allow to add gapfill after the last perimeter

supermerill/SuperSlicer#982

resources/ui_layout/print.ui

@@ -55,6 +55,7 @@ group:Advanced
 	line:Gap Fill
 		setting:label$_:gap_fill
 		setting:width$5:gap_fill_min_area
+		setting:width$5:gap_fill_last
 	end_line
 	line:Seam
 		setting:label_width$12:sidetext_width$0:seam_position

src/libslic3r/Layer.cpp

@@ -158,6 +158,7 @@ void Layer::make_perimeters()
                 && config.extra_perimeters_odd_layers == other_config.extra_perimeters_odd_layers
                 && config.extra_perimeters_overhangs == other_config.extra_perimeters_overhangs
                 && config.gap_fill                  == other_config.gap_fill
+                && config.gap_fill_last             == other_config.gap_fill_last
                 && config.gap_fill_min_area         == other_config.gap_fill_min_area
                 && config.gap_fill_overlap          == other_config.gap_fill_overlap
                 && config.gap_fill_speed            == other_config.gap_fill_speed

src/libslic3r/PerimeterGenerator.cpp

@@ -638,7 +638,7 @@ void PerimeterGenerator::process()
                     // look for gaps
                     if (this->config->gap_fill 
                         //check if we are going to have an other perimeter
-                        && (i <= loop_number || has_overhang || next_onion.empty()))
+                        && (i <= loop_number || has_overhang || next_onion.empty() || (this->config->gap_fill_last.value && i == loop_number+1)))
                         // not using safety offset here would "detect" very narrow gaps
                         // (but still long enough to escape the area threshold) that gap fill
                         // won't be able to fill but we'd still remove from infill area

src/libslic3r/Preset.cpp

@@ -515,6 +515,7 @@ const std::vector<std::string>& Preset::print_options()
         "travel_speed", "travel_speed_z",
         // gapfill
         "gap_fill",
+        "gap_fill_last",
         "gap_fill_min_area",
         "gap_fill_overlap",
         "gap_fill_speed",

src/libslic3r/PrintConfig.cpp

@@ -1876,6 +1876,14 @@ void PrintConfigDef::init_fff_params()
     def->mode = comExpert;
     def->set_default_value(new ConfigOptionBool(true));
 
+    def = this->add("gap_fill_last", coBool);
+    def->label = L("after last perimeter");
+    def->full_label = L("Gapfill after last perimeter");
+    def->category = OptionCategory::perimeter;
+    def->tooltip = L("All gaps between the alst periemter and the infill which are thinner than a perimeter will be filled by gapfill.");
+    def->mode = comExpert;
+    def->set_default_value(new ConfigOptionBool{true });
+
     def = this->add("gap_fill_min_area", coFloatOrPercent);
     def->label = L("Min surface");
     def->full_label = L("Min gap-fill surface");
@@ -5494,6 +5502,7 @@ void PrintConfigDef::to_prusa(t_config_option_key& opt_key, std::string& value,
 "gap_fill",
 "gap_fill_min_area",
 "gap_fill_overlap",
+"gap_fill_infill",
 "infill_dense",
 "infill_connection",
 "infill_dense_algo",

src/libslic3r/PrintConfig.hpp

@@ -790,6 +790,7 @@ public:
     ConfigOptionPercent             fill_smooth_distribution;
     ConfigOptionFloatOrPercent      fill_smooth_width;
     ConfigOptionBool                gap_fill;
+    ConfigOptionBool                gap_fill_last;
     ConfigOptionFloatOrPercent      gap_fill_min_area;
     ConfigOptionPercent             gap_fill_overlap;
     ConfigOptionFloat               gap_fill_speed;
@@ -905,6 +906,7 @@ protected:
         OPT_PTR(fill_smooth_distribution);
         OPT_PTR(fill_smooth_width);
         OPT_PTR(gap_fill);
+        OPT_PTR(gap_fill_last);
         OPT_PTR(gap_fill_min_area);
         OPT_PTR(gap_fill_overlap);
         OPT_PTR(gap_fill_speed);

src/libslic3r/PrintObject.cpp

@@ -678,6 +678,7 @@ namespace Slic3r {
         for (const t_config_option_key& opt_key : opt_keys) {
             if (
                 opt_key == "gap_fill"
+                || opt_key == "gap_fill_last"
                 || opt_key == "gap_fill_min_area"
                 || opt_key == "only_one_perimeter_top"
                 || opt_key == "only_one_perimeter_top_other_algo"

src/slic3r/GUI/ConfigManipulation.cpp

@@ -377,7 +377,8 @@ void ConfigManipulation::toggle_print_fff_options(DynamicPrintConfig* config)
 
     toggle_field("perimeter_loop_seam", config->opt_bool("perimeter_loop"));
 
-    toggle_field("gap_fill_min_area", config->opt_bool("gap_fill"));
+    for (auto el : { "gap_fill_last", "gap_fill_min_area" })
+        toggle_field(el, config->opt_bool("gap_fill"));
 
     toggle_field("avoid_crossing_not_first_layer", config->opt_bool("avoid_crossing_perimeters"));