#ifndef slic3r_EdgeGrid_hpp_
#define slic3r_EdgeGrid_hpp_

#include <stdint.h>
#include <math.h>

#include "Point.hpp"
#include "BoundingBox.hpp"
#include "ExPolygon.hpp"
#include "ExPolygonCollection.hpp"

namespace Slic3r {
namespace EdgeGrid {

struct Grid
{
	Grid();
	~Grid();

	void create(const Polygons &polygons, coord_t resolution);
	void create(const ExPolygon &expoly, coord_t resolution);
	void create(const ExPolygons &expolygons, coord_t resolution);
	void create(const ExPolygonCollection &expolygons, coord_t resolution);

	// Fill in a rough m_signed_distance_field from the edge grid.
	// The rough SDF is used by signed_distance() for distances outside of the search_radius.
	void calculate_sdf();

	// Return an estimate of the signed distance based on m_signed_distance_field grid.
	float signed_distance_bilinear(const Point &pt) const;

	// Calculate a signed distance to the contours in search_radius from the point.
	bool signed_distance_edges(const Point &pt, coord_t search_radius, coordf_t &result_min_dist, bool *pon_segment = NULL) const;

	// Calculate a signed distance to the contours in search_radius from the point. If no edge is found in search_radius,
	// return an interpolated value from m_signed_distance_field, if it exists.
	bool signed_distance(const Point &pt, coord_t search_radius, coordf_t &result_min_dist) const;

	const BoundingBox& 	bbox() const { return m_bbox; }
	const coord_t 		resolution() const { return m_resolution; }
	const size_t		rows() const { return m_rows; }
	const size_t		cols() const { return m_cols; }

protected:
	void create_from_m_contours(coord_t resolution);

	// Bounding box around the contours.
	BoundingBox 								m_bbox;
	// Grid dimensions.
	coord_t										m_resolution;
	size_t										m_rows;
	size_t										m_cols;

	// Referencing the source contours.
	// This format allows one to work with any Slic3r fixed point contour format
	// (Polygon, ExPolygon, ExPolygonCollection etc).
	std::vector<const Slic3r::Points*>			m_contours;

	// Referencing a contour and a line segment of m_contours.
	std::vector<std::pair<size_t, size_t> >		m_cell_data;

	struct Cell {
		Cell() : begin(0), end(0) {}
		size_t begin;
		size_t end;
	};
	// Full grid of cells.
	std::vector<Cell> 							m_cells;

	// Distance field derived from the edge grid, seed filled by the Danielsson chamfer metric.
	// May be empty.
	std::vector<float>							m_signed_distance_field;
};

#ifdef SLIC3R_GUI
// Debugging utility. Save the signed distance field.
extern void save_png(const Grid &grid, const BoundingBox &bbox, coord_t resolution, const char *path);
#endif /* SLIC3R_GUI */

} // namespace EdgeGrid
} // namespace Slic3r

#endif /* slic3r_EdgeGrid_hpp_ */