+    return true;
+}
+
+bool loadMeshSTL_binary(Mesh* mesh, const char* filename, const FMatrix3x3& matrix)
+{
+    FILE* f = fopen(filename, "rb");
+
+    fseek(f, 0L, SEEK_END);
+    long long file_size = ftell(f); //The file size is the position of the cursor after seeking to the end.
+    rewind(f); //Seek back to start.
+    size_t face_count = (file_size - 80 - sizeof(uint32_t)) / 50; //Subtract the size of the header. Every face uses exactly 50 bytes.
+
+    char buffer[80];
+    //Skip the header
+    if (fread(buffer, 80, 1, f) != 1)
+    {
+        fclose(f);
+        return false;
+    }
+
+    uint32_t reported_face_count;
+    //Read the face count. We'll use it as a sort of redundancy code to check for file corruption.
+    if (fread(&reported_face_count, sizeof(uint32_t), 1, f) != 1)
+    {
+        fclose(f);
+        return false;
+    }
+    if (reported_face_count != face_count)
+    {
+        logWarning("Face count reported by file (%s) is not equal to actual face count (%s). File could be corrupt!\n", std::to_string(reported_face_count).c_str(), std::to_string(face_count).c_str());
+    }
+
+    //For each face read:
+    //float(x,y,z) = normal, float(X,Y,Z)*3 = vertexes, uint16_t = flags
+    // Every Face is 50 Bytes: Normal(3*float), Vertices(9*float), 2 Bytes Spacer
+    mesh->faces.reserve(face_count);
+    mesh->vertices.reserve(face_count);
+    for (unsigned int i = 0; i < face_count; i++)
+    {
+        if (fread(buffer, 50, 1, f) != 1)
+        {
+            fclose(f);
+            return false;
+        }
+        float *v= ((float*)buffer)+3;
+
+        Point3 v0 = matrix.apply(FPoint3(v[0], v[1], v[2]));
+        Point3 v1 = matrix.apply(FPoint3(v[3], v[4], v[5]));
+        Point3 v2 = matrix.apply(FPoint3(v[6], v[7], v[8]));
+        mesh->addFace(v0, v1, v2);
+    }
+    fclose(f);
+    mesh->finish();
+    return true;
+}
+
+bool loadMeshSTL(Mesh* mesh, const char* filename, const FMatrix3x3& matrix)
+{
+    FILE* f = fopen(filename, "r");
+    if (f == nullptr)
+    {
+        return false;
+    }
+
+    //Skip any whitespace at the beginning of the file.
+    unsigned long long num_whitespace = 0; //Number of whitespace characters.
+    unsigned char whitespace;
+    if (fread(&whitespace, 1, 1, f) != 1)
+    {
+        fclose(f);
+        return false;
+    }
+    while(isspace(whitespace))
+    {
+        num_whitespace++;
+        if (fread(&whitespace, 1, 1, f) != 1)
+        {
+            fclose(f);
+            return false;
+        }
+    }
+    fseek(f, num_whitespace, SEEK_SET); //Seek to the place after all whitespace (we may have just read too far).
+
+    char buffer[6];
+    if (fread(buffer, 5, 1, f) != 1)
+    {
+        fclose(f);
+        return false;
+    }
+    fclose(f);
+
+    buffer[5] = '\0';
+    if (stringcasecompare(buffer, "solid") == 0)
+    {
+        bool load_success = loadMeshSTL_ascii(mesh, filename, matrix);
+        if (!load_success)
+            return false;
+
+        // This logic is used to handle the case where the file starts with
+        // "solid" but is a binary file.
+        if (mesh->faces.size() < 1)
+        {
+            mesh->clear();
+            return loadMeshSTL_binary(mesh, filename, matrix);
+        }
+        return true;
+    }
+    return loadMeshSTL_binary(mesh, filename, 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))
+    {
+        Mesh mesh = object_parent_settings ? Mesh(object_parent_settings) : Mesh(meshgroup); //If we have object_parent_settings, use them as parent settings. Otherwise, just use meshgroup.
+        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;
+        }
+    }
+    return false;
+}
+
+}//namespace cura

src/MeshGroup.h

@@ -0,0 +1,60 @@
+/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#ifndef MESH_GROUP_H
+#define MESH_GROUP_H
+
+#include "utils/NoCopy.h"
+#include "mesh.h"
+#include "ExtruderTrain.h"
+
+namespace cura
+{
+    
+/*!
+ * A MeshGroup is a collection with 1 or more 3D meshes.
+ * 
+ * One MeshGroup is a whole which is printed at once.
+ * Generally there is one single MeshGroup, though when using one-at-a-time printing, multiple MeshGroups are processed consecutively.
+ */
+class MeshGroup : public SettingsBase, NoCopy
+{
+    ExtruderTrain* extruders[MAX_EXTRUDERS] = {nullptr};
+    mutable int extruder_count; //!< The number of extruders. (mutable because of lazy evaluation)
+public:
+    int getExtruderCount() const;
+
+    MeshGroup(SettingsBaseVirtual* settings_base);
+    
+    ~MeshGroup();
+    
+    /*!
+     * Create a new extruder train for the @p extruder_nr, or return the one which already exists.
+     */
+    ExtruderTrain* createExtruderTrain(unsigned int extruder_nr);
+
+    ExtruderTrain* getExtruderTrain(unsigned int extruder_nr);
+
+    const ExtruderTrain* getExtruderTrain(unsigned int extruder_nr) const;
+
+    std::vector<Mesh> meshes;
+
+    Point3 min() const; //! minimal corner of bounding box
+    Point3 max() const; //! maximal corner of bounding box
+
+    void clear();
+
+    void finalize();
+};
+
+/*!
+ * Load a Mesh from file and store it in the \p meshgroup.
+ * 
+ * \param meshgroup The meshgroup where to store the mesh
+ * \param filename The filename of the mesh file
+ * \param transformation The transformation applied to all vertices
+ * \param object_parent_settings (optional) The parent settings object of the new mesh. Defaults to \p meshgroup if none is given.
+ * \return whether the file could be loaded
+ */
+bool loadMeshIntoMeshGroup(MeshGroup* meshgroup, const char* filename, const FMatrix3x3& transformation, SettingsBaseVirtual* object_parent_settings = nullptr);
+
+}//namespace cura
+#endif//MESH_GROUP_H

src/Preheat.cpp

@@ -0,0 +1,195 @@
+#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;
+        if (limited_time_window < 0.0)
+        {
+            result.heating_time = 0.0;
+            result.lowest_temperature = temp_start;
+            return result;
+        }
+    }
+    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 = 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;
+        if (limited_time_window < 0.0)
+        {
+            result.cooling_time = 0.0;
+            result.highest_temperature = temp_end;
+            return result;
+        }
+    }
+    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 = temp_start;
+            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

@@ -0,0 +1,203 @@
+#ifndef PREHEAT_H
+#define PREHEAT_H
+
+#include <cassert>
+#include <algorithm> // max
+
+#include "utils/logoutput.h"
+#include "MeshGroup.h"
+
+#include "FlowTempGraph.h"
+
+
+namespace cura 
+{
+
+
+
+/*!
+ * Class for computing heatup and cooldown times used for computing the time the printer needs to heat up to a printing temperature.
+ */
+class Preheat 
+{
+    /*!
+     * The nozzle and material temperature settings for an extruder train.
+     */
+    class Config
+    {
+    public:
+        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
+    };
+
+    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
+     * \return the standby temp
+     */
+    double getStandbyTemp(int extruder)
+    {
+        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(const MeshGroup& meshgroup);
+
+    bool usesFlowDependentTemp(int extruder_nr)
+    {
+        return config_per_extruder[extruder_nr].flow_dependent_temperature;
+    }
+public:
+    /*!
+     * Get the optimal temperature corresponding to a given average flow,
+     * or the initial layer temperature.
+     * 
+     * \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, bool is_initial_layer);
+
+    /*!
+     * 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  \/    .
+     * 
+     * \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_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
+     */
+    WarmUpResult getWarmUpPointAfterCoolDown(double time_window, unsigned int extruder, double temp_start, double temp_mid, double temp_end, bool during_printing);
+
+    /*!
+     * 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.
+     * 
+    //               _> 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_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
+     */
+    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 
+
+#endif // PREHEAT_H

src/PrimeTower.cpp

@@ -0,0 +1,299 @@
+#include "PrimeTower.h"
+
+#include <limits>
+
+#include "ExtruderTrain.h"
+#include "sliceDataStorage.h"
+#include "gcodeExport.h"
+#include "gcodePlanner.h"
+#include "infill.h"
+#include "PrintFeature.h"
+
+namespace cura 
+{
+
+PrimeTower::PrimeTower()
+: is_hollow(false)
+, wipe_from_middle(false)
+, current_pre_wipe_location_idx(0)
+{
+    for (int extruder_nr = 0; extruder_nr < MAX_EXTRUDERS; extruder_nr++)
+    {
+        last_prime_tower_poly_printed[extruder_nr] = -1;
+    }
+}
+
+
+
+void PrimeTower::initConfigs(const MeshGroup* meshgroup)
+{
+    extruder_count = meshgroup->getExtruderCount();
+
+    for (int extr = 0; extr < extruder_count; extr++)
+    {
+        config_per_extruder.emplace_back(PrintFeatureType::Support);// so that visualization in the old Cura still works (TODO)
+    }
+    for (int extr = 0; extr < extruder_count; extr++)
+    {
+        const ExtruderTrain* train = meshgroup->getExtruderTrain(extr);
+        config_per_extruder[extr].init(train->getSettingInMillimetersPerSecond("speed_prime_tower"), train->getSettingInMillimetersPerSecond("acceleration_prime_tower"), train->getSettingInMillimetersPerSecond("jerk_prime_tower"), train->getSettingInMicrons("prime_tower_line_width"), train->getSettingInPercentage("prime_tower_flow"));
+    }
+}
+
+void PrimeTower::setConfigs(const MeshGroup* meshgroup, const int layer_thickness)
+{
+    extruder_count = meshgroup->getExtruderCount();
+
+    for (int extr = 0; extr < extruder_count; extr++)
+    {
+        GCodePathConfig& conf = config_per_extruder[extr];
+        conf.setLayerHeight(layer_thickness);
+    }
+}
+
+void PrimeTower::generateGroundpoly(const SliceDataStorage& storage)
+{
+    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)
+    {
+        is_hollow = true;
+    }
+
+    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
+    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));
+    middle = Point(x - tower_size / 2, y + 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(const SliceDataStorage& storage)
+{
+    enabled = storage.max_print_height_second_to_last_extruder >= 0
+            && storage.getSettingBoolean("prime_tower_enable")
+            && storage.getSettingInMicrons("prime_tower_wall_thickness") > 10
+            && storage.getSettingInMicrons("prime_tower_size") > 10;
+    if (enabled)
+    {
+        generatePaths_denseInfill(storage);
+        generateWipeLocations(storage);
+    }
+}
+
+void PrimeTower::generatePaths_denseInfill(const SliceDataStorage& storage)
+{
+    int n_patterns = 2; // alternating patterns between layers
+    int infill_overlap = 60; // so that it can't be zero; EDIT: wtf?
+    int extra_infill_shift = 0;
+
+    generateGroundpoly(storage);
+
+    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<ExtrusionMoves>& patterns = patterns_per_extruder.back();
+        patterns.resize(n_patterns);
+        for (int pattern_idx = 0; pattern_idx < n_patterns; pattern_idx++)
+        {
+            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_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(const SliceDataStorage& storage, GCodePlanner& gcodeLayer, const GCodeExport& gcode, const int layer_nr, const int prev_extruder, const int new_extruder)
+{
+    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)
+    { // don't print the prime tower if it has been printed already
+        return;
+    }
+
+    if (layer_nr > storage.max_print_height_second_to_last_extruder + 1)
+    {
+        return;
+    }
+
+    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");
+
+    if (prev_extruder == new_extruder)
+    {
+        pre_wipe = false;
+        post_wipe = false;
+    }
+    // pre-wipe:
+    if (pre_wipe)
+    {
+        preWipe(storage, gcodeLayer, new_extruder);
+    }
+
+    addToGcode_denseInfill(storage, gcodeLayer, gcode, layer_nr, prev_extruder, new_extruder);
+
+    // post-wipe:
+    if (post_wipe)
+    { //Make sure we wipe the old extruder on the prime tower.
+        gcodeLayer.addTravel(post_wipe_point - gcode.getExtruderOffset(prev_extruder) + gcode.getExtruderOffset(new_extruder));
+    }
+}
+
+void PrimeTower::addToGcode_denseInfill(const SliceDataStorage& storage, GCodePlanner& gcodeLayer, const GCodeExport& gcode, const int layer_nr, const int prev_extruder, const int new_extruder)
+{
+    ExtrusionMoves& pattern = patterns_per_extruder[new_extruder][((layer_nr % 2) + 2) % 2]; // +2) %2 to handle negative layer numbers
+
+    GCodePathConfig& config = config_per_extruder[new_extruder];
+
+    gcodeLayer.addPolygonsByOptimizer(pattern.polygons, &config);
+    gcodeLayer.addLinesByOptimizer(pattern.lines, &config, SpaceFillType::Lines);
+
+    last_prime_tower_poly_printed[new_extruder] = layer_nr;
+}
+
+Point PrimeTower::getLocationBeforePrimeTower(const SliceDataStorage& storage)
+{
+    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"))
+        {
+            ret += Point(train.getSettingInMicrons("machine_extruder_start_pos_x"), train.getSettingInMicrons("machine_extruder_start_pos_y"));
+            absolute_starting_points++;
+        }
+    }
+    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++)
+    {
+        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"));
+    }
+
+    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);
+    }
+    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 extruder_nr)
+{
+    const ClosestPolygonPoint wipe_location = pre_wipe_locations[current_pre_wipe_location_idx];
+    current_pre_wipe_location_idx = (current_pre_wipe_location_idx + pre_wipe_location_skip) % number_of_pre_wipe_locations;
+
+    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, &config_per_extruder[extruder_nr], SpaceFillType::None, flow);
+}
+
+
+}//namespace cura

src/PrimeTower.h

@@ -0,0 +1,163 @@
+#ifndef PRIME_TOWER_H
+#define PRIME_TOWER_H
+
+#include <vector>
+
+#include "GCodePathConfig.h"
+#include "MeshGroup.h"
+#include "utils/polygon.h" // Polygons
+#include "utils/polygonUtils.h"
+
+namespace cura 
+{
+
+    
+class SliceDataStorage;
+class GCodePlanner;
+class GCodeExport;
+
+/*!
+ * 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:
+    struct ExtrusionMoves
+    {
+        Polygons polygons;
+        Polygons lines;
+    };
+    bool enabled; //!< Whether the prime tower is enabled
+
+    int extruder_count; //!< number of extruders
+    std::vector<GCodePathConfig> config_per_extruder; //!< Path config for prime tower for each extruder
+
+    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
+    int current_pre_wipe_location_idx; //!< Index into \ref PrimeTower::wipe_locations of where to pre-wipe the nozzle
+
+public:
+    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
+
+    /*!
+     * Initialize \ref PrimeTower::config_per_extruder with speed and line width settings.
+     * 
+     * \param meshgroup Where to retrieve the setttings for each extruder
+     */
+    void initConfigs(const MeshGroup* meshgroup);
+
+    /*!
+     * Complete the \ref PrimeTower::config_per_extruder by settings the layer height.
+     * 
+     * \param meshgroup Where to retrieve the setttings for each extruder
+     * \param layer_thickness The current layer thickness
+     */
+    void setConfigs(const MeshGroup* meshgroup, const int layer_thickness);
+
+    /*!
+     * 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);
+
+    /*!
+     * Generate the area where the prime tower should be.
+     * 
+     * \param storage where to get settings from
+     * \param total_layers The total number of layers 
+     */
+    void generatePaths(const SliceDataStorage& storage);
+
+    PrimeTower(); //!< basic constructor
+
+    /*!
+     * 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);
+private:
+    /*!
+     * 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.
+     */
+    int last_prime_tower_poly_printed[MAX_EXTRUDERS];
+
+    /*!
+     * 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);
+
+    /*!
+     * \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 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_denseInfill(const SliceDataStorage& storage, GCodePlanner& gcode_layer, const GCodeExport& gcode, const int layer_nr, const int prev_extruder, const int new_extruder);
+
+    /*!
+     * 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 extruder_nr The current extruder
+     */
+    void preWipe(const SliceDataStorage& storage, GCodePlanner& gcode_layer, const int extruder_nr);
+};
+
+
+
+
+}//namespace cura
+
+#endif // PRIME_TOWER_H

src/PrintFeature.h

@@ -0,0 +1,27 @@
+#ifndef PRINT_FEATURE
+#define PRINT_FEATURE
+
+namespace cura
+{
+
+enum class PrintFeatureType: unsigned char
+{
+    NoneType, // used to mark unspecified jumps in polygons. libArcus depends on it
+    OuterWall,
+    InnerWall,
+    Skin,
+    Support,
+    SkirtBrim,
+    Infill,
+    SupportInfill,
+    MoveCombing,
+    MoveRetraction,
+    SupportInterface
+};
+
+
+
+
+} // namespace cura
+
+#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 +1,187 @@
+/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#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);
+        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);
+        }
+        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
+}
+
+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/SpaceFillType.h

@@ -0,0 +1,25 @@
+#ifndef SPACE_FILL_TYPE
+#define SPACE_FILL_TYPE
+
+
+namespace cura
+{
+
+/*!
+ * Enum class enumerating the strategies with which an area can be occupied with filament
+ * 
+ * The walls/perimeters are Polygons
+ * ZigZag infill is PolyLines, and so is following mesh surface mode for non-polygon surfaces
+ * Grid, Triangles and lines infill is Lines
+ */
+enum class SpaceFillType
+{
+    None,
+    Polygons,
+    PolyLines,
+    Lines
+};
+
+} // namespace cura
+
+#endif // SPACE_FILL_TYPE

src/WallsComputation.cpp

@@ -0,0 +1,80 @@
+/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#include "WallsComputation.h"
+#include "utils/polygonUtils.h"
+namespace cura {
+
+WallsComputation::WallsComputation(int wall_0_inset, int line_width_0, int line_width_x, int insetCount, bool recompute_outline_based_on_outer_wall)
+: wall_0_inset(wall_0_inset)
+, line_width_0(line_width_0)
+, line_width_x(line_width_x)
+, insetCount(insetCount)
+, recompute_outline_based_on_outer_wall(recompute_outline_based_on_outer_wall)
+{
+}
+
+void WallsComputation::generateInsets(SliceLayerPart* part)
+{
+    if (insetCount == 0)
+    {
+        part->insets.push_back(part->outline);
+        part->print_outline = part->outline;
+        return;
+    }
+    
+    for(int i=0; i<insetCount; i++)
+    {
+        part->insets.push_back(Polygons());
+        if (i == 0)
+        {
+            part->insets[0] = part->outline.offset(-line_width_0 / 2 - wall_0_inset);
+        } else if (i == 1)
+        {
+            part->insets[1] = part->insets[0].offset(-line_width_0 / 2 + wall_0_inset - line_width_x / 2);
+        } else
+        {
+            part->insets[i] = part->insets[i-1].offset(-line_width_x);
+        }
+        
+        
+        //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)
+            {
+                part->print_outline = part->insets[0].offset(line_width_0 / 2);
+            }
+            else
+            {
+                part->print_outline = part->outline;
+            }
+        }
+        if (part->insets[i].size() < 1)
+        {
+            part->insets.pop_back();
+            break;
+        }
+    }
+}
+
+void WallsComputation::generateInsets(SliceLayer* layer)
+{
+    for(unsigned int partNr = 0; partNr < layer->parts.size(); partNr++)
+    {
+        generateInsets(&layer->parts[partNr]);
+    }
+    
+    //Remove the parts which did not generate an inset. As these parts are too small to print,
+    // and later code can now assume that there is always minimal 1 inset line.
+    for(unsigned int partNr = 0; partNr < layer->parts.size(); partNr++)
+    {
+        if (layer->parts[partNr].insets.size() < 1)
+        {
+            layer->parts.erase(layer->parts.begin() + partNr);
+            partNr -= 1;
+        }
+    }
+}
+
+}//namespace cura

src/WallsComputation.h

@@ -0,0 +1,69 @@
+/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
+#ifndef WALLS_COMPUTATION_H
+#define WALLS_COMPUTATION_H
+
+#include "sliceDataStorage.h"
+
+namespace cura 
+{
+
+/*!
+ * Function container for computing the outer walls / insets / perimeters polygons of a layer
+ */
+class WallsComputation
+{
+public:
+    /*!
+     * The offset applied to the outer wall
+     */
+    int wall_0_inset;
+    /*!
+     * line width of the outer wall
+     */
+    int line_width_0;
+    /*!
+     * line width of other walls
+     */
+    int line_width_x;
+    /*!
+     * The number of insets to to generate
+     */
+    int insetCount;
+    /*!
+     * Whether to compute a more accurate poly representation of the printed outlines, based on the outer wall
+     */
+    bool recompute_outline_based_on_outer_wall;
+
+    /*!
+     * Basic constructor initializing the parameters with which to perform the walls computation
+     * 
+     * \param wall_0_inset The offset applied to the outer wall
+     * \param line_width_0 line width of the outer wall
+     * \param line_width_x line width of other walls
+     * \param insetCount The number of insets to to generate
+     * \param recompute_outline_based_on_outer_wall Whether to compute a more accurate poly representation of the printed outlines, based on the outer wall
+     */
+    WallsComputation(int wall_0_inset, int line_width_0, int line_width_x, int insetCount, bool recompute_outline_based_on_outer_wall);
+
+    /*!
+     * Generates the insets / perimeters for all parts in a layer.
+     * 
+     * Note that the second inset gets offsetted by WallsComputation::line_width_0 instead of the first, 
+     * which leads to better results for a smaller WallsComputation::line_width_0 than WallsComputation::line_width_x and when printing the outer wall last.
+     * 
+     * \param layer The layer for which to generate the insets.
+     */ 
+    void generateInsets(SliceLayer* layer);
+
+private:
+    /*!
+     * Generates the insets / perimeters for a single layer part.
+     * 
+     * \param part The part for which to generate the insets.
+     */
+    void generateInsets(SliceLayerPart* part);
+
+};
+}//namespace cura
+
+#endif//WALLS_COMPUTATION_H

src/Weaver.cpp

@@ -4,42 +4,45 @@
 #include <fstream> // debug IO
 #include <unistd.h>
 
+#include "progress/Progress.h"
 #include "weaveDataStorage.h"
+#include "PrintFeature.h"
 
 namespace cura 
 {
 
-void Weaver::weave(PrintObject* object, CommandSocket* commandSocket)
-{
-    int maxz = object->max().z;
+void Weaver::weave(MeshGroup* meshgroup)
+{   
+    wireFrame.meshgroup = meshgroup;
+    
+    int maxz = meshgroup->max().z;
 
     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;
 
-    for(Mesh& mesh : object->meshes)
+    for(Mesh& mesh : meshgroup->meshes)
     {
         cura::Slicer* slicer = new cura::Slicer(&mesh, initial_layer_thickness, connectionHeight, layer_count, mesh.getSettingBoolean("meshfix_keep_open_polygons"), mesh.getSettingBoolean("meshfix_extensive_stitching"));
         slicerList.push_back(slicer);
     }
 
-    
     int starting_layer_idx;
     { // find first non-empty layer
         for (starting_layer_idx = 0; starting_layer_idx < layer_count; starting_layer_idx++)
         {
             Polygons parts;
             for (cura::Slicer* slicer : slicerList)
-                parts.add(slicer->layers[starting_layer_idx].polygonList);  
+                parts.add(slicer->layers[starting_layer_idx].polygons);  
             
             if (parts.size() > 0)
                 break;
         }
         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);
         }
     }
     
@@ -48,35 +51,41 @@ void Weaver::weave(PrintObject* object, CommandSocket* commandSocket)
     {
         int starting_z = -1;
         for (cura::Slicer* slicer : slicerList)
-            wireFrame.bottom_outline.add(slicer->layers[starting_layer_idx].polygonList);
+            wireFrame.bottom_outline.add(slicer->layers[starting_layer_idx].polygons);
         
-        if (commandSocket)
-            commandSocket->sendPolygons(Inset0Type, 0, wireFrame.bottom_outline, 1);
+        CommandSocket::sendPolygons(PrintFeatureType::OuterWall, /*0,*/ wireFrame.bottom_outline, 1);
         
-        wireFrame.z_bottom = slicerList[0]->layers[starting_layer_idx].z;
+        if (slicerList.empty()) //Wait, there is nothing to slice.
+        {
+            wireFrame.z_bottom = 0;
+        }
+        else
+        {
+            wireFrame.z_bottom = slicerList[0]->layers[starting_layer_idx].z;
+        }
         
         Point starting_point_in_layer;
         if (wireFrame.bottom_outline.size() > 0)
             starting_point_in_layer = (wireFrame.bottom_outline.max() + wireFrame.bottom_outline.min()) / 2;
         else 
-            starting_point_in_layer = (Point(0,0) + object->max() + object->min()) / 2;
+            starting_point_in_layer = (Point(0,0) + meshgroup->max() + meshgroup->min()) / 2;
         
+        Progress::messageProgressStage(Progress::Stage::INSET_SKIN, nullptr);
         for (int layer_idx = starting_layer_idx + 1; layer_idx < layer_count; layer_idx++)
         {
-            logProgress("inset", layer_idx+1, layer_count); // abuse the progress system of the normal mode of CuraEngine
+            Progress::messageProgress(Progress::Stage::INSET_SKIN, layer_idx+1, layer_count); // abuse the progress system of the normal mode of CuraEngine
             
             Polygons parts1;
             for (cura::Slicer* slicer : slicerList)
-                parts1.add(slicer->layers[layer_idx].polygonList);
+                parts1.add(slicer->layers[layer_idx].polygons);
 
             
             Polygons chainified;
 
             chainify_polygons(parts1, starting_point_in_layer, chainified, false);
             
-            if (commandSocket)
-                commandSocket->sendPolygons(Inset0Type, 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;
@@ -97,9 +106,10 @@ void Weaver::weave(PrintObject* object, CommandSocket* commandSocket)
     {
         Polygons* lower_top_parts = &wireFrame.bottom_outline;
         
+        Progress::messageProgressStage(Progress::Stage::SUPPORT, nullptr);
         for (unsigned int layer_idx = 0; layer_idx < wireFrame.layers.size(); layer_idx++)
         {
-            logProgress("skin", layer_idx+1, wireFrame.layers.size()); // abuse the progress system of the normal mode of CuraEngine
+            Progress::messageProgress(Progress::Stage::SUPPORT, layer_idx+1, wireFrame.layers.size()); // abuse the progress system of the normal mode of CuraEngine
             
             WeaveLayer& layer = wireFrame.layers[layer_idx];
             
@@ -131,16 +141,21 @@ void Weaver::weave(PrintObject* object, CommandSocket* commandSocket)
 
 
     { // roofs:
-        
-        WeaveLayer& top_layer = wireFrame.layers.back();
-        Polygons to_be_supported; // empty for the top layer
-        fillRoofs(top_layer.supported, to_be_supported, -1, top_layer.z1, top_layer.roofs);
+        if (!wireFrame.layers.empty()) //If there are no layers, create no roof.
+        {
+            WeaveLayer& top_layer = wireFrame.layers.back();
+            Polygons to_be_supported; // empty for the top layer
+            fillRoofs(top_layer.supported, to_be_supported, -1, top_layer.z1, top_layer.roofs);
+        }
     }
     
     
     { // bottom:
-        Polygons to_be_supported; // is empty for the bottom layer, cause the order of insets doesn't really matter (in a sense everything is to be supported)
-        fillRoofs(wireFrame.bottom_outline, to_be_supported, -1, wireFrame.layers.front().z0, wireFrame.bottom_infill);
+        if (!wireFrame.layers.empty()) //If there are no layers, create no bottom.
+        {
+            Polygons to_be_supported; // is empty for the bottom layer, cause the order of insets doesn't really matter (in a sense everything is to be supported)
+            fillRoofs(wireFrame.bottom_outline, to_be_supported, -1, wireFrame.layers.front().z0, wireFrame.bottom_infill);
+        }
     }
     
