virtualx-engine/core/math/a_star.h
2024-01-05 11:47:46 +01:00

215 lines
6.8 KiB
C++

/**************************************************************************/
/* a_star.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. */
/**************************************************************************/
#ifndef A_STAR_H
#define A_STAR_H
#include "core/oa_hash_map.h"
#include "core/reference.h"
/**
A* pathfinding algorithm
@author Juan Linietsky <reduzio@gmail.com>
*/
class AStar : public Reference {
GDCLASS(AStar, Reference);
friend class AStar2D;
struct Point {
Point() :
id(0),
enabled(false),
neighbours(4u),
unlinked_neighbours(4u),
prev_point(nullptr),
open_pass(0) {}
int id;
Vector3 pos;
real_t weight_scale;
bool enabled;
OAHashMap<int, Point *> neighbours;
OAHashMap<int, Point *> unlinked_neighbours;
// Used for pathfinding.
Point *prev_point;
real_t g_score;
real_t f_score;
uint64_t open_pass;
uint64_t closed_pass;
};
struct SortPoints {
_FORCE_INLINE_ bool operator()(const Point *A, const Point *B) const { // Returns true when the Point A is worse than Point B.
if (A->f_score > B->f_score) {
return true;
} else if (A->f_score < B->f_score) {
return false;
} else {
return A->g_score < B->g_score; // If the f_costs are the same then prioritize the points that are further away from the start.
}
}
};
struct Segment {
union {
struct {
int32_t u;
int32_t v;
};
uint64_t key;
};
enum {
NONE = 0,
FORWARD = 1,
BACKWARD = 2,
BIDIRECTIONAL = FORWARD | BACKWARD
};
unsigned char direction;
bool operator<(const Segment &p_s) const { return key < p_s.key; }
Segment() {
key = 0;
direction = NONE;
}
Segment(int p_from, int p_to) {
if (p_from < p_to) {
u = p_from;
v = p_to;
direction = FORWARD;
} else {
u = p_to;
v = p_from;
direction = BACKWARD;
}
}
};
int last_free_id;
uint64_t pass;
OAHashMap<int, Point *> points;
Set<Segment> segments;
bool _solve(Point *begin_point, Point *end_point);
protected:
static void _bind_methods();
virtual real_t _estimate_cost(int p_from_id, int p_to_id);
virtual real_t _compute_cost(int p_from_id, int p_to_id);
public:
int get_available_point_id() const;
void add_point(int p_id, const Vector3 &p_pos, real_t p_weight_scale = 1);
Vector3 get_point_position(int p_id) const;
void set_point_position(int p_id, const Vector3 &p_pos);
real_t get_point_weight_scale(int p_id) const;
void set_point_weight_scale(int p_id, real_t p_weight_scale);
void remove_point(int p_id);
bool has_point(int p_id) const;
PoolVector<int> get_point_connections(int p_id);
Array get_points();
void set_point_disabled(int p_id, bool p_disabled = true);
bool is_point_disabled(int p_id) const;
void connect_points(int p_id, int p_with_id, bool bidirectional = true);
void disconnect_points(int p_id, int p_with_id, bool bidirectional = true);
bool are_points_connected(int p_id, int p_with_id, bool bidirectional = true) const;
int get_point_count() const;
int get_point_capacity() const;
void reserve_space(int p_num_nodes);
void clear();
int get_closest_point(const Vector3 &p_point, bool p_include_disabled = false) const;
Vector3 get_closest_position_in_segment(const Vector3 &p_point) const;
PoolVector<Vector3> get_point_path(int p_from_id, int p_to_id);
PoolVector<int> get_id_path(int p_from_id, int p_to_id);
AStar();
~AStar();
};
class AStar2D : public Reference {
GDCLASS(AStar2D, Reference);
AStar astar;
bool _solve(AStar::Point *begin_point, AStar::Point *end_point);
protected:
static void _bind_methods();
virtual real_t _estimate_cost(int p_from_id, int p_to_id);
virtual real_t _compute_cost(int p_from_id, int p_to_id);
public:
int get_available_point_id() const;
void add_point(int p_id, const Vector2 &p_pos, real_t p_weight_scale = 1);
Vector2 get_point_position(int p_id) const;
void set_point_position(int p_id, const Vector2 &p_pos);
real_t get_point_weight_scale(int p_id) const;
void set_point_weight_scale(int p_id, real_t p_weight_scale);
void remove_point(int p_id);
bool has_point(int p_id) const;
PoolVector<int> get_point_connections(int p_id);
Array get_points();
void set_point_disabled(int p_id, bool p_disabled = true);
bool is_point_disabled(int p_id) const;
void connect_points(int p_id, int p_with_id, bool p_bidirectional = true);
void disconnect_points(int p_id, int p_with_id, bool p_bidirectional = true);
bool are_points_connected(int p_id, int p_with_id, bool p_bidirectional = true) const;
int get_point_count() const;
int get_point_capacity() const;
void reserve_space(int p_num_nodes);
void clear();
int get_closest_point(const Vector2 &p_point, bool p_include_disabled = false) const;
Vector2 get_closest_position_in_segment(const Vector2 &p_point) const;
PoolVector<Vector2> get_point_path(int p_from_id, int p_to_id);
PoolVector<int> get_id_path(int p_from_id, int p_to_id);
AStar2D();
~AStar2D();
};
#endif // A_STAR_H