Add extra travel move to outer wall start position

CMakeLists.txt

@@ -163,6 +163,7 @@ set(engine_SRCS # Except main.cpp.
         src/geometry/Polyline.cpp
         src/geometry/ClosedPolyline.cpp
         src/geometry/MixedLinesSet.cpp
+        src/geometry/Point2D.cpp
 )
 
 add_library(_CuraEngine STATIC ${engine_SRCS} ${engine_PB_SRCS})

Cura.proto

@@ -87,6 +87,8 @@ message Polygon {
         MoveRetractionType = 9;
         SupportInterfaceType = 10;
         PrimeTowerType = 11;
+        MoveUnretractionType = 12;
+
     }
     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)

include/GCodePathConfig.h

@@ -19,7 +19,7 @@ namespace cura
 struct GCodePathConfig
 {
     coord_t z_offset{}; //<! vertical offset from 'full' layer height
-    PrintFeatureType type{}; //!< name of the feature type
+    PrintFeatureType type_{}; //!< name of the feature type
     coord_t line_width{}; //!< width of the line extruded
     coord_t layer_thickness{}; //!< current layer height in micron
     Ratio flow{}; //!< extrusion flow modifier.
@@ -28,6 +28,7 @@ struct GCodePathConfig
     double fan_speed{ FAN_SPEED_DEFAULT }; //!< fan speed override for this path, value should be within range 0-100 (inclusive) and ignored otherwise
     double extrusion_mm3_per_mm{ calculateExtrusion() }; //!< current mm^3 filament moved per mm line traversed
     static constexpr double FAN_SPEED_DEFAULT = -1;
+    bool is_unretraction_path{ false }; // whether current config is used for unretraction path
 
     [[nodiscard]] constexpr bool operator==(const GCodePathConfig& other) const noexcept = default;
     [[nodiscard]] constexpr auto operator<=>(const GCodePathConfig& other) const = default;
@@ -56,6 +57,8 @@ struct GCodePathConfig
 
     [[nodiscard]] bool isTravelPath() const noexcept;
 
+    [[nodiscard]] bool isUnretractionMove() const noexcept;
+
     [[nodiscard]] bool isBridgePath() const noexcept;
 
     [[nodiscard]] double getFanSpeed() const noexcept;
@@ -66,6 +69,8 @@ struct GCodePathConfig
 
     [[nodiscard]] PrintFeatureType getPrintFeatureType() const noexcept;
 
+    void setPrintFeatureType(PrintFeatureType type);
+
 private:
     [[nodiscard]] double calculateExtrusion() const noexcept;
 };

include/InsetOrderOptimizer.h

@@ -36,6 +36,7 @@ class InsetOrderOptimizer
      * line widths, flows, speeds, etc to print this mesh with.
      * \param part The part from which to read the previously generated insets.
      * \param layer_nr The current layer number.
+     * \param is_outer_shell determines if the element added is the outer wall/shell of the mesh
      */
     InsetOrderOptimizer(
         const FffGcodeWriter& gcode_writer,
@@ -56,8 +57,10 @@ class InsetOrderOptimizer
         const size_t wall_x_extruder_nr,
         const ZSeamConfig& z_seam_config,
         const std::vector<VariableWidthLines>& paths,
+        const bool is_outer_shell = false,
         const Shape& disallowed_areas_for_seams = {});
 
+
     /*!
      * Adds the insets to the given layer plan.
      *
@@ -107,6 +110,7 @@ class InsetOrderOptimizer
     const ZSeamConfig& z_seam_config_;
     const std::vector<VariableWidthLines>& paths_;
     const LayerIndex layer_nr_;
+    const bool is_outer_shell_;
     Shape disallowed_areas_for_seams_;
 
     std::vector<std::vector<const Polygon*>> inset_polys_; // vector of vectors holding the inset polygons

include/LayerPlan.h

@@ -313,10 +313,10 @@ class LayerPlan : public NoCopy
      * The first travel move in a layer will result in a bogus travel move with
      * no combing and no retraction. This travel move needs to be fixed
      * afterwards.
-     * \param p The point to travel to.
+     * \param pos The point to travel to.
      * \param force_retract Whether to force a retraction to occur.
      */
-    GCodePath& addTravel(const Point2LL& p, const bool force_retract = false, const coord_t z_offset = 0);
+    GCodePath& addTravel(const Point2LL& pos, const bool force_retract = false, const coord_t z_offset = 0);
 
