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godot/core/math/a_star_grid_2d.cpp

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/*************************************************************************/
/* a_star_grid_2d.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2022 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.*/
/* 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. */
/*************************************************************************/
#include "a_star_grid_2d.h"
#include "core/variant/typed_array.h"
static real_t heuristic_euclidian(const Vector2i &p_from, const Vector2i &p_to) {
real_t dx = (real_t)ABS(p_to.x - p_from.x);
real_t dy = (real_t)ABS(p_to.y - p_from.y);
return (real_t)Math::sqrt(dx * dx + dy * dy);
}
static real_t heuristic_manhattan(const Vector2i &p_from, const Vector2i &p_to) {
real_t dx = (real_t)ABS(p_to.x - p_from.x);
real_t dy = (real_t)ABS(p_to.y - p_from.y);
return dx + dy;
}
static real_t heuristic_octile(const Vector2i &p_from, const Vector2i &p_to) {
real_t dx = (real_t)ABS(p_to.x - p_from.x);
real_t dy = (real_t)ABS(p_to.y - p_from.y);
real_t F = Math_SQRT2 - 1;
return (dx < dy) ? F * dx + dy : F * dy + dx;
}
static real_t heuristic_chebyshev(const Vector2i &p_from, const Vector2i &p_to) {
real_t dx = (real_t)ABS(p_to.x - p_from.x);
real_t dy = (real_t)ABS(p_to.y - p_from.y);
return MAX(dx, dy);
}
static real_t (*heuristics[AStarGrid2D::HEURISTIC_MAX])(const Vector2i &, const Vector2i &) = { heuristic_euclidian, heuristic_manhattan, heuristic_octile, heuristic_chebyshev };
void AStarGrid2D::set_size(const Size2i &p_size) {
ERR_FAIL_COND(p_size.x < 0 || p_size.y < 0);
if (p_size != size) {
size = p_size;
dirty = true;
}
}
Size2i AStarGrid2D::get_size() const {
return size;
}
void AStarGrid2D::set_offset(const Vector2 &p_offset) {
if (!offset.is_equal_approx(p_offset)) {
offset = p_offset;
dirty = true;
}
}
Vector2 AStarGrid2D::get_offset() const {
return offset;
}
void AStarGrid2D::set_cell_size(const Size2 &p_cell_size) {
if (!cell_size.is_equal_approx(p_cell_size)) {
cell_size = p_cell_size;
dirty = true;
}
}
Size2 AStarGrid2D::get_cell_size() const {
return cell_size;
}
void AStarGrid2D::update() {
points.clear();
for (int64_t y = 0; y < size.y; y++) {
LocalVector<Point> line;
for (int64_t x = 0; x < size.x; x++) {
line.push_back(Point(Vector2i(x, y), offset + Vector2(x, y) * cell_size));
}
points.push_back(line);
}
dirty = false;
}
bool AStarGrid2D::is_in_bounds(int p_x, int p_y) const {
return p_x >= 0 && p_x < size.width && p_y >= 0 && p_y < size.height;
}
bool AStarGrid2D::is_in_boundsv(const Vector2i &p_id) const {
return p_id.x >= 0 && p_id.x < size.width && p_id.y >= 0 && p_id.y < size.height;
}
bool AStarGrid2D::is_dirty() const {
return dirty;
}
void AStarGrid2D::set_jumping_enabled(bool p_enabled) {
jumping_enabled = p_enabled;
}
bool AStarGrid2D::is_jumping_enabled() const {
return jumping_enabled;
}
void AStarGrid2D::set_diagonal_mode(DiagonalMode p_diagonal_mode) {
ERR_FAIL_INDEX((int)p_diagonal_mode, (int)DIAGONAL_MODE_MAX);
diagonal_mode = p_diagonal_mode;
}
AStarGrid2D::DiagonalMode AStarGrid2D::get_diagonal_mode() const {
return diagonal_mode;
}
void AStarGrid2D::set_default_heuristic(Heuristic p_heuristic) {
ERR_FAIL_INDEX((int)p_heuristic, (int)HEURISTIC_MAX);
default_heuristic = p_heuristic;
