#360 skirt extrusion width

resources/ui_layout/print.ui

@@ -232,6 +232,7 @@ group:Extrusion width
 	setting:solid_infill_extrusion_width
 	setting:top_infill_extrusion_width
 	setting:support_material_extrusion_width
+	setting:skirt_extrusion_width
 group:Overlap
 	line:Perimeter overlap
 		setting:label$External:external_perimeter_overlap

src/libslic3r/Print.cpp

@@ -1599,7 +1599,9 @@ Flow Print::brim_flow(size_t extruder_id) const
 
 Flow Print::skirt_flow(size_t extruder_id) const
 {
-    ConfigOptionFloatOrPercent width = m_config.first_layer_extrusion_width;
+    ConfigOptionFloatOrPercent width = m_config.skirt_extrusion_width;
+    if (width.value <= 0 && m_config.first_layer_extrusion_width.value > 0)
+        width = m_config.first_layer_extrusion_width;
     if (width.value <= 0) 
         width = m_regions.front()->config().perimeter_extrusion_width;
     if (width.value <= 0)
@@ -1610,6 +1612,7 @@ Flow Print::skirt_flow(size_t extruder_id) const
        extruders and take the one with, say, the smallest index;
        The same logic should be applied to the code that selects the extruder during G-code
        generation as well. */
+    /* or select the used extruder with the highest nozzle diameter, to be on the safe side.*/
     return Flow::new_from_config_width(
         frPerimeter,
 		width,

src/libslic3r/PrintConfig.cpp

@@ -2625,6 +2625,15 @@ void PrintConfigDef::init_fff_params()
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionInt(1));
 
+    def = this->add("skirt_extrusion_width", coFloatOrPercent);
+    def->label = L("Skirt");
+    def->category = OptionCategory::width;
+    def->tooltip = L("Horizontal width of the skirt that will be printed around each object.");
+    def->sidetext = L("mm");
+    def->min = 0;
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionFloatOrPercent(0, false));
+
     def = this->add("draft_shield", coBool);
     def->label = L("Draft shield");
     def->tooltip = L("If enabled, the skirt will be as tall as a highest printed object. "

src/libslic3r/PrintConfig.hpp

@@ -1096,6 +1096,7 @@ public:
     ConfigOptionBools               retract_layer_change;
     ConfigOptionFloat               skirt_distance;
     ConfigOptionInt                 skirt_height;
+    ConfigOptionFloatOrPercent      skirt_extrusion_width;
     ConfigOptionBool                draft_shield;
     ConfigOptionInt                 skirts;
     ConfigOptionInts                slowdown_below_layer_time;
@@ -1184,6 +1185,7 @@ protected:
         OPT_PTR(retract_before_travel);
         OPT_PTR(retract_layer_change);
         OPT_PTR(skirt_distance);
+        OPT_PTR(skirt_extrusion_width);
         OPT_PTR(skirt_height);
         OPT_PTR(draft_shield);
         OPT_PTR(skirts);

src/slic3r/GUI/ConfigManipulation.cpp

@@ -364,6 +364,7 @@ void ConfigManipulation::toggle_print_fff_options(DynamicPrintConfig* config)
 
     bool have_skirt = config->opt_int("skirts") > 0;
     toggle_field("skirt_height", have_skirt && !config->opt_bool("draft_shield"));
+    toggle_field("skirt_width", have_skirt);
     for (auto el : { "skirt_distance", "draft_shield", "min_skirt_length" })
         toggle_field(el, have_skirt);
 

src/slic3r/GUI/Preset.cpp

@@ -474,6 +474,7 @@ const std::vector<std::string>& Preset::print_options()
         "bridge_acceleration", "first_layer_acceleration", "default_acceleration", 
         "duplicate_distance",
         "skirts", "skirt_distance", "skirt_height",
+		"skirt_extrusion_width",
         "min_skirt_length",
         "draft_shield",
         "brim_inside_holes",