Print unsupported walls last (#15411)

src/libslic3r/PrintConfig.cpp

@@ -5547,6 +5547,16 @@ void PrintConfigDef::init_fff_params()
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionBool(true));
 
+    def = this->add("unsupported_wall_last", coBool);
+    def->label = L("Print unsupported walls last");
+    def->category = L("Quality");
+    def->tooltip = L("Wall loops that lie entirely in mid air are printed once something can hold them:\n"
+                     "they are extruded after the other walls of their island, innermost first, whatever the wall order is.\n"
+                     "A loop that only the bridges of this layer can anchor waits until those bridges are printed, while a loop running "
+                     "alongside a supported wall keeps its place before the infill, which needs it as an anchor.");
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionBool(false));
+
     def = this->add("outer_wall_filament_id", coInt);
     def->gui_type = ConfigOptionDef::GUIType::i_enum_open;
     def->label = L("Outer walls");