     /*!
      * Add a travel path to a certain point and retract if needed.
@@ -502,6 +502,8 @@ class LayerPlan : public NoCopy
      * polyline).
      * \param is_reversed Whether to print this wall in reverse direction.
      * \param is_linked_path Whether the path is a continuation off the previous path
+     * \param smooth_approach Whether we should make a smoothed approach to the first point,
+     * or just move straight to it
      */
     void addWall(
         const ExtrusionLine& wall,
@@ -515,7 +517,8 @@ class LayerPlan : public NoCopy
         bool always_retract,
         const bool is_closed,
         const bool is_reversed,
-        const bool is_linked_path);
+        const bool is_linked_path,
+        const bool smooth_approach = false);
 
     /*!
      * Add an infill wall to the g-code
@@ -806,6 +809,28 @@ class LayerPlan : public NoCopy
         const coord_t wipe_dist,
         const Ratio flow_ratio,
         const double fan_speed);
+
+    void addTravelBeforeSeam(const Point2LL& p, const GCodePathConfig& config);
+
+    /*!
+     * Begin the first wall with a travel move, executing specific procedures to optimize the process.
+     *
+     * Special conditions for this function are:
+     * - If `always_retract` is true, a retraction is always performed regardless of other factors.
+     * - If there's an optional `next` point provided, the function adds an intermediate position where the nozzle should go to begin printing the segment with optimal nozzle speed
+     * and extrusion parameters.
+     * - The focus of this method is the travel move for the first wall or layer in a print action, specifically optimizing retraction, travel speed, and the starting point for
+     * extrusion, if any.
+     *
+     * Note: This function is for handling very specific cases (such as initial layer or wall) in 3D printing G-code generation and should be used appropriately.
+     *
+     * \param pos The point to travel to.
+     * \param always_retract Whether to always enforce a retraction action.
+     * \param next the subsequent point of the segment moving towards. If provided, an intermediate travel point is added, when feasible, to optimize the start of the actual print
+     * action with proper nozzle speed and extrusion.
+     */
+
+    void addFirstWallTravel(const Point2LL& pos, const bool force_retract, const Point2LL* next, const GCodePathConfig& config, const Ratio& flow, const Ratio& width_factor);
 };
 
 } // namespace cura

include/PrintFeature.h

@@ -4,7 +4,7 @@
 namespace cura
 {
 
-enum class PrintFeatureType: unsigned char
+enum class PrintFeatureType : unsigned char
 {
     NoneType = 0, // used to mark unspecified jumps in polygons. libArcus depends on it
     OuterWall = 1,
@@ -18,14 +18,13 @@ enum class PrintFeatureType: unsigned char
     MoveRetraction = 9,
     SupportInterface = 10,
     PrimeTower = 11,
-    NumPrintFeatureTypes = 12 // this number MUST be the last one because other modules will
+    MoveUnretraction = 12,
+    NumPrintFeatureTypes = 13 // this number MUST be the last one because other modules will
                               // use this symbol to get the total number of types, which can
                               // be used to create an array or so
 };
 
 
-
-
 } // namespace cura
 
 #endif // PRINT_FEATURE

include/gcodeExport.h

@@ -8,6 +8,7 @@
 #ifdef BUILD_TESTS
 #include <gtest/gtest_prod.h> //To allow tests to use protected members.
 #endif
+#include <optional>
 #include <sstream> // for stream.str()
 #include <stdio.h>
 
@@ -26,6 +27,7 @@ namespace cura
 
 class RetractionConfig;
 class SliceDataStorage;
+class SliceLayerPart;
 struct WipeScriptConfig;
 
