Fix of #8488 - Infinite loop in the lightning infill.

3 files changed, 6 insertions, 3 deletions

diff --git a/src/libslic3r/Fill/Lightning/DistanceField.cpp b/src/libslic3r/Fill/Lightning/DistanceField.cpp
index 0cbfa9af5..ad1a85ac6 100644
--- a/src/libslic3r/Fill/Lightning/DistanceField.cpp
+++ b/src/libslic3r/Fill/Lightning/DistanceField.cpp
@@ -17,7 +17,7 @@ namespace Slic3r::FillLightning
 constexpr coord_t radius_per_cell_size = 6;  // The cell-size should be small compared to the radius, but not so small as to be inefficient.
 
 #ifdef LIGHTNING_DISTANCE_FIELD_DEBUG_OUTPUT
-void export_distance_field_to_svg(const std::string &path, const Polygons &outline, const Polygons &overhang, const std::list<DistanceField::UnsupportedCell> &unsupported_points, const Points &points = {})
+void export_distance_field_to_svg(const std::string &path, const Polygons &outline, const Polygons &overhang, const std::vector<DistanceField::UnsupportedCell> &unsupported_points, const Points &points = {})
 {
     coordf_t    stroke_width = scaled<coordf_t>(0.01);
     BoundingBox bbox         = get_extents(outline);
diff --git a/src/libslic3r/Fill/Lightning/DistanceField.hpp b/src/libslic3r/Fill/Lightning/DistanceField.hpp
index 007ac235e..6e7224384 100644
--- a/src/libslic3r/Fill/Lightning/DistanceField.hpp
+++ b/src/libslic3r/Fill/Lightning/DistanceField.hpp
@@ -200,7 +200,7 @@ protected:
     }
 
 #ifdef LIGHTNING_DISTANCE_FIELD_DEBUG_OUTPUT
-    friend void export_distance_field_to_svg(const std::string &path, const Polygons &outline, const Polygons &overhang, const std::list<DistanceField::UnsupportedCell> &unsupported_points, const Points &points);
+    friend void export_distance_field_to_svg(const std::string &path, const Polygons &outline, const Polygons &overhang, const std::vector<DistanceField::UnsupportedCell> &unsupported_points, const Points &points);
 #endif
 };
 
diff --git a/src/libslic3r/Fill/Lightning/Generator.cpp b/src/libslic3r/Fill/Lightning/Generator.cpp
index ebd3afc0e..48377f427 100644
--- a/src/libslic3r/Fill/Lightning/Generator.cpp
+++ b/src/libslic3r/Fill/Lightning/Generator.cpp
@@ -66,10 +66,11 @@ void Generator::generateInitialInternalOverhangs(const PrintObject &print_object
                 if (surface.surface_type == stInternal || surface.surface_type == stInternalVoid)
                     append(infill_area_here, to_polygons(surface.expolygon));
 
+        infill_area_here = union_(infill_area_here);
         // Remove the part of the infill area that is already supported by the walls.
         Polygons overhang = diff(offset(infill_area_here, -float(m_wall_supporting_radius)), infill_area_above);
         // Filter out unprintable polygons and near degenerated polygons (three almost collinear points and so).
-        overhang = opening(std::move(overhang), SCALED_EPSILON, SCALED_EPSILON);
+        overhang = opening(overhang, SCALED_EPSILON, SCALED_EPSILON);
 
         m_overhang_per_layer[layer_nr] = overhang;
         infill_area_above = std::move(infill_area_here);
@@ -95,6 +96,8 @@ void Generator::generateTrees(const PrintObject &print_object, const std::functi
             for (const Surface &surface : layerm->fill_surfaces.surfaces)
                 if (surface.surface_type == stInternal || surface.surface_type == stInternalVoid)
                     append(infill_outlines[layer_id], to_polygons(surface.expolygon));
+
+        infill_outlines[layer_id] = union_(infill_outlines[layer_id]);
     }
 
     // For various operations its beneficial to quickly locate nearby features on the polygon: