Fills were reimplemented in C++.

While reimplementing the FillPlanePath code, the octagon infill was fixed to extrude the right amount of material.

xs/src/libslic3r/Fill/FillHoneycomb.hpp

@@ -0,0 +1,50 @@
+#ifndef slic3r_FillHoneycomb_hpp_
+#define slic3r_FillHoneycomb_hpp_
+
+#include <map>
+
+#include "../libslic3r.h"
+
+#include "FillBase.hpp"
+
+namespace Slic3r {
+
+class FillHoneycomb : public FillWithDirection
+{
+public:
+    virtual ~FillHoneycomb() {}
+    virtual Polylines fill_surface(const Surface *surface, const FillParams &params);
+
+protected:
+	// Caching the 
+	struct CacheID 
+	{
+		CacheID(float adensity, coordf_t aspacing) : 
+			density(adensity), spacing(aspacing) {}
+		float		density;
+		coordf_t	spacing;
+		bool operator<(const CacheID &other) const 
+			{ return (density < other.density) || (density == other.density && spacing < other.spacing); }
+		bool operator==(const CacheID &other) const 
+			{ return density == other.density && spacing == other.spacing; }
+	};
+	struct CacheData
+	{
+		coord_t	distance;
+        coord_t hex_side;
+        coord_t hex_width;
+        coord_t	pattern_height;
+        coord_t y_short;
+        coord_t x_offset;
+        coord_t	y_offset;
+        Point	hex_center;
+    };
+    typedef std::map<CacheID, CacheData> Cache;
+	Cache cache;
+
+    virtual float _layer_angle(size_t idx) const { return 0.5f * float(M_PI) * (idx % 3); }
+};
+
+} // namespace Slic3r
+
+#endif // slic3r_FillHoneycomb_hpp_