Support filament shrinkage

Ported from SuperSlicer

Signed-off-by: SoftFever <softfeverever@gmail.com>
#360

src/libslic3r/Preset.cpp

@@ -778,7 +778,7 @@ static std::vector<std::string> s_Preset_filament_options {
     "filament_wipe_distance", "additional_cooling_fan_speed",
     "bed_temperature_difference", "nozzle_temperature_range_low", "nozzle_temperature_range_high",
     //SoftFever
-    "enable_pressure_advance", "pressure_advance","chamber_temperature" /*,"filament_seam_gap"*/
+    "enable_pressure_advance", "pressure_advance","chamber_temperature", "filament_shrink"/*,"filament_seam_gap"*/
 };
 
 static std::vector<std::string> s_Preset_machine_limits_options {

src/libslic3r/Print.cpp

@@ -187,6 +187,7 @@ bool Print::invalidate_state_by_config_options(const ConfigOptionResolver & /* n
         } else if (
                opt_key == "initial_layer_print_height"
             || opt_key == "nozzle_diameter"
+            || opt_key == "filament_shrink"
             // Spiral Vase forces different kind of slicing than the normal model:
             // In Spiral Vase mode, holes are closed and only the largest area contour is kept at each layer.
             // Therefore toggling the Spiral Vase on / off requires complete reslicing.

src/libslic3r/PrintConfig.cpp

@@ -1290,6 +1290,18 @@ void PrintConfigDef::init_fff_params()
     def->min = 0;
     def->set_default_value(new ConfigOptionFloats { 1.75 });
 
+    def = this->add("filament_shrink", coPercents);
+    def->label = L("Shrinkage");
+    def->tooltip = L("Enter the shrinkage percentage that the filament will get after cooling (94% if you measure 94mm instead of 100mm)."
+        " The part will be scaled in xy to compensate."
+        " Only the filament used for the perimeter is taken into account."
+        "\nBe sure to allow enough space between objects, as this compensation is done after the checks.");
+    def->sidetext = L("%");
+    def->ratio_over = "";
+    def->min = 10;
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionPercents{ 100 });
+
     def = this->add("filament_density", coFloats);
     def->label = L("Density");
     def->tooltip = L("Filament density. For statistics only");

src/libslic3r/PrintConfig.hpp

@@ -981,6 +981,9 @@ PRINT_CONFIG_CLASS_DERIVED_DEFINE(
     ((ConfigOptionPoints,              thumbnails))
     // BBS: move from PrintObjectConfig
     ((ConfigOptionBool, independent_support_layer_height))
+    // SoftFever
+    ((ConfigOptionPercents,             filament_shrink))
+
 )
 
 // This object is mapped to Perl as Slic3r::Config::Full.

src/libslic3r/PrintObjectSlice.cpp

@@ -236,6 +236,8 @@ static std::vector<PrintObjectRegions::LayerRangeRegions>::const_iterator layer_
 }
 
 static std::vector<std::vector<ExPolygons>> slices_to_regions(
+    const PrintConfig                                        &print_config,
+    const PrintObject                                        &print_object,
     ModelVolumePtrs                                           model_volumes,
     const PrintObjectRegions                                 &print_object_regions,
     const std::vector<float>                                 &zs,
@@ -437,6 +439,22 @@ static std::vector<std::vector<ExPolygons>> slices_to_regions(
             });
     }
 
+    // SoftFever: ported from SuperSlicer
+    // filament shrink
+    for (const std::unique_ptr<PrintRegion>& pr : print_object_regions.all_regions) {
+        if (pr.get()) {
+            std::vector<ExPolygons>& region_polys = slices_by_region[pr->print_object_region_id()];
+            const size_t extruder_id = pr->extruder(FlowRole::frPerimeter) - 1;
+            double scale = print_config.filament_shrink.values[extruder_id] * 0.01;
+            if (scale != 1) {
+                scale = 1 / scale;
+                for (ExPolygons& polys : region_polys)
+                    for (ExPolygon& poly : polys)
+                        poly.scale(scale);
+            }
+        }
+    }
+
     return slices_by_region;
 }
 
@@ -900,10 +918,9 @@ void PrintObject::slice_volumes()
     groupingVolumes(objSliceByVolumeParts, firstLayerObjSliceByGroups, scaled_resolution);
     applyNegtiveVolumes(this->model_object()->volumes, objSliceByVolume, firstLayerObjSliceByGroups, scaled_resolution);
 
-    std::vector<std::vector<ExPolygons>> region_slices = slices_to_regions(this->model_object()->volumes, *m_shared_regions, slice_zs,
-        std::move(objSliceByVolume),
-        PrintObject::clip_multipart_objects,
-        throw_on_cancel_callback);
+    std::vector<std::vector<ExPolygons>> region_slices =
+        slices_to_regions(print->config(), *this, this->model_object()->volumes, *m_shared_regions, slice_zs,
+                          std::move(objSliceByVolume), PrintObject::clip_multipart_objects, throw_on_cancel_callback);
 
     for (size_t region_id = 0; region_id < region_slices.size(); ++ region_id) {
         std::vector<ExPolygons> &by_layer = region_slices[region_id];

src/slic3r/GUI/Tab.cpp

@@ -2567,6 +2567,7 @@ void TabFilament::build()
         optgroup->append_single_option_line("pressure_advance");
 
         optgroup->append_single_option_line("filament_density");
+        optgroup->append_single_option_line("filament_shrink");
         optgroup->append_single_option_line("filament_cost");
         //BBS
         optgroup->append_single_option_line("temperature_vitrification");
@@ -2657,7 +2658,7 @@ void TabFilament::build()
         //};
         //optgroup->append_line(line);
         optgroup = page->new_optgroup(L("Cooling for specific layer"), L"param_cooling");
-    optgroup->append_single_option_line("close_fan_the_first_x_layers", "auto-cooling");
+        optgroup->append_single_option_line("close_fan_the_first_x_layers", "auto-cooling");
         //optgroup->append_single_option_line("full_fan_speed_layer");
 
         optgroup = page->new_optgroup(L("Part cooling fan"), L"param_cooling_fan");