text: /*************************************************************************/
  /*  nav_utils.h                                                          */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://godotengine.org                          */
  /*************************************************************************/
  /* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
  /* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
  /*                                                                       */
  /* Permission is hereby granted, free of charge, to any person obtaining */
  /* a copy of this software and associated documentation files (the       */
  /* "Software"), to deal in the Software without restriction, including   */
  /* without limitation the rights to use, copy, modify, merge, publish,   */
  /* distribute, sublicense, and/or sell copies of the Software, and to    */
  /* permit persons to whom the Software is furnished to do so, subject to */
  /* the following conditions:                                             */
  /*                                                                       */
  /* The above copyright notice and this permission notice shall be        */
  /* included in all copies or substantial portions of the Software.       */
  /*                                                                       */
  /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
  /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
  /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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  /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
  /*************************************************************************/
  
  #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 = -1;
  
  	/// Other Polygon
  	Polygon *other_polygon = nullptr;
  
  	/// The other `Polygon` at this edge id has this `Polygon`.
  	int other_edge = -1;
  
  	Edge() {}
  };
  
  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 = nullptr;
  	int A_edge = -1;
  	Polygon *B = nullptr;
  	int B_edge = -1;
  
  	Connection() {}
  };
  
  struct NavigationPoly {
  	uint32_t self_id = 0;
  	/// This poly.
  	const Polygon *poly;
  	/// The previous navigation poly (id in the `navigation_poly` array).
  	int prev_navigation_poly_id = -1;
  	/// The edge id in this `Poly` to reach the `prev_navigation_poly_id`.
  	uint32_t back_navigation_edge = 0;
  	/// The entry location of this poly.
  	Vector3 entry;
  	/// The distance to the destination.
  	float traveled_distance = 0.0;
  
  	NavigationPoly(const Polygon *p_poly) :
  			poly(p_poly) {}
  
  	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
  