}
AStarGrid2D::Heuristic AStarGrid2D::get_default_heuristic() const {
return default_heuristic;
}
void AStarGrid2D::set_point_solid(const Vector2i &p_id, bool p_solid) {
ERR_FAIL_COND_MSG(dirty, "Grid is not initialized. Call the update method.");
ERR_FAIL_COND_MSG(!is_in_boundsv(p_id), vformat("Can't set if point is disabled. Point out of bounds (%s/%s, %s/%s).", p_id.x, size.width, p_id.y, size.height));
points[p_id.y][p_id.x].solid = p_solid;
}
bool AStarGrid2D::is_point_solid(const Vector2i &p_id) const {
ERR_FAIL_COND_V_MSG(dirty, false, "Grid is not initialized. Call the update method.");
ERR_FAIL_COND_V_MSG(!is_in_boundsv(p_id), false, vformat("Can't get if point is disabled. Point out of bounds (%s/%s, %s/%s).", p_id.x, size.width, p_id.y, size.height));
return points[p_id.y][p_id.x].solid;
}
AStarGrid2D::Point *AStarGrid2D::_jump(Point *p_from, Point *p_to) {
if (!p_to || p_to->solid) {
return nullptr;
}
if (p_to == end) {
return p_to;
}
int64_t from_x = p_from->id.x;
int64_t from_y = p_from->id.y;
int64_t to_x = p_to->id.x;
int64_t to_y = p_to->id.y;
int64_t dx = to_x - from_x;
int64_t dy = to_y - from_y;
if (diagonal_mode == DIAGONAL_MODE_ALWAYS || diagonal_mode == DIAGONAL_MODE_AT_LEAST_ONE_WALKABLE) {
if (dx != 0 && dy != 0) {
if ((_is_walkable(to_x - dx, to_y + dy) && !_is_walkable(to_x - dx, to_y)) || (_is_walkable(to_x + dx, to_y - dy) && !_is_walkable(to_x, to_y - dy))) {
return p_to;
}
if (_jump(p_to, _get_point(to_x + dx, to_y)) != nullptr) {
return p_to;
}
if (_jump(p_to, _get_point(to_x, to_y + dy)) != nullptr) {
return p_to;
}
} else {
if (dx != 0) {
if ((_is_walkable(to_x + dx, to_y + 1) && !_is_walkable(to_x, to_y + 1)) || (_is_walkable(to_x + dx, to_y - 1) && !_is_walkable(to_x, to_y - 1))) {
return p_to;
}
} else {
if ((_is_walkable(to_x + 1, to_y + dy) && !_is_walkable(to_x + 1, to_y)) || (_is_walkable(to_x - 1, to_y + dy) && !_is_walkable(to_x - 1, to_y))) {
return p_to;
}
}
}
if (_is_walkable(to_x + dx, to_y + dy) && (diagonal_mode == DIAGONAL_MODE_ALWAYS || (_is_walkable(to_x + dx, to_y) || _is_walkable(to_x, to_y + dy)))) {
return _jump(p_to, _get_point(to_x + dx, to_y + dy));
}
} else if (diagonal_mode == DIAGONAL_MODE_ONLY_IF_NO_OBSTACLES) {
if (dx != 0 && dy != 0) {
if ((_is_walkable(to_x + dx, to_y + dy) && !_is_walkable(to_x, to_y + dy)) || !_is_walkable(to_x + dx, to_y)) {
return p_to;
}
if (_jump(p_to, _get_point(to_x + dx, to_y)) != nullptr) {
return p_to;
}
if (_jump(p_to, _get_point(to_x, to_y + dy)) != nullptr) {
return p_to;
}
} else {
if (dx != 0) {
if ((_is_walkable(to_x, to_y + 1) && !_is_walkable(to_x - dx, to_y + 1)) || (_is_walkable(to_x, to_y - 1) && !_is_walkable(to_x - dx, to_y - 1))) {
return p_to;
}
} else {
if ((_is_walkable(to_x + 1, to_y) && !_is_walkable(to_x + 1, to_y - dy)) || (_is_walkable(to_x - 1, to_y) && !_is_walkable(to_x - 1, to_y - dy))) {
return p_to;
}
}
}
if (_is_walkable(to_x + dx, to_y + dy) && _is_walkable(to_x + dx, to_y) && _is_walkable(to_x, to_y + dy)) {
return _jump(p_to, _get_point(to_x + dx, to_y + dy));
}
} else { // DIAGONAL_MODE_NEVER
if (dx != 0) {
if (!_is_walkable(to_x + dx, to_y)) {
return p_to;
}
if (_jump(p_to, _get_point(to_x, to_y + 1)) != nullptr) {
return p_to;
}
if (_jump(p_to, _get_point(to_x, to_y - 1)) != nullptr) {
return p_to;
}
} else {
if (!_is_walkable(to_x, to_y + dy)) {
