gyroid & 3Dhoneycomb: now 'connected lines' follow the perimeters

src/libslic3r/Fill/FillBase.hpp

@@ -109,6 +109,8 @@ protected:
 
     virtual std::pair<float, Point> _infill_direction(const Surface *surface) const;
 
+    void connect_infill(const Polylines &infill_ordered, const ExPolygon &boundary, Polylines &polylines_out);
+
 public:
     static coord_t  _adjust_solid_spacing(const coord_t width, const coord_t distance);