 }
@@ -151,7 +166,7 @@ void Weaver::createHorizontalFill(Polygons& lower_top_parts, WeaveLayer& layer,
 {
     int64_t bridgable_dist = connectionHeight;
     
-    Polygons& polys_below = lower_top_parts;
+//     Polygons& polys_below = lower_top_parts;
     Polygons& polys_here = layer.supported;
     Polygons& polys_above = layer_above;
 
@@ -191,8 +206,8 @@ void Weaver::fillRoofs(Polygons& supporting, Polygons& to_be_supported, int dire
     Polygons roof_outlines; 
     Polygons roof_holes;
     { // split roofs into outlines and holes
-        std::vector<Polygons> roof_parts = roofs.splitIntoParts();
-        for (Polygons& roof_part : roof_parts)
+        std::vector<PolygonsPart> roof_parts = roofs.splitIntoParts();
+        for (PolygonsPart& roof_part : roof_parts)
         {
             roof_outlines.add(roof_part[0]);
             for (unsigned int hole_idx = 1; hole_idx < roof_part.size(); hole_idx++)
@@ -206,8 +221,8 @@ void Weaver::fillRoofs(Polygons& supporting, Polygons& to_be_supported, int dire
     
     Polygons supporting_outlines;
     
-    std::vector<Polygons> supporting_parts = supporting.splitIntoParts();
-    for (Polygons& supporting_part : supporting_parts) 
+    std::vector<PolygonsPart> supporting_parts = supporting.splitIntoParts();
+    for (PolygonsPart& supporting_part : supporting_parts) 
         supporting_outlines.add(supporting_part[0]); // only add outlines, not the holes
     
     
@@ -253,11 +268,11 @@ void Weaver::fillFloors(Polygons& supporting, Polygons& to_be_supported, int dir
     if (floors.size() == 0) return;
     
     
-    std::vector<Polygons> floor_parts = floors.splitIntoParts();
+    std::vector<PolygonsPart> floor_parts = floors.splitIntoParts();
     
     Polygons floor_outlines;
     Polygons floor_holes;
-    for (Polygons& floor_part : floor_parts)
+    for (PolygonsPart& floor_part : floor_parts)
     {
         floor_outlines.add(floor_part[0]);
         for (unsigned int hole_idx = 1; hole_idx < floor_part.size(); hole_idx++)
@@ -309,7 +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;
@@ -318,9 +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())
@@ -370,13 +387,11 @@ 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];
         
-        ClosestPolygonPoint closestInPoly = findClosest(start_close_to, upperPart);
+        ClosestPolygonPoint closestInPoly = PolygonUtils::findClosest(start_close_to, upperPart);
 
         
         PolygonRef part_top = result.newPoly();
@@ -385,9 +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 = 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) 
@@ -412,7 +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;
     }
     
@@ -437,7 +452,7 @@ void Weaver::connect_polygons(Polygons& supporting, int z0, Polygons& supported,
         for (const Point& upper_point : upperPart)
         {
             
-            ClosestPolygonPoint lowerPolyPoint = findClosest(upper_point, supporting);
+            ClosestPolygonPoint lowerPolyPoint = PolygonUtils::findClosest(upper_point, supporting);
             Point& lower = lowerPolyPoint.location;
             
             Point3 lower3 = Point3(lower.X, lower.Y, z0);
@@ -458,16 +473,4 @@ void Weaver::connect_polygons(Polygons& supporting, int z0, Polygons& supported,
 }
 
 
-
-
-
-
-
-
-
-
-
-
-
-} // namespace cura
-    
+}//namespace cura

src/Weaver.h

@@ -3,23 +3,22 @@
 
 #include "weaveDataStorage.h"
 #include "commandSocket.h"
-#include "settings.h"
+#include "settings/settings.h"
 
-#include "modelFile/modelFile.h" // PrintObject
+#include "MeshGroup.h"
 #include "slicer.h"
 
+#include "utils/NoCopy.h"
 #include "utils/polygon.h"
 #include "utils/polygonUtils.h"
 
-#include "debug.h"
-
 namespace cura
 {
 
 /*!
  * The main weaver / WirePrint / wireframe printing class, which computes the basic paths to be followed.
  */
-class Weaver : public SettingsBase
+class Weaver : public SettingsMessenger, NoCopy
 {
     friend class Wireframe2gcode;
 private:
@@ -29,7 +28,7 @@ private:
     
     int initial_layer_thickness;
     int connectionHeight; 
-    int extrusionWidth;
+    int line_width;
     
     int roof_inset; 
     
@@ -40,14 +39,13 @@ private:
    
     
 public:
-    
-    Weaver(SettingsBase* settings_base) : SettingsBase(settings_base) 
+    Weaver(SettingsBase* settings_base) : SettingsMessenger(settings_base) 
     {
         
         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");      // ___       ___   .
@@ -60,10 +58,9 @@ public:
      * This is the main function for Neith / Weaving / WirePrinting / Webbed printing.
      * Creates a wireframe for the model consisting of horizontal 'flat' parts and connections between consecutive flat parts consisting of UP moves and diagonally DOWN moves.
      * 
-     * \param object The object for which to create a wireframe print
-     * \param commandSocket the commandSocket
+     * \param objects The objects for which to create a wireframe print
      */
-    void weave(PrintObject* object, CommandSocket* commandSocket);
+    void weave(MeshGroup* objects);
     
 
 private:

src/Wireframe2gcode.cpp

@@ -3,52 +3,54 @@
 #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/brim.
 
 namespace cura 
 {
 
 
-void Wireframe2gcode::writeGCode(CommandSocket* commandSocket, int& maxObjectHeight)
+void Wireframe2gcode::writeGCode()
 {
 
-    if (commandSocket)
-        commandSocket->beginGCode();
+    gcode.preSetup(wireFrame.meshgroup);
     
-    maxObjectHeight = wireFrame.layers.back().z1;
+    gcode.setInitialTemps(*wireFrame.meshgroup);
     
-    { // starting Gcode
-        if (hasSetting("material_bed_temperature") && getSettingInDegreeCelsius("material_bed_temperature") > 0)
-            gcode.writeBedTemperatureCommand(getSettingInDegreeCelsius("material_bed_temperature"), true);
-        if (hasSetting("material_print_temperature") && getSettingInDegreeCelsius("material_print_temperature") > 0)
-            gcode.writeTemperatureCommand(getSettingAsIndex("extruder_nr"), getSettingInDegreeCelsius("material_print_temperature"));
-        
-        gcode.writeCode(getSettingString("machine_start_gcode").c_str());
-        if (gcode.getFlavor() == GCODE_FLAVOR_BFB)
-        {
-            gcode.writeComment("enable auto-retraction");
-            std::ostringstream tmp;
-            tmp << "M227 S" << (getSettingInMicrons("retraction_amount") * 2560 / 1000) << " P" << (getSettingInMicrons("retraction_amount") * 2560 / 1000);  // TODO: put hard coded value in a variable with an explanatory name (and make var a parameter, and perhaps even a setting?)
-            gcode.writeLine(tmp.str().c_str());
-        }
+    if (CommandSocket::getInstance())
+        CommandSocket::getInstance()->beginGCode();
+    
+    processStartingCode();
+    
+    int maxObjectHeight;
+    if (wireFrame.layers.empty())
+    {
+        maxObjectHeight = 0;
+    }
+    else
+    {
+        maxObjectHeight = wireFrame.layers.back().z1;
     }
-    
-    
-            
-    unsigned int totalLayers = 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);
         }
     }
     
@@ -64,7 +66,7 @@ void Wireframe2gcode::writeGCode(CommandSocket* commandSocket, int& maxObjectHei
                         writeMoveWithRetract(segment.to); 
                     } else 
                     {
-                        gcode.writeMove(segment.to, speedBottom, extrusion_per_mm_connection); 
+                        gcode.writeMove(segment.to, speedBottom, extrusion_mm3_per_mm_connection);
                     }
                 }   
             , 
@@ -74,21 +76,19 @@ void Wireframe2gcode::writeGCode(CommandSocket* commandSocket, int& maxObjectHei
                     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);
     for (unsigned int layer_nr = 0; layer_nr < wireFrame.layers.size(); layer_nr++)
     {
-        
-        logProgress("export", layer_nr+1, totalLayers); // abuse the progress system of the normal mode of CuraEngine
-        if (commandSocket) commandSocket->sendProgress(2.0/3.0 + 1.0/3.0 * float(layer_nr) / float(totalLayers));
+        Progress::messageProgress(Progress::Stage::EXPORT, layer_nr+1, total_layers); // abuse the progress system of the normal mode of CuraEngine
         
         WeaveLayer& layer = wireFrame.layers[layer_nr];
         
         gcode.writeLayerComment(layer_nr+1);
         
-        int fanSpeed = getSettingInPercentage("cool_fan_speed_max");
+        double fanSpeed = getSettingInPercentage("cool_fan_speed_max");
         if (layer_nr == 0)
             fanSpeed = getSettingInPercentage("cool_fan_speed_min");
         gcode.writeFanCommand(fanSpeed);
@@ -99,7 +99,7 @@ void Wireframe2gcode::writeGCode(CommandSocket* commandSocket, int& maxObjectHei
        
             if (part.connection.segments.size() == 0) continue;
             
-            gcode.writeTypeComment("SUPPORT"); // connection
+            gcode.writeTypeComment(PrintFeatureType::Support); // connection
             {
                 if (vSize2(gcode.getPositionXY() - part.connection.from) > connectionHeight)
                 {
@@ -115,7 +115,7 @@ void Wireframe2gcode::writeGCode(CommandSocket* commandSocket, int& maxObjectHei
             
             
             
-            gcode.writeTypeComment("WALL-OUTER"); // top
+            gcode.writeTypeComment(PrintFeatureType::OuterWall); // top
             {
                 for (unsigned int segment_idx = 0; segment_idx < part.connection.segments.size(); segment_idx++)
                 {
@@ -126,7 +126,7 @@ void Wireframe2gcode::writeGCode(CommandSocket* commandSocket, int& maxObjectHei
                         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);
                     }
                 }
@@ -148,7 +148,7 @@ void Wireframe2gcode::writeGCode(CommandSocket* commandSocket, int& maxObjectHei
                         // 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);
                     }
                 });
@@ -168,15 +168,7 @@ void Wireframe2gcode::writeGCode(CommandSocket* commandSocket, int& maxObjectHei
     
     gcode.writeFanCommand(0);
 
-    if (commandSocket)
-    {
-        gcode.finalize(maxObjectHeight, getSettingInMillimetersPerSecond("speed_travel"), getSettingString("machine_end_gcode").c_str());
-        for(int e=0; e<MAX_EXTRUDERS; e++)
-            gcode.writeTemperatureCommand(e, 0, false);
-
-        commandSocket->sendGCodeLayer();
-        commandSocket->endSendSlicedObject();
-    }
+    finalize();
 }
 
     
@@ -188,7 +180,7 @@ 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;
@@ -200,14 +192,14 @@ 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);
     }
 }
 
@@ -216,7 +208,7 @@ 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())
     {
@@ -244,11 +236,14 @@ void Wireframe2gcode::strategy_retract(WeaveLayer& layer, WeaveConnectionPart& p
     
     RetractionConfig retraction_config;
     // TODO: get these from the settings!
-    retraction_config.amount = 500; //INT2MM(getSettingInt("retractionAmount"))
-    retraction_config.primeAmount = 0;//INT2MM(getSettingInt("retractionPrime
+    retraction_config.distance = 500; //INT2MM(getSettingInt("retraction_amount"))
+    retraction_config.prime_volume = 0;//INT2MM(getSettingInt("retractionPrime
     retraction_config.speed = 20; // 40;
     retraction_config.primeSpeed = 15; // 30;
     retraction_config.zHop = 0; //getSettingInt("retraction_hop");
+    retraction_config.retraction_count_max = getSettingAsCount("retraction_count_max");
+    retraction_config.retraction_extrusion_window = getSettingInMillimeters("retraction_extrusion_window");
+    retraction_config.retraction_min_travel_distance = getSettingInMicrons("retraction_min_travel");
 
     double top_retract_pause = 2.0;
     int retract_hop_dist = 1000;
@@ -263,7 +258,7 @@ 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.writeMove(lower, speedUp, extrusion_mm3_per_mm_connection);
         gcode.writeRetraction(&retraction_config);
         gcode.writeMove(to + lowering, speedUp, 0);
         gcode.writeDelay(top_retract_pause);
@@ -272,7 +267,7 @@ void Wireframe2gcode::strategy_retract(WeaveLayer& layer, WeaveConnectionPart& p
         
     } else 
     {
-        gcode.writeMove(to, speedUp, extrusion_per_mm_connection);
+        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);
@@ -310,7 +305,7 @@ 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) 
 {
@@ -325,7 +320,7 @@ 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)
@@ -389,12 +384,12 @@ 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:
@@ -406,16 +401,16 @@ void Wireframe2gcode::handle_roof_segment(WeaveRoofPart& inset, WeaveConnectionP
 
 
 
-void Wireframe2gcode::writeFill(std::vector<WeaveRoofPart>& fill_insets, Polygons& roof_outlines
+void Wireframe2gcode::writeFill(std::vector<WeaveRoofPart>& infill_insets, Polygons& roof_outlines
     , std::function<void (Wireframe2gcode& thiss, WeaveRoofPart& inset, WeaveConnectionPart& part, unsigned int segment_idx)> connectionHandler
     , std::function<void (Wireframe2gcode& thiss, WeaveConnectionSegment& p)> flatHandler)
 {
         
     // bottom:
-    gcode.writeTypeComment("FILL");
-    for (unsigned int inset_idx = 0; inset_idx < fill_insets.size(); inset_idx++)
+    gcode.writeTypeComment(PrintFeatureType::Infill);
+    for (unsigned int inset_idx = 0; inset_idx < infill_insets.size(); inset_idx++)
     {
-        WeaveRoofPart& inset = fill_insets[inset_idx];
+        WeaveRoofPart& inset = infill_insets[inset_idx];
         
         
         for (unsigned int inset_part_nr = 0; inset_part_nr < inset.connections.size(); inset_part_nr++)
@@ -423,7 +418,7 @@ void Wireframe2gcode::writeFill(std::vector<WeaveRoofPart>& fill_insets, Polygon
             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;
@@ -439,7 +434,7 @@ void Wireframe2gcode::writeFill(std::vector<WeaveRoofPart>& fill_insets, Polygon
                 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];
@@ -453,7 +448,7 @@ void Wireframe2gcode::writeFill(std::vector<WeaveRoofPart>& fill_insets, Polygon
         
     }
     
-    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]);
@@ -484,25 +479,24 @@ void Wireframe2gcode::writeMoveWithRetract(Point to)
 }
 
 Wireframe2gcode::Wireframe2gcode(Weaver& weaver, GCodeExport& gcode, SettingsBase* settings_base) 
-: SettingsBase(settings_base) 
+: SettingsMessenger(settings_base) 
 , gcode(gcode)
+, wireFrame(weaver.wireFrame)
 {
-    wireFrame = weaver.wireFrame;
     initial_layer_thickness = getSettingInMicrons("layer_height_0");
     connectionHeight = getSettingInMicrons("wireframe_height"); 
     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 * double(flowConnection) / 100.0;
-    extrusion_per_mm_flat = lineArea / filament_area * double(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_/       .
@@ -542,14 +536,107 @@ Wireframe2gcode::Wireframe2gcode(Weaver& weaver, GCodeExport& gcode, SettingsBas
     roof_outer_delay = getSettingInSeconds("wireframe_roof_outer_delay");
     
     
-    standard_retraction_config.amount = INT2MM(getSettingInMicrons("retraction_amount"));
-    standard_retraction_config.primeAmount = INT2MM(getSettingInMicrons("retraction_extra_prime_amount"));
+    standard_retraction_config.distance = getSettingInMillimeters("retraction_amount");
+    standard_retraction_config.prime_volume = getSettingInCubicMillimeters("retraction_extra_prime_amount");
     standard_retraction_config.speed = getSettingInMillimetersPerSecond("retraction_retract_speed");
     standard_retraction_config.primeSpeed = getSettingInMillimetersPerSecond("retraction_prime_speed");
     standard_retraction_config.zHop = getSettingInMicrons("retraction_hop");
+    standard_retraction_config.retraction_count_max = getSettingAsCount("retraction_count_max");
+    standard_retraction_config.retraction_extrusion_window = getSettingInMillimeters("retraction_extrusion_window");
+    standard_retraction_config.retraction_min_travel_distance = getSettingInMicrons("retraction_min_travel");
+}
 
+void Wireframe2gcode::processStartingCode()
+{
+    if (!CommandSocket::isInstantiated())
+    {
+        std::string prefix = gcode.getFileHeader();
+        gcode.writeCode(prefix.c_str());
+    }
 
+    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)
+            {
+                gcode.writeBedTemperatureCommand(getSettingInDegreeCelsius("material_bed_temperature"), getSettingBoolean("material_bed_temp_wait"));
+            }
+        }
+
+        if (getSettingBoolean("material_print_temp_prepend"))
+        {
+            for (int extruder_nr = 0; extruder_nr < getSettingAsCount("machine_extruder_count"); extruder_nr++)
+            {
+                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++)
+                {
+                    double print_temp = getSettingInDegreeCelsius("material_print_temperature");
+                    gcode.writeTemperatureCommand(extruder_nr, print_temp, true);
+                }
+            }
+        }
+    }
+
+    gcode.writeCode(getSettingString("machine_start_gcode").c_str());
+
+    if (gcode.getFlavor() == EGCodeFlavor::BFB)
+    {
+        gcode.writeComment("enable auto-retraction");
+        std::ostringstream tmp;
+        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);
+    }
 }
 
 
-} // namespace cura    
+void Wireframe2gcode::processSkirt()
+{
+    if (wireFrame.bottom_outline.size() == 0) //If we have no layers, don't create a skirt either.
+    {
+        return;
+    }
+    Polygons skirt = wireFrame.bottom_outline.offset(100000+5000).offset(-100000);
+    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];
+        PolygonRef poly = skirt[poly_idx];
+        gcode.writeMove(poly[order.polyStart[poly_idx]], getSettingInMillimetersPerSecond("speed_travel"), 0);
+        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_brim_speed"), getSettingInMillimeters("skirt_brim_line_width") * INT2MM(initial_layer_thickness));
+        }
+    }
+}
+
+
+void Wireframe2gcode::finalize()
+{
+    gcode.finalize(getSettingString("machine_end_gcode").c_str());
+    for(int e=0; e<getSettingAsCount("machine_extruder_count"); e++)
+        gcode.writeTemperatureCommand(e, 0, false);
+}
+}//namespace cura    

src/Wireframe2gcode.h

@@ -4,25 +4,25 @@
 
 #include <functional> // passing function pointer or lambda as argument to a function
 
+#include "utils/NoCopy.h"
+
 #include "weaveDataStorage.h"
 #include "commandSocket.h"
-#include "settings.h"
+#include "settings/settings.h"
 
-#include "modelFile/modelFile.h" // PrintObject
+#include "MeshGroup.h"
 #include "slicer.h"
 
 #include "utils/polygon.h"
 #include "Weaver.h"
 
-#include "debug.h"
-
 namespace cura
 {
 
 /*!
  * Export class for exporting wireframe print gcode / weaver gcode / wireprint gcode.
  */
-class Wireframe2gcode : public SettingsBase
+class Wireframe2gcode : public SettingsMessenger, NoCopy
 {
 private:
     static const int STRATEGY_COMPENSATE = 0;
@@ -31,36 +31,36 @@ private:
     
     int initial_layer_thickness;
     int filament_diameter;
-    int extrusionWidth;
-    int flowConnection;// = getSettingInt("wireframeFlowConnection");
-    int flowFlat; // = getSettingInt("wireframeFlowFlat");
-    double extrusion_per_mm_connection; // = lineArea / filament_area * double(flowConnection) / 100.0;
-    double extrusion_per_mm_flat; // = lineArea / filament_area * double(flowFlat) / 100.0;
-    int nozzle_outer_diameter; // = getSettingInt("machineNozzleTipOuterDiameter"); // ___       ___   .
-    int nozzle_head_distance; // = getSettingInt("machineNozzleHeadDistance");      //    |     |      .
-    int nozzle_expansion_angle; // = getSettingInt("machineNozzleExpansionAngle");  //     \_U_/       .
-    int nozzle_clearance; // = getSettingInt("wireframeNozzleClearance");    // at least line width
-    int nozzle_top_diameter; // = tan(static_cast<double>(nozzle_expansion_angle)/180.0 * M_PI) * connectionHeight + nozzle_outer_diameter + nozzle_clearance;
-    int moveSpeed; // = 40;
-    int speedBottom; // =  getSettingInt("wireframePrintspeedBottom");
-    int speedUp; // = getSettingInt("wireframePrintspeedUp");
-    int speedDown; // = getSettingInt("wireframePrintspeedDown");
-    int speedFlat; // = getSettingInt("wireframePrintspeedFlat");
-    int connectionHeight; // = getSettingInt("wireframeConnectionHeight"); 
-    int roof_inset; // = getSettingInt("wireframeRoofInset"); 
-    double flat_delay; // = getSettingInt("wireframeFlatDelay")/100.0;
-    double bottom_delay; // = getSettingInt("wireframeBottomDelay")/100.0;
-    double top_delay; // = getSettingInt("wireframeTopDelay")/100.0;
-    int up_dist_half_speed; // = getSettingInt("wireframeUpDistHalfSpeed");
-    int top_jump_dist; // = getSettingInt("wireframeTopJump");
-    int fall_down; // = getSettingInt("wireframeFallDown");
-    int drag_along; // = getSettingInt("wireframeDragAlong");
-    int strategy; // = getSettingInt("wireframeStrategy"); //  HIGHER_BEND_NO_STRAIGHTEN; // RETRACT_TO_STRAIGHTEN; // MOVE_TO_STRAIGHTEN; // 
-    double go_back_to_last_top; // = false;
-    int straight_first_when_going_down; // = getSettingInt("wireframeStraightBeforeDown"); // %
-    int roof_fall_down; // = getSettingInt("wireframeRoofFallDown");
-    int roof_drag_along; // = getSettingInt("wireframeRoofDragAlong");
-    double roof_outer_delay; // = getSettingInt("wireframeRoofOuterDelay")/100.0;
+    int line_width;
+    double flowConnection;
+    double flowFlat; 
+    double extrusion_mm3_per_mm_connection;
+    double extrusion_mm3_per_mm_flat;
+    int nozzle_outer_diameter;
+    int nozzle_head_distance;
+    double nozzle_expansion_angle;
+    int nozzle_clearance;
+    int nozzle_top_diameter;
+    double moveSpeed;
+    double speedBottom;
+    double speedUp;
+    double speedDown;
+    double speedFlat;
+    int connectionHeight;
+    int roof_inset;
+    double flat_delay;
+    double bottom_delay;
+    double top_delay;
+    int up_dist_half_speed;
+    int top_jump_dist;
+    int fall_down;
+    int drag_along;
+    int strategy;
+    double go_back_to_last_top;
+    int straight_first_when_going_down;
+    int roof_fall_down;
+    int roof_drag_along;
+    double roof_outer_delay;
     
     RetractionConfig standard_retraction_config; //!< The standard retraction settings used for moves between parts etc.
     
@@ -69,13 +69,28 @@ public:
     
     Wireframe2gcode(Weaver& weaver, GCodeExport& gcode, SettingsBase* settings_base);
     
-    void writeGCode(CommandSocket* commandSocket, int& maxObjectHeight);
+    void writeGCode();
 
 
 private:
-    WireFrame wireFrame;
+    WireFrame& wireFrame;
     
-    void writeFill(std::vector<WeaveRoofPart>& fill_insets, Polygons& outlines
+    /*!
+     * Startup gcode: nozzle temp up, retraction settings, bed temp
+     */
+    void processStartingCode();
+    
+    /*!
+     * Lay down a skirt
+     */
+    void processSkirt();
+    
+    /*!
+     * End gcode: nozzle temp down
+     */
+    void finalize();
+    
+    void writeFill(std::vector<WeaveRoofPart>& infill_insets, Polygons& outlines
         , std::function<void (Wireframe2gcode& thiss, WeaveRoofPart& inset, WeaveConnectionPart& part, unsigned int segment_idx)> connectionHandler
         , std::function<void (Wireframe2gcode& thiss, WeaveConnectionSegment& p)> flatHandler);
     

src/bridge.cpp

@@ -1,6 +1,8 @@
 /** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
 #include "bridge.h"
 