return p_to;
}
if (_jump(p_to, _get_point(to_x + 1, to_y)) != nullptr) {
return p_to;
}
if (_jump(p_to, _get_point(to_x - 1, to_y)) != nullptr) {
return p_to;
}
}
if (_is_walkable(to_x + dx, to_y + dy) && _is_walkable(to_x + dx, to_y) && _is_walkable(to_x, to_y + dy)) {
return _jump(p_to, _get_point(to_x + dx, to_y + dy));
}
}
return nullptr;
}
void AStarGrid2D::_get_nbors(Point *p_point, List<Point *> &r_nbors) {
bool ts0 = false, td0 = false,
ts1 = false, td1 = false,
ts2 = false, td2 = false,
ts3 = false, td3 = false;
Point *left = nullptr;
Point *right = nullptr;
Point *top = nullptr;
Point *bottom = nullptr;
Point *top_left = nullptr;
Point *top_right = nullptr;
Point *bottom_left = nullptr;
Point *bottom_right = nullptr;
{
bool has_left = false;
bool has_right = false;
if (p_point->id.x - 1 >= 0) {
left = _get_point_unchecked(p_point->id.x - 1, p_point->id.y);
has_left = true;
}
if (p_point->id.x + 1 < size.width) {
right = _get_point_unchecked(p_point->id.x + 1, p_point->id.y);
has_right = true;
}
if (p_point->id.y - 1 >= 0) {
top = _get_point_unchecked(p_point->id.x, p_point->id.y - 1);
if (has_left) {
top_left = _get_point_unchecked(p_point->id.x - 1, p_point->id.y - 1);
}
if (has_right) {
top_right = _get_point_unchecked(p_point->id.x + 1, p_point->id.y - 1);
}
}
if (p_point->id.y + 1 < size.height) {
bottom = _get_point_unchecked(p_point->id.x, p_point->id.y + 1);
if (has_left) {
bottom_left = _get_point_unchecked(p_point->id.x - 1, p_point->id.y + 1);
}
if (has_right) {
bottom_right = _get_point_unchecked(p_point->id.x + 1, p_point->id.y + 1);
}
}
}
if (top && !top->solid) {
r_nbors.push_back(top);
ts0 = true;
}
if (right && !right->solid) {
r_nbors.push_back(right);
ts1 = true;
}
if (bottom && !bottom->solid) {
r_nbors.push_back(bottom);
ts2 = true;
}
if (left && !left->solid) {
r_nbors.push_back(left);
ts3 = true;
}
switch (diagonal_mode) {
case DIAGONAL_MODE_ALWAYS: {
td0 = true;
td1 = true;
td2 = true;
td3 = true;
} break;
case DIAGONAL_MODE_NEVER: {
} break;
case DIAGONAL_MODE_AT_LEAST_ONE_WALKABLE: {
td0 = ts3 || ts0;
td1 = ts0 || ts1;
td2 = ts1 || ts2;
td3 = ts2 || ts3;
} break;
case DIAGONAL_MODE_ONLY_IF_NO_OBSTACLES: {
td0 = ts3 && ts0;
td1 = ts0 && ts1;
td2 = ts1 && ts2;
td3 = ts2 && ts3;
} break;
default:
break;
}
if (td0 && (top_left && !top_left->solid)) {
r_nbors.push_back(top_left);
}
if (td1 && (top_right && !top_right->solid)) {
r_nbors.push_back(top_right);
}
if (td2 && (bottom_right && !bottom_right->solid)) {
r_nbors.push_back(bottom_right);
}
if (td3 && (bottom_left && !bottom_left->solid)) {
r_nbors.push_back(bottom_left);
}
}
bool AStarGrid2D::_solve(Point *p_begin_point, Point *p_end_point) {
pass++;
if (p_end_point->solid) {
return false;
}
bool found_route = false;
Vector<Point *> open_list;
SortArray<Point *, SortPoints> sorter;
p_begin_point->g_score = 0;
p_begin_point->f_score = _estimate_cost(p_begin_point->id, p_end_point->id);
open_list.push_back(p_begin_point);
end = p_end_point;
while (!open_list.is_empty()) {
Point *p = open_list[0]; // The currently processed point.
if (p == p_end_point) {
found_route = true;
break;
}
sorter.pop_heap(0, open_list.size(), open_list.ptrw()); // Remove the current point from the open list.
open_list.remove_at(open_list.size() - 1);
p->closed_pass = pass; // Mark the point as closed.
