Finished porting LayerRegion to C++

xs/src/libslic3r/Layer.hpp

@@ -40,8 +40,7 @@ class LayerRegion
 
     // collection of expolygons representing the bridged areas (thus not
     // needing support material)
-    // (this could be just a Polygons object)
-    ExPolygonCollection bridged;
+    Polygons bridged;
 
     // collection of polylines representing the unsupported bridge edges
     PolylineCollection unsupported_bridge_edges;
@@ -58,6 +57,8 @@ class LayerRegion
     void merge_slices();
     void prepare_fill_surfaces();
     void make_perimeters(const SurfaceCollection &slices, SurfaceCollection* fill_surfaces);
+    void process_external_surfaces(const Layer* lower_layer);
+    double infill_area_threshold() const;
     
     private:
     Layer *_layer;