 // The GCodeExport class writes the actual GCode. This is the only class that knows how GCode looks and feels.
@@ -192,6 +194,8 @@ class GCodeExport : public NoCopy
      */
     double mm3ToE(double mm3);
 
+    double mm3ToMm(double mm3);
+
     /*!
      * Convert a distance value to an E value (which might be linear/distance based as well) for the current extruder.
      *
@@ -250,7 +254,7 @@ class GCodeExport : public NoCopy
 
     bool getExtruderIsUsed(const int extruder_nr) const; //!< return whether the extruder has been used throughout printing all meshgroup up till now
 
-    Point2LL getGcodePos(const coord_t x, const coord_t y, const int extruder_train) const;
+    Point2LL getGcodePos(const coord_t x, const coord_t y, const size_t extruder_train) const;
 
     void setFlavor(EGCodeFlavor flavor);
     EGCodeFlavor getFlavor() const;
@@ -446,13 +450,26 @@ class GCodeExport : public NoCopy
      * Write the F, X, Y, Z and E value (if they are not different from the last)
      *
      * convenience function called from writeExtrusion and writeTravel
+     */
+    // void writeFXYZE(const Velocity& speed, const coord_t x, const coord_t y, const coord_t z, const double e, const PrintFeatureType& feature);
+
+    /*!
+     * \brief Write a G0/G1 command
      *
      * This function also applies the gcode offset by calling \ref GCodeExport::getGcodePos
      * This function updates the \ref GCodeExport::total_bounding_box
      * It estimates the time in \ref GCodeExport::estimateCalculator for the correct feature
      * It updates \ref GCodeExport::currentPosition, \ref GCodeExport::current_e_value and \ref GCodeExport::currentSpeed
+     *
+     * \param command_name The actual command name, which should be "G0" or "G1" (but no check is performed)
+     * \param Tpeed movement speed
+     * \param x Target X position
+     * \param y Target Y position
+     * \param z Target Z position
+     * \param e_delta Extrusion amount to be performed while moving
+     * \param feature The type of feature being printed
      */
-    void writeFXYZE(const Velocity& speed, const coord_t x, const coord_t y, const coord_t z, const double e, const PrintFeatureType& feature);
+    void writeGCommand(const char* command_name, const Velocity& speed, const coord_t x, const coord_t y, const coord_t z, const double e_delta, const PrintFeatureType feature);
 
     /*!
      * The writeTravel and/or writeExtrusion when flavor == BFB
@@ -470,6 +487,8 @@ class GCodeExport : public NoCopy
      */
     void processInitialLayerBedTemperature();
 
+    void sendTravelLine(const Point2LL& pos, PrintFeatureType line_type, const Velocity& speed);
+
 public:
     /*!
      * Get ready for extrusion moves:
@@ -479,7 +498,7 @@ class GCodeExport : public NoCopy
      * It estimates the time in \ref GCodeExport::estimateCalculator
      * It updates \ref GCodeExport::current_e_value and \ref GCodeExport::currentSpeed
      */
-    void writeUnretractionAndPrime();
+    void writeUnretractionAndPrime(const std::optional<Point2LL>& pos = {}, const std::optional<Velocity>& override_speed = {}, const std::optional<double>& override_amount = {});
     void writeRetraction(const RetractionConfig& config, bool force = false, bool extruder_switch = false);
 
     /*!
@@ -613,6 +632,13 @@ class GCodeExport : public NoCopy
      * \param wipe_config Config with wipe script settings.
      */
     void insertWipeScript(const WipeScriptConfig& wipe_config);
+
+    void writeApproachToSeam(
+        const Point2LL& pos,
+        const Velocity& speed,
+        const std::vector<SliceLayerPart>& current_mesh_parts,
+        const coord_t wall_line_width,
+        const coord_t z_seam_approach_inset);
 };
 
 } // namespace cura

include/geometry/ClosedPolyline.h

@@ -133,6 +133,8 @@ class ClosedPolyline : public Polyline
      * \return An open polyline instance, with the end point at the same position of the start point
      */
     [[nodiscard]] OpenPolyline toPseudoOpenPolyline() const;
+
+    [[nodiscard]] const_segments_iterator loopOverSegments(const const_segments_iterator& start, const_segments_iterator::difference_type diff) const;
 };
 
