godot/scene/resources/polygon_path_finder.cpp
2017-01-16 08:49:52 +01:00

642 lines
15 KiB
C++

/*************************************************************************/
/* polygon_path_finder.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 "polygon_path_finder.h"
#include "geometry.h"
bool PolygonPathFinder::_is_point_inside(const Vector2& p_point) const {
int crosses=0;
for (Set<Edge>::Element *E=edges.front();E;E=E->next()) {
const Edge& e=E->get();
Vector2 a = points[e.points[0]].pos;
Vector2 b = points[e.points[1]].pos;
if (Geometry::segment_intersects_segment_2d(a,b,p_point,outside_point,NULL)) {
crosses++;
}
}
return crosses&1;
}
void PolygonPathFinder::setup(const Vector<Vector2>& p_points, const Vector<int>& p_connections) {
ERR_FAIL_COND(p_connections.size()&1);
points.clear();
edges.clear();
//insert points
int point_count=p_points.size();
points.resize(point_count+2);
bounds=Rect2();
for(int i=0;i<p_points.size();i++) {
points[i].pos=p_points[i];
points[i].penalty=0;
outside_point.x = i==0?p_points[0].x:(MAX( p_points[i].x, outside_point.x ));
outside_point.y = i==0?p_points[0].y:(MAX( p_points[i].y, outside_point.y ));
if (i==0) {
bounds.pos=points[i].pos;
} else {
bounds.expand_to(points[i].pos);
}
}
outside_point.x+=20.451+Math::randf()*10.2039;
outside_point.y+=21.193+Math::randf()*12.5412;
//insert edges (which are also connetions)
for(int i=0;i<p_connections.size();i+=2) {
Edge e(p_connections[i],p_connections[i+1]);
ERR_FAIL_INDEX(e.points[0],point_count);
ERR_FAIL_INDEX(e.points[1],point_count);
points[p_connections[i]].connections.insert(p_connections[i+1]);
points[p_connections[i+1]].connections.insert(p_connections[i]);
edges.insert(e);
}
//fill the remaining connections based on visibility
for(int i=0;i<point_count;i++) {
for(int j=i+1;j<point_count;j++) {
if (edges.has(Edge(i,j)))
continue; //if in edge ignore
Vector2 from=points[i].pos;
Vector2 to=points[j].pos;
if (!_is_point_inside(from*0.5+to*0.5)) //connection between points in inside space
continue;
bool valid=true;
for (Set<Edge>::Element *E=edges.front();E;E=E->next()) {
const Edge& e=E->get();
if (e.points[0]==i || e.points[1]==i || e.points[0]==j || e.points[1]==j )
continue;
Vector2 a = points[e.points[0]].pos;
Vector2 b = points[e.points[1]].pos;
if (Geometry::segment_intersects_segment_2d(a,b,from,to,NULL)) {
valid=false;
break;
}
}
if (valid) {
points[i].connections.insert(j);
points[j].connections.insert(i);
}
}
}
}
Vector<Vector2> PolygonPathFinder::find_path(const Vector2& p_from, const Vector2& p_to) {
Vector<Vector2> path;
Vector2 from=p_from;
Vector2 to=p_to;
Edge ignore_from_edge(-1,-1);
Edge ignore_to_edge(-1,-1);
if (!_is_point_inside(from)) {
float closest_dist=1e20;
Vector2 closest_point;
for (Set<Edge>::Element *E=edges.front();E;E=E->next()) {
const Edge& e=E->get();
Vector2 seg[2]={
points[e.points[0]].pos,
points[e.points[1]].pos
};
Vector2 closest = Geometry::get_closest_point_to_segment_2d(from,seg);
float d = from.distance_squared_to(closest);
if (d<closest_dist) {
ignore_from_edge=E->get();
closest_dist=d;
closest_point=closest;
}
}
from=closest_point;
};
if (!_is_point_inside(to)) {
float closest_dist=1e20;
Vector2 closest_point;
for (Set<Edge>::Element *E=edges.front();E;E=E->next()) {
const Edge& e=E->get();
Vector2 seg[2]={
points[e.points[0]].pos,
points[e.points[1]].pos
};
Vector2 closest = Geometry::get_closest_point_to_segment_2d(to,seg);
float d = to.distance_squared_to(closest);
if (d<closest_dist) {
ignore_to_edge=E->get();
closest_dist=d;
closest_point=closest;
}
}
to=closest_point;
};
//test direct connection
{
bool can_see_eachother=true;
for (Set<Edge>::Element *E=edges.front();E;E=E->next()) {
const Edge& e=E->get();
if (e.points[0]==ignore_from_edge.points[0] && e.points[1]==ignore_from_edge.points[1])
continue;
if (e.points[0]==ignore_to_edge.points[0] && e.points[1]==ignore_to_edge.points[1])
continue;
Vector2 a = points[e.points[0]].pos;
Vector2 b = points[e.points[1]].pos;
if (Geometry::segment_intersects_segment_2d(a,b,from,to,NULL)) {
can_see_eachother=false;
break;
}
}
if (can_see_eachother) {
path.push_back(from);
path.push_back(to);
return path;
}
}
//add to graph
int aidx = points.size()-2;
int bidx = points.size()-1;
points[aidx].pos=from;
points[bidx].pos=to;
points[aidx].distance=0;
points[bidx].distance=0;
points[aidx].prev=-1;
points[bidx].prev=-1;
points[aidx].penalty=0;
points[bidx].penalty=0;
for(int i=0;i<points.size()-2;i++) {
bool valid_a=true;