+#include "sliceDataStorage.h"
+
 namespace cura {
 
 int bridgeAngle(Polygons outline, SliceLayer* prevLayer)

src/bridge.h

@@ -2,9 +2,9 @@
 #ifndef BRIDGE_H
 #define BRIDGE_H
 
-#include "sliceDataStorage.h"
-
 namespace cura {
+    class Polygons;
+    class SliceLayer;
 
 int bridgeAngle(Polygons outline, SliceLayer* prevLayer);
 

src/comb.cpp

@@ -1,237 +0,0 @@
-/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
-#include "comb.h"
-
-namespace cura {
-
-bool Comb::preTest(Point startPoint, Point endPoint)
-{
-    return collisionTest(startPoint, endPoint);
-}
-
-bool Comb::collisionTest(Point startPoint, Point endPoint)
-{
-    Point diff = endPoint - startPoint;
-
-    matrix = PointMatrix(diff);
-    sp = matrix.apply(startPoint);
-    ep = matrix.apply(endPoint);
-    
-    for(unsigned int n=0; n<boundery.size(); n++)
-    {
-        if (boundery[n].size() < 1)
-            continue;
-        Point p0 = matrix.apply(boundery[n][boundery[n].size()-1]);
-        for(unsigned int i=0; i<boundery[n].size(); i++)
-        {
-            Point p1 = matrix.apply(boundery[n][i]);
-            if ((p0.Y > sp.Y && p1.Y < sp.Y) || (p1.Y > sp.Y && p0.Y < sp.Y))
-            {
-                int64_t x = p0.X + (p1.X - p0.X) * (sp.Y - p0.Y) / (p1.Y - p0.Y);
-                
-                if (x > sp.X && x < ep.X)
-                    return true;
-            }
-            p0 = p1;
-        }
-    }
-    return false;
-}
-
-void Comb::calcMinMax()
-{
-    for(unsigned int n=0; n<boundery.size(); n++)
-    {
-        minX[n] = INT64_MAX;
-        maxX[n] = INT64_MIN;
-        Point p0 = matrix.apply(boundery[n][boundery[n].size()-1]);
-        for(unsigned int i=0; i<boundery[n].size(); i++)
-        {
-            Point p1 = matrix.apply(boundery[n][i]);
-            if ((p0.Y > sp.Y && p1.Y < sp.Y) || (p1.Y > sp.Y && p0.Y < sp.Y))
-            {
-                int64_t x = p0.X + (p1.X - p0.X) * (sp.Y - p0.Y) / (p1.Y - p0.Y);
-                
-                if (x >= sp.X && x <= ep.X)
-                {
-                    if (x < minX[n]) { minX[n] = x; minIdx[n] = i; }
-                    if (x > maxX[n]) { maxX[n] = x; maxIdx[n] = i; }
-                }
-            }
-            p0 = p1;
-        }
-    }
-}
-
-unsigned int Comb::getPolygonAbove(int64_t x)
-{
-    int64_t min = POINT_MAX;
-    unsigned int ret = NO_INDEX;
-    for(unsigned int n=0; n<boundery.size(); n++)
-    {
-        if (minX[n] > x && minX[n] < min)
-        {
-            min = minX[n];
-            ret = n;
-        }
-    }
-    return ret;
-}
-
-Point Comb::getBounderyPointWithOffset(unsigned int polygonNr, unsigned int idx)
-{
-    Point p0 = boundery[polygonNr][(idx > 0) ? (idx - 1) : (boundery[polygonNr].size() - 1)];
-    Point p1 = boundery[polygonNr][idx];
-    Point p2 = boundery[polygonNr][(idx < (boundery[polygonNr].size() - 1)) ? (idx + 1) : (0)];
-    
-    Point off0 = crossZ(normal(p1 - p0, MM2INT(1.0)));
-    Point off1 = crossZ(normal(p2 - p1, MM2INT(1.0)));
-    Point n = normal(off0 + off1, MM2INT(0.2));
-    
-    return p1 + n;
-}
-
-Comb::Comb(Polygons& _boundery)
-: boundery(_boundery)
-{
-    minX = new int64_t[boundery.size()];
-    maxX = new int64_t[boundery.size()];
-    minIdx = new unsigned int[boundery.size()];
-    maxIdx = new unsigned int[boundery.size()];
-}
-
-Comb::~Comb()
-{
-    delete[] minX;
-    delete[] maxX;
-    delete[] minIdx;
-    delete[] maxIdx;
-}
-
-bool Comb::moveInside(Point* p, int distance)
-{
-    Point ret = *p;
-    int64_t bestDist = MM2INT(2.0) * MM2INT(2.0);
-    for(unsigned int n=0; n<boundery.size(); n++)
-    {
-        if (boundery[n].size() < 1)
-            continue;
-        Point p0 = boundery[n][boundery[n].size()-1];
-        for(unsigned int i=0; i<boundery[n].size(); i++)
-        {
-            Point p1 = boundery[n][i];
-            
-            //Q = A + Normal( B - A ) * ((( B - A ) dot ( P - A )) / VSize( A - B ));
-            Point pDiff = p1 - p0;
-            int64_t lineLength = vSize(pDiff);
-            int64_t distOnLine = dot(pDiff, *p - p0) / lineLength;
-            if (distOnLine < 10)
-                distOnLine = 10;
-            if (distOnLine > lineLength - 10)
-                distOnLine = lineLength - 10;
-            Point q = p0 + pDiff * distOnLine / lineLength;
-            
-            int64_t dist = vSize2(q - *p);
-            if (dist < bestDist)
-            {
-                bestDist = dist;
-                ret = q + crossZ(normal(p1 - p0, distance));
-            }
-            
-            p0 = p1;
-        }
-    }
-    if (bestDist < MM2INT(2.0) * MM2INT(2.0))
-    {
-        *p = ret;
-        return true;
-    }
-    return false;
-}
-
-bool Comb::calc(Point startPoint, Point endPoint, std::vector<Point>& combPoints)
-{
-    if (shorterThen(endPoint - startPoint, MM2INT(1.5)))
-        return true;
-    
-    bool addEndpoint = false;
-    //Check if we are inside the comb boundaries
-    if (!boundery.inside(startPoint))
-    {
-        if (!moveInside(&startPoint))    //If we fail to move the point inside the comb boundary we need to retract.
-            return false;
-        combPoints.push_back(startPoint);
-    }
-    if (!boundery.inside(endPoint))
-    {
-        if (!moveInside(&endPoint))    //If we fail to move the point inside the comb boundary we need to retract.
-            return false;
-        addEndpoint = true;
-    }
-    
-    //Check if we are crossing any bounderies, and pre-calculate some values.
-    if (!preTest(startPoint, endPoint))
-    {
-        //We're not crossing any boundaries. So skip the comb generation.
-        if (!addEndpoint && combPoints.size() == 0) //Only skip if we didn't move the start and end point.
-            return true;
-    }
-    
-    //Calculate the minimum and maximum positions where we cross the comb boundary
-    calcMinMax();
-    
-    int64_t x = sp.X;
-    std::vector<Point> pointList;
-    //Now walk trough the crossings, for every boundary we cross, find the initial cross point and the exit point. Then add all the points in between
-    // to the pointList and continue with the next boundary we will cross, until there are no more boundaries to cross.
-    // This gives a path from the start to finish curved around the holes that it encounters.
-    while(true)
-    {
-        unsigned int n = getPolygonAbove(x);
-        if (n == NO_INDEX) break;
-        
-        pointList.push_back(matrix.unapply(Point(minX[n] - MM2INT(0.2), sp.Y)));
-        if ( (minIdx[n] - maxIdx[n] + boundery[n].size()) % boundery[n].size() > (maxIdx[n] - minIdx[n] + boundery[n].size()) % boundery[n].size())
-        {
-            for(unsigned int i=minIdx[n]; i != maxIdx[n]; i = (i < boundery[n].size() - 1) ? (i + 1) : (0))
-            {
-                pointList.push_back(getBounderyPointWithOffset(n, i));
-            }
-        }else{
-            if (minIdx[n] == 0)
-                minIdx[n] = boundery[n].size() - 1;
-            else
-                minIdx[n]--;
-            if (maxIdx[n] == 0)
-                maxIdx[n] = boundery[n].size() - 1;
-            else
-                maxIdx[n]--;
-            
-            for(unsigned int i=minIdx[n]; i != maxIdx[n]; i = (i > 0) ? (i - 1) : (boundery[n].size() - 1))
-            {
-                pointList.push_back(getBounderyPointWithOffset(n, i));
-            }
-        }
-        pointList.push_back(matrix.unapply(Point(maxX[n] + MM2INT(0.2), sp.Y)));
-        
-        x = maxX[n];
-    }
-    pointList.push_back(endPoint);
-    
-    //Optimize the pointList, skip each point we could already reach by not crossing a boundary. This smooths out the path and makes it skip any unneeded corners.
-    Point p0 = startPoint;
-    for(unsigned int n=1; n<pointList.size(); n++)
-    {
-        if (collisionTest(p0, pointList[n]))
-        {
-            if (collisionTest(p0, pointList[n-1]))
-                return false;
-            p0 = pointList[n-1];
-            combPoints.push_back(p0);
-        }
-    }
-    if (addEndpoint)
-        combPoints.push_back(endPoint);
-    return true;
-}
-
-}//namespace cura

src/comb.h

@@ -1,44 +0,0 @@
-/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
-#ifndef COMB_H
-#define COMB_H
-
-#include "utils/polygon.h"
-
-namespace cura {
-
-class Comb
-{
-private:
-    Polygons& boundery;
-
-    int64_t* minX;
-    int64_t* maxX;
-    unsigned int* minIdx;
-    unsigned int* maxIdx;
-
-    PointMatrix matrix;
-    Point sp;
-    Point ep;
-
-    bool preTest(Point startPoint, Point endPoint);    
-    bool collisionTest(Point startPoint, Point endPoint);
-
-    void calcMinMax();
-    
-    unsigned int getPolygonAbove(int64_t x);
-    
-    Point getBounderyPointWithOffset(unsigned int polygonNr, unsigned int idx);
-    
-public:
-    Comb(Polygons& _boundery);
-    ~Comb();
-    
-    bool inside(const Point p) { return boundery.inside(p); }
-    bool moveInside(Point* p, int distance = 100);
-    
-    bool calc(Point startPoint, Point endPoint, std::vector<Point>& combPoints);
-};
-
-}//namespace cura
-
-#endif//COMB_H

src/commandSocket.cpp

@@ -1,202 +1,620 @@
 #include "utils/logoutput.h"
 #include "commandSocket.h"
-#include "fffProcessor.h"
+#include "FffProcessor.h"
+#include "progress/Progress.h"
 
 #include <thread>
 #include <cinttypes>
 
+#ifdef ARCUS
 #include <Arcus/Socket.h>
+#include <Arcus/SocketListener.h>
+#include <Arcus/Error.h>
+#endif
+
+#include <string> // stoi
 
 #ifdef _WIN32
 #include <windows.h>
 #endif
 
+#define DEBUG_OUTPUT_OBJECT_STL_THROUGH_CERR(x) 
+
+// std::cerr << x;
+
 namespace cura {
 
 #define BYTES_PER_FLOAT 4
 #define FLOATS_PER_VECTOR 3
 #define VECTORS_PER_FACE 3
 
+CommandSocket* CommandSocket::instance = nullptr; // instantiate instance
+
+#ifdef ARCUS
+class Listener : public Arcus::SocketListener
+{
+public:
+    void stateChanged(Arcus::SocketState::SocketState newState) override
+    {
+    }
+
+    void messageReceived() override
+    {
+    }
+
+    void error(const Arcus::Error & error) override
+    {
+        if (error.getErrorCode() == Arcus::ErrorCode::Debug)
+        {
+            log("%s\n", error.toString().c_str());
+        }
+        else
+        {
+            logError("%s\n", error.toString().c_str());
+        }
+    }
+};
+
+/*!
+ * 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()
-        : processor(nullptr)
-        , socket(nullptr)
+        : socket(nullptr)
         , object_count(0)
-        , current_object_number(0)
-        , currentSlicedObject(nullptr)
-        , slicedObjects(0)
     { }
 
-    Cura::Layer* getLayerById(int id);
+    std::shared_ptr<cura::proto::Layer> getLayerById(int id);
 
-    fffProcessor* processor;
+    std::shared_ptr<cura::proto::LayerOptimized> getOptimizedLayerById(int id);
 
     Arcus::Socket* socket;
-
+    
+    // Number of objects that need to be sliced
     int object_count;
-    int current_object_number;
 
-    std::shared_ptr<Cura::SlicedObjectList> slicedObjectList;
-    Cura::SlicedObject* currentSlicedObject;
-    int slicedObjects;
-    std::vector<int64_t> objectIds;
-
-    std::string tempGCodeFile;
+    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::shared_ptr<PrintObject> objectToSlice;
+    SliceDataStruct<cura::proto::Layer> sliced_layers;
+    SliceDataStruct<cura::proto::LayerOptimized> optimized_layers;
 };
 
-CommandSocket::CommandSocket(fffProcessor* processor)
-    : d(new Private)
+/*!
+ * PathCompiler buffers and prepares the sliced data to be sent to the front end and saves them in
+ * appropriate buffers
+ */
+class CommandSocket::PathCompiler
 {
-    d->processor = processor;
-    d->processor->setCommandSocket(this);
+    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, Polygon 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
+#endif
 }
 
+CommandSocket* CommandSocket::getInstance()
+{
+    return instance;
+}
+
+void CommandSocket::instantiate()
+{
+    instance = new CommandSocket();
+}
+
+bool CommandSocket::isInstantiated()
+{
+    return instance != nullptr;
+}
+
+
 void CommandSocket::connect(const std::string& ip, int port)
 {
-    d->socket = new Arcus::Socket();
-    d->socket->registerMessageType(1, &Cura::ObjectList::default_instance());
-    d->socket->registerMessageType(2, &Cura::SlicedObjectList::default_instance());
-    d->socket->registerMessageType(3, &Cura::Progress::default_instance());
-    d->socket->registerMessageType(4, &Cura::GCodeLayer::default_instance());
-    d->socket->registerMessageType(5, &Cura::ObjectPrintTime::default_instance());
-    d->socket->registerMessageType(6, &Cura::SettingList::default_instance());
-    d->socket->registerMessageType(7, &Cura::GCodePrefix::default_instance());
+#ifdef ARCUS
+    private_data->socket = new Arcus::Socket();
+    private_data->socket->addListener(new Listener());
 
-    d->socket->connect(ip, 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::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());
 
-    while(d->socket->state() != Arcus::SocketState::Closed && d->socket->state() != Arcus::SocketState::Error)
+    private_data->socket->connect(ip, port);
+
+    log("Connecting to %s:%i\n", ip.c_str(), port);
+
+    while(private_data->socket->getState() != Arcus::SocketState::Connected && private_data->socket->getState() != Arcus::SocketState::Error)
     {
-        if(d->objectToSlice)
+        std::this_thread::sleep_for(std::chrono::milliseconds(100));
+    }
+
+    log("Connected to %s:%i\n", ip.c_str(), port);
+    
+    bool slice_another_time = true;
+    
+    // Start & continue listening as long as socket is not closed and there is no error.
+    while(private_data->socket->getState() != Arcus::SocketState::Closed && private_data->socket->getState() != Arcus::SocketState::Error && slice_another_time)
+    {
+        // 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);
+        }
+        */
+
+        /*
+         * 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);
+        }
+        */
+
+        // 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, 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();
+            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
-            d->processor->processModel(d->objectToSlice.get());
-            d->objectToSlice.reset();
-            d->processor->resetFileNumber();
+            //private_data->processor->processModel(private_data->object_to_slice.get());
+            //private_data->object_to_slice.reset();
+            //private_data->processor->resetFileNumber();
 
-            sendPrintTime();
-        }
-
-        Arcus::MessagePtr message = d->socket->takeNextMessage();
-
-        Cura::SettingList* settingList = dynamic_cast<Cura::SettingList*>(message.get());
-        if(settingList)
-        {
-            handleSettingList(settingList);
-        }
-
-        Cura::ObjectList* objectList = dynamic_cast<Cura::ObjectList*>(message.get());
-        if(objectList)
-        {
-            handleObjectList(objectList);
+            //sendPrintTimeMaterialEstimates();
         }
 
         std::this_thread::sleep_for(std::chrono::milliseconds(250));
-
-        if(!d->socket->errorString().empty()) {
-            logError("%s\n", d->socket->errorString().data());
-            d->socket->clearError();
-        }
     }
+    log("Closing connection\n");
+    private_data->socket->close();
+#endif
 }
 
-void CommandSocket::handleObjectList(Cura::ObjectList* list)
+#ifdef ARCUS
+void CommandSocket::handleObjectList(cura::proto::ObjectList* list, const google::protobuf::RepeatedPtrField<cura::proto::Extruder> settings_per_extruder_train)
 {
-    FMatrix3x3 matrix;
-    d->object_count = 0;
-    d->objectIds.clear();
-
-    d->objectToSlice = std::make_shared<PrintObject>(d->processor);
-    for(auto object : list->objects())
+    if (list->objects_size() <= 0)
     {
-        d->objectToSlice->meshes.emplace_back(d->objectToSlice.get()); //Construct a new mesh and put it into printObject's mesh list.
-        Mesh& mesh = d->objectToSlice->meshes.back();
+        return;
+    }
 
-        int bytesPerFace = BYTES_PER_FLOAT * FLOATS_PER_VECTOR * VECTORS_PER_FACE;
-        int faceCount = object.vertices().size() / bytesPerFace;
-        for(int i = 0; i < faceCount; ++i)
-        {
-            //TODO: Apply matrix
-            std::string data = object.vertices().substr(i * bytesPerFace, bytesPerFace);
-            const FPoint3* floatVerts = reinterpret_cast<const FPoint3*>(data.data());
+    FMatrix3x3 matrix;
+    //private_data->object_count = 0;
+    //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();
 
-            Point3 verts[3];
-            verts[0] = matrix.apply(floatVerts[0]);
-            verts[1] = matrix.apply(floatVerts[1]);
-            verts[2] = matrix.apply(floatVerts[2]);
-            mesh.addFace(verts[0], verts[1], verts[2]);
+    // load meshgroup settings
+    for (auto setting : list->settings())
+    {
+        meshgroup->setSetting(setting.name(), setting.value());
+    }
+
+    { // 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 setting : object.settings())
+        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;
+        int face_count = object.vertices().size() / bytes_per_face;
+
+        if (face_count <= 0)
+        {
+            logWarning("Got an empty mesh, ignoring it!");
+            continue;
+        }
+        DEBUG_OUTPUT_OBJECT_STL_THROUGH_CERR("solid Cura_out\n");
+
+        // 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")
+            {
+                extruder_train_nr = std::stoi(setting.value());
+                break;
+            }
+        }
+        SettingsBase* extruder_train = meshgroup->getExtruderTrain(extruder_train_nr);
+
+        meshgroup->meshes.push_back(extruder_train); //Construct a new mesh (with the corresponding extruder train as settings parent object) and put it into MeshGroup's mesh list.
+        Mesh& mesh = meshgroup->meshes.back();
+
+        for (int i = 0; i < face_count; ++i)
+        {
+            //TODO: Apply matrix
+            std::string data = object.vertices().substr(i * bytes_per_face, bytes_per_face);
+            const FPoint3* float_vertices = reinterpret_cast<const FPoint3*>(data.data());
+
+            Point3 verts[3];
+            verts[0] = matrix.apply(float_vertices[0]);
+            verts[1] = matrix.apply(float_vertices[1]);
+            verts[2] = matrix.apply(float_vertices[2]);
+            mesh.addFace(verts[0], verts[1], verts[2]);
+
+            DEBUG_OUTPUT_OBJECT_STL_THROUGH_CERR("  facet normal -1 0 0\n");
+            DEBUG_OUTPUT_OBJECT_STL_THROUGH_CERR("    outer loop\n");
+            DEBUG_OUTPUT_OBJECT_STL_THROUGH_CERR("      vertex "<<INT2MM(verts[0].x) <<" " << INT2MM(verts[0].y) <<" " << INT2MM(verts[0].z) << "\n");
+            DEBUG_OUTPUT_OBJECT_STL_THROUGH_CERR("      vertex "<<INT2MM(verts[1].x) <<" " << INT2MM(verts[1].y) <<" " << INT2MM(verts[1].z) << "\n");
+            DEBUG_OUTPUT_OBJECT_STL_THROUGH_CERR("      vertex "<<INT2MM(verts[2].x) <<" " << INT2MM(verts[2].y) <<" " << INT2MM(verts[2].z) << "\n");
+            DEBUG_OUTPUT_OBJECT_STL_THROUGH_CERR("    endloop\n");
+            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());
         }
 
-        d->objectIds.push_back(object.id());
         mesh.finish();
     }
-    d->object_count++;
-    d->objectToSlice->finalize();
+
+    private_data->object_count++;
+    meshgroup->finalize();
 }
+#endif
 
-void CommandSocket::handleSettingList(Cura::SettingList* list)
+void CommandSocket::sendOptimizedLayerInfo(int layer_nr, int32_t z, int32_t height)
 {
-    for(auto setting : list->settings())
-    {
-        d->processor->setSetting(setting.name(), setting.value());
-    }
-}
-
-void CommandSocket::sendLayerInfo(int layer_nr, int32_t z, int32_t height)
-{
-    if(!d->currentSlicedObject)
-    {
-        return;
-    }
-
-    Cura::Layer* layer = d->getLayerById(layer_nr);
+#ifdef ARCUS
+    std::shared_ptr<cura::proto::LayerOptimized> layer = private_data->getOptimizedLayerById(layer_nr);
     layer->set_height(z);
     layer->set_thickness(height);
+#endif
 }
 
-void CommandSocket::sendPolygons(PolygonType type, int layer_nr, Polygons& polygons, int line_width)
+void CommandSocket::sendPolygons(PrintFeatureType type, const Polygons& polygons, int line_width)
 {
-    if(!d->currentSlicedObject)
-        return;
-    
+#ifdef ARCUS
     if (polygons.size() == 0)
-        return;
-
-    Cura::Layer* layer = d->getLayerById(layer_nr);
-
-    for(unsigned int i = 0; i < polygons.size(); ++i)
     {
-        Cura::Polygon* p = layer->add_polygons();
-        p->set_type(static_cast<Cura::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, Polygon& 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)
 {
-    auto message = std::make_shared<Cura::Progress>();
+#ifdef ARCUS
+    auto message = std::make_shared<cura::proto::Progress>();
+    amount /= private_data->object_count;
+    amount += private_data->optimized_layers.sliced_objects * (1. / private_data->object_count);
     message->set_amount(amount);
-    d->socket->sendMessage(message);
+    private_data->socket->sendMessage(message);
+#endif
 }
 
-void CommandSocket::sendPrintTime()
+void CommandSocket::sendProgressStage(Progress::Stage stage)
 {
-    auto message = std::make_shared<Cura::ObjectPrintTime>();
-    message->set_time(d->processor->getTotalPrintTime());
-    message->set_material_amount(d->processor->getTotalFilamentUsed(0));
-    d->socket->sendMessage(message);
+    // TODO
+}
+
+void CommandSocket::sendPrintTimeMaterialEstimates()
+{
+#ifdef ARCUS
+    logDebug("Sending print time and material estimates.\n");
+    auto message = std::make_shared<cura::proto::PrintTimeMaterialEstimates>();
+
+    message->set_time(FffProcessor::getInstance()->getTotalPrintTime());
+    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
 }
 
 void CommandSocket::sendPrintMaterialForObject(int index, int extruder_nr, float print_time)
@@ -208,67 +626,202 @@ void CommandSocket::sendPrintMaterialForObject(int index, int extruder_nr, float
 //     socket.sendFloat32(print_time);
 }
 
-void CommandSocket::beginSendSlicedObject()
+void CommandSocket::sendLayerData()
 {
-    if(!d->slicedObjectList)
-    {
-        d->slicedObjectList = std::make_shared<Cura::SlicedObjectList>();
-    }
+#ifdef ARCUS
+#endif
+#ifdef ARCUS
+    auto& data = private_data->sliced_layers;
 
-    d->currentSlicedObject = d->slicedObjectList->add_objects();
-    d->currentSlicedObject->set_id(d->objectIds[d->slicedObjects]);
+    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 : data.slice_data) //Note: This is in no particular order!
+        {
+            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
 }
 
-void CommandSocket::endSendSlicedObject()
+void CommandSocket::sendOptimizedLayerData()
 {
-    d->slicedObjects++;
-    if(d->slicedObjects >= d->object_count)
+#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)
     {
-        d->socket->sendMessage(d->slicedObjectList);
-        d->slicedObjects = 0;
-        d->slicedObjectList.reset();
-        d->currentSlicedObject = nullptr;
+        for (std::pair<const int, std::shared_ptr<cura::proto::LayerOptimized>> entry : data.slice_data) //Note: This is in no particular order!
+        {
+            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
+}
+
+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
 }
 
 void CommandSocket::beginGCode()
 {
-    d->processor->setTargetStream(&d->gcode_output_stream);
+#ifdef ARCUS
+    FffProcessor::getInstance()->setTargetStream(&private_data->gcode_output_stream);
+#endif
 }
 
-void CommandSocket::sendGCodeLayer()
+void CommandSocket::flushGcode()
 {
-    auto message = std::make_shared<Cura::GCodeLayer>();
-    message->set_id(d->objectIds[0]);
-    message->set_data(d->gcode_output_stream.str());
-    d->socket->sendMessage(message);
+#ifdef ARCUS
+    auto message = std::make_shared<cura::proto::GCodeLayer>();
+    message->set_data(private_data->gcode_output_stream.str());
+    private_data->socket->sendMessage(message);
     
-    d->gcode_output_stream.str("");
+    private_data->gcode_output_stream.str("");
+#endif
 }
 
 void CommandSocket::sendGCodePrefix(std::string prefix)
 {
-    auto message = std::make_shared<Cura::GCodePrefix>();
+#ifdef ARCUS
+    auto message = std::make_shared<cura::proto::GCodePrefix>();
     message->set_data(prefix);
-    d->socket->sendMessage(message);
+    private_data->socket->sendMessage(message);
+#endif
 }
 
-Cura::Layer* CommandSocket::Private::getLayerById(int id)
+#ifdef ARCUS
+std::shared_ptr<cura::proto::Layer> CommandSocket::Private::getLayerById(int id)
 {
-    auto itr = std::find_if(currentSlicedObject->mutable_layers()->begin(), currentSlicedObject->mutable_layers()->end(), [id](Cura::Layer& l) { return l.id() == id; });
+    id += sliced_layers.current_layer_offset;
 
-    Cura::Layer* layer = nullptr;
-    if(itr != currentSlicedObject->mutable_layers()->end())
+    auto itr = sliced_layers.slice_data.find(id);
+
+    std::shared_ptr<cura::proto::Layer> layer;
+    if (itr != sliced_layers.slice_data.end())
     {
-        layer = &(*itr);
+        layer = itr->second;
     }
     else
     {
-        layer = currentSlicedObject->add_layers();
+        layer = std::make_shared<cura::proto::Layer>();
         layer->set_id(id);
+        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, Polygon 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

@@ -3,41 +3,154 @@
 
 #include "utils/socket.h"
 #include "utils/polygon.h"
-#include "settings.h"
+#include "settings/settings.h"
+#include "progress/Progress.h"
+#include "PrintFeature.h"
 
 #include <memory>
 
+#ifdef ARCUS
 #include "Cura.pb.h"
+#endif
 
-namespace cura {
+namespace cura
+{
 
-class fffProcessor;
 class CommandSocket
 {
-public:
-    CommandSocket(fffProcessor* processor);
+private:
+    static CommandSocket* instance; //!< May be a nullptr in case it hasn't been instantiated.
 
