polygon_path_finder.h

/**************************************************************************/
/*  polygon_path_finder.h                                                 */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
/*                                                                        */
/* 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. */
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
/**************************************************************************/

#pragma once

#include "core/io/resource.h"

class PolygonPathFinder : public Resource {
	GDCLASS(PolygonPathFinder, Resource);

	struct Point {
		Vector2 pos;
		HashSet<int> connections;
		float distance = 0.0;
		float penalty = 0.0;
		int prev = 0;
	};

	union Edge {
		struct {
			int32_t points[2];
		};
		uint64_t key = 0;

		_FORCE_INLINE_ bool operator==(const Edge &p_edge) const {
			return key == p_edge.key;
		}
		_FORCE_INLINE_ static uint32_t hash(const Edge &p_edge) {
			return hash_one_uint64(p_edge.key);
		}

		Edge(int a = 0, int b = 0) {
			if (a > b) {
				SWAP(a, b);
			}
			points[0] = a;
			points[1] = b;
		}
	};

	Vector2 outside_point;
	Rect2 bounds;

	Vector<Point> points;
	HashSet<Edge, Edge> edges;

	bool _is_point_inside(const Vector2 &p_point) const;

	void _set_data(const Dictionary &p_data);
	Dictionary _get_data() const;

protected:
	static void _bind_methods();

public:
	void setup(const Vector<Vector2> &p_points, const Vector<int> &p_connections);
	Vector<Vector2> find_path(const Vector2 &p_from, const Vector2 &p_to);

	void set_point_penalty(int p_point, float p_penalty);
	float get_point_penalty(int p_point) const;

	bool is_point_inside(const Vector2 &p_point) const;
	Vector2 get_closest_point(const Vector2 &p_point) const;
	Vector<Vector2> get_intersections(const Vector2 &p_from, const Vector2 &p_to) const;
	Rect2 get_bounds() const;

	PolygonPathFinder();
};