 } // namespace cura

include/geometry/Point2D.h

@@ -0,0 +1,52 @@
+// Copyright (c) 2024 UltiMaker
+// CuraEngine is released under the terms of the AGPLv3 or higher.
+
+#ifndef UTILS_POINT2D_H
+#define UTILS_POINT2D_H
+
+#include "geometry/Point2LL.h"
+
+namespace cura
+{
+
+class Point2D
+{
+private:
+    double x_{ 0.0 };
+    double y_{ 0.0 };
+
+public:
+    Point2D(double x, double y);
+
+    Point2D(const Point2LL& other);
+
+    [[nodiscard]] Point2D operator*(const coord_t scale) const;
+
+    [[nodiscard]] Point2D operator*(const double scale) const;
+
+    [[nodiscard]] Point2D operator/(const double scale) const;
+
+    [[nodiscard]] double getX() const
+    {
+        return x_;
+    }
+
+    [[nodiscard]] double getY() const
+    {
+        return y_;
+    }
+
+    [[nodiscard]] double size() const;
+
+    [[nodiscard]] double size2() const;
+
+    [[nodiscard]] Point2D normalized() const;
+
+    void normalize();
+
+    Point2LL toPoint2LL() const;
+};
+
+} // namespace cura
+
+#endif // UTILS_POINT2D_H

include/geometry/Point2LL.h

@@ -157,6 +157,12 @@ INLINE double vSizeMM(const Point2LL& p0)
     return std::sqrt(fx * fx + fy * fy);
 }
 
+INLINE Point2LL vResize(const Point2LL& point, coord_t size)
+{
+    double size_factor = static_cast<double>(size) / static_cast<double>(vSize(point));
+    return point * size_factor;
+}
+
 INLINE Point2LL normal(const Point2LL& p0, coord_t length)
 {
     const coord_t len{ vSize(p0) };

include/geometry/Polygon.h

@@ -86,6 +86,11 @@ class Polygon : public ClosedPolyline
         return ClipperLib::Area(getPoints());
     }
 
+    [[nodiscard]] bool isHole() const
+    {
+        return area() < 0.0;
+    }
+
     [[nodiscard]] Point2LL centerOfMass() const;
 
     [[nodiscard]] Shape offset(int distance, ClipperLib::JoinType join_type = ClipperLib::jtMiter, double miter_limit = 1.2) const;

include/geometry/Polyline.h

@@ -98,10 +98,10 @@ class Polyline : public PointsSet
     [[nodiscard]] const_segments_iterator endSegments() const;
 
     /*! \brief Provides a begin iterator to iterate over all the segments of the line */
-    segments_iterator beginSegments();
+    [[nodiscard]] segments_iterator beginSegments();
 
     /*! \brief Provides an end iterator to iterate over all the segments of the line */
-    segments_iterator endSegments();
+    [[nodiscard]] segments_iterator endSegments();
 
     /*!
      * Split these poly line objects into several line segment objects consisting of only two verts

include/geometry/SegmentIterator.h

@@ -42,6 +42,10 @@ struct SegmentIterator
     source_iterator_type before_end_;
 
 public:
+    SegmentIterator()
+    {
+    }
+
     SegmentIterator(source_iterator_type pos, source_iterator_type begin, source_iterator_type end)
         : current_pos_(pos)
         , begin_(begin)
@@ -58,12 +62,24 @@ struct SegmentIterator
         return Segment{ *current_pos_, *std::next(current_pos_) };
     }
 
+    SegmentIterator& operator--()
+    {
+        current_pos_--;
+        return *this;
+    }
+
     SegmentIterator& operator++()
     {
         current_pos_++;
         return *this;
     }
 
+    SegmentIterator& operator+=(difference_type diff)
+    {
+        current_pos_ += (diff);
+        return *this;
+    }
+
     bool operator==(const SegmentIterator& other) const
     {
         return current_pos_ == other.current_pos_;