New sparse infill: "stars" - David's star shaped infill.

This is very similar to a "triangles" infill, but maximum two lines
intersect at a single point.

added utility function get_extents_vector()

4 files changed, 28 insertions, 2 deletions

diff --git a/xs/src/libslic3r/Fill/FillBase.cpp b/xs/src/libslic3r/Fill/FillBase.cpp
index f471d539c..6cd508acb 100644
--- a/xs/src/libslic3r/Fill/FillBase.cpp
+++ b/xs/src/libslic3r/Fill/FillBase.cpp
@@ -25,6 +25,7 @@ Fill* Fill::new_from_type(const InfillPattern type)
     case ipLine:                return new FillLine();
     case ipGrid:                return new FillGrid2();
     case ipTriangles:           return new FillTriangles();
+    case ipStars:               return new FillStars();
     case ipCubic:               return new FillCubic();
 //  case ipGrid:                return new FillGrid();
     case ipArchimedeanChords:   return new FillArchimedeanChords();
diff --git a/xs/src/libslic3r/Fill/FillBase.hpp b/xs/src/libslic3r/Fill/FillBase.hpp
index b628ab31b..5f83e6b9c 100644
--- a/xs/src/libslic3r/Fill/FillBase.hpp
+++ b/xs/src/libslic3r/Fill/FillBase.hpp
@@ -49,7 +49,7 @@ public:
     // in radians, ccw, 0 = East
     float       angle;
     // In scaled coordinates. Maximum lenght of a perimeter segment connecting two infill lines.
-    // Used by the FillRectilinear2, FillGrid2, FillTriangles and FillCubic.
+    // Used by the FillRectilinear2, FillGrid2, FillTriangles, FillStars and FillCubic.
     // If left to zero, the links will not be limited.
     coord_t     link_max_length;
     // In scaled coordinates. Used by the concentric infill pattern to clip the loops to create extrusion paths.
diff --git a/xs/src/libslic3r/Fill/FillRectilinear2.cpp b/xs/src/libslic3r/Fill/FillRectilinear2.cpp
index 3d32f164e..20709cbde 100644
--- a/xs/src/libslic3r/Fill/FillRectilinear2.cpp
+++ b/xs/src/libslic3r/Fill/FillRectilinear2.cpp
@@ -1517,12 +1517,26 @@ Polylines FillTriangles::fill_surface(const Surface *surface, const FillParams &
     Polylines polylines_out;
     if (! fill_surface_by_lines(surface, params2, 0.f, 0., polylines_out) ||
         ! fill_surface_by_lines(surface, params2, float(M_PI / 3.), 0., polylines_out) ||
-        ! fill_surface_by_lines(surface, params2, float(2. * M_PI / 3.), 0., polylines_out)) {
+        ! fill_surface_by_lines(surface, params2, float(2. * M_PI / 3.), 0.5 * this->spacing / params2.density, polylines_out)) {
         printf("FillTriangles::fill_surface() failed to fill a region.\n");
     }
     return polylines_out;
 }
 
+Polylines FillStars::fill_surface(const Surface *surface, const FillParams &params)
+{
+    // Each linear fill covers 1/3 of the target coverage.
+    FillParams params2 = params;
+    params2.density *= 0.333333333f;
+    Polylines polylines_out;
+    if (! fill_surface_by_lines(surface, params2, 0.f, 0., polylines_out) ||
+        ! fill_surface_by_lines(surface, params2, float(M_PI / 3.), 0., polylines_out) ||
+        ! fill_surface_by_lines(surface, params2, float(2. * M_PI / 3.), 0., polylines_out)) {
+        printf("FillStars::fill_surface() failed to fill a region.\n");
+    }
+    return polylines_out;
+}
+
 Polylines FillCubic::fill_surface(const Surface *surface, const FillParams &params)
 {
     // Each linear fill covers 1/3 of the target coverage.
diff --git a/xs/src/libslic3r/Fill/FillRectilinear2.hpp b/xs/src/libslic3r/Fill/FillRectilinear2.hpp
index d8afc76ad..b8e56f90c 100644
--- a/xs/src/libslic3r/Fill/FillRectilinear2.hpp
+++ b/xs/src/libslic3r/Fill/FillRectilinear2.hpp
@@ -41,6 +41,17 @@ protected:
     virtual float _layer_angle(size_t idx) const { return 0.f; }
 };
 
+class FillStars : public FillRectilinear2
+{
+public:
+    virtual ~FillStars() {}
+    virtual Polylines fill_surface(const Surface *surface, const FillParams &params);
+
+protected:
+    // The grid fill will keep the angle constant between the layers, see the implementation of Slic3r::Fill.
+    virtual float _layer_angle(size_t idx) const { return 0.f; }
+};
+
 class FillCubic : public FillRectilinear2
 {
 public: