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			489 lines
		
	
	
	
		
			12 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			489 lines
		
	
	
	
		
			12 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
/*************************************************************************/
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/*  a_star.cpp                                                           */
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/*************************************************************************/
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/*                       This file is part of:                           */
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/*                           GODOT ENGINE                                */
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/*                      https://godotengine.org                          */
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/*************************************************************************/
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/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
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/* Copyright (c) 2014-2017 Godot Engine contributors (cf. AUTHORS.md)    */
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/*                                                                       */
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/* Permission is hereby granted, free of charge, to any person obtaining */
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/* a copy of this software and associated documentation files (the       */
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/* "Software"), to deal in the Software without restriction, including   */
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/* without limitation the rights to use, copy, modify, merge, publish,   */
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/* distribute, sublicense, and/or sell copies of the Software, and to    */
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/* permit persons to whom the Software is furnished to do so, subject to */
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/* the following conditions:                                             */
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/*                                                                       */
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/* The above copyright notice and this permission notice shall be        */
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/* included in all copies or substantial portions of the Software.       */
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/*                                                                       */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
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/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
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/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
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/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
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/*************************************************************************/
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#include "a_star.h"
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#include "geometry.h"
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#include "scene/scene_string_names.h"
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#include "script_language.h"
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int AStar::get_available_point_id() const {
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	if (points.empty()) {
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		return 1;
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	}
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	return points.back()->key() + 1;
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}
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void AStar::add_point(int p_id, const Vector3 &p_pos, real_t p_weight_scale) {
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	ERR_FAIL_COND(p_id < 0);
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	ERR_FAIL_COND(p_weight_scale < 1);
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	if (!points.has(p_id)) {
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		Point *pt = memnew(Point);
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		pt->id = p_id;
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		pt->pos = p_pos;
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		pt->weight_scale = p_weight_scale;
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		pt->prev_point = NULL;
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		pt->last_pass = 0;
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		points[p_id] = pt;
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	} else {
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		points[p_id]->pos = p_pos;
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		points[p_id]->weight_scale = p_weight_scale;
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	}
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}
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Vector3 AStar::get_point_position(int p_id) const {
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	ERR_FAIL_COND_V(!points.has(p_id), Vector3());
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	return points[p_id]->pos;
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}
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void AStar::set_point_position(int p_id, const Vector3 &p_pos) {
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	ERR_FAIL_COND(!points.has(p_id));
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	points[p_id]->pos = p_pos;
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}
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real_t AStar::get_point_weight_scale(int p_id) const {
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	ERR_FAIL_COND_V(!points.has(p_id), 0);
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	return points[p_id]->weight_scale;
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}
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void AStar::set_point_weight_scale(int p_id, real_t p_weight_scale) {
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	ERR_FAIL_COND(!points.has(p_id));
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	ERR_FAIL_COND(p_weight_scale < 1);
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	points[p_id]->weight_scale = p_weight_scale;
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}
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void AStar::remove_point(int p_id) {
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	ERR_FAIL_COND(!points.has(p_id));
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	Point *p = points[p_id];
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	for (int i = 0; i < p->neighbours.size(); i++) {
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		Segment s(p_id, p->neighbours[i]->id);
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		segments.erase(s);
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		p->neighbours[i]->neighbours.erase(p);
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	}
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	memdelete(p);
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	points.erase(p_id);
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}
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void AStar::connect_points(int p_id, int p_with_id, bool bidirectional) {
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	ERR_FAIL_COND(!points.has(p_id));
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	ERR_FAIL_COND(!points.has(p_with_id));
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	ERR_FAIL_COND(p_id == p_with_id);
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	Point *a = points[p_id];
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	Point *b = points[p_with_id];
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	a->neighbours.push_back(b);
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	if (bidirectional)
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		b->neighbours.push_back(a);
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	Segment s(p_id, p_with_id);
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	if (s.from == p_id) {
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		s.from_point = a;
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		s.to_point = b;
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	} else {
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		s.from_point = b;
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		s.to_point = a;
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	}
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	segments.insert(s);
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}
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void AStar::disconnect_points(int p_id, int p_with_id) {
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	Segment s(p_id, p_with_id);
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	ERR_FAIL_COND(!segments.has(s));
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	segments.erase(s);
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	Point *a = points[p_id];
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	Point *b = points[p_with_id];
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	a->neighbours.erase(b);
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	b->neighbours.erase(a);
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}
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bool AStar::has_point(int p_id) const {
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	return points.has(p_id);
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}
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Array AStar::get_points() {
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	Array point_list;
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	for (const Map<int, Point *>::Element *E = points.front(); E; E = E->next()) {
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		point_list.push_back(E->key());
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	}
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	return point_list;
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}
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PoolVector<int> AStar::get_point_connections(int p_id) {
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	ERR_FAIL_COND_V(!points.has(p_id), PoolVector<int>());
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	PoolVector<int> point_list;
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	Point *p = points[p_id];
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	for (int i = 0; i < p->neighbours.size(); i++) {
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		point_list.push_back(p->neighbours[i]->id);
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	}
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	return point_list;
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}
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bool AStar::are_points_connected(int p_id, int p_with_id) const {
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	Segment s(p_id, p_with_id);
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	return segments.has(s);
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}
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void AStar::clear() {
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	for (const Map<int, Point *>::Element *E = points.front(); E; E = E->next()) {
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		memdelete(E->get());
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	}
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	segments.clear();
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	points.clear();
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}
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int AStar::get_closest_point(const Vector3 &p_point) const {
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	int closest_id = -1;
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	real_t closest_dist = 1e20;
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	for (const Map<int, Point *>::Element *E = points.front(); E; E = E->next()) {
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		real_t d = p_point.distance_squared_to(E->get()->pos);
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		if (closest_id < 0 || d < closest_dist) {
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			closest_dist = d;
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			closest_id = E->key();
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		}
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	}
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	return closest_id;
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}
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Vector3 AStar::get_closest_position_in_segment(const Vector3 &p_point) const {
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	real_t closest_dist = 1e20;
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	bool found = false;
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	Vector3 closest_point;
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	for (const Set<Segment>::Element *E = segments.front(); E; E = E->next()) {
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		Vector3 segment[2] = {
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			E->get().from_point->pos,
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			E->get().to_point->pos,
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		};
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		Vector3 p = Geometry::get_closest_point_to_segment(p_point, segment);
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		real_t d = p_point.distance_squared_to(p);
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		if (!found || d < closest_dist) {
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			closest_point = p;
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			closest_dist = d;
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			found = true;
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		}
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	}
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	return closest_point;
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}
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bool AStar::_solve(Point *begin_point, Point *end_point) {
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	pass++;
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	SelfList<Point>::List open_list;
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	bool found_route = false;
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	for (int i = 0; i < begin_point->neighbours.size(); i++) {
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		Point *n = begin_point->neighbours[i];
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		n->prev_point = begin_point;
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		n->distance = _compute_cost(begin_point->id, n->id) * n->weight_scale;
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		n->last_pass = pass;
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		open_list.add(&n->list);
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		if (end_point == n) {
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			found_route = true;
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			break;
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		}
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	}
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	while (!found_route) {
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		if (open_list.first() == NULL) {
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			// No path found
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			break;
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		}
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		// Check open list
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		SelfList<Point> *least_cost_point = NULL;
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		real_t least_cost = 1e30;
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		// TODO: Cache previous results
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		for (SelfList<Point> *E = open_list.first(); E; E = E->next()) {
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			Point *p = E->self();
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			real_t cost = p->distance;
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			cost += _estimate_cost(p->id, end_point->id);
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			if (cost < least_cost) {
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				least_cost_point = E;
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				least_cost = cost;
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			}
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		}
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		Point *p = least_cost_point->self();
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		// Open the neighbours for search
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		int es = p->neighbours.size();
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		for (int i = 0; i < es; i++) {
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			Point *e = p->neighbours[i];
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			real_t distance = _compute_cost(p->id, e->id) * e->weight_scale + p->distance;
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			if (e->last_pass == pass) {
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				// Already visited, is this cheaper?
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				if (e->distance > distance) {
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					e->prev_point = p;
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					e->distance = distance;
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				}
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			} else {
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				// Add to open neighbours
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				e->prev_point = p;
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				e->distance = distance;
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				e->last_pass = pass; // Mark as used
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				open_list.add(&e->list);
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				if (e == end_point) {
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					// End reached; stop algorithm
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					found_route = true;
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					break;
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				}
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			}
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		}
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		if (found_route)
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			break;
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		open_list.remove(least_cost_point);
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	}
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	// Clear the openf list
