WIP: MMU segmentation without top and bottom layers

src/libslic3r/Print.hpp

@@ -240,6 +240,8 @@ public:
     // Helpers to project custom facets on slices
     void project_and_append_custom_facets(bool seam, EnforcerBlockerType type, std::vector<ExPolygons>& expolys) const;
 
+    // Returns MMU segmentation based on painting in MMU segmentation gizmo
+    std::vector<std::vector<std::pair<ExPolygon, size_t>>> mmu_segmentation_by_painting();
 private:
     // to be called from Print only.
     friend class Print;