+    CommandSocket(); //!< The single constructor is known only privately, since this class is similar to a singleton class (except the single object doesn't need to be instantiated)
+
+public:
+    static CommandSocket* getInstance(); //!< Get the CommandSocket instance, or nullptr if it hasn't been instantiated.
+
+    static void instantiate(); //!< Instantiate the CommandSocket.
+
+    static bool isInstantiated(); //!< Check whether the singleton is instantiated
+
+    /*!
+     * Connect with the GUI
+     * This creates and initialises the arcus socket and then continues listening for messages. 
+     * \param ip string containing the ip to connect with
+     * \param port int of the port to connect with.
+     */
     void connect(const std::string& ip, int port);
 
-    void handleObjectList(Cura::ObjectList* list);
-    void handleSettingList(Cura::SettingList* list);
-    
-    void sendLayerInfo(int layer_nr, int32_t z, int32_t height);
-    void sendPolygons(cura::PolygonType type, int layer_nr, cura::Polygons& polygons, int line_width);
-    void sendProgress(float amount);
-    void sendPrintTime();
-    void sendPrintMaterialForObject(int index, int extruder_nr, float material_amount);
+#ifdef ARCUS
+    /*! 
+     * 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, const google::protobuf::RepeatedPtrField<cura::proto::Extruder> settings_per_extruder_train);
+#endif
 
-    void beginSendSlicedObject();
-    void endSendSlicedObject();
+    /*!
+     * Send info on an optimized layer to be displayed by the forntend: set the z and the thickness of the layer.
+     */
+    void sendOptimizedLayerInfo(int layer_nr, int32_t z, int32_t height);
+
+    /*! 
+     * Send a polygon to the front-end. This is used for the layerview in the GUI
+     */
+    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, Polygon& 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
+     */
+    void sendProgress(float amount);
+    
+    /*!
+     * Send the current stage of the process to the GUI (starting, slicing infill, etc) 
+     */
+    void sendProgressStage(Progress::Stage stage);
+    
+    /*!
+     * Send time estimate of how long print would take.
+     */
+    void sendPrintTimeMaterialEstimates();
+    
+    /*!
+     * Does nothing at the moment
+     */
+    void sendPrintMaterialForObject(int index, int extruder_nr, float material_amount);
+    
+    /*!
+     * Send the slices of the model as polygons to the GUI.
+     *
+     * 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.
+     *
+     * This should indicate that no more data (g-code, prefix/postfix, metadata
+     * or otherwise) should be sent any more regarding the latest slice job.
+     */
+    void sendFinishedSlicing();
 
     void beginGCode();
-    void sendGCodeLayer();
+    
+    /*!
+     * Flush the gcode in gcode_output_stream into a message queued in the socket.
+     */
+    void flushGcode();
     void sendGCodePrefix(std::string prefix);
 
+#ifdef ARCUS
 private:
     class Private;
-    const std::unique_ptr<Private> d;
+    const std::unique_ptr<Private> private_data;
+    class PathCompiler;
+    const std::unique_ptr<PathCompiler> path_comp;
+#endif
 };
 
 }//namespace cura

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 0
-
-#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.h

@@ -4,196 +4,373 @@
 
 #include <stdio.h>
 #include <deque> // for extrusionAmountAtPreviousRetractions
+#include <sstream> // for stream.str()
 
-#include "settings.h"
+#include "settings/settings.h"
 #include "utils/intpoint.h"
+#include "utils/NoCopy.h"
 #include "timeEstimate.h"
+#include "MeshGroup.h"
+#include "commandSocket.h"
+#include "RetractionConfig.h"
 
 namespace cura {
 
-class RetractionConfig
+/*!
+ * Coasting configuration used during printing.
+ * Can differ per extruder.
+ * 
+ * Might be used in the future to have different coasting per feature, e.g. outer wall only.
+ */
+struct CoastingConfig
 {
-public:
-    double amount; //!< The amount
-    int speed;
-    int primeSpeed;
-    double primeAmount;
-    int zHop;
+    bool coasting_enable; //!< Whether coasting is enabled on the extruder to which this config is attached 
+    double coasting_volume; //!< The volume leeked when printing without feeding
+    double coasting_speed; //!< A modifier (0-1) on the last used travel speed to move slower during coasting
+    double coasting_min_volume;  //!< The minimal volume printed to build up enough pressure to leek the coasting_volume
 };
 
-//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:
-    int speed;
-    int line_width;
-    int flow;
-    int layer_thickness;
-    double extrusion_mm3_per_mm;
-public:
-    const char* name;
-    bool spiralize;
-    RetractionConfig* retraction_config;
-    
-    GCodePathConfig() : speed(0), line_width(0), extrusion_mm3_per_mm(0.0), name(nullptr), spiralize(false), retraction_config(nullptr) {}
-    GCodePathConfig(RetractionConfig* retraction_config, const char* name) : speed(0), line_width(0), extrusion_mm3_per_mm(0.0), name(name), spiralize(false), retraction_config(retraction_config) {}
-    
-    void setSpeed(int speed)
-    {
-        this->speed = speed;
-    }
-    
-    void setLineWidth(int line_width)
-    {
-        this->line_width = line_width;
-        calculateExtrusion();
-    }
-    
-    void setLayerHeight(int layer_height)
-    {
-        this->layer_thickness = layer_height;
-        calculateExtrusion();
-    }
-    
-    void setFlow(int flow)
-    {
-        this->flow = flow;
-        calculateExtrusion();
-    }
-    
-    void smoothSpeed(int min_speed, int layer_nr, int max_speed_layer)
-    {
-        speed = (speed*layer_nr)/max_speed_layer + (min_speed*(max_speed_layer-layer_nr)/max_speed_layer);
-    }
-    
-    double getExtrusionMM3perMM()
-    {
-        return extrusion_mm3_per_mm;
-    }
-    
-    int getSpeed()
-    {
-        return speed;
-    }
-    
-    int getLineWidth()
-    {
-        return line_width;
-    }
-
-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.
-class GCodeExport
+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
+
+        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.
+
+        double retraction_e_amount_current; //!< The current retracted amount (in mm or mm^3), or zero(i.e. false) if it is not currently retracted (positive values mean retracted amount, so negative impact on E values)
+        double retraction_e_amount_at_e_start; //!< The ExtruderTrainAttributes::retraction_amount_current value at E0, i.e. the offset (in mm or mm^3) from E0 to the situation where the filament is at the tip of the nozzle.
+
+        double prime_volume; //!< Amount of material (in mm^3) to be primed after an unretration (due to oozing and/or coasting)
+        double last_retraction_prime_speed; //!< The last prime speed (in mm/s) of the to-be-primed amount
+
+        std::deque<double> extruded_volume_at_previous_n_retractions; // in mm^3
+
+        ExtruderTrainAttributes()
+        : 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("")
+        , filament_area(0)
+        , totalFilament(0)
+        , currentTemperature(0)
+        , initial_temp(0)
+        , retraction_e_amount_current(0.0)
+        , retraction_e_amount_at_e_start(0.0)
+        , prime_volume(0.0)
+        , last_retraction_prime_speed(0.0)
+        { }
+    };
+    ExtruderTrainAttributes extruder_attr[MAX_EXTRUDERS];
+    unsigned int extruder_count;
+    bool use_extruder_offset_to_offset_coords;
+    Point3 machine_dimensions;
+    std::string machine_name;
+
     std::ostream* output_stream;
-    double extrusion_amount; // in mm or mm^3
-    double extruderSwitchRetraction;
-    int extruderSwitchRetractionSpeed;
-    int extruderSwitchPrimeSpeed;
-    double retraction_extrusion_window;
-    double retraction_count_max;
-    std::deque<double> extrusion_amount_at_previous_n_retractions; // in mm or mm^3
+    std::string new_line;
+
+    double current_e_value; //!< The last E value written to gcode (in mm or mm^3)
     Point3 currentPosition;
-    Point3 startPosition;
-    Point extruderOffset[MAX_EXTRUDERS];
-    char extruderCharacter[MAX_EXTRUDERS];
-    int currentTemperature[MAX_EXTRUDERS];
-    int currentSpeed;
-    int zPos;
-    bool isRetracted;
-    bool isZHopped;
-    int retractionPrimeSpeed;
+    double currentSpeed; //!< The current speed (F values / 60) in mm/s
+    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;
     int currentFanSpeed;
     EGCodeFlavor flavor;
-    std::string preSwitchExtruderCode[MAX_EXTRUDERS];
-    std::string postSwitchExtruderCode[MAX_EXTRUDERS];
-    
-    double totalFilament[MAX_EXTRUDERS]; // in mm^3
-    double filament_diameter[MAX_EXTRUDERS]; // in mm^3
-    double totalPrintTime;
+
+    double totalPrintTime; //!< The total estimated print time in seconds
     TimeEstimateCalculator estimateCalculator;
     
     bool is_volumatric;
+    bool firmware_retract; //!< whether retractions are done in the firmware, or hardcoded in E values.
+
+    unsigned int layer_nr; //!< for sending travel data
+
+    int initial_bed_temp; //!< bed temperature at the beginning of the print.
+protected:
+    /*!
+     * Convert an E value to a value in mm (if it wasn't already in mm) for the current extruder.
+     * 
+     * E values are either in mm or in mm^3
+     * The current extruder is used to determine the filament area to make the conversion.
+     * 
+     * \param e the value to convert
+     * \return the value converted to mm
+     */
+    double eToMm(double e);
+
+    /*!
+     * Convert a volume value to an E value (which might be volumetric as well) for the current extruder.
+     * 
+     * E values are either in mm or in mm^3
+     * The current extruder is used to determine the filament area to make the conversion.
+     * 
+     * \param mm3 the value to convert
+     * \return the value converted to mm or mm3 depending on whether the E axis is volumetric
+     */
+    double mm3ToE(double mm3);
+
+    /*!
+     * Convert a distance value to an E value (which might be linear/distance based as well) for the current extruder.
+     * 
+     * E values are either in mm or in mm^3
+     * The current extruder is used to determine the filament area to make the conversion.
+     * 
+     * \param mm the value to convert
+     * \return the value converted to mm or mm3 depending on whether the E axis is volumetric
+     */
+    double mmToE(double mm);
+
 public:
     
     GCodeExport();
     ~GCodeExport();
+
+    /*!
+     * Get the gcode file header (e.g. ";FLAVOR:UltiGCode\n")
+     * 
+     * \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 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<std::string>& mat_ids = std::vector<std::string>());
+
+    void setLayerNr(unsigned int layer_nr);
     
     void setOutputStream(std::ostream* stream);
-    
-    void setExtruderOffset(int id, Point p);
-    Point getExtruderOffset(int id);
-    void setSwitchExtruderCode(int id, std::string preSwitchExtruderCode, std::string postSwitchExtruderCode);
+
+    bool getExtruderIsUsed(const int extruder_nr) const; //!< Returns whether the extruder with the given index is used up until the current meshgroup
+
+    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();
-        
-    void setRetractionSettings(int extruderSwitchRetraction, int extruderSwitchRetractionSpeed, int extruderSwitchPrimeSpeed, int minimalExtrusionBeforeRetraction, int retraction_count_max);
     
     void setZ(int z);
     
+    void addLastCoastedVolume(double last_coasted_volume) 
+    {
+        extruder_attr[current_extruder].prime_volume += last_coasted_volume; 
+    }
+    
     Point3 getPosition();
     
     Point getPositionXY();
-    
-    void resetStartPosition();
-
-    Point getStartPositionXY();
 
     int getPositionZ();
 
     int getExtruderNr();
     
     void setFilamentDiameter(unsigned int n, int diameter);
-    double getFilamentArea(unsigned int extruder);
     
-    double getExtrusionAmountMM3(unsigned int extruder);
-    
-    double getTotalFilamentUsed(int e);
+    double getCurrentExtrudedVolume();
 
+    /*!
+     * Get the total extruded volume for a specific extruder in mm^3
+     * 
+     * Retractions and unretractions don't contribute to this.
+     * 
+     * \param extruder_nr The extruder number for which to get the total netto extruded volume
+     * \return total filament printed in mm^3
+     */
+    double getTotalFilamentUsed(int extruder_nr);
+
+    /*!
+     * Get the total estimated print time in seconds
+     * 
+     * \return total print time in seconds
+     */
     double getTotalPrintTime();
     void updateTotalPrintTime();
     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);
     
     void writeLine(const char* line);
     
+    /*!
+     * Reset the current_e_value to prevent too high E values.
+     * 
+     * The current extruded volume is added to the current extruder_attr.
+     */
     void resetExtrusionValue();
     
     void writeDelay(double timeAmount);
     
-    void writeMove(Point p, int speed, double extrusion_per_mm);
+    void writeMove(Point p, double speed, double extrusion_mm3_per_mm);
     
-    void writeMove(Point3 p, int 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, int 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_mm3_per_mm);
 public:
-    void writeRetraction(RetractionConfig* config, bool force=false);
-    
-    void switchExtruder(int newExtruder);
-    
+    void writeRetraction(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);
     
-    void writeFanCommand(int speed);
+    /*!
+     * 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(double travel_speed);
     
-    void writeTemperatureCommand(int extruder, int temperature, bool wait = false);
-    void writeBedTemperatureCommand(int temperature, bool wait = false);
+    void writeFanCommand(double speed);
     
-    void finalize(int maxObjectHeight, int moveSpeed, const char* endCode);
+    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(const MeshGroup* settings);
+
+    /*!
+     * Handle the initial (bed/nozzle) temperatures before any gcode is processed.
+     * These temperatures are set in the pre-print setup in the firmware.
+     * 
+     * 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
+     */
+    void setInitialTemps(const MeshGroup& settings);
+
+    /*!
+     * Override or set an initial nozzle temperature as written by GCodeExport::setInitialTemps
+     * This is used primarily during better specification of temperatures in LayerPlanBuffer::insertPreheatCommand
+     * 
+     * \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
+     */
+    void setInitialTemp(int extruder_nr, double temp);
+
+    /*!
+     * Finish the gcode: turn fans off, write end gcode and flush all gcode left in the buffer.
+     * 
+     * \param endCode The end gcode to be appended at the very end.
+     */
+    void finalize(const char* endCode);
+
 };
 
 }
 
 #endif//GCODEEXPORT_H
+

src/gcodePlanner.h

@@ -1,124 +1,723 @@
+/** 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 "utils/polygon.h"
 #include "utils/logoutput.h"
+#include "wallOverlap.h"
+#include "commandSocket.h"
+#include "FanSpeedLayerTime.h"
+#include "SpaceFillType.h"
+#include "GCodePathConfig.h"
+
+#include "utils/optional.h"
 
 namespace cura 
 {
 
+class SliceDataStorage;
+class SliceLayerPart;
+
+/*!
+ * 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)
+    {
+        assert(temperature != 0 && temperature != -1 && "Temperature command must be set!");
+    }
+    
+    /*!
+     * 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 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)
+    : 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;
-    bool retract;
-    int extruder;
-    std::vector<Point> points;
-    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.
+    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.
+    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;
+    }
 };
 
-//The GCodePlanner class stores multiple moves that are planned.
-// It facilitates the combing to keep the head inside the print.
-// It also keeps track of the print time estimate for this planning so speed adjustments can be made for the minimal-layer-time.
-class GCodePlanner
-{
-private:
-    GCodeExport& gcode;
+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.
+ * 
+ * It allows for temperature command inserts which can be inserted in between paths.
+ */
+class ExtruderPlan
+{
+    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 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, Point start_position, int layer_nr, bool is_initial_layer, int layer_thickness, FanSpeedLayerTimeSettings& fan_speed_layer_time_settings, const RetractionConfig& retraction_config);
+
+    /*!
+     * Add a new Insert, constructed with the given arguments
+     * 
+     * \see NozzleTempInsert
+     * 
+     * \param contructor_args The arguments for the constructor of an insert 
+     */
+    template<typename... Args>
+    void insertCommand(Args&&... contructor_args)
+    {
+        inserts.emplace_back(contructor_args...);
+    }
+
+    /*!
+     * Insert the inserts into gcode which should be inserted before \p path_idx
+     * 
+     * \param path_idx The index into ExtruderPlan::paths which is currently being consider for temperature command insertion
+     * \param gcode The gcode exporter to which to write the temperature command.
+     */
+    void handleInserts(unsigned int& path_idx, GCodeExport& gcode)
+    {
+        while ( ! inserts.empty() && path_idx >= inserts.front().path_idx)
+        { // handle the Insert to be inserted before this path_idx (and all inserts not handled yet)
+            inserts.front().write(gcode);
+            inserts.pop_front();
+        }
+    }
+
+    /*!
+     * Insert all remaining temp inserts into gcode, to be called at the end of an extruder plan
+     * 
+     * Inserts temperature commands which should be inserted _after_ the last path.
+     * Also inserts all temperatures which should have been inserted earlier,
+     * but for which ExtruderPlan::handleInserts hasn't been called correctly.
+     * 
+     * \param gcode The gcode exporter to which to write the temperature command.
+     */
+    void handleAllRemainingInserts(GCodeExport& gcode)
+    { 
+        while ( ! inserts.empty() )
+        { // handle the Insert to be inserted before this path_idx (and all inserts not handled yet)
+            NozzleTempInsert& insert = inserts.front();
+            assert(insert.path_idx == paths.size());
+            insert.write(gcode);
+            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
+
+    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
+
+/*! 
+ * The GCodePlanner class stores multiple moves that are planned.
+ * 
+ * 
+ * It facilitates the combing to keep the head inside the print.
+ * It also keeps track of the print time estimate for this planning so speed adjustments can be made for the minimal-layer-time.
+ * 
+ * A GCodePlanner is also knows as a 'layer plan'.
+ * 
+ */
+class GCodePlanner : public NoCopy
+{
+    friend class LayerPlanBuffer;
+    friend class GCodePlannerTest;
+private:
+    SliceDataStorage& storage; //!< The polygon data obtained from FffPolygonProcessor
+
+    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; 
+    
+    int layer_thickness;
+    
+    Point start_position;
     Point lastPosition;
-    std::vector<GCodePath> paths;
+    
+    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.
+    SliceLayerPart* was_inside; //!< The layer part the last planned (extrusion) move was inside (if any)
+    SliceLayerPart* is_inside; //!< The layer part the destination of the next planned travel move is inside (if any)
+    Polygons comb_boundary_inside; //!< The boundary within which to comb, or to move into when performing a retraction.
     Comb* comb;
 
-    GCodePathConfig travelConfig;
-    int extrudeSpeedFactor;
-    int travelSpeedFactor;
-    int currentExtruder;
-    int retractionMinimalDistance;
-    bool forceRetraction;
-    bool alwaysRetract;
-    double extraTime;
-    double totalPrintTime;
+
+    std::vector<FanSpeedLayerTimeSettings>& fan_speed_layer_time_settings_per_extruder;
     
 private:
-    GCodePath* getLatestPathWithConfig(GCodePathConfig* config);
-    void forceNewPathStart();
+    /*!
+     * Either create a new path with the given config or return the last path if it already had that config.
+     * If GCodePlanner::forceNewPathStart has been called a new path will always be returned.
+     * 
+     * \param config The config used for the path returned
+     * \param space_fill_type The type of space filling which this path employs
+     * \param flow (optional) A ratio for the extrusion speed
+     * \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);
+
 public:
-    GCodePlanner(GCodeExport& gcode, RetractionConfig* retraction_config, int travelSpeed, int retractionMinimalDistance);
+    /*!
+     * Force GCodePlanner::getLatestPathWithConfig to return a new path.
+     * 
+     * This function is introduced because in some cases 
+     * GCodePlanner::getLatestPathWithConfig is called consecutively with the same config pointer, 
+     * though the content of the config has changed.
+     * 
+     * Example cases: 
+     * - when changing extruder, the same travel config is used, but its extruder field is changed.
+     */
+    void forceNewPathStart();
+
+    /*!
+     * 
+     * \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, int layer_nr, int z, int layer_height, Point last_position, int current_extruder, 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();
 
-    bool setExtruder(int extruder)
+    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.
+     * \param combing_mode Whether combing is enabled and full or within infill only.
+     * \return the comb_boundary_inside
+     */
+    Polygons computeCombBoundaryInside(CombingMode combing_mode);
+
+public:
+    int getLayerNr()
     {
-        if (extruder == currentExtruder)
-            return false;
-        currentExtruder = extruder;
-        return true;
+        return layer_nr;
+    }
+    
+    Point getLastPosition()
+    {
+        return lastPosition;
     }
 
+    /*!
+     * return whether the last position planned was inside the mesh (used in combing)
+     */
+    bool getIsInsideMesh()
+    {
+        return was_inside;
+    }
+    /*!
+     * 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)
+    {
+        CommandSocket::sendLineTo(print_feature_type, to, line_width);
+    }
+
+    /*!
+    * Set whether the next destination is inside a layer part or not.
+    * 
+    * Features like infill, walls, skin etc. are considered inside.
+    * Features like prime tower and support are considered outside.
+    * \param inside_part The part in which the newly planned position is inside, or nullptr if not inside anything
+    */
+    void setIsInside(SliceLayerPart* inside_part);
+    
+    bool setExtruder(int extruder);
+
+    /*!
+     * Get the last planned extruder.
+     */
     int getExtruder()
     {
-        return currentExtruder;
+        return extruder_plans.back().extruder;
     }
 
-    void setCombBoundary(Polygons* polygons)
-    {
-        if (comb)
-            delete comb;
-        if (polygons)
-            comb = new Comb(*polygons);
-        else
-            comb = nullptr;
-    }
 
-    void setAlwaysRetract(bool alwaysRetract)
-    {
-        this->alwaysRetract = alwaysRetract;
-    }
-
-    void forceRetract()
-    {
-        forceRetraction = true;
-    }
-
-    void setExtrudeSpeedFactor(int speedFactor)
-    {
-        if (speedFactor < 1) speedFactor = 1;
-        this->extrudeSpeedFactor = speedFactor;
-    }
-    int getExtrudeSpeedFactor()
-    {
-        return this->extrudeSpeedFactor;
-    }
-    void setTravelSpeedFactor(int speedFactor)
-    {
-        if (speedFactor < 1) speedFactor = 1;
-        this->travelSpeedFactor = speedFactor;
-    }
-    int getTravelSpeedFactor()
-    {
-        return this->travelSpeedFactor;
-    }
-
-    void addTravel(Point p);
-
-    void addExtrusionMove(Point p, GCodePathConfig* config);
-
-    void moveInsideCombBoundary(int distance);
-
-    void addPolygon(PolygonRef polygon, int startIdx, GCodePathConfig* config);
-
-    void addPolygonsByOptimizer(Polygons& polygons, GCodePathConfig* config);
-
-    void addLinesByOptimizer(Polygons& polygons, GCodePathConfig* config);
-
-    void forceMinimalLayerTime(double minTime, int minimalSpeed, double travelTime, double extrusionTime);
     
-    void getTimes(double& travelTime, double& extrudeTime);
+    /*!
+     * Add a travel path to a certain point, retract if needed and when avoiding boundary crossings:
+     * avoiding obstacles and comb along the boundary of parts.
+     * 
+     * \param p The point to travel to
+     */
+    GCodePath& addTravel(Point p);
+    
+    /*!
+     * Add a travel path to a certain point and retract if needed.
+     * 
+     * No combing is performed.
+     * 
+     * \param p The point to travel to
+     * \param path (optional) The travel path to which to add the point \p p
+     */
+    GCodePath& addTravel_simple(Point p, GCodePath* path = nullptr);
 
-    void writeGCode(bool liftHeadIfNeeded, int layerThickness);
+    /*!
+     * Add an extrusion move to a certain point, optionally with a different flow than the one in the \p config.
+     * 
+     * \param p The point to extrude to
+     * \param config The config with which to extrude
+     * \param space_fill_type Of what space filling type this extrusion move is a part
+     * \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);
+
+    /*!
+     * Add polygon to the gcode starting at vertex \p startIdx
+     * \param polygon The polygon
+     * \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, coord_t wall_0_wipe_dist = 0, bool spiralize = false);
+
+    /*!
+     * Add polygons to the gcode with optimized order.
+     * 
+     * When \p spiralize is true, each polygon will gradually increase from a z corresponding to this layer to the z corresponding to the next layer.
+     * Doing this for each polygon means there is a chance for the print head to crash into already printed parts,
+     * but doing it for the last polygon only would mean you are printing half of the layer in non-spiralize mode,
+     * while each layer starts with a different part.
+     * Two towers would result in alternating spiralize and non-spiralize layers.
+     * 
+     * \param polygons The polygons
+     * \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 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, coord_t wall_0_wipe_dist = 0, bool spiralize = false);
+
+    /*!
+     * Add lines to the gcode with optimized order.
+     * \param polygons The lines
+     * \param config The config of the lines
+     * \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);
+
+    /*!
+     * 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();
+    
+    /*!
+     * Write the planned paths to gcode
+     * 
+     * \param gcode The gcode to write the planned paths to
+     */
+    void writeGCode(GCodeExport& gcode);
+    
+    /*!
+     * Complete all GcodePathConfigs by
+     * - altering speeds to conform to speed_print_layer_0 and
+     *   speed_travel_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.
+     * 
+     * \param gcode The gcode to write the planned paths to
+     * \param extruder_plan_idx The index of the current extruder plan
+     * \param path_idx The index of the current retracted path 
+     * \return Whether the path should be an extgruder switch retracted path
+     */
+    bool makeRetractSwitchRetract(GCodeExport& gcode, unsigned int extruder_plan_idx, unsigned int path_idx);
+    
+    /*!
+     * Writes a path to GCode and performs coasting, or returns false if it did nothing.
+     * 
+     * Coasting replaces the last piece of an extruded path by move commands and uses the oozed material to lay down lines.
+     * 
+     * \param gcode The gcode to write the planned paths to
+     * \param extruder_plan_idx The index of the current extruder plan
+     * \param path_idx The index into GCodePlanner::paths for the next path to be written to GCode.
+     * \param layerThickness The height of the current layer.
+     * \param coasting_volume The volume otherwise leaked during a normal move.
+     * \param coasting_speed The speed at which to move during move-coasting.
+     * \param coasting_min_volume The minimal volume a path should have (before starting to coast) which builds up enough pressure to ooze as much as \p coasting_volume.
+     * \return Whether any GCode has been written for the path.
+     */
+    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);
+
+    /*!
+     * Applying speed corrections for minimal layer times and determine the fanSpeed. 
+     */
+    void processFanSpeedAndMinimalLayerTime();
+    
+    /*!
+     * Add a travel move to the layer plan to move inside the current layer part by a given distance away from the outline.
+     * This is supposed to be called when the nozzle is around the boundary of a layer part, not when the nozzle is in the middle of support, or in the middle of the air.
+     * 
+     * \param distance The distance to the comb boundary after we moved inside it.
+     * \param part_outline The part in which we last resided
+     */
+    void moveInsideCombBoundary(int distance, const SliceLayerPart& part);
 };
 
 }//namespace cura

src/infill.cpp

@@ -2,185 +2,214 @@
 #include "infill.h"
 #include "functional"
 #include "utils/polygonUtils.h"
+#include "utils/logoutput.h"
+
 namespace cura {
 
-    
-      
-void generateConcentricInfillDense(Polygons outline, Polygons& result, Polygons* in_between, int extrusionWidth, bool avoidOverlappingPerimeters)
+int Infill::computeScanSegmentIdx(int x, int line_width)
 {
-    while(outline.size() > 0)
+    if (x < 0)
     {
-        for (unsigned int polyNr = 0; polyNr < outline.size(); polyNr++)
-        {
-            PolygonRef r = outline[polyNr];
-            result.add(r);
-        }
-        Polygons next_outline;
-        offsetExtrusionWidth(outline, true, extrusionWidth, next_outline, in_between, avoidOverlappingPerimeters);
-        outline = next_outline;
-    } 
-
+        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 generateConcentricInfill(Polygons outline, Polygons& result, int inset_value)
+void Infill::generate(Polygons& result_polygons, Polygons& result_lines)
 {
-    while(outline.size() > 0)
+    if (in_outline.size() == 0) return;
+    if (line_distance == 0) return;
+    Polygons outline_offsetted;
+    switch(pattern)
     {
-        for (unsigned int polyNr = 0; polyNr < outline.size(); polyNr++)
+    case EFillMethod::GRID:
+        generateGridInfill(result_lines);
+        break;
+    case EFillMethod::LINES:
+        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:
+        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;
+    default:
+        logError("Fill pattern has unknown value.\n");
+        break;
+    }
+}
+
+void Infill::generateConcentricInfill(Polygons& result, int inset_value)
+{
+    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
+
+    result.add(first_concentric_wall);
+    if (perimeter_gaps)
+    {
+        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)
+{
+    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)
         {
-            PolygonRef r = outline[polyNr];
-            result.add(r);
+            const Polygons outer = prev_inset->offset(-infill_line_width / 2 - perimeter_gaps_extra_offset);
+            const Polygons inner = next_inset.offset(infill_line_width / 2 + perimeter_gaps_extra_offset);
+            const Polygons gaps_here = outer.difference(inner);
+            perimeter_gaps->add(gaps_here);
         }
-        outline = outline.offset(-inset_value);
-    } 
+        prev_inset = &next_inset;
+    }
 }
 
-
-void generateGridInfill(const Polygons& in_outline, int outlineOffset, Polygons& result,
-                        int extrusionWidth, int lineSpacing, int infillOverlap,
-                        double rotation)
+void Infill::generateConcentric3DInfill(Polygons& result)
 {
-    generateLineInfill(in_outline, outlineOffset, result, extrusionWidth, lineSpacing,
-                       infillOverlap, rotation);
-    generateLineInfill(in_outline, outlineOffset, result, extrusionWidth, lineSpacing,
-                       infillOverlap, rotation + 90);
+    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 generateTriangleInfill(const Polygons& in_outline, int outlineOffset, Polygons& result,
-                        int extrusionWidth, int lineSpacing, int infillOverlap,
-                        double rotation)
+void Infill::generateGridInfill(Polygons& result)
 {
-    generateLineInfill(in_outline, outlineOffset, result, extrusionWidth, lineSpacing,
-                       infillOverlap, rotation);
-    generateLineInfill(in_outline, outlineOffset, result, extrusionWidth, lineSpacing,
-                       infillOverlap, rotation + 60);
-    generateLineInfill(in_outline, outlineOffset, result, extrusionWidth, lineSpacing,
-                       infillOverlap, rotation + 120);
+    generateLineInfill(result, line_distance, fill_angle, 0);
+    generateLineInfill(result, line_distance, fill_angle + 90, 0);
 }
 