List<Point *> nbors;
_get_nbors(p, nbors);
for (List<Point *>::Element *E = nbors.front(); E; E = E->next()) {
Point *e = E->get(); // The neighbour point.
if (jumping_enabled) {
e = _jump(p, e);
if (!e || e->closed_pass == pass) {
continue;
}
} else {
if (e->solid || e->closed_pass == pass) {
continue;
}
}
real_t tentative_g_score = p->g_score + _compute_cost(p->id, e->id);
bool new_point = false;
if (e->open_pass != pass) { // The point wasn't inside the open list.
e->open_pass = pass;
open_list.push_back(e);
new_point = true;
} else if (tentative_g_score >= e->g_score) { // The new path is worse than the previous.
continue;
}
e->prev_point = p;
e->g_score = tentative_g_score;
e->f_score = e->g_score + _estimate_cost(e->id, p_end_point->id);
if (new_point) { // The position of the new points is already known.
sorter.push_heap(0, open_list.size() - 1, 0, e, open_list.ptrw());
} else {
sorter.push_heap(0, open_list.find(e), 0, e, open_list.ptrw());
}
}
}
return found_route;
}
real_t AStarGrid2D::_estimate_cost(const Vector2i &p_from_id, const Vector2i &p_to_id) {
real_t scost;
if (GDVIRTUAL_CALL(_estimate_cost, p_from_id, p_to_id, scost)) {
return scost;
}
return heuristics[default_heuristic](p_from_id, p_to_id);
}
real_t AStarGrid2D::_compute_cost(const Vector2i &p_from_id, const Vector2i &p_to_id) {
real_t scost;
if (GDVIRTUAL_CALL(_compute_cost, p_from_id, p_to_id, scost)) {
return scost;
}
return heuristics[default_heuristic](p_from_id, p_to_id);
}
void AStarGrid2D::clear() {
points.clear();
size = Vector2i();
}
Vector<Vector2> AStarGrid2D::get_point_path(const Vector2i &p_from_id, const Vector2i &p_to_id) {
ERR_FAIL_COND_V_MSG(dirty, Vector<Vector2>(), "Grid is not initialized. Call the update method.");
ERR_FAIL_COND_V_MSG(!is_in_boundsv(p_from_id), Vector<Vector2>(), vformat("Can't get id path. Point out of bounds (%s/%s, %s/%s)", p_from_id.x, size.width, p_from_id.y, size.height));
ERR_FAIL_COND_V_MSG(!is_in_boundsv(p_to_id), Vector<Vector2>(), vformat("Can't get id path. Point out of bounds (%s/%s, %s/%s)", p_to_id.x, size.width, p_to_id.y, size.height));
Point *a = _get_point(p_from_id.x, p_from_id.y);
Point *b = _get_point(p_to_id.x, p_to_id.y);
if (a == b) {
Vector<Vector2> ret;
ret.push_back(a->pos);
return ret;
}
Point *begin_point = a;
Point *end_point = b;
bool found_route = _solve(begin_point, end_point);
if (!found_route) {
return Vector<Vector2>();
}
Point *p = end_point;
int64_t pc = 1;
while (p != begin_point) {
pc++;
p = p->prev_point;
}
Vector<Vector2> path;
path.resize(pc);
{
Vector2 *w = path.ptrw();
p = end_point;
int64_t idx = pc - 1;
while (p != begin_point) {
w[idx--] = p->pos;
p = p->prev_point;
}
w[0] = p->pos;
}
return path;
}
TypedArray<Vector2i> AStarGrid2D::get_id_path(const Vector2i &p_from_id, const Vector2i &p_to_id) {
ERR_FAIL_COND_V_MSG(dirty, TypedArray<Vector2i>(), "Grid is not initialized. Call the update method.");
ERR_FAIL_COND_V_MSG(!is_in_boundsv(p_from_id), TypedArray<Vector2i>(), vformat("Can't get id path. Point out of bounds (%s/%s, %s/%s)", p_from_id.x, size.width, p_from_id.y, size.height));
ERR_FAIL_COND_V_MSG(!is_in_boundsv(p_to_id), TypedArray<Vector2i>(), vformat("Can't get id path. Point out of bounds (%s/%s, %s/%s)", p_to_id.x, size.width, p_to_id.y, size.height));
Point *a = _get_point(p_from_id.x, p_from_id.y);
Point *b = _get_point(p_to_id.x, p_to_id.y);
if (a == b) {
TypedArray<Vector2i> ret;
ret.push_back(a);
return ret;
}
Point *begin_point = a;
Point *end_point = b;
bool found_route = _solve(begin_point, end_point);
