Port overhang extra perimeters from PrusaSlicer (#1939)

* Port overhang extra perimeters from PrusaSlicer

* Reduce duplicated code

* Add credits

---------

Co-authored-by: SoftFever <softfeverever@gmail.com>
Co-authored-by: PavelMikus <pavel.mikus.mail@seznam.cz>

src/libslic3r/PerimeterGenerator.hpp

@@ -79,6 +79,7 @@ class PerimeterGenerator {
 private:
     std::map<int, Polygons> generate_lower_polygons_series(float width);
     void split_top_surfaces(const ExPolygons &orig_polygons, ExPolygons &top_fills, ExPolygons &non_top_polygons, ExPolygons &fill_clip) const;
+    void apply_extra_perimeters();
 
 private:
     bool        m_spiral_vase;

src/libslic3r/Polyline.hpp

@@ -102,6 +102,9 @@ class Polyline : public MultiPoint {
     void append(const Polyline& src);
     void append(Polyline&& src);
 
+    Point& operator[](Points::size_type idx) { return this->points[idx]; }
+    const Point& operator[](Points::size_type idx) const { return this->points[idx]; }
+
     const Point& last_point() const override { return this->points.back(); }
     const Point& leftmost_point() const;
     Lines lines() const override;

src/libslic3r/Preset.cpp

@@ -718,7 +718,7 @@ bool Preset::has_cali_lines(PresetBundle* preset_bundle)
 static std::vector<std::string> s_Preset_print_options {
     "layer_height", "initial_layer_print_height", "wall_loops", "slice_closing_radius", "spiral_mode", "slicing_mode",
     "top_shell_layers", "top_shell_thickness", "bottom_shell_layers", "bottom_shell_thickness",
-    "ensure_vertical_shell_thickness", "reduce_crossing_wall", "detect_thin_wall", "detect_overhang_wall",
+    "extra_perimeters_on_overhangs", "ensure_vertical_shell_thickness", "reduce_crossing_wall", "detect_thin_wall", "detect_overhang_wall",
     "seam_position", "staggered_inner_seams", "wall_infill_order", "sparse_infill_density", "sparse_infill_pattern", "top_surface_pattern", "bottom_surface_pattern",
     "infill_direction",
     "minimum_sparse_infill_area", "reduce_infill_retraction","internal_solid_infill_pattern",

src/libslic3r/PrintConfig.cpp

@@ -779,6 +779,13 @@ void PrintConfigDef::init_fff_params()
     def->tooltip = L("Use only one wall on first layer, to give more space to the bottom infill pattern");
     def->set_default_value(new ConfigOptionBool(false));
 
+    def = this->add("extra_perimeters_on_overhangs", coBool);
+    def->label = L("Extra perimeters on overhangs");
+    def->category = L("Quality");
+    def->tooltip = L("Create additional perimeter paths over steep overhangs and areas where bridges cannot be anchored. ");
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionBool(false));
+
     def = this->add("overhang_speed_classic", coBool);
     def->label = L("Classic mode");
     def->category = L("Speed");

src/libslic3r/PrintConfig.hpp

@@ -804,7 +804,8 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionFloatOrPercent,       infill_anchor_max))
 
     // Orca
-    ((ConfigOptionBool,               make_overhang_printable))
+    ((ConfigOptionBool,                 make_overhang_printable))
+    ((ConfigOptionBool,                 extra_perimeters_on_overhangs))
 )
 
 PRINT_CONFIG_CLASS_DEFINE(

src/libslic3r/PrintObject.cpp

@@ -719,6 +719,7 @@ bool PrintObject::invalidate_state_by_config_options(
                opt_key == "wall_loops"
             || opt_key == "only_one_wall_top"
             || opt_key == "only_one_wall_first_layer"
+            || opt_key == "extra_perimeters_on_overhangs"
             || opt_key == "initial_layer_line_width"
             || opt_key == "inner_wall_line_width"
             || opt_key == "infill_wall_overlap"

src/libslic3r/SupportMaterial.cpp

@@ -1446,7 +1446,7 @@ namespace SupportMaterialInternal {
         // remove the entire bridges and only support the unsupported edges
         //FIXME the brided regions are already collected as layerm.bridged. Use it?
         for (const Surface &surface : layerm.fill_surfaces.surfaces)
-            if (surface.surface_type == stBottomBridge && surface.bridge_angle != -1)
+            if (surface.surface_type == stBottomBridge && surface.bridge_angle >= 0.0)
                 polygons_append(bridges, surface.expolygon);
         //FIXME add the gap filled areas. Extrude the gaps with a bridge flow?
         // Remove the unsupported ends of the bridges from the bridged areas.

src/slic3r/GUI/ConfigManipulation.cpp

@@ -508,7 +508,7 @@ void ConfigManipulation::toggle_print_fff_options(DynamicPrintConfig *config, co
     auto gcflavor = preset_bundle->printers.get_edited_preset().config.option<ConfigOptionEnum<GCodeFlavor>>("gcode_flavor")->value;
 
     bool have_perimeters = config->opt_int("wall_loops") > 0;
-    for (auto el : { "ensure_vertical_shell_thickness", "detect_thin_wall", "detect_overhang_wall",
+    for (auto el : { "extra_perimeters_on_overhangs", "ensure_vertical_shell_thickness", "detect_thin_wall", "detect_overhang_wall",
                     "seam_position", "staggered_inner_seams", "wall_infill_order", "outer_wall_line_width",
                     "inner_wall_speed", "outer_wall_speed", "small_perimeter_speed", "small_perimeter_threshold" })
         toggle_field(el, have_perimeters);

src/slic3r/GUI/Tab.cpp

@@ -1899,6 +1899,7 @@ void TabPrint::build()
         optgroup->append_single_option_line("make_overhang_printable_hole_size");
         optgroup->append_single_option_line("reduce_crossing_wall");
         optgroup->append_single_option_line("max_travel_detour_distance");
+        optgroup->append_single_option_line("extra_perimeters_on_overhangs");
 
     page = add_options_page(L("Strength"), "empty");
         optgroup = page->new_optgroup(L("Walls"), L"param_wall");