-void addLineInfill(Polygons& result, PointMatrix matrix, int scanline_min_idx, int lineSpacing, AABB boundary, std::vector<std::vector<int64_t> > cutList, int extrusionWidth)
+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, 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, int64_t shift)
 {
     auto addLine = [&](Point from, Point to)
-    {            
+    {
         PolygonRef p = result.newPoly();
-        p.add(matrix.unapply(from));
-        p.add(matrix.unapply(to));
+        p.add(rotation_matrix.unapply(from));
+        p.add(rotation_matrix.unapply(to));
     };
-    
+
     auto compare_int64_t = [](const void* a, const void* b)
     {
         int64_t n = (*(int64_t*)a) - (*(int64_t*)b);
-        if (n < 0) return -1;
-        if (n > 0) return 1;
+        if (n < 0)
+        {
+            return -1;
+        }
+        if (n > 0)
+        {
+            return 1;
+        }
         return 0;
     };
-    
+
     int scanline_idx = 0;
-    for(int64_t x = scanline_min_idx * lineSpacing; x < boundary.max.X; x += lineSpacing)
+    for(int64_t x = scanline_min_idx * line_distance + shift; x < boundary.max.X; x += line_distance)
     {
-        qsort(cutList[scanline_idx].data(), cutList[scanline_idx].size(), sizeof(int64_t), compare_int64_t);
-        for(unsigned int i = 0; i + 1 < cutList[scanline_idx].size(); i+=2)
+        std::vector<int64_t>& crossings = cut_list[scanline_idx];
+        qsort(crossings.data(), crossings.size(), sizeof(int64_t), compare_int64_t);
+        for(unsigned int crossing_idx = 0; crossing_idx + 1 < crossings.size(); crossing_idx += 2)
         {
-            if (cutList[scanline_idx][i+1] - cutList[scanline_idx][i] < extrusionWidth / 5)
+            if (crossings[crossing_idx + 1] - crossings[crossing_idx] < infill_line_width / 5)
+            { // segment is too short to create infill
                 continue;
-            addLine(Point(x, cutList[scanline_idx][i]), Point(x, cutList[scanline_idx][i+1]));
+            }
+            addLine(Point(x, crossings[crossing_idx]), Point(x, crossings[crossing_idx + 1]));
         }
         scanline_idx += 1;
     }
 }
 
-/*!
- * generate lines within the area of \p in_outline, at regular intervals of \p lineSpacing
- * 
- * idea:
- * intersect a regular grid of 'scanlines' with the area inside \p in_outline
- * 
- * we call the areas between two consecutive scanlines a 'scansegment'.
- * Scansegment x is the area between scanline x and scanline x+1
- * 
- * algorithm:
- * 1) for each line segment of each polygon:
- *      store the intersections of that line segment with all scanlines in a mapping (vector of vectors) from scanline to intersections
- *      (zigzag): add boundary segments to result
- * 2) for each scanline:
- *      sort the associated intersections 
- *      and connect them using the even-odd rule
- * 
- */
-void generateLineInfill(const Polygons& in_outline, int outlineOffset, Polygons& result, int extrusionWidth, int lineSpacing, int infillOverlap, double rotation)
+void Infill::generateLineInfill(Polygons& result, int line_distance, const double& fill_angle, int64_t shift)
 {
-    if (in_outline.size() == 0) return;
-    Polygons outline = in_outline.offset(extrusionWidth * infillOverlap / 100 + outlineOffset);
-    if (outline.size() == 0) return;
-    
-    PointMatrix matrix(rotation);
-    
-    outline.applyMatrix(matrix);
+    PointMatrix rotation_matrix(fill_angle);
+    NoZigZagConnectorProcessor lines_processor(rotation_matrix, result);
+    bool connected_zigzags = false;
+    generateLinearBasedInfill(outline_offset, result, line_distance, rotation_matrix, lines_processor, connected_zigzags, shift);
+}
 
-    
-    AABB boundary(outline);
-    
-    int scanline_min_idx = boundary.min.X / lineSpacing;
-    int lineCount = (boundary.max.X + (lineSpacing - 1)) / lineSpacing - scanline_min_idx;
-  
-    std::vector<std::vector<int64_t> > cutList; // mapping from scanline to all intersections with polygon segments
-    
-    for(int n=0; n<lineCount; n++)
-        cutList.push_back(std::vector<int64_t>());
-    
-    for(unsigned int poly_idx=0; poly_idx < outline.size(); poly_idx++)
+
+void Infill::generateZigZagInfill(Polygons& result, const int line_distance, const double& fill_angle, const bool connected_zigzags, const bool use_endpieces)
+{
+
+    PointMatrix rotation_matrix(fill_angle);
+    if (use_endpieces)
     {
-        Point p0 = outline[poly_idx][outline[poly_idx].size()-1];
-        for(unsigned int i=0; i < outline[poly_idx].size(); i++)
+        if (connected_zigzags)
         {
-            Point p1 = outline[poly_idx][i];
-            int64_t xMin = p1.X, xMax = p0.X;
-            if (xMin == xMax) {
-                p0 = p1;
-                continue; 
-            }
-            if (xMin > xMax) { xMin = p0.X; xMax = p1.X; }
-            
-            int scanline_idx0 = (p0.X + ((p0.X > 0)? -1 : -lineSpacing)) / lineSpacing; // -1 cause a linesegment on scanline x counts as belonging to scansegment x-1   ...
-            int scanline_idx1 = (p1.X + ((p1.X > 0)? -1 : -lineSpacing)) / lineSpacing; // -linespacing because a line between scanline -n and -n-1 belongs to scansegment -n-1 (for n=positive natural number)
-            int direction = 1;
-            if (p0.X > p1.X) 
-            { 
-                direction = -1; 
-                scanline_idx1 += 1; // only consider the scanlines in between the scansegments
-            } else scanline_idx0 += 1; // only consider the scanlines in between the scansegments
-            
-            for(int scanline_idx = scanline_idx0; scanline_idx != scanline_idx1+direction; scanline_idx+=direction)
-            {
-                int x = scanline_idx * lineSpacing;
-                int y = p1.Y + (p0.Y - p1.Y) * (x - p1.X) / (p0.X - p1.X);
-                cutList[scanline_idx - scanline_min_idx].push_back(y);
-            }
-            p0 = p1;
+            ZigzagConnectorProcessorConnectedEndPieces zigzag_processor(rotation_matrix, result);
+            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, result, line_distance, rotation_matrix, zigzag_processor, connected_zigzags, 0);
         }
     }
-    
-    addLineInfill(result, matrix, scanline_min_idx, lineSpacing, boundary, cutList, extrusionWidth);
+    else 
+    {
+        ZigzagConnectorProcessorNoEndPieces zigzag_processor(rotation_matrix, result);
+        generateLinearBasedInfill(outline_offset - infill_line_width / 2, result, line_distance, rotation_matrix, zigzag_processor, connected_zigzags, 0);
+    }
 }
 
-
-void generateZigZagInfill(const Polygons& in_outline, Polygons& result, int extrusionWidth, int lineSpacing, int infillOverlap, double rotation, bool connect_zigzags, bool use_endPieces)
-{
-    if (use_endPieces) return generateZigZagInfill_endPieces(in_outline, result, extrusionWidth, lineSpacing, infillOverlap, rotation, connect_zigzags);
-    else return generateZigZagInfill_noEndPieces(in_outline, result, extrusionWidth, lineSpacing, infillOverlap, rotation);
-}
-
-/*!
- * adapted from generateLineInfill(.)
- * 
- * generate lines within the area of [in_outline], at regular intervals of [lineSpacing]
- * idea:
- * intersect a regular grid of 'scanlines' with the area inside [in_outline]
- * sigzag:
- * include pieces of boundary, connecting the lines, forming an accordion like zigzag instead of separate lines    |_|^|_|
- * 
- * we call the areas between two consecutive scanlines a 'scansegment'
- * 
+/* 
  * algorithm:
  * 1. for each line segment of each polygon:
  *      store the intersections of that line segment with all scanlines in a mapping (vector of vectors) from scanline to intersections
@@ -189,288 +218,137 @@ void generateZigZagInfill(const Polygons& in_outline, Polygons& result, int extr
  *      sort the associated intersections 
  *      and connect them using the even-odd rule
  * 
- * zigzag algorithm:
+ * rough explanation of the zigzag algorithm:
  * while walking around (each) polygon (1.)
  *  if polygon intersects with even scanline
  *      start boundary segment (add each following segment to the [result])
  *  when polygon intersects with a scanline again
  *      stop boundary segment (stop adding segments to the [result])
- *      if polygon intersects with even scanline again (instead of odd)
- *          dont add the last line segment to the boundary (unless [connect_zigzags])
+ *  (see infill/ZigzagConnectorProcessor.h for actual implementation details)
  * 
  * 
- *     <--
- *     ___
- *    |   |   |
- *    |   |   |
- *    |   |___|
- *         -->
- * 
- *        ^ = even scanline
- * 
- * start boundary from even scanline! :D
- * 
- * 
- *          _____
- *   |     |     | ,
- *   |     |     |  |
- *   |_____|     |__/
- * 
- *   ^     ^     ^    scanlines
- *                 ^  disconnected end piece
+ * we call the areas between two consecutive scanlines a 'scansegment'.
+ * Scansegment x is the area between scanline x and scanline x+1
+ * 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 generateZigZagInfill_endPieces(const Polygons& in_outline, Polygons& result, int extrusionWidth, int lineSpacing, int infillOverlap, double rotation, bool connect_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 (in_outline.size() == 0) return;
-//     Polygons outline = in_outline.offset(extrusionWidth * infillOverlap / 100 - extrusionWidth / 2);
-    Polygons empty;
-    Polygons outline = in_outline.difference(empty); // copy
-    if (outline.size() == 0) return;
-    
-    PointMatrix matrix(rotation);
-    
-    outline.applyMatrix(matrix);
-    
-    auto addLine = [&](Point from, Point to)
-    {            
-        PolygonRef p = result.newPoly();
-        p.add(matrix.unapply(from));
-        p.add(matrix.unapply(to));
-    };   
-        
-    AABB boundary(outline);
-    
-    int scanline_min_idx = boundary.min.X / lineSpacing;
-    int lineCount = (boundary.max.X + (lineSpacing - 1)) / lineSpacing - scanline_min_idx;
-    
-    std::vector<std::vector<int64_t> > cutList; // mapping from scanline to all intersections with polygon segments
-    
-    for(int n=0; n<lineCount; n++)
-        cutList.push_back(std::vector<int64_t>());
-    for(unsigned int polyNr=0; polyNr < outline.size(); polyNr++)
+    if (line_distance == 0)
     {
-        std::vector<Point> firstBoundarySegment;
-        std::vector<Point> unevenBoundarySegment; // stored cause for connected_zigzags a boundary segment which ends in an uneven scanline needs to be included
-        
-        bool isFirstBoundarySegment = true;
-        bool firstBoundarySegmentEndsInEven;
-        
-        bool isEvenScanSegment = false; 
-        
-        
-        Point p0 = outline[polyNr][outline[polyNr].size()-1];
-        Point lastPoint = p0;
-        for(unsigned int i=0; i < outline[polyNr].size(); i++)
+        return;
+    }
+    if (in_outline.size() == 0)
+    {
+        return;
+    }
+
+    int shift = extra_shift + this->shift;
+
+    Polygons outline;
+    if (outline_offset != 0)
+    {
+        outline = in_outline.offset(outline_offset);
+        if (perimeter_gaps)
         {
-            Point p1 = outline[polyNr][i];
-            int64_t xMin = p1.X, xMax = p0.X;
-            if (xMin == xMax) {
-                lastPoint = p1;
+            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);
+
+    if (outline.size() == 0)
+    {
+        return;
+    }
+
+    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 = 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
+
+    for(int scanline_idx = 0; scanline_idx < line_count; scanline_idx++)
+    {
+        cut_list.push_back(std::vector<int64_t>());
+    }
+
+    for(unsigned int poly_idx = 0; poly_idx < outline.size(); poly_idx++)
+    {
+        PolygonRef poly = outline[poly_idx];
+        Point p0 = poly.back();
+        zigzag_connector_processor.registerVertex(p0); // always adds the first point to ZigzagConnectorProcessorEndPieces::first_zigzag_connector when using a zigzag infill type
+        for(unsigned int point_idx = 0; point_idx < poly.size(); point_idx++)
+        {
+            Point p1 = poly[point_idx];
+            if (p1.X == p0.X)
+            {
+                zigzag_connector_processor.registerVertex(p1); 
+                // TODO: how to make sure it always adds the shortest line? (in order to prevent overlap with the zigzag connectors)
+                // note: this is already a problem for normal infill, but hasn't really cothered anyone so far.
                 p0 = p1;
                 continue; 
             }
-            if (xMin > xMax) { xMin = p0.X; xMax = p1.X; }
-            
-            int scanline_idx0 = (p0.X + ((p0.X > 0)? -1 : -lineSpacing)) / lineSpacing; // -1 cause a linesegment on scanline x counts as belonging to scansegment x-1   ...
-            int scanline_idx1 = (p1.X + ((p1.X > 0)? -1 : -lineSpacing)) / lineSpacing; // -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) 
             { 
+                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
+            {
                 direction = -1; 
-                scanline_idx1 += 1; // only consider the scanlines in between the scansegments
-            } else scanline_idx0 += 1; // only consider the scanlines in between the scansegments
-            
-            
-            if (isFirstBoundarySegment) firstBoundarySegment.push_back(p0);
-            for(int scanline_idx = scanline_idx0; scanline_idx != scanline_idx1+direction; scanline_idx+=direction)
+                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 * lineSpacing;
+                int x = scanline_idx * line_distance + shift;
                 int y = p1.Y + (p0.Y - p1.Y) * (x - p1.X) / (p0.X - p1.X);
-                cutList[scanline_idx - scanline_min_idx].push_back(y);
-                
-                
-                bool last_isEvenScanSegment = isEvenScanSegment;
-                if (scanline_idx % 2 == 0) isEvenScanSegment = true;
-                else isEvenScanSegment = false;
-                
-                if (!isFirstBoundarySegment)
-                {
-                    if (last_isEvenScanSegment && (connect_zigzags || !isEvenScanSegment))
-                        addLine(lastPoint, Point(x,y));
-                    else if (connect_zigzags && !last_isEvenScanSegment && !isEvenScanSegment) // if we end an uneven boundary in an uneven segment
-                    { // add whole unevenBoundarySegment (including the just obtained point)
-                        for (unsigned int p = 1; p < unevenBoundarySegment.size(); p++)
-                        {
-                            addLine(unevenBoundarySegment[p-1], unevenBoundarySegment[p]);
-                        }
-                        addLine(unevenBoundarySegment[unevenBoundarySegment.size()-1], Point(x,y));
-                        unevenBoundarySegment.clear();
-                    } 
-                    if (connect_zigzags && last_isEvenScanSegment && !isEvenScanSegment)
-                        unevenBoundarySegment.push_back(Point(x,y));
-                    else 
-                        unevenBoundarySegment.clear();
-                        
-                }
-                lastPoint = Point(x,y);
-                
-                if (isFirstBoundarySegment) 
-                {
-                    firstBoundarySegment.emplace_back(x,y);
-                    firstBoundarySegmentEndsInEven = isEvenScanSegment;
-                    isFirstBoundarySegment = false;
-                }
-                
+                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);
             }
-            if (!isFirstBoundarySegment)
-            {
-                if (isEvenScanSegment)
-                    addLine(lastPoint, p1);
-                else if (connect_zigzags)
-                    unevenBoundarySegment.push_back(p1);
-            }
-            
-            lastPoint = p1;
+            zigzag_connector_processor.registerVertex(p1);
             p0 = p1;
         }
-        
-        if (isEvenScanSegment || isFirstBoundarySegment || connect_zigzags)
-        {
-            for (unsigned int i = 1; i < firstBoundarySegment.size() ; i++)
-            {
-                if (i < firstBoundarySegment.size() - 1 || !firstBoundarySegmentEndsInEven || connect_zigzags) // only add last element if connect_zigzags or boundary segment ends in uneven scanline
-                    addLine(firstBoundarySegment[i-1], firstBoundarySegment[i]);
-            }   
-        }
-        else if (!firstBoundarySegmentEndsInEven)
-            addLine(firstBoundarySegment[firstBoundarySegment.size()-2], firstBoundarySegment[firstBoundarySegment.size()-1]);
-    } 
-    
-    if (cutList.size() == 0) return;
-    if (connect_zigzags && cutList.size() == 1 && cutList[0].size() <= 2) return;  // don't add connection if boundary already contains whole outline!
-    
-    addLineInfill(result, matrix, scanline_min_idx, lineSpacing, boundary, cutList, extrusionWidth);
-}
+        zigzag_connector_processor.registerPolyFinished();
+    }
 
-
-void generateZigZagInfill_noEndPieces(const Polygons& in_outline, Polygons& result, int extrusionWidth, int lineSpacing, int infillOverlap, double rotation)
-{
-    if (in_outline.size() == 0) return;
-    Polygons outline = in_outline.offset(extrusionWidth * infillOverlap / 100 - extrusionWidth / 2);
-    if (outline.size() == 0) return;
-    
-    PointMatrix matrix(rotation);
-    
-    outline.applyMatrix(matrix);
-    
-    auto addLine = [&](Point from, Point to)
-    {            
-        PolygonRef p = result.newPoly();
-        p.add(matrix.unapply(from));
-        p.add(matrix.unapply(to));
-    };   
-        
-    AABB boundary(outline);
-    
-    int scanline_min_idx = boundary.min.X / lineSpacing;
-    int lineCount = (boundary.max.X + (lineSpacing - 1)) / lineSpacing - scanline_min_idx;
-    
-    std::vector<std::vector<int64_t> > cutList; // mapping from scanline to all intersections with polygon segments
-    
-    for(int n=0; n<lineCount; n++)
-        cutList.push_back(std::vector<int64_t>());
-    for(unsigned int polyNr=0; polyNr < outline.size(); polyNr++)
+    if (cut_list.size() == 0)
     {
-        std::vector<Point> firstBoundarySegment;
-        std::vector<Point> boundarySegment;
-        
-        bool isFirstBoundarySegment = true;
-        bool firstBoundarySegmentEndsInEven;
-        
-        bool isEvenScanSegment = false; 
-        
-        
-        Point p0 = outline[polyNr][outline[polyNr].size()-1];
-        for(unsigned int i=0; i < outline[polyNr].size(); i++)
-        {
-            Point p1 = outline[polyNr][i];
-            int64_t xMin = p1.X, xMax = p0.X;
-            if (xMin == xMax) {
-                p0 = p1;
-                continue; 
-            }
-            if (xMin > xMax) { xMin = p0.X; xMax = p1.X; }
-            
-            int scanline_idx0 = (p0.X + ((p0.X > 0)? -1 : -lineSpacing)) / lineSpacing; // -1 cause a linesegment on scanline x counts as belonging to scansegment x-1   ...
-            int scanline_idx1 = (p1.X + ((p1.X > 0)? -1 : -lineSpacing)) / lineSpacing; // -linespacing because a line between scanline -n and -n-1 belongs to scansegment -n-1 (for n=positive natural number)
-            int direction = 1;
-            if (p0.X > p1.X) 
-            { 
-                direction = -1; 
-                scanline_idx1 += 1; // only consider the scanlines in between the scansegments
-            } else scanline_idx0 += 1; // only consider the scanlines in between the scansegments
-            
-            
-            if (isFirstBoundarySegment) firstBoundarySegment.push_back(p0);
-            else boundarySegment.push_back(p0);
-            for(int scanline_idx = scanline_idx0; scanline_idx != scanline_idx1+direction; scanline_idx+=direction)
-            {
-                int x = scanline_idx * lineSpacing;
-                int y = p1.Y + (p0.Y - p1.Y) * (x - p1.X) / (p0.X - p1.X);
-                cutList[scanline_idx - scanline_min_idx].push_back(y);
-                
-                
-                bool last_isEvenScanSegment = isEvenScanSegment;
-                if (scanline_idx % 2 == 0) isEvenScanSegment = true;
-                else isEvenScanSegment = false;
-                
-                if (!isFirstBoundarySegment)
-                {
-                    if (last_isEvenScanSegment && !isEvenScanSegment)
-                    { // add whole boundarySegment (including the just obtained point)
-                        for (unsigned int p = 1; p < boundarySegment.size(); p++)
-                        {
-                            addLine(boundarySegment[p-1], boundarySegment[p]);
-                        }
-                        addLine(boundarySegment[boundarySegment.size()-1], Point(x,y));
-                        boundarySegment.clear();
-                    } 
-                    else if (isEvenScanSegment) // we are either in an end piece or an uneven boundary segment
-                    {
-                        boundarySegment.clear();
-                        boundarySegment.emplace_back(x,y);
-                    } else
-                        boundarySegment.clear();
-                        
-                }
-                
-                if (isFirstBoundarySegment) 
-                {
-                    firstBoundarySegment.emplace_back(x,y);
-                    firstBoundarySegmentEndsInEven = isEvenScanSegment;
-                    isFirstBoundarySegment = false;
-                    boundarySegment.emplace_back(x,y);
-                }
-                
-            }
-            if (!isFirstBoundarySegment && isEvenScanSegment)
-                boundarySegment.push_back(p1);
-            
-            
-            p0 = p1;
-        }
-        
-        if (!isFirstBoundarySegment && isEvenScanSegment && !firstBoundarySegmentEndsInEven)
-        {
-            for (unsigned int i = 1; i < firstBoundarySegment.size() ; i++)
-                addLine(firstBoundarySegment[i-1], firstBoundarySegment[i]);
-        }
-    } 
-    
-
-    addLineInfill(result, matrix, scanline_min_idx, lineSpacing, boundary, cutList, extrusionWidth);
+        return;
+    }
+    if (connected_zigzags && cut_list.size() == 1 && cut_list[0].size() <= 2)
+    {
+        return;  // don't add connection if boundary already contains whole outline!
+    }
 
+    addLineInfill(result, rotation_matrix, scanline_min_idx, line_distance, boundary, cut_list, shift);
 }
 
-
 }//namespace cura

src/infill.h

@@ -3,17 +3,239 @@
 #define INFILL_H
 
 #include "utils/polygon.h"
+#include "settings/settings.h"
+// #include "ZigzagConnectorProcessor.h"
+#include "infill/ZigzagConnectorProcessor.h"
+#include "infill/NoZigZagConnectorProcessor.h"
+#include "infill/ActualZigzagConnectorProcessor.h"
+#include "infill/ZigzagConnectorProcessorNoEndPieces.h"
+#include "infill/ZigzagConnectorProcessorEndPieces.h"
+#include "infill/ZigzagConnectorProcessorConnectedEndPieces.h"
+#include "infill/ZigzagConnectorProcessorDisconnectedEndPieces.h"
+#include "utils/intpoint.h"
+#include "utils/AABB.h"
 
-namespace cura {
+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
+    int infill_line_width; //!< The line width of the infill lines to generate
+    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:
+    /*!
+     * \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)
+    , infill_line_width(infill_line_width)
+    , 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)
+    {
+    }
+    /*!
+     * Generate the infill.
+     * 
+     * \param result_polygons (output) The resulting polygons (from concentric infill)
+     * \param result_lines (output) The resulting line segments (from linear infill types)
+     */
+    void generate(Polygons& result_polygons, Polygons& result_lines);
+
+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
+     * 
+     * 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& 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
+     * \param result (output) The resulting lines
+     */
+    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);
+    
+    /*!
+     * 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
+     * \param rotation_matrix The rotation matrix (un)applied to enforce the angle of the infill 
+     * \param scanline_min_idx The lowest index of all scanlines crossing the polygon
+     * \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, int64_t total_shift);
+
+    /*!
+     * generate lines within the area of \p in_outline, at regular intervals of \p line_distance
+     * 
+     * idea:
+     * intersect a regular grid of 'scanlines' with the area inside \p in_outline
+     * 
+     * \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, int64_t extra_shift);
+    
+    /*!
+     * Function for creating linear based infill types (Lines, ZigZag).
+     * 
+     * This function implements the basic functionality of Infill::generateLineInfill (see doc of that function),
+     * but makes calls to a ZigzagConnectorProcessor which handles what to do with each line segment - scanline intersection.
+     * 
+     * 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 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, Polygons& result, const int line_distance, const PointMatrix& rotation_matrix, ZigzagConnectorProcessor& zigzag_connector_processor, const bool connected_zigzags, int64_t extra_shift);
+
+    /*!
+     * 
+     * generate lines within the area of [in_outline], at regular intervals of [line_distance]
+     * idea:
+     * intersect a regular grid of 'scanlines' with the area inside [in_outline] (see generateLineInfill)
+     * zigzag:
+     * include pieces of boundary, connecting the lines, forming an accordion like zigzag instead of separate lines    |_|^|_|
+     * 
+     * Note that ZigZag consists of 3 types:
+     * - without endpieces
+     * - with disconnected endpieces
+     * - with connected endpieces
+     * 
+     *     <--
+     *     ___
+     *    |   |   |
+     *    |   |   |
+     *    |   |___|
+     *         -->
+     * 
+     *        ^ = even scanline
+     *  ^            ^ no endpieces
+     * 
+     * start boundary from even scanline! :D
+     * 
+     * 
+     *                 v  disconnected end piece: leave out last line segment
+     *          _____
+     *   |     |     |  \                     .
+     *   |     |     |  |
+     *   |_____|     |__/
+     * 
+     *   ^     ^     ^    scanlines
+     * 
+     * 
+     *                 v  connected end piece
+     *          ________
+     *   |     |     |  \                      .
+     *   |     |     |  |
+     *   |_____|     |__/                       .
+     * 
+     *   ^     ^     ^    scanlines
+     * 
+     * \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 connected_zigzags Whether to connect the endpiece zigzag segments on both sides to the same infill line
+     * \param use_endpieces Whether to include zigzag segments connecting a scanline to itself
+     */
+    void generateZigZagInfill(Polygons& result, const int line_distance, const double& fill_angle, const bool connected_zigzags, const bool use_endpieces);
+};
 
-void generateConcentricInfill(Polygons outline, Polygons& result, int inset_value);
-void generateConcentricInfillDense(Polygons outline, Polygons& result, Polygons* in_between, int extrusionWidth, bool avoidOverlappingPerimeters);
-void generateGridInfill(const Polygons& in_outline, int outlineOffset, Polygons& result, int extrusionWidth, int lineSpacing, int infillOverlap, double rotation);
-void generateTriangleInfill(const Polygons& in_outline, int outlineOffset, Polygons& result, int extrusionWidth, int lineSpacing, int infillOverlap, double rotation);
-void generateLineInfill(const Polygons& in_outline, int outlineOffset, Polygons& result, int extrusionWidth, int lineSpacing, int infillOverlap, double rotation);
-void generateZigZagInfill(const Polygons& in_outline, Polygons& result, int extrusionWidth, int lineSpacing, int infillOverlap, double rotation, bool connect_zigzags, bool use_endPieces);
-void generateZigZagInfill_endPieces(const Polygons& in_outline, Polygons& result, int extrusionWidth, int lineSpacing, int infillOverlap, double rotation, bool connect_zigzags);
-void generateZigZagInfill_noEndPieces(const Polygons& in_outline, Polygons& result, int extrusionWidth, int lineSpacing, int infillOverlap, double rotation);
 }//namespace cura
 
 #endif//INFILL_H

src/infill/ActualZigzagConnectorProcessor.h

@@ -0,0 +1,47 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef INFILL_ACTUAL_ZIGZAG_CONNECTOR_PROCESSOR_H
+#define INFILL_ACTUAL_ZIGZAG_CONNECTOR_PROCESSOR_H
+
+
+#include "../utils/polygon.h"
+#include "ZigzagConnectorProcessor.h"
+#include "../utils/intpoint.h"
+
+namespace cura
+{
+
+/*!
+ * In contrast to NoZigZagConnectorProcessor
+ */
+class ActualZigzagConnectorProcessor : public ZigzagConnectorProcessor
+{
+protected:
+    /*!
+     * The line segments belonging the zigzag connector to which the very first vertex belongs. 
+     * This will be combined with the last handled zigzag_connector, which combine to a whole zigzag connector.
+     * 
+     * Because the boundary polygon may start in in the middle of a zigzag connector, 
+     */
+    std::vector<Point> first_zigzag_connector; 
+    /*!
+     * The currently built up zigzag connector (not the first/last) or end piece or discarded boundary segment
+     */
+    std::vector<Point> zigzag_connector; 
+
+    bool is_first_zigzag_connector; //!< Whether we're still in the first zigzag connector
+    bool first_zigzag_connector_ends_in_even_scanline; //!< Whether the first zigzag connector ends in an even scanline
+    bool last_scanline_is_even;  //!< Whether the last seen scanline-boundary intersection was with an even scanline
+
+    ActualZigzagConnectorProcessor(const PointMatrix& rotation_matrix, Polygons& result)
+    : ZigzagConnectorProcessor(rotation_matrix, result)
+    , is_first_zigzag_connector(true)
+    , first_zigzag_connector_ends_in_even_scanline(true)
+    , last_scanline_is_even(false) 
+    {
+    }
+};
+
+} // namespace cura
+
+
+#endif // INFILL_ACTUAL_ZIGZAG_CONNECTOR_PROCESSOR_H

src/infill/NoZigZagConnectorProcessor.cpp

@@ -0,0 +1,25 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#include "NoZigZagConnectorProcessor.h"
+
+
+namespace cura 
+{
+
+void NoZigZagConnectorProcessor::registerVertex(const Point& vertex)
+{
+
+}
+
+void NoZigZagConnectorProcessor::registerScanlineSegmentIntersection(const Point& intersection, bool scanline_is_even)
+{
+
+}
+
+void NoZigZagConnectorProcessor::registerPolyFinished()
+{
+
+}
+
+
+
+} // namespace cura 

src/infill/NoZigZagConnectorProcessor.h

@@ -0,0 +1,28 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef INFILL_NO_ZIGZAG_CONNECTOR_PROCESSOR_H
+#define INFILL_NO_ZIGZAG_CONNECTOR_PROCESSOR_H
+
+#include "../utils/polygon.h"
+#include "ZigzagConnectorProcessor.h"
+
+namespace cura
+{
+
+class NoZigZagConnectorProcessor : public ZigzagConnectorProcessor
+{
+public:
+    NoZigZagConnectorProcessor(const PointMatrix& rotation_matrix, Polygons& result)
+    : ZigzagConnectorProcessor(rotation_matrix, result)
+    {
+    }
+
+    void registerVertex(const Point& vertex);
+    void registerScanlineSegmentIntersection(const Point& intersection, bool scanline_is_even);
+    void registerPolyFinished();
+};
+
+
+} // namespace cura
+
+
+#endif // INFILL_NO_ZIGZAG_CONNECTOR_PROCESSOR_H

src/infill/ZigzagConnectorProcessor.h

@@ -0,0 +1,154 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef INFILL_ZIGZAG_CONNECTOR_PROCESSOR_H
+#define INFILL_ZIGZAG_CONNECTOR_PROCESSOR_H
+
+#include "../utils/polygon.h"
+
+namespace cura
+{
+
+/*!
+ * Processor class for processing the connections between lines which makes the infill a zigzag pattern.
+ * 
+ * During the creation of the infill lines, calls are made to a ZigzagConnectorProcessor so that the zigzag connector segments are created 
+ * at the same time as the lines are created.
+ *
+ * generate lines within the area of [in_outline], at regular intervals of [line_distance]
+ *  idea:
+ * intersect a regular grid of 'scanlines' with the area inside [in_outline] (see generateLineInfill)
+ * zigzag:
+ * include pieces of boundary, connecting the lines, forming an accordion like zigzag instead of separate lines    |_|^|_|
+ * 
+ * we call the areas between two consecutive scanlines a 'scansegment'
+ * 
+ * algorithm:
+ * 1. for each line segment of each polygon:
+ *      store the intersections of that line segment with all scanlines in a mapping (vector of vectors) from scanline to intersections
+ *      (zigzag): add boundary segments to result
+ * 2. for each scanline:
+ *      sort the associated intersections 
+ *      and connect them using the even-odd rule
+ * 
+ * zigzag algorithm:
+ *  while walking around (each) polygon (1.)
+ *  if polygon intersects with even scanline
+ *      start boundary segment (add each following segment to the [result])
+ *  when polygon intersects with a scanline again
+ *      stop boundary segment (stop adding segments to the [result])
+ *      if polygon intersects with even scanline again (instead of odd)
+ *           dont add the last line segment to the boundary (unless [connected_zigzags])
+ * 
+ * Note that ZigZag consists of 3 types:
+ * - without endpieces
+ * - with disconnected endpieces
+ * - with connected endpieces
+ * 
+ * Each of these has a base class for which ZigzagConnectorProcessor is an ancestor.
+ * The inheritance structure is as such:
+ *                                                                      ZigzagConnectorProcessor
+ *                                                                           /             \                                    .
+ *                                                                          /               \                                   .
+ *                                                  ActualZigzagConnectorProcessor      NoZigZagConnectorProcessor
+ *                                                         /                \             for lines infill                                      .
+ *                                                        /                  \                                                  .
+ *                          ZigzagConnectorProcessorEndPieces   ZigzagConnectorProcessorNoEndPieces
+ *                                     /            \                 for zigzag infill (without end pieces)                                                          .
+ *                                    /              \                                                                          .
+ * ZigzagConnectorProcessorConnectedEndPieces     ZigzagConnectorProcessorDisconnectedEndPieces
+ * for zigzag support with normal endpieces          for zigzag support with disconnected endpieces for more easy removability
+ * 
+ *      v   v   zigzag connectors
+ *     <--
+ *    :___:   :      < scanlines
+ *    |   |   |
+ *    |   |   |      < infill lines along scanlines
+ *    |   |___|
+ *    :   :   :
+ *         -->       winding order of polygon
+ * 
+ *        ^ = even scanline
+ *  ^            ^ no endpieces
+ * 
+ * start boundary from even scanline! :D
+ * include only a boundary segment if it starts in an even scanline and ends in an odd scanline
+ * 
+ *          ________
+ *   |     |     |  \                      .
+ *   |     |     |  |
+ *   |_____|     |__/                       .
+ * 
+ *   ^     ^     ^    scanlines
+ *                 ^  connected end piece
+ * include a boundary segment also if it starts in an odd scanline and ends odd, 
+ * or starts in an even scanline and ends in an even scanline,
+ * but not when it starts in an odd and ends in an even scanline (see top left or bottom middle).
+ * 
+ *          _____
+ *   |     |     |  \                     .
+ *   |     |     |  |
+ *   |_____|     |__/
+ * 
+ *   ^     ^     ^    scanlines
+ *                 ^  disconnected end piece
+ * Leave out the last line segment of the boundary polygon: from a vertex to the linesegment-scanline intersection.
+ */
+class ZigzagConnectorProcessor 
+{
+protected:
+    const PointMatrix& rotation_matrix; //!< The rotation matrix used to enforce the infill angle
+    Polygons& result; //!< The result of the computation
+
+    virtual ~ZigzagConnectorProcessor()
+    {}
+
+    /*!
+     * Add a line to the result bu unapplying the rotation rotation_matrix.
+     * 
+     * \param from The one end of the line segment
+     * \param to The other end of the line segment
+     */
+    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));
+    }
+
+    /*!
+     * Basic constructor. Inheriting children should call this constructor.
+     * 
+     * \param rotation_matrix The rotation matrix used to enforce the infill angle
+     * \param result The resulting line segments (Each line segment is a Polygon with 2 points)
+     */
+    ZigzagConnectorProcessor(const PointMatrix& rotation_matrix, Polygons& result)
+    : rotation_matrix(rotation_matrix)
+    , result(result)
+    {}
+public:
+
+    /*!
+     * Handle the next vertex on the outer boundary.
+     * \param vertex The vertex
+     */
+    virtual void registerVertex(const Point& vertex) = 0;
+    
+    /*!
+     * Handle the next intersection between a scanline and the outer boundary.
+     * 
+     * \param intersection The intersection
+     * \param scanline_is_even Whether the scanline was even
+     */
+    virtual void registerScanlineSegmentIntersection(const Point& intersection, bool scanline_is_even) = 0;
+    
+    /*!
+     * Handle the end of a polygon and prepare for the next.
+     * This function should reset all member variables.
+     */
+    virtual void registerPolyFinished() = 0;
+};
+
+
+} // namespace cura
+
+
+#endif // INFILL_ZIGZAG_CONNECTOR_PROCESSOR_H

src/infill/ZigzagConnectorProcessorConnectedEndPieces.cpp

@@ -0,0 +1,75 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#include "ZigzagConnectorProcessorConnectedEndPieces.h"
+
+
+namespace cura 
+{
+
+
+void ZigzagConnectorProcessorConnectedEndPieces::registerScanlineSegmentIntersection(const Point& intersection, bool scanline_is_even)
+{
+    bool previous_scanline_is_even = last_scanline_is_even;
+    last_scanline_is_even = scanline_is_even;
+    bool this_scanline_is_even = last_scanline_is_even;
+    
+    if (is_first_zigzag_connector)
+    {
+        first_zigzag_connector.push_back(intersection);
+        first_zigzag_connector_ends_in_even_scanline = this_scanline_is_even;
+        is_first_zigzag_connector = false;
+    }
+    else
+    {
+        if (previous_scanline_is_even)
+        { // when a boundary segment starts in an even scanline it is either a normal zigzag connector or an endpiece, so it should be included anyway
+            addLine(last_connector_point, intersection);
+        }
+        else if (!previous_scanline_is_even && !this_scanline_is_even) // if we end an odd boundary in an odd segment
+        { // add whole zigzag_connector (including the just obtained point)
+            for (unsigned int point_idx = 1; point_idx < zigzag_connector.size(); point_idx++)
+            {
+                addLine(zigzag_connector[point_idx - 1], zigzag_connector[point_idx]);
+            }
+            addLine(zigzag_connector.back(), intersection);
+            zigzag_connector.clear();
+        }
+
+    }
+    zigzag_connector.clear(); // we're starting a new (odd) zigzag connector, so clear the old one
+    if (!this_scanline_is_even) // we are either in an end piece or an boundary segment starting in an odd scanline
+    { // only when a boundary segment starts in an odd scanline it depends on whether it ends in an odd scanline for whether this segment should be included or not
+        zigzag_connector.push_back(intersection);
+    }
+
+    last_connector_point = intersection;
+}
+
+
+void ZigzagConnectorProcessorConnectedEndPieces::registerPolyFinished()
+{
+    // write end segment if needed (first half of start/end-crossing segment)
+    if (!last_scanline_is_even && !first_zigzag_connector_ends_in_even_scanline)
+    {
+        for (unsigned int point_idx = 1; point_idx < zigzag_connector.size(); point_idx++)
+        {
+            addLine(zigzag_connector[point_idx - 1], zigzag_connector[point_idx]);
+        }
+    }
+    // write begin segment if needed (second half of start/end-crossing segment)
+    if (last_scanline_is_even || (!last_scanline_is_even && !first_zigzag_connector_ends_in_even_scanline)
+        || is_first_zigzag_connector)
+    {
+        for (unsigned int point_idx = 1; point_idx < first_zigzag_connector.size(); point_idx++)
+        {
+            addLine(first_zigzag_connector[point_idx - 1], first_zigzag_connector[point_idx]);
+        }
+    }
+    // reset member variables
+    is_first_zigzag_connector = true;
+    first_zigzag_connector_ends_in_even_scanline = true;
+    last_scanline_is_even = false; 
+    first_zigzag_connector.clear();
+    zigzag_connector.clear();
+}
+
+} // namespace cura 

src/infill/ZigzagConnectorProcessorConnectedEndPieces.h

@@ -0,0 +1,27 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef INFILL_ZIGZAG_CONNECTOR_PROCESSOR_CONNECTED_END_PIECES_H
+#define INFILL_ZIGZAG_CONNECTOR_PROCESSOR_CONNECTED_END_PIECES_H
+
+#include "../utils/polygon.h"
+#include "ZigzagConnectorProcessorEndPieces.h"
+#include "../utils/intpoint.h"
+
+namespace cura
+{
+
+
+class ZigzagConnectorProcessorConnectedEndPieces : public ZigzagConnectorProcessorEndPieces
+{
+public:
+    ZigzagConnectorProcessorConnectedEndPieces(const PointMatrix& rotation_matrix, Polygons& result)
+    : ZigzagConnectorProcessorEndPieces(rotation_matrix, result)
+    {
+    }
+    void registerScanlineSegmentIntersection(const Point& intersection, bool scanline_is_even);
+    void registerPolyFinished();
+};
+
+} // namespace cura
+
+
+#endif // INFILL_ZIGZAG_CONNECTOR_PROCESSOR_CONNECTED_END_PIECES_H

src/infill/ZigzagConnectorProcessorDisconnectedEndPieces.cpp

@@ -0,0 +1,79 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#include "ZigzagConnectorProcessorDisconnectedEndPieces.h"
+
+
+namespace cura 
+{
+
+void ZigzagConnectorProcessorDisconnectedEndPieces::registerScanlineSegmentIntersection(const Point& intersection, bool scanline_is_even)
+{
+    bool previous_scanline_is_even = last_scanline_is_even;
+    last_scanline_is_even = scanline_is_even;
+    bool this_scanline_is_even = last_scanline_is_even;
+    
+    if (is_first_zigzag_connector) 
+    {
+        first_zigzag_connector.push_back(intersection);
+        first_zigzag_connector_ends_in_even_scanline = this_scanline_is_even;
+        is_first_zigzag_connector = false;
+    }
+    else
+    {
+        if (previous_scanline_is_even && !this_scanline_is_even)
+        { // if we left from an even scanline, but not if this is the line segment connecting that zigzag_connector to an even scanline
+            addLine(last_connector_point, intersection);
+        }
+        else if (!previous_scanline_is_even && !this_scanline_is_even) // if we end an odd boundary in an odd segment
+        { // add whole oddBoundarySegment (including the just obtained point)
+            for (unsigned int point_idx = 1; point_idx < zigzag_connector.size(); point_idx++)
+            {
+                addLine(zigzag_connector[point_idx - 1], zigzag_connector[point_idx]);
+            }
+            // skip the last segment to the [intersection]
+            zigzag_connector.clear();
+        }
+        
+    }
+    zigzag_connector.clear(); // we're starting a new (odd) zigzag connector, so clear the old one
+    if (!this_scanline_is_even) // we are either in an end piece or an boundary segment starting in an odd scanline
+    { // only when a boundary segment starts in an odd scanline it depends on whether it ends in an odd scanline for whether this segment should be included or not
+        zigzag_connector.push_back(intersection);
+    }
+
+    last_connector_point = intersection;
+}
+
+
+void ZigzagConnectorProcessorDisconnectedEndPieces::registerPolyFinished()
+{
+    // write end segment if needed (first half of start/end-crossing segment)
+    if (!last_scanline_is_even && !first_zigzag_connector_ends_in_even_scanline)
+    {
+        for (unsigned int point_idx = 1; point_idx < zigzag_connector.size(); point_idx++)
+        {
+            addLine(zigzag_connector[point_idx - 1], zigzag_connector[point_idx]);
+        }
+    }
+    // write begin segment if needed (second half of start/end-crossing segment)
+    if (last_scanline_is_even || is_first_zigzag_connector)
+    {
+        for (unsigned int point_idx = 1; point_idx < first_zigzag_connector.size() - 1; point_idx++) // -1 cause skipping very last line segment!
+        {
+            addLine(first_zigzag_connector[point_idx - 1], first_zigzag_connector[point_idx]);
+        }
+    }
+    // write very last line segment if needed
+    if (last_scanline_is_even && !first_zigzag_connector_ends_in_even_scanline)
+    { // only add last element if boundary segment ends in odd scanline
+        addLine(first_zigzag_connector[first_zigzag_connector.size() - 2], first_zigzag_connector[first_zigzag_connector.size() - 1]);
+    }
+    // reset member variables
+    is_first_zigzag_connector = true;
+    first_zigzag_connector_ends_in_even_scanline = true;
+    last_scanline_is_even = false; 
+    first_zigzag_connector.clear();
+    zigzag_connector.clear();
+}
+
+
+} // namespace cura 

src/infill/ZigzagConnectorProcessorDisconnectedEndPieces.h

@@ -0,0 +1,26 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef INFILL_ZIGZAG_CONNECTOR_PROCESSOR_DISCONNECTED_END_PIECES_H
+#define INFILL_ZIGZAG_CONNECTOR_PROCESSOR_DISCONNECTED_END_PIECES_H
+
+#include "../utils/polygon.h"
+#include "ZigzagConnectorProcessorEndPieces.h"
+
+namespace cura
+{
+
+class ZigzagConnectorProcessorDisconnectedEndPieces : public ZigzagConnectorProcessorEndPieces
+{
+
+public:
+    ZigzagConnectorProcessorDisconnectedEndPieces(const PointMatrix& rotation_matrix, Polygons& result)
+    : ZigzagConnectorProcessorEndPieces(rotation_matrix, result)
+    {
+    }
+    void registerScanlineSegmentIntersection(const Point& intersection, bool scanline_is_even);
+    void registerPolyFinished();
+};
+
+} // namespace cura
+
+
+#endif // INFILL_ZIGZAG_CONNECTOR_PROCESSOR_DISCONNECTED_END_PIECES_H

src/infill/ZigzagConnectorProcessorEndPieces.cpp

@@ -0,0 +1,27 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#include "ZigzagConnectorProcessorEndPieces.h"
+
+
+namespace cura 
+{
+
+void ZigzagConnectorProcessorEndPieces::registerVertex(const Point& vertex)
+{
+    if (is_first_zigzag_connector)
+    {
+        first_zigzag_connector.push_back(vertex);
+    }
+    else if (last_scanline_is_even)
+    { // when a boundary segments starts in an even scanline it's either a normal zigzag connector or an endpiece to be included
+        // note that for ZigzagConnectorProcessorDisconnectedEndPieces only the last line segment from a boundary vertex to a scanline-boundary intersection is omitted
+        addLine(last_connector_point, vertex);
+    }
+    else
+    { // it's yet unclear whether the line segment should be included, so we store it until we know
+        zigzag_connector.push_back(vertex);
+    }
+    last_connector_point = vertex;
+}
+
+
+} // namespace cura 

src/infill/ZigzagConnectorProcessorEndPieces.h

@@ -0,0 +1,32 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef INFILL_ZIGZAG_CONNECTOR_PROCESSOR_END_PIECES_H
+#define INFILL_ZIGZAG_CONNECTOR_PROCESSOR_END_PIECES_H
+
+#include "../utils/polygon.h"
+#include "ActualZigzagConnectorProcessor.h"
+
+namespace cura
+{
+
+
+class ZigzagConnectorProcessorEndPieces : public ActualZigzagConnectorProcessor
+{
+protected:
+    Point last_connector_point; //!< last registered boundary vertex or scanline-coundary intersection
+
+    ZigzagConnectorProcessorEndPieces(const PointMatrix& rotation_matrix, Polygons& result)
+    : ActualZigzagConnectorProcessor(rotation_matrix, result)
+    , last_connector_point(0,0)
+    {
+    }
+
+public:
+    void registerVertex(const Point& vertex);
+};
+
+
+
+} // namespace cura
+
+
+#endif // INFILL_ZIGZAG_CONNECTOR_PROCESSOR_END_PIECES_H

src/infill/ZigzagConnectorProcessorNoEndPieces.cpp

@@ -0,0 +1,72 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#include "ZigzagConnectorProcessorNoEndPieces.h"
+
+
+namespace cura 
+{
+
+void ZigzagConnectorProcessorNoEndPieces::registerVertex(const Point& vertex)
+{
+    if (is_first_zigzag_connector)
+    {
+        first_zigzag_connector.push_back(vertex);
+    }
+    else if (last_scanline_is_even)
+    {
+        zigzag_connector.push_back(vertex);
+    }
+}
+
+
+void ZigzagConnectorProcessorNoEndPieces::registerScanlineSegmentIntersection(const Point& intersection, bool scanline_is_even)
+{
+    bool previous_scanline_is_even = last_scanline_is_even;
+    last_scanline_is_even = scanline_is_even;
+    bool this_scanline_is_even = last_scanline_is_even; // for conceptual clarity
+    
+    if (is_first_zigzag_connector) 
+    {
+        first_zigzag_connector.push_back(intersection);
+        first_zigzag_connector_ends_in_even_scanline = this_scanline_is_even;
+        is_first_zigzag_connector = false;
+    }
+    else
+    {
+        if (previous_scanline_is_even && !this_scanline_is_even)
+        { // add whole zigzag_connector (including the just obtained point)
+            for (unsigned int point_idx = 1; point_idx < zigzag_connector.size(); point_idx++)
+            {
+                addLine(zigzag_connector[point_idx - 1], zigzag_connector[point_idx]);
+            }
+            addLine(zigzag_connector.back(), intersection);
+            zigzag_connector.clear();
+        }
+    }
+    zigzag_connector.clear(); // we're starting a new zigzag connector, so clear the old one
+    if (this_scanline_is_even) // only boundary segments starting in an even segment are considered
+    {
+        zigzag_connector.push_back(intersection);
+    }
+    
+}
+
+
+void ZigzagConnectorProcessorNoEndPieces::registerPolyFinished()
+{
+    if (!is_first_zigzag_connector && last_scanline_is_even && !first_zigzag_connector_ends_in_even_scanline)
+    { // only if it's a normal zigzag connector; not when the whole boundary didn't cross any scanlines
+        for (unsigned int point_idx = 1; point_idx < first_zigzag_connector.size() ; point_idx++)
+        {
+            addLine(first_zigzag_connector[point_idx - 1], first_zigzag_connector[point_idx]);
+        }
+    }
+    // reset member variables
+    is_first_zigzag_connector = true;
+    first_zigzag_connector_ends_in_even_scanline = true;
+    last_scanline_is_even = false; 
+    first_zigzag_connector.clear();
+    zigzag_connector.clear();
+}
+
+
+} // namespace cura 

src/infill/ZigzagConnectorProcessorNoEndPieces.h

@@ -0,0 +1,29 @@
+/** Copyright (C) 2016 Ultimaker - Released under terms of the AGPLv3 License */
+#ifndef INFILL_ZIGZAG_CONNECTOR_PROCESSOR_NO_ENDPIECES_H
+#define INFILL_ZIGZAG_CONNECTOR_PROCESSOR_NO_ENDPIECES_H
+
+#include "../utils/polygon.h"
+#include "ActualZigzagConnectorProcessor.h"
+#include "../utils/intpoint.h"
+
+namespace cura
+{
+
+class ZigzagConnectorProcessorNoEndPieces : public ActualZigzagConnectorProcessor
+{
+public:
+    ZigzagConnectorProcessorNoEndPieces(const PointMatrix& rotation_matrix, Polygons& result)
+    : ActualZigzagConnectorProcessor(rotation_matrix, result)
+    {
+    }
+
+    void registerVertex(const Point& vertex);
+    void registerScanlineSegmentIntersection(const Point& intersection, bool scanline_is_even);
+    void registerPolyFinished();
+};
+
+
+} // namespace cura
+
+
+#endif // INFILL_ZIGZAG_CONNECTOR_PROCESSOR_NO_ENDPIECES_H

src/inset.cpp

@@ -1,60 +0,0 @@
-/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
-#include "inset.h"
-#include "polygonOptimizer.h"
-#include "utils/polygonUtils.h"
-namespace cura {
-
-void generateInsets(SliceLayerPart* part, int line_width_0, int line_width_x, int insetCount, bool avoidOverlappingPerimeters)
-{
-    int combBoundaryInset = line_width_x/2; // hard coded value
-    part->combBoundery = part->outline.offset(-combBoundaryInset);
-    if (insetCount == 0)
-    {
-        part->insets.push_back(part->outline);
-        return;
-    }
-    
-    for(int i=0; i<insetCount; i++)
-    {
-        part->insets.push_back(Polygons());
-        if (i == 0)
-        {
-            offsetSafe(part->outline, - line_width_x/2, line_width_x, part->insets[i], avoidOverlappingPerimeters);
-        } else if (i == 1)
-        {
-            offsetExtrusionWidth(part->insets[i-1], true, line_width_0, part->insets[i], &part->perimeterGaps, avoidOverlappingPerimeters);
-        } else
-        {
-            offsetExtrusionWidth(part->insets[i-1], true, line_width_x, part->insets[i], &part->perimeterGaps, avoidOverlappingPerimeters);
-        }
-            
-        optimizePolygons(part->insets[i]);
-        if (part->insets[i].size() < 1)
-        {
-            part->insets.pop_back();
-            break;
-        }
-    }
-}
-
-
-void generateInsets(SliceLayer* layer, int line_width_0, int line_width_x, int insetCount, bool avoidOverlappingPerimeters)
-{
-    for(unsigned int partNr = 0; partNr < layer->parts.size(); partNr++)
-    {
-        generateInsets(&layer->parts[partNr], line_width_0, line_width_x, insetCount, avoidOverlappingPerimeters);
-    }
-    
-    //Remove the parts which did not generate an inset. As these parts are too small to print,
-    // and later code can now assume that there is always minimal 1 inset line.
-    for(unsigned int partNr = 0; partNr < layer->parts.size(); partNr++)
-    {
-        if (layer->parts[partNr].insets.size() < 1)
-        {
-            layer->parts.erase(layer->parts.begin() + partNr);
-            partNr -= 1;
-        }
-    }
-}
-
-}//namespace cura

src/inset.h

@@ -1,34 +0,0 @@
-/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
-#ifndef INSET_H
-#define INSET_H
-
-#include "sliceDataStorage.h"
-
-namespace cura 
-{
-
-/*!
- * Generates the insets / perimeters for a single layer part.
- * 
- * \param part The part for which to generate the insets.
- * \param line_width_0 Line width of the outer wall
- * \param line_width_x Line width of other walls
- * \param insetCount The number of insets to to generate
- * \param avoidOverlappingPerimeters Whether to remove the parts of two consecutive perimeters where they have overlap (and store the gaps thus created in the \p part)
- */
-void generateInsets(SliceLayerPart* part, int line_width_0, int line_width_x, int insetCount, bool avoidOverlappingPerimeters);
-
-/*!
- * Generates the insets / perimeters for all parts in a layer.
- * 
- * \param layer The layer for which to generate the insets.
- * \param line_width_0 Line width of the outer wall
- * \param line_width_x Line width of other walls
- * \param insetCount The number of insets to to generate
- * \param avoidOverlappingPerimeters Whether to remove the parts of two consecutive perimeters where they have overlap (and store the gaps thus created in the \p part)
- */ 
-void generateInsets(SliceLayer* layer, int line_width_0, int line_width_x, int insetCount, bool avoidOverlappingPerimeters);
-
-}//namespace cura
-
-#endif//INSET_H

src/layerPart.cpp

@@ -1,8 +1,10 @@
 /** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
-#include <stdio.h>
 
 #include "layerPart.h"
-#include "settings.h"
+#include "settings/settings.h"
+#include "progress/Progress.h"
+
+#include "utils/SVG.h" // debug output
 
 /*
 The layer-part creation step is the first step in creating actual useful data for 3D printing.
@@ -11,7 +13,7 @@ each of these groups is called a "part", which sometimes are also known as "isla
 isolated areas in the 2D layer with possible holes.
 
 Creating "parts" is an important step, as all elements in a single part should be printed before going to another part.
-And all every bit inside a single part can be printed without the nozzle leaving the boundery of this part.
+And all every bit inside a single part can be printed without the nozzle leaving the boundary of this part.
 
