virtualx-engine/core/math/a_star.cpp
Juan Linietsky 118eed485e ObjectTypeDB was renamed to ClassDB. Types are meant to be more generic to Variant.
All usages of "type" to refer to classes were renamed to "class"
ClassDB has been exposed to GDScript.
OBJ_TYPE() macro is now GDCLASS()
2017-01-02 23:03:46 -03:00

440 lines
9.6 KiB
C++

/*************************************************************************/
/* a_star.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 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. */
/*************************************************************************/
#include "a_star.h"
#include "geometry.h"
int AStar::get_available_point_id() const {
if (points.empty()) {
return 1;
}
return points.back()->key()+1;
}
void AStar::add_point(int p_id, const Vector3 &p_pos, float p_weight_scale) {
ERR_FAIL_COND(p_id<0);
if (!points.has(p_id)) {
Point *pt = memnew( Point );
pt->id=p_id;
pt->pos=p_pos;
pt->weight_scale=p_weight_scale;
pt->prev_point=NULL;
pt->last_pass=0;
points[p_id]=pt;
} else {
points[p_id]->pos=p_pos;
points[p_id]->weight_scale=p_weight_scale;
}
}
Vector3 AStar::get_point_pos(int p_id) const{
ERR_FAIL_COND_V(!points.has(p_id),Vector3());
return points[p_id]->pos;
}
float AStar::get_point_weight_scale(int p_id) const{
ERR_FAIL_COND_V(!points.has(p_id),0);
return points[p_id]->weight_scale;
}
void AStar::remove_point(int p_id){
ERR_FAIL_COND(!points.has(p_id));
Point* p = points[p_id];
for(int i=0;i<p->neighbours.size();i++) {
Segment s(p_id,p->neighbours[i]->id);
segments.erase(s);
p->neighbours[i]->neighbours.erase(p);
}
memdelete(p);
points.erase(p_id);
}
void AStar::connect_points(int p_id,int p_with_id){
ERR_FAIL_COND(!points.has(p_id));
ERR_FAIL_COND(!points.has(p_with_id));
ERR_FAIL_COND(p_id==p_with_id);
Point* a = points[p_id];
Point* b = points[p_with_id];
a->neighbours.push_back(b);
b->neighbours.push_back(a);
Segment s(p_id,p_with_id);
if (s.from==p_id) {
s.from_point=a;
s.to_point=b;
} else {
s.from_point=b;
s.to_point=a;
}
segments.insert(s);
}
void AStar::disconnect_points(int p_id,int p_with_id){
Segment s(p_id,p_with_id);
ERR_FAIL_COND(!segments.has(s));
segments.erase(s);
Point *a = points[p_id];
Point *b = points[p_with_id];
a->neighbours.erase(b);
b->neighbours.erase(a);
}
bool AStar::are_points_connected(int p_id,int p_with_id) const{
Segment s(p_id,p_with_id);
return segments.has(s);
}
void AStar::clear(){
for (const Map<int,Point*>::Element *E=points.front();E;E=E->next()) {
memdelete(E->get());
}
segments.clear();
points.clear();
}
int AStar::get_closest_point(const Vector3& p_point) const{
int closest_id=-1;
float closest_dist=1e20;
for (const Map<int,Point*>::Element *E=points.front();E;E=E->next()) {
float d = p_point.distance_squared_to(E->get()->pos);
if (closest_id<0 || d<closest_dist) {
closest_dist=d;
closest_id=E->key();
}
}
return closest_id;
}
Vector3 AStar::get_closest_pos_in_segment(const Vector3& p_point) const {
float closest_dist = 1e20;
bool found=false;
Vector3 closest_point;
for (const Set<Segment>::Element *E=segments.front();E;E=E->next()) {
Vector3 segment[2]={
E->get().from_point->pos,
E->get().to_point->pos,
};
Vector3 p = Geometry::get_closest_point_to_segment(p_point,segment);
float d = p_point.distance_squared_to(p);
if (!found || d<closest_dist) {
closest_point=p;
closest_dist=d;
found=true;
}
}
return closest_point;
}
bool AStar::_solve(Point* begin_point, Point* end_point) {
pass++;
SelfList<Point>::List open_list;
bool found_route=false;
for(int i=0;i<begin_point->neighbours.size();i++) {
Point *n = begin_point->neighbours[i];
n->prev_point=begin_point;
n->distance=n->pos.distance_to(begin_point->pos);
n->distance*=n->weight_scale;
n->last_pass=pass;
open_list.add(&n->list);
if (end_point==n) {
found_route=true;
break;
}
}
while(!found_route) {
if (open_list.first()==NULL) {
//could not find path sadly
break;
}
//check open list
SelfList<Point> *least_cost_point=NULL;
float least_cost=1e30;
//this could be faster (cache previous results)
for (SelfList<Point> *E=open_list.first();E;E=E->next()) {
Point *p=E->self();
float cost=p->distance;
cost+=p->pos.distance_to(end_point->pos);
cost*=p->weight_scale;
if (cost<least_cost) {
least_cost_point=E;
least_cost=cost;
}
}
Point *p=least_cost_point->self();
//open the neighbours for search
int es = p->neighbours.size();
for(int i=0;i<es;i++) {
Point* e=p->neighbours[i];
float distance = p->pos.distance_to(e->pos) + p->distance;
distance*=e->weight_scale;
if (e->last_pass==pass) {
//oh this was visited already, can we win the cost?