if (!found_route) {
return TypedArray<Vector2i>();
}
Point *p = end_point;
int64_t pc = 1;
while (p != begin_point) {
pc++;
p = p->prev_point;
}
TypedArray<Vector2i> path;
path.resize(pc);
{
p = end_point;
int64_t idx = pc - 1;
while (p != begin_point) {
path[idx--] = p->id;
p = p->prev_point;
}
path[0] = p->id;
}
return path;
}
void AStarGrid2D::_bind_methods() {
ClassDB::bind_method(D_METHOD("set_size", "size"), &AStarGrid2D::set_size);
ClassDB::bind_method(D_METHOD("get_size"), &AStarGrid2D::get_size);
ClassDB::bind_method(D_METHOD("set_offset", "offset"), &AStarGrid2D::set_offset);
ClassDB::bind_method(D_METHOD("get_offset"), &AStarGrid2D::get_offset);
ClassDB::bind_method(D_METHOD("set_cell_size", "cell_size"), &AStarGrid2D::set_cell_size);
ClassDB::bind_method(D_METHOD("get_cell_size"), &AStarGrid2D::get_cell_size);
ClassDB::bind_method(D_METHOD("is_in_bounds", "x", "y"), &AStarGrid2D::is_in_bounds);
ClassDB::bind_method(D_METHOD("is_in_boundsv", "id"), &AStarGrid2D::is_in_boundsv);
ClassDB::bind_method(D_METHOD("is_dirty"), &AStarGrid2D::is_dirty);
ClassDB::bind_method(D_METHOD("update"), &AStarGrid2D::update);
ClassDB::bind_method(D_METHOD("set_jumping_enabled", "enabled"), &AStarGrid2D::set_jumping_enabled);
ClassDB::bind_method(D_METHOD("is_jumping_enabled"), &AStarGrid2D::is_jumping_enabled);
ClassDB::bind_method(D_METHOD("set_diagonal_mode", "mode"), &AStarGrid2D::set_diagonal_mode);
ClassDB::bind_method(D_METHOD("get_diagonal_mode"), &AStarGrid2D::get_diagonal_mode);
ClassDB::bind_method(D_METHOD("set_default_heuristic", "heuristic"), &AStarGrid2D::set_default_heuristic);
ClassDB::bind_method(D_METHOD("get_default_heuristic"), &AStarGrid2D::get_default_heuristic);
ClassDB::bind_method(D_METHOD("set_point_solid", "id", "solid"), &AStarGrid2D::set_point_solid, DEFVAL(true));
ClassDB::bind_method(D_METHOD("is_point_solid", "id"), &AStarGrid2D::is_point_solid);
ClassDB::bind_method(D_METHOD("clear"), &AStarGrid2D::clear);
ClassDB::bind_method(D_METHOD("get_point_path", "from_id", "to_id"), &AStarGrid2D::get_point_path);
ClassDB::bind_method(D_METHOD("get_id_path", "from_id", "to_id"), &AStarGrid2D::get_id_path);
GDVIRTUAL_BIND(_estimate_cost, "from_id", "to_id")
GDVIRTUAL_BIND(_compute_cost, "from_id", "to_id")
ADD_PROPERTY(PropertyInfo(Variant::VECTOR2I, "size"), "set_size", "get_size");
ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "offset"), "set_offset", "get_offset");
ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "cell_size"), "set_cell_size", "get_cell_size");
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "jumping_enabled"), "set_jumping_enabled", "is_jumping_enabled");
ADD_PROPERTY(PropertyInfo(Variant::INT, "default_heuristic", PROPERTY_HINT_ENUM, "Euclidean,Manhattan,Octile,Chebyshev,Max"), "set_default_heuristic", "get_default_heuristic");
ADD_PROPERTY(PropertyInfo(Variant::INT, "diagonal_mode", PROPERTY_HINT_ENUM, "Never,Always,At Least One Walkable,Only If No Obstacles,Max"), "set_diagonal_mode", "get_diagonal_mode");
BIND_ENUM_CONSTANT(HEURISTIC_EUCLIDEAN);
BIND_ENUM_CONSTANT(HEURISTIC_MANHATTAN);
BIND_ENUM_CONSTANT(HEURISTIC_OCTILE);
BIND_ENUM_CONSTANT(HEURISTIC_CHEBYSHEV);
BIND_ENUM_CONSTANT(HEURISTIC_MAX);
BIND_ENUM_CONSTANT(DIAGONAL_MODE_ALWAYS);
BIND_ENUM_CONSTANT(DIAGONAL_MODE_NEVER);
BIND_ENUM_CONSTANT(DIAGONAL_MODE_AT_LEAST_ONE_WALKABLE);
BIND_ENUM_CONSTANT(DIAGONAL_MODE_ONLY_IF_NO_OBSTACLES);
BIND_ENUM_CONSTANT(DIAGONAL_MODE_MAX);
}
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