Add "one perimeter for top surface"

resources/profiles/PrusaResearch.ini

@@ -48,6 +48,7 @@ bottom_fill_pattern = rectilinear
 external_perimeters_first = 0
 external_perimeter_extrusion_width = 0.45
 extra_perimeters = 0
+only_one_perimeter_top = 0
 extruder_clearance_height = 20
 extruder_clearance_radius = 20
 extrusion_width = 0.45

slic3r.pl

@@ -395,6 +395,7 @@ Usage: slic3r.pl [ OPTIONS ] [ file.stl ] [ file2.stl ] ...
   
    Quality options (slower slicing):
     --extra-perimeters  Add more perimeters when needed (default: yes)
+    --one-top-perimeter   Only draw 1 perimeter for the top layers (default: yes)
     --ensure-vertical-shell-thickness Add solid infill near sloping surfaces to guarantee the vertical shell thickness (top+bottom solid layers). (default: no)
     --avoid-crossing-perimeters Optimize travel moves so that no perimeters are crossed (default: no)
     --thin-walls        Detect single-width walls (default: yes)

t/perimeters.t

@@ -290,6 +290,7 @@ use Slic3r::Test;
     $config->set('layer_height', 0.4);
     $config->set('first_layer_height', 0.35);
     $config->set('extra_perimeters', 1);
+    $config->set('only_one_perimeter_top', 1);
     $config->set('cooling', [ 0 ]);                 # to prevent speeds from being altered
     $config->set('first_layer_speed', '100%');      # to prevent speeds from being altered
     $config->set('perimeter_speed', 99);

xs/src/libslic3r/LayerRegion.cpp

@@ -75,6 +75,8 @@ LayerRegion::make_perimeters(const SurfaceCollection &slices, SurfaceCollection*
     if (this->layer()->lower_layer != NULL)
         // Cummulative sum of polygons over all the regions.
         g.lower_slices = &this->layer()->lower_layer->slices;
+    if (this->layer()->upper_layer != NULL)
+        g.upper_slices = &this->layer()->upper_layer->slices;
     
     g.layer_id              = this->layer()->id();
     g.ext_perimeter_flow    = this->flow(frExternalPerimeter);

xs/src/libslic3r/PerimeterGenerator.cpp

@@ -53,9 +53,17 @@ PerimeterGenerator::process()
     // extra perimeters for each one
     for (const Surface &surface : this->slices->surfaces) {
         // detect how many perimeters must be generated for this island
-        const int loop_number = this->config->perimeters + surface.extra_perimeters -1;  // 0-indexed loops
+        int loop_number =  
-        
+		//(config->only_one_perimeter_top && surface.is_external() && !surface.is_bridge() && surface.surface_type == stTop) ? 
+		//	0 : // only 1 perimeter for top surface if the option is set (0-indexed loops)
+			(this->config->perimeters + surface.extra_perimeters -1);  // normal case (0-indexed loops)
+		
+		if(config->only_one_perimeter_top && this->upper_slices == NULL){
+			loop_number = 0;
+		}
+		
         Polygons gaps;
+        Polygons stored;
         
         Polygons last = surface.expolygon.simplify_p(SCALED_RESOLUTION);
         if (loop_number >= 0) {  // no loops = -1
@@ -165,7 +173,21 @@ PerimeterGenerator::process()
                         holes[i].push_back(loop);
                     }
                 }
+					
+				if(i==0 && config->only_one_perimeter_top && this->upper_slices != NULL){
+					//split the polygons with top/not_top
+					Polygons upper_polygons((*(this->upper_slices)));
+					Polygons stored_toosmall = diff(last, (upper_polygons), true);
+					Polygons last_toosmall = diff(last, stored_toosmall, true);
+					// increase a bit the inner scpace to fill the frontier between last and stored.
+					stored = union_(stored, intersection(offset(stored_toosmall, perimeter_spacing/2), last));
+					last = intersection(offset(last_toosmall, perimeter_spacing/2), last);
+				}
+				
             }
+			
+			// add stored polygons
+			last = union_(last, stored);
             
             // nest loops: holes first
             for (int d = 0; d <= loop_number; ++d) {

xs/src/libslic3r/PerimeterGenerator.hpp

@@ -39,6 +39,7 @@ class PerimeterGenerator {
 public:
     // Inputs:
     const SurfaceCollection* slices;
+    const ExPolygonCollection* upper_slices;
     const ExPolygonCollection* lower_slices;
     double layer_height;
     int layer_id;
@@ -69,7 +70,7 @@ public:
         ExtrusionEntityCollection*  gap_fill,
         // Infills without the gap fills
         SurfaceCollection*          fill_surfaces)
-        : slices(slices), lower_slices(NULL), layer_height(layer_height),
+        : slices(slices), lower_slices(NULL), upper_slices(NULL), layer_height(layer_height),
             layer_id(-1), perimeter_flow(flow), ext_perimeter_flow(flow),
             overhang_flow(flow), solid_infill_flow(flow),
             config(config), object_config(object_config), print_config(print_config),