 It's also the first step that stores the result in the "data storage" so all other steps can access it.
 */
@@ -20,70 +22,75 @@ namespace cura {
 
 void createLayerWithParts(SliceLayer& storageLayer, SlicerLayer* layer, bool union_layers, bool union_all_remove_holes)
 {
-    storageLayer.openLines = layer->openPolygons;
+    storageLayer.openPolyLines = layer->openPolylines;
 
     if (union_all_remove_holes)
     {
-        for(unsigned int i=0; i<layer->polygonList.size(); i++)
+        for(unsigned int i=0; i<layer->polygons.size(); i++)
         {
-            if (layer->polygonList[i].orientation())
-                layer->polygonList[i].reverse();
+            if (layer->polygons[i].orientation())
+                layer->polygons[i].reverse();
         }
     }
     
-    std::vector<Polygons> result;
-    result = layer->polygonList.splitIntoParts(union_layers || union_all_remove_holes);
+    std::vector<PolygonsPart> result;
+    result = layer->polygons.splitIntoParts(union_layers || union_all_remove_holes);
     for(unsigned int i=0; i<result.size(); i++)
     {
-        storageLayer.parts.push_back(SliceLayerPart());
+        storageLayer.parts.emplace_back();
         storageLayer.parts[i].outline = result[i];
         storageLayer.parts[i].boundaryBox.calculate(storageLayer.parts[i].outline);
     }
 }
-
-void createLayerParts(SliceMeshStorage& storage, Slicer* slicer, bool union_layers, bool union_all_remove_holes)
+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++)
     {
-        storage.layers.push_back(SliceLayer());
-        storage.layers[layer_nr].sliceZ = slicer->layers[layer_nr].z;
-        storage.layers[layer_nr].printZ = slicer->layers[layer_nr].z;
-        createLayerWithParts(storage.layers[layer_nr], &slicer->layers[layer_nr], union_layers, union_all_remove_holes);
-        
-        logProgress("layerparts", layer_nr + 1, slicer->layers.size());
+        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);
     }
 }
 
-void dumpLayerparts(SliceDataStorage& storage, const char* filename)
+void layerparts2HTML(SliceDataStorage& storage, const char* filename, bool all_layers, int layer_nr)
 {
+    
     FILE* out = fopen(filename, "w");
     fprintf(out, "<!DOCTYPE html><html><body>");
     Point3 modelSize = storage.model_size;
     Point3 modelMin = storage.model_min;
     
+    Point model_min_2d = Point(modelMin.x, modelMin.y);
+    Point model_max_2d = Point(modelSize.x, modelSize.y) + model_min_2d;
+    AABB aabb(model_min_2d, model_max_2d);
+    
+    SVG svg(filename, aabb);
+    
     for(SliceMeshStorage& mesh : storage.meshes)
     {
-        for(SliceLayer& layer : mesh.layers)
+        for(unsigned int layer_idx = 0; layer_idx < mesh.layers.size(); layer_idx++)
         {
-            fprintf(out, "<svg xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" style=\"width: 500px; height:500px\">\n");
+            if (!(all_layers || int(layer_idx) == layer_nr)) { continue; }
+            SliceLayer& layer = mesh.layers[layer_idx];
+//             fprintf(out, "<svg xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" style=\"width: 500px; height:500px\">\n");
             for(SliceLayerPart& part : layer.parts)
             {
-                for(unsigned int j=0;j<part.outline.size();j++)
-                {
-                    fprintf(out, "<polygon points=\"");
-                    for(unsigned int k=0;k<part.outline[j].size();k++)
-                        fprintf(out, "%f,%f ", float(part.outline[j][k].X - modelMin.x)/modelSize.x*500, float(part.outline[j][k].Y - modelMin.y)/modelSize.y*500);
-                    if (j == 0)
-                        fprintf(out, "\" style=\"fill:gray; stroke:black;stroke-width:1\" />\n");
-                    else
-                        fprintf(out, "\" style=\"fill:red; stroke:black;stroke-width:1\" />\n");
-                }
+                svg.writeAreas(part.outline);
+                svg.writePoints(part.outline);
+//                 for(unsigned int j=0;j<part.outline.size();j++)
+//                 {
+//                     fprintf(out, "<polygon points=\"");
+//                     for(unsigned int k=0;k<part.outline[j].size();k++)
+//                         fprintf(out, "%f,%f ", float(part.outline[j][k].X - modelMin.x)/modelSize.x*500, float(part.outline[j][k].Y - modelMin.y)/modelSize.y*500);
+//                     if (j == 0)
+//                         fprintf(out, "\" style=\"fill:gray; stroke:black;stroke-width:1\" />\n");
+//                     else
+//                         fprintf(out, "\" style=\"fill:red; stroke:black;stroke-width:1\" />\n");
+//                 }
             }
-            fprintf(out, "</svg>\n");
+//             fprintf(out, "</svg>\n");
         }
     }
-    fprintf(out, "</body></html>");
-    fclose(out);
 }
 
 }//namespace cura

src/layerPart.h

@@ -4,6 +4,7 @@
 
 #include "sliceDataStorage.h"
 #include "slicer.h"
+#include "commandSocket.h"
 
 /*
 The layer-part creation step is the first step in creating actual useful data for 3D printing.
@@ -12,7 +13,7 @@ each of these groups is called a "part", which sometimes are also known as "isla
 isolated areas in the 2D layer with possible holes.
 
 Creating "parts" is an important step, as all elements in a single part should be printed before going to another part.
-And all every bit inside a single part can be printed without the nozzle leaving the boundery of this part.
+And all every bit inside a single part can be printed without the nozzle leaving the boundary of this part.
 
 It's also the first step that stores the result in the "data storage" so all other steps can access it.
 */
@@ -21,9 +22,9 @@ namespace cura {
 
 void createLayerWithParts(SliceLayer& storageLayer, SlicerLayer* layer, bool union_layers, bool union_all_remove_holes);
 
-void createLayerParts(SliceMeshStorage& storage, Slicer* slicer, bool union_layers, bool union_all_remove_holes);
+void createLayerParts(SliceMeshStorage& mesh, Slicer* slicer, bool union_layers, bool union_all_remove_holes);
 
-void dumpLayerparts(SliceDataStorage& storage, const char* filename);
+void layerparts2HTML(SliceDataStorage& mesh, const char* filename, bool all_layers = true, int layer_nr = -1);
 
 }//namespace cura
 

src/main.cpp

@@ -14,30 +14,43 @@
 #include "utils/gettime.h"
 #include "utils/logoutput.h"
 #include "utils/string.h"
-#include "sliceDataStorage.h"
 
-#include "modelFile/modelFile.h"
-#include "settings.h"
-#include "settingRegistry.h"
-#include "multiVolumes.h"
-#include "polygonOptimizer.h"
-#include "slicer.h"
-#include "layerPart.h"
-#include "inset.h"
-#include "skin.h"
-#include "infill.h"
-#include "bridge.h"
-#include "support.h"
-#include "pathOrderOptimizer.h"
-#include "skirt.h"
-#include "raft.h"
-#include "comb.h"
-#include "gcodeExport.h"
-#include "fffProcessor.h"
+#include "FffProcessor.h"
+#include "settings/SettingRegistry.h"
 
+#include "settings/SettingsToGV.h"
+
+namespace cura
+{
+    
 void print_usage()
 {
-    cura::logError("usage: CuraEngine [-h] [-v] [-m 3x3matrix] [-c <config file>] [-s <settingkey>=<value>] -o <output.gcode> <model.stl>\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.
@@ -48,6 +61,233 @@ void signal_FPE(int n)
     exit(1);
 }
 
+void print_call(int argc, char **argv)
+{
+    cura::logError("Command called:\n");
+    for (int idx= 0; idx < argc; idx++)
+        cura::logError("%s ", argv[idx]);
+    cura::logError("\n");
+}
+
+void connect(int argc, char **argv)
+{
+    std::string ip;
+    int port = 49674;
+
+    // parse ip port
+    std::string ip_port(argv[2]);
+    if (ip_port.find(':') != std::string::npos)
+    {
+        ip = ip_port.substr(0, ip_port.find(':'));
+        port = std::stoi(ip_port.substr(ip_port.find(':') + 1).data());
+    }
+
+    for(int argn = 3; argn < argc; argn++)
+    {
+        char* str = argv[argn];
+        if (str[0] == '-')
+        {
+            for(str++; *str; str++)
+            {
+                switch(*str)
+                {
+                case 'v':
+                    cura::increaseVerboseLevel();
+                    break;
+                case 'j':
+                    argn++;
+                    if (SettingRegistry::getInstance()->loadJSONsettings(argv[argn], FffProcessor::getInstance()))
+                    {
+                        cura::logError("Failed to load json file: %s\n", argv[argn]);
+                        std::exit(1);
+                    }
+                    break;
+                default:
+                    cura::logError("Unknown option: %c\n", *str);
+                    print_call(argc, argv);
+                    print_usage();
+                    break;
+                }
+            }
+        }
+    }
+
+    CommandSocket::instantiate();
+    CommandSocket::getInstance()->connect(ip, port);
+}
+
+void slice(int argc, char **argv)
+{   
+    FffProcessor::getInstance()->time_keeper.restart();
+    
+    FMatrix3x3 transformation; // the transformation applied to a model when loaded
+                        
+    MeshGroup* meshgroup = new MeshGroup(FffProcessor::getInstance());
+    
+    int extruder_train_nr = 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++)
+    {
+        char* str = argv[argn];
+        if (str[0] == '-')
+        {
+            if (str[1] == '-')
+            {
+                if (stringcasecompare(str, "--next") == 0)
+                {
+                    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.
+                        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
+                            meshgroup->createExtruderTrain(extruder_nr); // create new extruder train objects or use already existing ones
+                        }
+
+                        meshgroup->finalize();
+
+                        //start slicing
+                        FffProcessor::getInstance()->processMeshGroup(meshgroup);
+                        
+                        // initialize loading of new meshes
+                        FffProcessor::getInstance()->time_keeper.restart();
+                        delete meshgroup;
+                        meshgroup = new MeshGroup(FffProcessor::getInstance());
+                        last_extruder_train = meshgroup->createExtruderTrain(0); 
+                        last_settings_object = meshgroup;
+                        
+                    }catch(...){
+                        cura::logError("Unknown exception\n");
+                        exit(1);
+                    }
+                }else{
+                    cura::logError("Unknown option: %s\n", str);
+                }
+            }else{
+                for(str++; *str; str++)
+                {
+                    switch(*str)
+                    {
+                    case 'v':
+                        cura::increaseVerboseLevel();
+                        break;
+                    case 'p':
+                        cura::enableProgressLogging();
+                        break;
+                    case 'j':
+                        argn++;
+                        if (SettingRegistry::getInstance()->loadJSONsettings(argv[argn], last_settings_object))
+                        {
+                            cura::logError("Failed to load json file: %s\n", argv[argn]);
+                            std::exit(1);
+                        }
+                        break;
+                    case 'e':
+                        str++;
+                        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;
+                        break;
+                    case 'l':
+                        argn++;
+                        
+                        log("Loading %s from disk...\n", argv[argn]);
+
+                        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 
+                        {
+                            last_settings_object = &(meshgroup->meshes.back()); // pointer is valid until a new object is added, so this is OK
+                        }
+                        break;
+                    case 'o':
+                        argn++;
+                        if (!FffProcessor::getInstance()->setTargetFile(argv[argn]))
+                        {
+                            cura::logError("Failed to open %s for output.\n", argv[argn]);
+                            exit(1);
+                        }
+                        break;
+                    case 'g':
+                        last_settings_object = meshgroup;
+                    case 's':
+                        {
+                            //Parse the given setting and store it.
+                            argn++;
+                            char* valuePtr = strchr(argv[argn], '=');
+                            if (valuePtr)
+                            {
+                                *valuePtr++ = '\0';
+
+                                last_settings_object->setSetting(argv[argn], valuePtr);
+                            }
+                        }
+                        break;
+                    default:
+                        cura::logError("Unknown option: %c\n", *str);
+                        print_call(argc, argv);
+                        print_usage();
+                        exit(1);
+                        break;
+                    }
+                }
+            }
+        }
+        else
+        {
+            
+            cura::logError("Unknown option: %s\n", argv[argn]);
+            print_call(argc, argv);
+            print_usage();
+            exit(1);
+        }
+    }
+
+    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
+        meshgroup->createExtruderTrain(extruder_train_nr); // create new extruder train objects or use already existing ones
+    }
+    
+    
+#ifndef DEBUG
+    try {
+#endif
+        //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());
+        
+        //start slicing
+        FffProcessor::getInstance()->processMeshGroup(meshgroup);
+
+#ifndef DEBUG
+    }catch(...){
+        cura::logError("Unknown exception\n");
+        exit(1);
+    }
+#endif
+    //Finalize the processor, this adds the end.gcode. And reports statistics.
+    FffProcessor::getInstance()->finalize();
+
+    delete meshgroup;
+}
+
+}//namespace cura
+
 using namespace cura;
 
 int main(int argc, char **argv)
@@ -62,149 +302,125 @@ int main(int argc, char **argv)
     signal(SIGFPE, signal_FPE);
 #endif
 
-    fffProcessor processor;
-    std::vector<std::string> files;
+    Progress::init();
+    
+    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");
 
-    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");
 
-    CommandSocket* commandSocket = NULL;
-    std::string ip;
-    int port = 49674;
-
-    for(int argn = 1; argn < argc; argn++)
+    if (argc < 2)
     {
-        char* str = argv[argn];
-        if (str[0] == '-')
+        print_usage();
+        exit(1);
+    }
+    
+    if (stringcasecompare(argv[1], "connect") == 0)
+    {
+        connect(argc, argv);
+    } 
+    else if (stringcasecompare(argv[1], "slice") == 0)
+    {
+        slice(argc, argv);
+    }
+    else if (stringcasecompare(argv[1], "help") == 0)
+    {
+        print_usage();
+        exit(0);
+    }
+    else if (stringcasecompare(argv[1], "analyse") == 0)
+    { // CuraEngine analyse [json] [output.gv] [engine_settings] -[p|i|e|w]
+        // p = show parent-child relations
+        // i = show inheritance function
+        // e = show error functions
+        // w = show warning functions
+        // dot refl_ff.gv -Tpng > rafl_ff_dotted.png
+        // see meta/HOWTO.txt
+        
+        bool parent_child_viz = false;
+        bool inherit_viz = false;
+        bool warning_viz = false;
+        bool error_viz = false;
+        bool global_only_viz = false;
+        if (argc >= 6)
         {
-            if (str[1] == '-')
+            char* str = argv[5];
+            if (str[0] == '-')
             {
-                if (stringcasecompare(str, "--connect") == 0)
-                {
-                    commandSocket = new CommandSocket(&processor);
-
-                    std::string ip_port(argv[argn + 1]);
-                    if (ip_port.find(':') != std::string::npos)
-                    {
-                        ip = ip_port.substr(0, ip_port.find(':'));
-                        port = std::stoi(ip_port.substr(ip_port.find(':') + 1).data());
-                    }
-
-                    argn += 1;
-                }
-                else if (stringcasecompare(str, "--") == 0)
-                {
-                    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.
-                        if (files.size() > 0)
-                            processor.processFiles(files);
-                        files.clear();
-                    }catch(...){
-                        cura::logError("Unknown exception\n");
-                        exit(1);
-                    }
-                    break;
-                }else{
-                    cura::logError("Unknown option: %s\n", str);
-                }
-            }else{
                 for(str++; *str; str++)
                 {
                     switch(*str)
                     {
-                    case 'h':
-                        print_usage();
-                        exit(1);
-                    case 'v':
-                        cura::increaseVerboseLevel();
-                        break;
-                    case 'j':
-                        argn++;
-                        if (!SettingRegistry::getInstance()->loadJSON(argv[argn]))
-                        {
-                            cura::logError("ERROR: Failed to load json file: %s\n", argv[argn]);
-                        }
-                        break;
                     case 'p':
-                        cura::enableProgressLogging();
+                        parent_child_viz = true;
                         break;
-                    case 'o':
-                        argn++;
-                        if (!processor.setTargetFile(argv[argn]))
-                        {
-                            cura::logError("Failed to open %s for output.\n", argv[argn]);
-                            exit(1);
-                        }
+                    case 'i':
+                        inherit_viz = true;
                         break;
-                    case 's':
-                        {
-                            //Parse the given setting and store it.
-                            argn++;
-                            char* valuePtr = strchr(argv[argn], '=');
-                            if (valuePtr)
-                            {
-                                *valuePtr++ = '\0';
-
-                                processor.setSetting(argv[argn], valuePtr);
-                            }
-                        }
+                    case 'e':
+                        error_viz = true;
+                        break;
+                    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);
+                        print_usage();
                         break;
                     }
                 }
             }
-        }else{
-            files.push_back(argv[argn]);
         }
-    }
-
-    if (!SettingRegistry::getInstance()->settingsLoaded())
-    {
-        //If no json file has been loaded, try to load the default.
-        if (!SettingRegistry::getInstance()->loadJSON("fdmprinter.json"))
+        else
         {
-            logError("ERROR: Failed to load json file: fdmprinter.json\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");
+    
         }
-    }
         
-    if(commandSocket)
-    {
-        commandSocket->connect(ip, port);
+        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("Failed to analyse json file: %s\n", argv[2]);
+        }
+        exit(0);
     }
     else
     {
-#ifndef DEBUG
-        try {
-#endif
-            //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.
-            if (files.size() > 0)
-                processor.processFiles(files);
-#ifndef DEBUG
-        }catch(...){
-            cura::logError("Unknown exception\n");
-            exit(1);
-        }
-#endif
-        //Finalize the processor, this adds the end.gcode. And reports statistics.
-        processor.finalize();
+        cura::logError("Unknown command: %s\n", argv[1]);
+        print_call(argc, argv);
+        print_usage();
+        exit(1);
     }
     
     return 0;
-}
+}

src/mesh.cpp

@@ -1,14 +1,20 @@
 #include "mesh.h"
 #include "utils/logoutput.h"
 
+namespace cura
+{
 
 const int vertex_meld_distance = MM2INT(0.03);
-static inline uint32_t pointHash(Point3& p)
+/*!
+ * returns a hash for the location, but first divides by the vertex_meld_distance,
+ * so that any point within a box of vertex_meld_distance by vertex_meld_distance would get mapped to the same hash.
+ */
+static inline uint32_t pointHash(const Point3& p)
 {
     return ((p.x + vertex_meld_distance/2) / vertex_meld_distance) ^ (((p.y + vertex_meld_distance/2) / vertex_meld_distance) << 10) ^ (((p.z + vertex_meld_distance/2) / vertex_meld_distance) << 20);
 }
 
-Mesh::Mesh(SettingsBase* parent)
+Mesh::Mesh(SettingsBaseVirtual* parent)
 : SettingsBase(parent)
 {
 }
@@ -47,40 +53,35 @@ 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]);
     }
 }
 
-Point3 Mesh::min()
+Point3 Mesh::min() const
 {
-    if (vertices.size() < 1)
-        return Point3(0, 0, 0);
-    Point3 ret = vertices[0].p;
-    for(unsigned int i=0; i<vertices.size(); i++)
-    {
-        ret.x = std::min(ret.x, vertices[i].p.x);
-        ret.y = std::min(ret.y, vertices[i].p.y);
-        ret.z = std::min(ret.z, vertices[i].p.z);
-    }
-    return ret;
+    return aabb.min;
 }
-Point3 Mesh::max()
+Point3 Mesh::max() const
 {
-    if (vertices.size() < 1)
-        return Point3(0, 0, 0);
-    Point3 ret = vertices[0].p;
-    for(unsigned int i=0; i<vertices.size(); i++)
+    return aabb.max;
+}
+AABB3D Mesh::getAABB() const
+{
+    return aabb;
+}
+void Mesh::expandXY(int64_t offset)
+{
+    if (offset)
     {
-        ret.x = std::max(ret.x, vertices[i].p.x);
-        ret.y = std::max(ret.y, vertices[i].p.y);
-        ret.z = std::max(ret.z, vertices[i].p.z);
+        aabb.expandXY(offset);
     }
-    return ret;
 }
 
-int Mesh::findIndexOfVertex(Point3& v)
+
+int Mesh::findIndexOfVertex(const Point3& v)
 {
     uint32_t hash = pointHash(v);
 
@@ -93,6 +94,9 @@ int Mesh::findIndexOfVertex(Point3& v)
     }
     vertex_hash_map[hash].push_back(vertices.size());
     vertices.emplace_back(v);
+    
+    aabb.include(v);
+    
     return vertices.size() - 1;
 }
 
@@ -120,17 +124,13 @@ See <a href="http://stackoverflow.com/questions/14066933/direct-way-of-computing
 
 
 */
-int Mesh::getFaceIdxWithPoints(int idx0, int idx1, int notFaceIdx)
+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!
@@ -140,12 +140,10 @@ int Mesh::getFaceIdxWithPoints(int idx0, int idx1, int notFaceIdx)
 
     }
 
-    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;
@@ -180,7 +178,6 @@ int Mesh::getFaceIdxWithPoints(int idx0, int idx1, int notFaceIdx)
         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)
         {
@@ -188,6 +185,8 @@ int Mesh::getFaceIdxWithPoints(int idx0, int idx1, int notFaceIdx)
             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;
 }
+
+}//namespace cura

src/mesh.h

@@ -1,8 +1,11 @@
 #ifndef MESH_H
 #define MESH_H
 
-#include "settings.h"
+#include "settings/settings.h"
+#include "utils/AABB3D.h"
 
+namespace cura
+{
 /*!
 Vertex type to be used in a Mesh.
 
@@ -14,7 +17,7 @@ public:
     Point3 p; //!< location of the vertex
     std::vector<uint32_t> connected_faces; //!< list of the indices of connected faces
 
-    MeshVertex(Point3 p) : p(p) {} //!< doesn't set connected_faces
+    MeshVertex(Point3 p) : p(p) {connected_faces.reserve(8);} //!< doesn't set connected_faces
 };
 
 /*! A MeshFace is a 3 dimensional model triangle with 3 points. These points are already converted to integers
@@ -54,29 +57,52 @@ See MeshFace for the specifics of how/when faces are connected.
 class Mesh : public SettingsBase // inherits settings
 {
     //! The vertex_hash_map stores a index reference of each vertex for the hash of that location. Allows for quick retrieval of points with the same location.
-    std::map<uint32_t, std::vector<uint32_t> > vertex_hash_map;
+    std::unordered_map<uint32_t, std::vector<uint32_t> > vertex_hash_map;
+    AABB3D aabb;
 public:
     std::vector<MeshVertex> vertices;//!< list of all vertices in the mesh
     std::vector<MeshFace> faces; //!< list of all faces in the mesh
 
-    Mesh(SettingsBase* parent); //!< initializes the settings
+    Mesh(SettingsBaseVirtual* parent); //!< initializes the settings
 
     void addFace(Point3& v0, Point3& v1, Point3& v2); //!< add a face to the mesh without settings it's connected_faces.
     void clear(); //!< clears all data
     void finish(); //!< complete the model : set the connected_face_index fields of the faces.
 
-    Point3 min(); //!< min (in x,y and z) vertex of the bounding box
-    Point3 max(); //!< max (in x,y and z) vertex of the bounding box
+    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).
+     * \param offset The offset byu which to offset the whole mesh.
+     */
+    void offset(Point3 offset)
+    {
+        if (offset == Point3(0,0,0)) { return; }
+        for(MeshVertex& v : vertices)
+            v.p += offset;
+        aabb.offset(offset);
+    }
 
 private:
-    int findIndexOfVertex(Point3& v); //!< find index of vertex close to the given point, or create a new vertex and return its index.
+    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);
+    int getFaceIdxWithPoints(int idx0, int idx1, int notFaceIdx, int notFaceVertexIdx) const;
 };
 
-
+}//namespace cura
 #endif//MESH_H
 

src/modelFile/modelFile.cpp

@@ -1,150 +0,0 @@
-/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
-#include <string.h>
-#include <strings.h>
-#include <stdio.h>
-
-#include "modelFile.h"
-#include "../utils/logoutput.h"
-#include "../utils/string.h"
-
-FILE* binaryMeshBlob = nullptr;
-
-/* Custom fgets function to support Mac line-ends in Ascii STL files. OpenSCAD produces this when used on Mac */
-void* fgets_(char* ptr, size_t len, FILE* f)
-{
-    while(len && fread(ptr, 1, 1, f) > 0)
-    {
-        if (*ptr == '\n' || *ptr == '\r')
-        {
-            *ptr = '\0';
-            return ptr;
-        }
-        ptr++;
-        len--;
-    }
-    return nullptr;
-}
-
-bool loadModelSTL_ascii(Mesh* mesh, const char* filename, FMatrix3x3& matrix)
-{
-    FILE* f = fopen(filename, "rt");
-    char buffer[1024];
-    FPoint3 vertex;
-    int n = 0;
-    Point3 v0(0,0,0), v1(0,0,0), v2(0,0,0);
-    while(fgets_(buffer, sizeof(buffer), f))
-    {
-        if (sscanf(buffer, " vertex %f %f %f", &vertex.x, &vertex.y, &vertex.z) == 3)
-        {
-            n++;
-            switch(n)
-            {
-            case 1:
-                v0 = matrix.apply(vertex);
-                break;
-            case 2:
-                v1 = matrix.apply(vertex);
-                break;
-            case 3:
-                v2 = matrix.apply(vertex);
-                mesh->addFace(v0, v1, v2);
-                n = 0;
-                break;
-            }
-        }
-    }
-    fclose(f);
-    mesh->finish();
-    return true;
-}
-
-bool loadModelSTL_binary(Mesh* mesh, const char* filename, FMatrix3x3& matrix)
-{
-    FILE* f = fopen(filename, "rb");
-    char buffer[80];
-    uint32_t faceCount;
-    //Skip the header
-    if (fread(buffer, 80, 1, f) != 1)
-    {
-        fclose(f);
-        return false;
-    }
-    //Read the face count
-    if (fread(&faceCount, sizeof(uint32_t), 1, f) != 1)
-    {
-        fclose(f);
-        return false;
-    }
-    //For each face read:
-    //float(x,y,z) = normal, float(X,Y,Z)*3 = vertexes, uint16_t = flags
-    for(unsigned int i=0;i<faceCount;i++)
-    {
-        if (fread(buffer, sizeof(float) * 3, 1, f) != 1)
-        {
-            fclose(f);
-            return false;
-        }
-        float v[9];
-        if (fread(v, sizeof(float) * 9, 1, f) != 1)
-        {
-            fclose(f);
-            return false;
-        }
-        Point3 v0 = matrix.apply(FPoint3(v[0], v[1], v[2]));
-        Point3 v1 = matrix.apply(FPoint3(v[3], v[4], v[5]));
-        Point3 v2 = matrix.apply(FPoint3(v[6], v[7], v[8]));
-        mesh->addFace(v0, v1, v2);
-        if (fread(buffer, sizeof(uint16_t), 1, f) != 1)
-        {
-            fclose(f);
-            return false;
-        }
-    }
-    fclose(f);
-    mesh->finish();
-    return true;
-}
-
-bool loadModelSTL(Mesh* mesh, const char* filename, FMatrix3x3& matrix)
-{
-    FILE* f = fopen(filename, "r");
-    char buffer[6];
-    if (f == nullptr)
-        return false;
-
-    if (fread(buffer, 5, 1, f) != 1)
-    {
-        fclose(f);
-        return false;
-    }
-    fclose(f);
-
-    buffer[5] = '\0';
-    if (stringcasecompare(buffer, "solid") == 0)
-    {
-        bool load_success = loadModelSTL_ascii(mesh, filename, matrix);
-        if (!load_success)
-            return false;
-
-        // This logic is used to handle the case where the file starts with
-        // "solid" but is a binary file.
-        if (mesh->faces.size() < 1)
-        {
-            mesh->clear();
-            return loadModelSTL_binary(mesh, filename, matrix);
-        }
-        return true;
-    }
-    return loadModelSTL_binary(mesh, filename, matrix);
-}
-
-bool loadMeshFromFile(PrintObject* object, const char* filename, FMatrix3x3& matrix)
-{
-    const char* ext = strrchr(filename, '.');
-    if (ext && (strcmp(ext, ".stl") == 0 || strcmp(ext, ".STL") == 0))
-    {
-        object->meshes.emplace_back(object);
-        return loadModelSTL(&object->meshes[object->meshes.size()-1], filename, matrix);
-    }
-    return false;
-}

src/modelFile/modelFile.h

@@ -1,98 +0,0 @@
-/** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
-#ifndef MODELFILE_H
-#define MODELFILE_H
-/**
-modelFile contains the model loaders for the slicer. The model loader turns any format that it can read into a list of triangles with 3 X/Y/Z points.
-
-The format returned is a Model class with an array of faces, which have integer points with a resolution of 1 micron. Giving a maximum object size of 4 meters.
-**/
-
-#include "../mesh.h"
-
-//A PrintObject is a 3D model with 1 or more 3D meshes.
-class PrintObject : public SettingsBase
-{
-public:
-    std::vector<Mesh> meshes;
-
-    PrintObject(SettingsBase* settings_base)
-    : SettingsBase(settings_base)
-    {
-    }
-
-    Point3 min() //! minimal corner of bounding box
-    {
-        if (meshes.size() < 1)
-            return Point3(0, 0, 0);
-        Point3 ret = meshes[0].min();
-        for(unsigned int i=1; i<meshes.size(); i++)
-        {
-            Point3 v = meshes[i].min();
-            ret.x = std::min(ret.x, v.x);
-            ret.y = std::min(ret.y, v.y);
-            ret.z = std::min(ret.z, v.z);
-        }
-        return ret;
-    }
-    Point3 max() //! maximal corner of bounding box
-    {
-        if (meshes.size() < 1)
-            return Point3(0, 0, 0);
-        Point3 ret = meshes[0].max();
-        for(unsigned int i=1; i<meshes.size(); i++)
-        {
-            Point3 v = meshes[i].max();
-            ret.x = std::max(ret.x, v.x);
-            ret.y = std::max(ret.y, v.y);
-            ret.z = std::max(ret.z, v.z);
-        }
-        return ret;
-    }
-
-    void clear()
-    {
-        for(Mesh& m : meshes)
-            m.clear();
-    }
-
-    void offset(Point3 offset)
-    {
-        for(Mesh& m : meshes)
-            for(MeshVertex& v : m.vertices)
-                v.p += offset;
-    }
-
-    void finalize()
-    {
-        // If a mesh position was given, put the mesh at this position in 3D space.
-        if (hasSetting("mesh_position_x") || hasSetting("mesh_position_y") || hasSetting("mesh_position_z"))
-        {
-            Point3 object_min = min();
-            Point3 object_max = max();
-            Point3 object_size = object_max - object_min;
-            Point3 object_offset = Point3(-object_min.x - object_size.x / 2, -object_min.y - object_size.y / 2, -object_min.z);
-            if (hasSetting("mesh_position_x"))
-                object_offset.x += getSettingInMicrons("mesh_position_x");
-            if (hasSetting("mesh_position_y"))
-                object_offset.y += getSettingInMicrons("mesh_position_y");
-            if (hasSetting("mesh_position_z"))
-                object_offset.z += getSettingInMicrons("mesh_position_z");
-            offset(object_offset);
-        }
-
-        //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.
-        if (hasSetting("machine_center_is_zero") && !getSettingBoolean("machine_center_is_zero"))
-        {
-            Point3 object_offset = Point3(0, 0, 0);
-            if (hasSetting("machine_width"))
-                object_offset.x = getSettingInMicrons("machine_width") / 2;
-            if (hasSetting("machine_depth"))
-                object_offset.y = getSettingInMicrons("machine_depth") / 2;
-            offset(object_offset);
-        }
-    }
-};
-
-bool loadMeshFromFile(PrintObject* object, const char* filename, FMatrix3x3& matrix);
-
-#endif//MODELFILE_H

src/multiVolumes.cpp

@@ -1,58 +1,97 @@
 #include "multiVolumes.h"
 