if (e->distance>distance) {
e->prev_point=p;
e->distance=distance;
}
} else {
//add to open neighbours
e->prev_point=p;
e->distance=distance;
e->last_pass=pass; //mark as used
open_list.add(&e->list);
if (e==end_point) {
//oh my reached end! stop algorithm
found_route=true;
break;
}
}
}
if (found_route)
break;
open_list.remove(least_cost_point);
}
//clear the openf list
while(open_list.first()) {
open_list.remove( open_list.first() );
}
return found_route;
}
DVector<Vector3> AStar::get_point_path(int p_from_id, int p_to_id) {
ERR_FAIL_COND_V(!points.has(p_from_id),DVector<Vector3>());
ERR_FAIL_COND_V(!points.has(p_to_id),DVector<Vector3>());
pass++;
Point* a = points[p_from_id];
Point* b = points[p_to_id];
if (a==b) {
DVector<Vector3> 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 DVector<Vector3>();
//midpoints
Point *p=end_point;
int pc=1; //begin point
while(p!=begin_point) {
pc++;
p=p->prev_point;
}
DVector<Vector3> path;
path.resize(pc);
{
DVector<Vector3>::Write w = path.write();
Point *p=end_point;
int idx=pc-1;
while(p!=begin_point) {
w[idx--]=p->pos;
p=p->prev_point;
}
w[0]=p->pos; //assign first
}
return path;
}
DVector<int> AStar::get_id_path(int p_from_id, int p_to_id) {
ERR_FAIL_COND_V(!points.has(p_from_id),DVector<int>());
ERR_FAIL_COND_V(!points.has(p_to_id),DVector<int>());
pass++;
Point* a = points[p_from_id];
Point* b = points[p_to_id];
if (a==b) {
DVector<int> ret;
ret.push_back(a->id);
return ret;
}
Point *begin_point=a;
Point *end_point=b;
bool found_route=_solve(begin_point,end_point);
if (!found_route)
return DVector<int>();
//midpoints
Point *p=end_point;
int pc=1; //begin point
while(p!=begin_point) {
pc++;
p=p->prev_point;
}
DVector<int> path;
path.resize(pc);
{
DVector<int>::Write w = path.write();
p=end_point;
int idx=pc-1;
while(p!=begin_point) {
w[idx--]=p->id;
p=p->prev_point;
}
w[0]=p->id; //assign first
}
return path;
}
void AStar::_bind_methods() {
ClassDB::bind_method(_MD("get_available_point_id"),&AStar::get_available_point_id);
ClassDB::bind_method(_MD("add_point","id","pos","weight_scale"),&AStar::add_point,DEFVAL(1.0));
ClassDB::bind_method(_MD("get_point_pos","id"),&AStar::get_point_pos);
ClassDB::bind_method(_MD("get_point_weight_scale","id"),&AStar::get_point_weight_scale);
ClassDB::bind_method(_MD("remove_point","id"),&AStar::remove_point);
ClassDB::bind_method(_MD("connect_points","id","to_id"),&AStar::connect_points);
ClassDB::bind_method(_MD("disconnect_points","id","to_id"),&AStar::disconnect_points);
ClassDB::bind_method(_MD("are_points_connected","id","to_id"),&AStar::are_points_connected);
ClassDB::bind_method(_MD("clear"),&AStar::clear);
ClassDB::bind_method(_MD("get_closest_point","to_pos"),&AStar::get_closest_point);
ClassDB::bind_method(_MD("get_closest_pos_in_segment","to_pos"),&AStar::get_closest_pos_in_segment);
ClassDB::bind_method(_MD("get_point_path","from_id","to_id"),&AStar::get_point_path);
ClassDB::bind_method(_MD("get_id_path","from_id","to_id"),&AStar::get_id_path);
}
AStar::AStar() {
pass=1;
}
AStar::~AStar() {
pass=1;
}