xs/src/libslic3r/PrintConfig.cpp

@@ -318,6 +318,14 @@ PrintConfigDef::PrintConfigDef()
                    "is supported.");
     def->cli = "extra-perimeters!";
     def->default_value = new ConfigOptionBool(true);
+	
+    def = this->add("only_one_perimeter_top", coBool);
+    def->label = "Only one perimeter on Top surfaces";
+    def->category = "Layers and Perimeters";
+    def->tooltip = "Use only one perimeter on flat top surface, to let more space to the top infill pattern.";
+    def->cli = "one-top-perimeter!";
+    def->default_value = new ConfigOptionBool(true);
+
 
     def = this->add("extruder", coInt);
     def->gui_type = "i_enum_open";

xs/src/libslic3r/PrintConfig.hpp

@@ -384,6 +384,7 @@ public:
     ConfigOptionFloatOrPercent      external_perimeter_speed;
     ConfigOptionBool                external_perimeters_first;
     ConfigOptionBool                extra_perimeters;
+    ConfigOptionBool                only_one_perimeter_top;
     ConfigOptionFloat               fill_angle;
     ConfigOptionPercent             fill_density;
     ConfigOptionEnum<InfillPattern> fill_pattern;
@@ -423,6 +424,7 @@ protected:
         OPT_PTR(external_perimeter_speed);
         OPT_PTR(external_perimeters_first);
         OPT_PTR(extra_perimeters);
+        OPT_PTR(only_one_perimeter_top);
         OPT_PTR(fill_angle);
         OPT_PTR(fill_density);
         OPT_PTR(fill_pattern);

xs/src/slic3r/GUI/Preset.cpp

@@ -179,7 +179,7 @@ const std::vector<std::string>& Preset::print_options()
 {    
     static std::vector<std::string> s_opts {
         "layer_height", "first_layer_height", "perimeters", "spiral_vase", "top_solid_layers", "bottom_solid_layers", 
-        "extra_perimeters", "ensure_vertical_shell_thickness", "avoid_crossing_perimeters", "thin_walls", "overhangs", 
+        "extra_perimeters", "only_one_perimeter_top", "ensure_vertical_shell_thickness", "avoid_crossing_perimeters", "thin_walls", "overhangs", 
         "seam_position", "external_perimeters_first", "fill_density", "fill_pattern", "top_fill_pattern", "bottom_fill_pattern", 
         "infill_every_layers", "infill_only_where_needed", "solid_infill_every_layers", "fill_angle", "bridge_angle", 
         "solid_infill_below_area", "only_retract_when_crossing_perimeters", "infill_first", "max_print_speed", 
@@ -199,7 +199,7 @@ const std::vector<std::string>& Preset::print_options()
         "perimeter_extrusion_width", "external_perimeter_extrusion_width", "infill_extrusion_width", "solid_infill_extrusion_width", 
         "top_infill_extrusion_width", "support_material_extrusion_width", "infill_overlap", "bridge_flow_ratio", "clip_multipart_objects", 
         "elefant_foot_compensation", "xy_size_compensation", "threads", "resolution", "wipe_tower", "wipe_tower_x", "wipe_tower_y",
-        "wipe_tower_width", "wipe_tower_per_color_wipe",
+        "wipe_tower_width", "wipe_tower_per_color_wipe", "only_one_perimeter_top", 
         "compatible_printers", "compatible_printers_condition"
     };
     return s_opts;

xs/src/slic3r/GUI/Tab.cpp

@@ -405,6 +405,7 @@ void TabPrint::build()
 
 		optgroup = page->new_optgroup(_(L("Quality (slower slicing)")));
 		optgroup->append_single_option_line("extra_perimeters");
+		optgroup->append_single_option_line("only_one_perimeter_top");
 		optgroup->append_single_option_line("ensure_vertical_shell_thickness");
 		optgroup->append_single_option_line("avoid_crossing_perimeters");
 		optgroup->append_single_option_line("thin_walls");
@@ -757,7 +758,7 @@ void TabPrint::update()
 	}
 
 	bool have_perimeters = m_config->opt_int("perimeters") > 0;
-	std::vector<std::string> vec_enable = {	"extra_perimeters", "ensure_vertical_shell_thickness", "thin_walls", "overhangs",
+	std::vector<std::string> vec_enable = {	"extra_perimeters", "only_one_perimeter_top", "ensure_vertical_shell_thickness", "thin_walls", "overhangs",
 											"seam_position", "external_perimeters_first", "external_perimeter_extrusion_width",
 											"perimeter_speed", "small_perimeter_speed", "external_perimeter_speed" };
 	for (auto el : vec_enable)