-namespace cura {
-
-void carveMultipleVolumes(std::vector<SliceMeshStorage> &volumes)
+namespace cura 
+{
+ 
+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 idx=0; idx < volumes.size(); idx++)
+    for (unsigned int volume_1_idx = 1; volume_1_idx < volumes.size(); volume_1_idx++)
     {
-        for(unsigned int idx2=0; idx2<idx; idx2++)
+        Slicer& volume_1 = *volumes[volume_1_idx];
+        if (volume_1.mesh->getSettingBoolean("infill_mesh") 
+            || volume_1.mesh->getSettingBoolean("anti_overhang_mesh")
+            || volume_1.mesh->getSettingBoolean("support_mesh")
+            )
         {
-            for(unsigned int layerNr=0; layerNr < volumes[idx].layers.size(); layerNr++)
+            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")
+                || volume_2.mesh->getSettingBoolean("anti_overhang_mesh")
+                || volume_2.mesh->getSettingBoolean("support_mesh")
+                )
             {
-                SliceLayer* layer1 = &volumes[idx].layers[layerNr];
-                SliceLayer* layer2 = &volumes[idx2].layers[layerNr];
-                for(unsigned int p1 = 0; p1 < layer1->parts.size(); p1++)
+                continue;
+            }
+            if (!volume_1.mesh->getAABB().hit(volume_2.mesh->getAABB()))
+            {
+                continue;
+            }
+            for (unsigned int layerNr = 0; layerNr < volume_1.layers.size(); layerNr++)
+            {
+                SlicerLayer& layer1 = volume_1.layers[layerNr];
+                SlicerLayer& layer2 = volume_2.layers[layerNr];
+                if (alternate_carve_order && layerNr % 2 == 0)
                 {
-                    for(unsigned int p2 = 0; p2 < layer2->parts.size(); p2++)
-                    {
-                        layer1->parts[p1].outline = layer1->parts[p1].outline.difference(layer2->parts[p2].outline);
-                    }
+                    layer2.polygons = layer2.polygons.difference(layer1.polygons);
+                }
+                else
+                {
+                    layer1.polygons = layer1.polygons.difference(layer2.polygons);
                 }
             }
         }
     }
 }
-
+ 
 //Expand each layer a bit and then keep the extra overlapping parts that overlap with other volumes.
 //This generates some overlap in dual extrusion, for better bonding in touching parts.
-void generateMultipleVolumesOverlap(std::vector<SliceMeshStorage> &volumes, int overlap)
+void generateMultipleVolumesOverlap(std::vector<Slicer*> &volumes)
 {
-    if (volumes.size() < 2 || overlap <= 0) return;
-    
-    for(unsigned int layerNr=0; layerNr < volumes[0].layers.size(); layerNr++)
+    if (volumes.size() < 2)
     {
-        Polygons fullLayer;
-        for(unsigned int volIdx = 0; volIdx < volumes.size(); volIdx++)
+        return;
+    }
+
+    int offset_to_merge_other_merged_volumes = 20;
+    for (Slicer* volume : 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)
         {
-            SliceLayer* layer1 = &volumes[volIdx].layers[layerNr];
-            for(unsigned int p1 = 0; p1 < layer1->parts.size(); p1++)
-            {
-                fullLayer = fullLayer.unionPolygons(layer1->parts[p1].outline.offset(20)); // TODO: put hard coded value in a variable with an explanatory name (and make var a parameter, and perhaps even a setting?)
-            }
+            continue;
         }
-        fullLayer = fullLayer.offset(-20); // TODO: put hard coded value in a variable with an explanatory name (and make var a parameter, and perhaps even a setting?)
-        
-        for(unsigned int volIdx = 0; volIdx < volumes.size(); volIdx++)
+        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++)
         {
-            SliceLayer* layer1 = &volumes[volIdx].layers[layerNr];
-            for(unsigned int p1 = 0; p1 < layer1->parts.size(); p1++)
+            Polygons all_other_volumes;
+            for (Slicer* other_volume : volumes)
             {
-                layer1->parts[p1].outline = fullLayer.intersection(layer1->parts[p1].outline.offset(overlap / 2));
+                if (other_volume->mesh->getSettingBoolean("infill_mesh")
+                    || other_volume->mesh->getSettingBoolean("anti_overhang_mesh")
+                    || other_volume->mesh->getSettingBoolean("support_mesh")
+                    || !other_volume->mesh->getAABB().hit(aabb)
+                    || other_volume == volume
+                )
+                {
+                    continue;
+                }
+                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));
             }
+
+            SlicerLayer& volume_layer = volume->layers[layer_nr];
+            volume_layer.polygons = volume_layer.polygons.unionPolygons(all_other_volumes.intersection(volume_layer.polygons.offset(overlap / 2)));
         }
     }
 }
  
+
 }//namespace cura

src/multiVolumes.h

@@ -2,15 +2,22 @@
 #define MULTIVOLUMES_H
 
 #include "sliceDataStorage.h"
+#include "slicer.h"
 
 /* This file contains code to help fixing up and changing layers that are build from multiple volumes. */
 namespace cura {
 
-void carveMultipleVolumes(std::vector<SliceMeshStorage> &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.
-//This generates some overlap in dual extrusion, for better bonding in touching parts.
-void generateMultipleVolumesOverlap(std::vector<SliceMeshStorage> &meshes, int overlap);
+/*!
+ * Expand each layer a bit and then keep the extra overlapping parts that overlap with other volumes.
+ * This generates some overlap in dual extrusion, for better bonding in touching parts.
+ */
+void generateMultipleVolumesOverlap(std::vector<Slicer*> &meshes);
 
 }//namespace cura
 

src/pathOrderOptimizer.cpp

@@ -1,9 +1,8 @@
 /** Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License */
-#include <map>
-
 #include "pathOrderOptimizer.h"
 #include "utils/logoutput.h"
-#include "utils/BucketGrid2D.h"
+#include "utils/SparsePointGridInclusive.h"
+#include "utils/linearAlg2D.h"
 
 #define INLINE static inline
 
@@ -17,17 +16,16 @@ void PathOrderOptimizer::optimize()
     bool picked[polygons.size()];
     memset(picked, false, sizeof(bool) * polygons.size());/// initialized as falses
     
-    for(unsigned int i_polygon=0 ; i_polygon<polygons.size() ; i_polygon++) /// find closest point to initial starting point within each polygon +initialize picked
+    for (PolygonRef poly : polygons) /// find closest point to initial starting point within each polygon +initialize picked
     {
         int best = -1;
         float bestDist = std::numeric_limits<float>::infinity();
-        PolygonRef poly = polygons[i_polygon];
-        for(unsigned int i_point=0; i_point<poly.size(); i_point++) /// get closest point in polygon
+        for (unsigned int point_idx = 0; point_idx < poly.size(); point_idx++) /// get closest point in polygon
         {
-            float dist = vSize2f(poly[i_point] - startPoint);
+            float dist = vSize2f(poly[point_idx] - startPoint);
             if (dist < bestDist)
             {
-                best = i_point;
+                best = point_idx;
                 bestDist = dist;
             }
         }
@@ -39,74 +37,113 @@ void PathOrderOptimizer::optimize()
 
 
     Point prev_point = startPoint;
-    for(unsigned int i_polygon=0 ; i_polygon<polygons.size() ; i_polygon++) /// actual path order optimizer
+    for (unsigned int poly_order_idx = 0; poly_order_idx < polygons.size(); poly_order_idx++) /// actual path order optimizer
     {
-        int best = -1;
+        int best_poly_idx = -1;
         float bestDist = std::numeric_limits<float>::infinity();
 
 
-        for(unsigned int i_polygon=0 ; i_polygon<polygons.size() ; i_polygon++)
+        for (unsigned int poly_idx = 0; poly_idx < polygons.size(); poly_idx++)
         {
-            if (picked[i_polygon] || polygons[i_polygon].size() < 1) /// skip single-point-polygons
+            if (picked[poly_idx] || polygons[poly_idx].size() < 1) /// skip single-point-polygons
+            {
                 continue;
+            }
 
-            assert (polygons[i_polygon].size() != 2);
+            assert (polygons[poly_idx].size() != 2);
 
-            float dist = vSize2f(polygons[i_polygon][polyStart[i_polygon]] - prev_point);
+            float dist = vSize2f(polygons[poly_idx][polyStart[poly_idx]] - prev_point);
             if (dist < bestDist)
             {
-                best = i_polygon;
+                best_poly_idx = poly_idx;
                 bestDist = dist;
             }
 
         }
 
 
-        if (best > -1) /// should always be true; we should have been able to identify the best next polygon
+        if (best_poly_idx > -1) /// should always be true; we should have been able to identify the best next polygon
         {
-            assert(polygons[best].size() != 2);
+            assert(polygons[best_poly_idx].size() != 2);
 
-            prev_point = polygons[best][polyStart[best]];
+            prev_point = polygons[best_poly_idx][polyStart[best_poly_idx]];
 
-            picked[best] = true;
-            polyOrder.push_back(best);
+            picked[best_poly_idx] = true;
+            polyOrder.push_back(best_poly_idx);
         }
         else
+        {
             logError("Failed to find next closest polygon.\n");
+        }
     }
 
     prev_point = startPoint;
-    for(unsigned int n=0; n<polyOrder.size(); n++) /// decide final starting points in each polygon
+    for (unsigned int order_idx = 0; order_idx < polyOrder.size(); order_idx++) /// decide final starting points in each polygon
     {
-        int i_polygon = polyOrder[n];
-        int best = getClosestPointInPolygon(prev_point, i_polygon);
-        polyStart[i_polygon] = best;
-        prev_point = polygons[i_polygon][best];
+        int poly_idx = polyOrder[order_idx];
+        int point_idx = getPolyStart(prev_point, poly_idx);
+        polyStart[poly_idx] = point_idx;
+        prev_point = polygons[poly_idx][point_idx];
 
     }
 }
 
-inline int PathOrderOptimizer::getClosestPointInPolygon(Point prev_point, int i_polygon)
+int PathOrderOptimizer::getPolyStart(Point prev_point, int poly_idx)
 {
-    PolygonRef poly = polygons[i_polygon];
-    int best = -1;
-    float bestDist = std::numeric_limits<float>::infinity();
-    bool orientation = poly.orientation();
-    for(unsigned int i_point=0 ; i_point<poly.size() ; i_point++)
+    switch (type)
     {
-        float dist = vSize2f(poly[i_point] - prev_point);
-        Point n0 = normal(poly[(i_point-1+poly.size())%poly.size()] - poly[i_point], 2000);
-        Point n1 = normal(poly[i_point] - poly[(i_point + 1) % poly.size()], 2000);
-        float dot_score = dot(n0, n1) - dot(crossZ(n0), n1); /// prefer binnenbocht
-        if (orientation)
-            dot_score = -dot_score;
-        if (dist + dot_score < bestDist)
+        case EZSeamType::BACK:      return getFarthestPointInPolygon(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);
+    }
+}
+
+
+int PathOrderOptimizer::getClosestPointInPolygon(Point prev_point, int poly_idx)
+{
+    PolygonRef 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()];
+        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
+        if (dist + is_on_inside_corner_score < best_point_score)
         {
-            best = i_point;
-            bestDist = dist;
+            best_point_idx = point_idx;
+            best_point_score = dist + is_on_inside_corner_score;
+        }
+        p0 = p1;
+    }
+    return best_point_idx;
+}
+
+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;
+    return best_point_idx;
 }
 
 
@@ -115,132 +152,120 @@ inline int PathOrderOptimizer::getClosestPointInPolygon(Point prev_point, int i_
 */
 void LineOrderOptimizer::optimize()
 {
-    int gridSize = 5000; // the size of the cells in the hash grid.
-    BucketGrid2D<unsigned int> line_bucket_grid(gridSize);
+    int gridSize = 5000; // the size of the cells in the hash grid. TODO
+    SparsePointGridInclusive<unsigned int> line_bucket_grid(gridSize);
     bool picked[polygons.size()];
     memset(picked, false, sizeof(bool) * polygons.size());/// initialized as falses
     
-    for(unsigned int i_polygon=0 ; i_polygon<polygons.size() ; i_polygon++) /// find closest point to initial starting point within each polygon +initialize picked
+    for (unsigned int poly_idx = 0; poly_idx < polygons.size(); poly_idx++) /// find closest point to initial starting point within each polygon +initialize picked
     {
-        int best = -1;
-        float bestDist = std::numeric_limits<float>::infinity();
-        PolygonRef poly = polygons[i_polygon];
-        for(unsigned int i_point=0; i_point<poly.size(); i_point++) /// get closest point from polygon
+        int best_point_idx = -1;
+        float best_point_dist = std::numeric_limits<float>::infinity();
+        PolygonRef 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[i_point] - startPoint);
-            if (dist < bestDist)
+            float dist = vSize2f(poly[point_idx] - startPoint);
+            if (dist < best_point_dist)
             {
-                best = i_point;
-                bestDist = dist;
+                best_point_idx = point_idx;
+                best_point_dist = dist;
             }
         }
-        polyStart.push_back(best);
+        polyStart.push_back(best_point_idx);
 
         assert(poly.size() == 2);
 
-        line_bucket_grid.insert(poly[0], i_polygon);
-        line_bucket_grid.insert(poly[1], i_polygon);
+        line_bucket_grid.insert(poly[0], poly_idx);
+        line_bucket_grid.insert(poly[1], poly_idx);
 
     }
 
 
-    Point incommingPerpundicularNormal(0, 0);
+    Point incoming_perpundicular_normal(0, 0);
     Point prev_point = startPoint;
-    for(unsigned int i_polygon=0 ; i_polygon<polygons.size() ; i_polygon++) /// actual path order optimizer
+    for (unsigned int order_idx = 0; order_idx < polygons.size(); order_idx++) /// actual path order optimizer
     {
-        int best = -1;
-        float bestDist = std::numeric_limits<float>::infinity();
+        int best_line_idx = -1;
+        float best_score = std::numeric_limits<float>::infinity(); // distance score for the best next line
 
-        for(unsigned int i_close_line_polygon :  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[i_close_line_polygon] || polygons[i_close_line_polygon].size() < 1)
+            if (picked[close_line_idx] || polygons[close_line_idx].size() < 1)
+            {
                 continue;
+            }
 
-
-            checkIfLineIsBest(i_close_line_polygon, best, bestDist, prev_point, incommingPerpundicularNormal);
-
+            updateBestLine(close_line_idx, best_line_idx, best_score, prev_point, incoming_perpundicular_normal);
         }
 
-        if (best == -1) /// if single-line-polygon hasn't been found yet
+        if (best_line_idx == -1) /// if single-line-polygon hasn't been found yet
         {
-           for(unsigned int i_polygon=0 ; i_polygon<polygons.size() ; i_polygon++)
+            for (unsigned int poly_idx = 0; poly_idx < polygons.size(); poly_idx++)
             {
-                if (picked[i_polygon] || polygons[i_polygon].size() < 1) /// skip single-point-polygons
+                if (picked[poly_idx] || polygons[poly_idx].size() < 1) /// skip single-point-polygons
+                {
                     continue;
-                assert(polygons[i_polygon].size() == 2);
+                }
+                assert(polygons[poly_idx].size() == 2);
 
-                checkIfLineIsBest(i_polygon, best, bestDist, prev_point, incommingPerpundicularNormal);
+                updateBestLine(poly_idx, best_line_idx, best_score, prev_point, incoming_perpundicular_normal);
 
             }
         }
 
-        if (best > -1) /// should always be true; we should have been able to identify the best next polygon
+        if (best_line_idx > -1) /// should always be true; we should have been able to identify the best next polygon
         {
-            assert(polygons[best].size() == 2);
+            PolygonRef best_line = polygons[best_line_idx];
+            assert(best_line.size() == 2);
 
-            int endIdx = polyStart[best] * -1 + 1; /// 1 -> 0 , 0 -> 1
-            prev_point = polygons[best][endIdx];
-            incommingPerpundicularNormal = crossZ(normal(polygons[best][endIdx] - polygons[best][polyStart[best]], 1000));
+            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];
+            prev_point = line_end;
+            incoming_perpundicular_normal = turn90CCW(normal(line_end - line_start, 1000));
 
-            picked[best] = true;
-            polyOrder.push_back(best);
+            picked[best_line_idx] = true;
+            polyOrder.push_back(best_line_idx);
         }
         else
-            logError("Failed to find next closest line.\n");
-    }
-
-    prev_point = startPoint;
-    for(unsigned int n=0; n<polyOrder.size(); n++) /// decide final starting points in each polygon
-    {
-        int nr = polyOrder[n];
-        PolygonRef poly = polygons[nr];
-        int best = -1;
-        float bestDist = std::numeric_limits<float>::infinity();
-        bool orientation = poly.orientation();
-        for(unsigned int i=0;i<poly.size(); i++)
         {
-            float dist = vSize2f(polygons[nr][i] - prev_point);
-            Point n0 = normal(poly[(i+poly.size()-1)%poly.size()] - poly[i], 2000);
-            Point n1 = normal(poly[i] - poly[(i + 1) % poly.size()], 2000);
-            float dot_score = dot(n0, n1) - dot(crossZ(n0), n1);
-            if (orientation)
-                dot_score = -dot_score;
-            if (dist + dot_score < bestDist)
-            {
-                best = i;
-                bestDist = dist + dot_score;
-            }
+            logError("Failed to find next closest line.\n");
         }
-
-        polyStart[nr] = best;
-        assert(poly.size() == 2);
-        prev_point = poly[best *-1 + 1]; /// 1 -> 0 , 0 -> 1
-
     }
 }
 
-inline void LineOrderOptimizer::checkIfLineIsBest(unsigned int i_line_polygon, int& best, float& bestDist, Point& prev_point, Point& incommingPerpundicularNormal)
+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];
+    float dot_score = getAngleScore(incoming_perpundicular_normal, p0, p1);
     { /// check distance to first point on line (0)
-        float dist = vSize2f(polygons[i_line_polygon][0] - prev_point);
-        dist += abs(dot(incommingPerpundicularNormal, normal(polygons[i_line_polygon][1] - polygons[i_line_polygon][0], 1000))) * 0.0001f; /// penalize sharp corners
-        if (dist < bestDist)
+        float score = vSize2f(p0 - prev_point) + dot_score; // prefer 90 degree corners
+        if (score < best_score)
         {
-            best = i_line_polygon;
-            bestDist = dist;
-            polyStart[i_line_polygon] = 0;
+            best = poly_idx;
+            best_score = score;
+            polyStart[poly_idx] = 0;
         }
     }
     { /// check distance to second point on line (1)
-        float dist = vSize2f(polygons[i_line_polygon][1] - prev_point);
-        dist += abs(dot(incommingPerpundicularNormal, normal(polygons[i_line_polygon][0] - polygons[i_line_polygon][1], 1000) )) * 0.0001f; /// penalize sharp corners
-        if (dist < bestDist)
+        float score = vSize2f(p1 - prev_point) + dot_score; // prefer 90 degree corners
+        if (score < best_score)
         {
-            best = i_line_polygon;
-            bestDist = dist;
-            polyStart[i_line_polygon] = 1;
+            best = poly_idx;
+            best_score = score;
+            polyStart[poly_idx] = 1;
         }
     }
 }
 
+float LineOrderOptimizer::getAngleScore(Point incoming_perpundicular_normal, Point p0, Point p1)
+{
+    return dot(incoming_perpundicular_normal, normal(p1 - p0, 1000)) * 0.0001f;
+}
+
+
 }//namespace cura

src/pathOrderOptimizer.h

@@ -4,25 +4,29 @@
 
 #include <stdint.h>
 #include "utils/polygon.h"
+#include "settings/settings.h"
 
 namespace cura {
-
-//! Parts order optimization class.
+ 
 /*!
-* Utility class for optimizing the path order by minimizing the distance traveled between printing different parts in the layer.
-* The order of polygons is optimized and the startingpoint within each polygon is chosen.
-*/
+ * Parts order optimization class.
+ * 
+ * Utility class for optimizing the path order by minimizing the distance traveled between printing different parts in the layer.
+ * The order of polygons is optimized and the startingpoint within each polygon is chosen.
+ */
 class PathOrderOptimizer
 {
 public:
-    Point startPoint; //!< The location of the nozzle before starting to print the current layer
+    EZSeamType type;
+    Point startPoint; //!< A location near the prefered start location
     std::vector<PolygonRef> 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)
+    PathOrderOptimizer(Point startPoint, EZSeamType type = EZSeamType::SHORTEST)
+    : type(type)
+    , startPoint(startPoint)
     {
-        this->startPoint = startPoint;
     }
 
     void addPolygon(PolygonRef polygon)
@@ -38,8 +42,11 @@ public:
 
     void optimize(); //!< sets #polyStart and #polyOrder
 
-    private:
-        int getClosestPointInPolygon(Point prev, int i_polygon); //!< returns the index of the closest point
+private:
+    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);
 
 
 };
@@ -74,8 +81,35 @@ public:
     void optimize(); //!< sets #polyStart and #polyOrder
 
 private:
-    void checkIfLineIsBest(unsigned int i_line_polygon, int& best, float& bestDist, Point& prev_point, Point& incommingPerpundicularNormal);
+    /*!
+     * Update LineOrderOptimizer::polyStart if the current line is better than the current best.
+     * 
+     * Besides looking at the distance from the previous line segment, we also look at the angle we make.
+     * 
+     * We prefer 90 degree angles; 180 degree turn arounds are slow on machines where the jerk is limited.
+     * 0 degree (straight ahead) 'corners' occur only when a single infill line is interrupted, 
+     * in which case the travel move might involve combing, which makes it rather longer.
+     * 
+     * \param poly_idx[in] The index in LineOrderOptimizer::polygons for the current line to test
+     * \param best[in, out] The index of current best line
+     * \param best_score[in, out] The distance score for the current best line
+     * \param prev_point[in] The previous point from which to find the next best line
+     * \param incoming_perpundicular_normal[in] The direction of movement when the print head arrived at \p prev_point, turned 90 degrees CCW
+     */
+    void updateBestLine(unsigned int poly_idx, int& best, float& best_score, Point prev_point, Point incoming_perpundicular_normal);
 
+    /*!
+     * Get a score to modify the distance score for measuring how good two lines follow each other.
+     * 
+     * The angle score is symmetric in \p from and \p to; they can be exchanged without altering the result. (Code relies on this property)
+     * 
+     * \param incoming_perpundicular_normal The direction in which the head was moving while printing the previous line, turned 90 degrees CCW
+     * \param from The one end of the next line
+     * \param to The other end of the next line
+     * \return A score measuring how good the angle is of the line between \p from and \p to when the previous line had a direction given by \p incoming_perpundicular_normal 
+     * 
+     */
+    static float getAngleScore(Point incoming_perpundicular_normal, Point from, Point to);
 };
 
 }//namespace cura

src/pathPlanning/Comb.cpp

@@ -0,0 +1,419 @@
+/** 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/PolygonsPointIndex.h"
+#include "../sliceDataStorage.h"
+#include "../utils/SVG.h"
+
+namespace cura {
+
+Polygons Comb::getCombOutlines()
+{
+    if (layer_nr >= 0)
+    {
+        bool include_helper_parts = false;
+        return storage.getLayerOutlines(layer_nr, include_helper_parts);
+    }
+    else
+    {
+        return storage.raftOutline;
+    }
+}
+
+LocToLineGrid& Comb::getOutsideLocToLine()
+{
+    return *outside_loc_to_line;
+}
+
+Polygons& Comb::getBoundaryOutside()
+{
+    return *boundary_outside;
+}
+  
+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_move_inside_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 )
+, partsView_inside( boundary_inside.splitIntoPartsView() ) // WARNING !! changes the order of boundary_inside !!
+, outlines(getCombOutlines())
+, 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 = 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)
+    {
+        coord_t max_move_inside_distance2_here = std::numeric_limits<coord_t>::max(); // the distance which would make the moveInside fail
+        if (storage.getSettingAsCombingMode("retraction_combing") == cura::CombingMode::NO_SKIN)
+        { // if we perform no_skin combing, then a far move inside is likely a consequence of there meing skin in between the destination point and the inside comb boundary
+            // if we perform normal combing, then a far move inside is likely to be a consequence of sharp pointy segments in the layer part
+            max_move_inside_distance2_here = max_move_inside_distance2;
+        }
+        Point original_dest_point = dest_point;
+        ClosestPolygonPoint cpp = PolygonUtils::ensureInsideOrOutside(boundary_inside, dest_point, offset_extra_start_end, max_move_inside_distance2_here, &boundary_inside, inside_loc_to_line);
+        if (!cpp.isValid())
+        {
+            return false;
+        }
+        else
+        {
+            if (vSize2(dest_point - original_dest_point) > max_move_inside_distance2 // only check for collision with outlines for long moves
+                && PolygonUtils::polygonCollidesWithLineSegment(outlines, dest_point, original_dest_point))
+            {
+                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 fest_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, const PolygonRef 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