/*************************************************************************/
/*  nav_utils.h                                                          */
/*************************************************************************/
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/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
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#ifndef NAV_UTILS_H
#define NAV_UTILS_H

#include "core/math/vector3.h"
#include <vector>

/**
	@author AndreaCatania
*/

class NavRegion;

namespace gd {
struct Polygon;

union PointKey {
	struct {
		int64_t x : 21;
		int64_t y : 22;
		int64_t z : 21;
	};

	uint64_t key;
	bool operator<(const PointKey &p_key) const { return key < p_key.key; }
};

struct EdgeKey {
	PointKey a;
	PointKey b;

	bool operator<(const EdgeKey &p_key) const {
		return (a.key == p_key.a.key) ? (b.key < p_key.b.key) : (a.key < p_key.a.key);
	}

	EdgeKey(const PointKey &p_a = PointKey(), const PointKey &p_b = PointKey()) :
			a(p_a),
			b(p_b) {
		if (a.key > b.key) {
			SWAP(a, b);
		}
	}
};

struct Point {
	Vector3 pos;
	PointKey key;
};

struct Edge {
	/// This edge ID
	int this_edge;

	/// Other Polygon
	Polygon *other_polygon;

	/// The other `Polygon` at this edge id has this `Polygon`.
	int other_edge;

	Edge() {
		this_edge = -1;
		other_polygon = NULL;
		other_edge = -1;
	}
};

struct Polygon {
	NavRegion *owner;

	/// The points of this `Polygon`
	std::vector<Point> points;

	/// Are the points clockwise ?
	bool clockwise;

	/// The edges of this `Polygon`
	std::vector<Edge> edges;

	/// The center of this `Polygon`
	Vector3 center;
};

struct Connection {
	Polygon *A;
	int A_edge;
	Polygon *B;
	int B_edge;

	Connection() {
		A = NULL;
		B = NULL;
		A_edge = -1;
		B_edge = -1;
	}
};

struct NavigationPoly {
	uint32_t self_id;
	/// This poly.
	const Polygon *poly;
	/// The previous navigation poly (id in the `navigation_poly` array).
	int prev_navigation_poly_id;
	/// The edge id in this `Poly` to reach the `prev_navigation_poly_id`.
	uint32_t back_navigation_edge;
	/// The entry location of this poly.
	Vector3 entry;
	/// The distance to the destination.
	float traveled_distance;

	NavigationPoly(const Polygon *p_poly) :
			self_id(0),
			poly(p_poly),
			prev_navigation_poly_id(-1),
			back_navigation_edge(0),
			traveled_distance(0.0) {
	}

	bool operator==(const NavigationPoly &other) const {
		return this->poly == other.poly;
	}

	bool operator!=(const NavigationPoly &other) const {
		return !operator==(other);
	}
};

struct FreeEdge {
	bool is_free;
	Polygon *poly;
	uint32_t edge_id;
	Vector3 edge_center;
	Vector3 edge_dir;
	float edge_len_squared;
};
} // namespace gd

#endif // NAV_UTILS_H