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	while (open_list.first()) {
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		open_list.remove(open_list.first());
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	}
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	return found_route;
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}
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float AStar::_estimate_cost(int p_from_id, int p_to_id) {
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	if (get_script_instance() && get_script_instance()->has_method(SceneStringNames::get_singleton()->_estimate_cost))
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		return get_script_instance()->call(SceneStringNames::get_singleton()->_estimate_cost, p_from_id, p_to_id);
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	return points[p_from_id]->pos.distance_to(points[p_to_id]->pos);
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}
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float AStar::_compute_cost(int p_from_id, int p_to_id) {
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	if (get_script_instance() && get_script_instance()->has_method(SceneStringNames::get_singleton()->_compute_cost))
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		return get_script_instance()->call(SceneStringNames::get_singleton()->_compute_cost, p_from_id, p_to_id);
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	return points[p_from_id]->pos.distance_to(points[p_to_id]->pos);
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}
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PoolVector<Vector3> AStar::get_point_path(int p_from_id, int p_to_id) {
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	ERR_FAIL_COND_V(!points.has(p_from_id), PoolVector<Vector3>());
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	ERR_FAIL_COND_V(!points.has(p_to_id), PoolVector<Vector3>());
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	pass++;
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	Point *a = points[p_from_id];
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	Point *b = points[p_to_id];
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	if (a == b) {
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		PoolVector<Vector3> ret;
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		ret.push_back(a->pos);
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		return ret;
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	}
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	Point *begin_point = a;
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	Point *end_point = b;
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	bool found_route = _solve(begin_point, end_point);
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	if (!found_route)
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		return PoolVector<Vector3>();
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	// Midpoints
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	Point *p = end_point;
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	int pc = 1; // Begin point
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	while (p != begin_point) {
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		pc++;
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		p = p->prev_point;
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	}
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	PoolVector<Vector3> path;
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	path.resize(pc);
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	{
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		PoolVector<Vector3>::Write w = path.write();
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		Point *p = end_point;
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		int idx = pc - 1;
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		while (p != begin_point) {
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			w[idx--] = p->pos;
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			p = p->prev_point;
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		}
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		w[0] = p->pos; // Assign first
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	}
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	return path;
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}
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PoolVector<int> AStar::get_id_path(int p_from_id, int p_to_id) {
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	ERR_FAIL_COND_V(!points.has(p_from_id), PoolVector<int>());
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	ERR_FAIL_COND_V(!points.has(p_to_id), PoolVector<int>());
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	pass++;
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	Point *a = points[p_from_id];
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	Point *b = points[p_to_id];
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	if (a == b) {
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		PoolVector<int> ret;
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		ret.push_back(a->id);
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		return ret;
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	}
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	Point *begin_point = a;
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	Point *end_point = b;
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	bool found_route = _solve(begin_point, end_point);
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	if (!found_route)
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		return PoolVector<int>();
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	// Midpoints
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	Point *p = end_point;
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	int pc = 1; // Begin point
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	while (p != begin_point) {
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		pc++;
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		p = p->prev_point;
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	}
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	PoolVector<int> path;
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	path.resize(pc);
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	{
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		PoolVector<int>::Write w = path.write();
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		p = end_point;
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		int idx = pc - 1;
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		while (p != begin_point) {
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			w[idx--] = p->id;
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			p = p->prev_point;
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		}
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		w[0] = p->id; // Assign first
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	}
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	return path;
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}
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void AStar::_bind_methods() {
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	ClassDB::bind_method(D_METHOD("get_available_point_id"), &AStar::get_available_point_id);
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	ClassDB::bind_method(D_METHOD("add_point", "id", "position", "weight_scale"), &AStar::add_point, DEFVAL(1.0));
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	ClassDB::bind_method(D_METHOD("get_point_position", "id"), &AStar::get_point_position);
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	ClassDB::bind_method(D_METHOD("set_point_position", "id", "position"), &AStar::set_point_position);
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						|
	ClassDB::bind_method(D_METHOD("get_point_weight_scale", "id"), &AStar::get_point_weight_scale);
 | 
						|
	ClassDB::bind_method(D_METHOD("set_point_weight_scale", "id", "weight_scale"), &AStar::set_point_weight_scale);
 | 
						|
	ClassDB::bind_method(D_METHOD("remove_point", "id"), &AStar::remove_point);
 | 
						|
	ClassDB::bind_method(D_METHOD("has_point", "id"), &AStar::has_point);
 | 
						|
	ClassDB::bind_method(D_METHOD("get_points"), &AStar::get_points);
 | 
						|
 | 
						|
	ClassDB::bind_method(D_METHOD("get_point_connections"), &AStar::get_point_connections);
 | 
						|
 | 
						|
	ClassDB::bind_method(D_METHOD("connect_points", "id", "to_id", "bidirectional"), &AStar::connect_points, DEFVAL(true));
 | 
						|
	ClassDB::bind_method(D_METHOD("disconnect_points", "id", "to_id"), &AStar::disconnect_points);
 | 
						|
	ClassDB::bind_method(D_METHOD("are_points_connected", "id", "to_id"), &AStar::are_points_connected);
 | 
						|
 | 
						|
	ClassDB::bind_method(D_METHOD("clear"), &AStar::clear);
 | 
						|
 | 
						|
	ClassDB::bind_method(D_METHOD("get_closest_point", "to_position"), &AStar::get_closest_point);
 | 
						|
	ClassDB::bind_method(D_METHOD("get_closest_position_in_segment", "to_position"), &AStar::get_closest_position_in_segment);
 | 
						|
 | 
						|
	ClassDB::bind_method(D_METHOD("get_point_path", "from_id", "to_id"), &AStar::get_point_path);
 | 
						|
	ClassDB::bind_method(D_METHOD("get_id_path", "from_id", "to_id"), &AStar::get_id_path);
 | 
						|
 | 
						|
	BIND_VMETHOD(MethodInfo("_estimate_cost", PropertyInfo(Variant::INT, "from_id"), PropertyInfo(Variant::INT, "to_id")));
 | 
						|
	BIND_VMETHOD(MethodInfo("_compute_cost", PropertyInfo(Variant::INT, "from_id"), PropertyInfo(Variant::INT, "to_id")));
 | 
						|
}
 | 
						|
 | 
						|
AStar::AStar() {
 | 
						|
 | 
						|
	pass = 1;
 | 
						|
}
 | 
						|
 | 
						|
AStar::~AStar() {
 | 
						|
 | 
						|
	pass = 1;
 | 
						|
	clear();
 | 
						|
}
 |