bool valid_b=true;
points[i].prev=-1;
points[i].distance=0;
if (!_is_point_inside(from*0.5+points[i].pos*0.5)) {
valid_a=false;
}
if (!_is_point_inside(to*0.5+points[i].pos*0.5)) {
valid_b=false;
}
for (Set<Edge>::Element *E=edges.front();E;E=E->next()) {
const Edge& e=E->get();
if (e.points[0]==i || e.points[1]==i)
continue;
Vector2 a = points[e.points[0]].pos;
Vector2 b = points[e.points[1]].pos;
if (valid_a) {
if (e.points[0]!=ignore_from_edge.points[1] &&
e.points[1]!=ignore_from_edge.points[1] &&
e.points[0]!=ignore_from_edge.points[0] &&
e.points[1]!=ignore_from_edge.points[0]) {
if (Geometry::segment_intersects_segment_2d(a,b,from,points[i].pos,NULL)) {
valid_a=false;
}
}
}
if (valid_b) {
if (e.points[0]!=ignore_to_edge.points[1] &&
e.points[1]!=ignore_to_edge.points[1] &&
e.points[0]!=ignore_to_edge.points[0] &&
e.points[1]!=ignore_to_edge.points[0]) {
if (Geometry::segment_intersects_segment_2d(a,b,to,points[i].pos,NULL)) {
valid_b=false;
}
}
}
if (!valid_a && !valid_b)
break;
}
if (valid_a) {
points[i].connections.insert(aidx);
points[aidx].connections.insert(i);
}
if (valid_b) {
points[i].connections.insert(bidx);
points[bidx].connections.insert(i);
}
}
//solve graph
Set<int> open_list;
points[aidx].distance=0;
points[aidx].prev=aidx;
for(Set<int>::Element *E=points[aidx].connections.front();E;E=E->next()) {
open_list.insert(E->get());
points[E->get()].distance=from.distance_to(points[E->get()].pos);
points[E->get()].prev=aidx;
}
bool found_route=false;
while(true) {
if (open_list.size()==0) {
printf("open list empty\n");
break;
}
//check open list
int least_cost_point=-1;
float least_cost=1e30;
//this could be faster (cache previous results)
for (Set<int>::Element *E=open_list.front();E;E=E->next()) {
const Point& p =points[E->get()];
float cost = p.distance;
cost+=p.pos.distance_to(to);
cost+=p.penalty;
if (cost<least_cost) {
least_cost_point=E->get();
least_cost=cost;
}
}
Point &np = points[least_cost_point];
//open the neighbours for search
for(Set<int>::Element *E=np.connections.front();E;E=E->next()) {
Point& p =points[E->get()];
float distance = np.pos.distance_to(p.pos) + np.distance;
if (p.prev!=-1) {
//oh this was visited already, can we win the cost?
if (p.distance>distance) {
p.prev=least_cost_point; //reasign previous
p.distance=distance;
}
} else {
//add to open neighbours
p.prev=least_cost_point;
p.distance=distance;
open_list.insert(E->get());
if (E->get()==bidx) {
//oh my reached end! stop algorithm
found_route=true;
break;
}
}
}
if (found_route)
break;
open_list.erase(least_cost_point);
}
if (found_route) {
int at = bidx;
path.push_back(points[at].pos);
do {
at=points[at].prev;
path.push_back(points[at].pos);
} while (at!=aidx);
path.invert();
}
for(int i=0;i<points.size()-2;i++) {
points[i].connections.erase(aidx);
points[i].connections.erase(bidx);
points[i].prev=-1;
points[i].distance=0;
}
points[aidx].connections.clear();
points[aidx].prev=-1;
points[aidx].distance=0;
points[bidx].connections.clear();
points[bidx].prev=-1;
points[bidx].distance=0;
return path;
}
void PolygonPathFinder::_set_data(const Dictionary& p_data) {
ERR_FAIL_COND(!p_data.has("points"));
ERR_FAIL_COND(!p_data.has("connections"));
ERR_FAIL_COND(!p_data.has("segments"));
ERR_FAIL_COND(!p_data.has("bounds"));
PoolVector<Vector2> p=p_data["points"];
Array c=p_data["connections"];
ERR_FAIL_COND(c.size()!=p.size());
if (c.size())
return;
int pc = p.size();
points.resize(pc+2);
PoolVector<Vector2>::Read pr=p.read();
for(int i=0;i<pc;i++) {
points[i].pos=pr[i];
PoolVector<int> con=c[i];
PoolVector<int>::Read cr=con.read();
int cc=con.size();
for(int j=0;j<cc;j++) {
points[i].connections.insert(cr[j]);
}
}
if (p_data.has("penalties")) {
PoolVector<float> penalties=p_data["penalties"];
if (penalties.size()==pc) {
PoolVector<float>::Read pr = penalties.read();
for(int i=0;i<pc;i++) {
points[i].penalty=pr[i];
}
}
}
PoolVector<int> segs=p_data["segments"];
int sc=segs.size();
ERR_FAIL_COND(sc&1);
PoolVector<int>::Read sr = segs.read();
for(int i=0;i<sc;i+=2) {
Edge e(sr[i],sr[i+1]);
edges.insert(e);
}
bounds=p_data["bounds"];
}
Dictionary PolygonPathFinder::_get_data() const{
Dictionary d;
PoolVector<Vector2> p;
PoolVector<int> ind;
Array connections;
p.resize(points.size()-2);
connections.resize(points.size()-2);
ind.resize(edges.size()*2);
PoolVector<float> penalties;
penalties.resize(points.size()-2);
{
PoolVector<Vector2>::Write wp=p.write();
PoolVector<float>::Write pw=penalties.write();
for(int i=0;i<points.size()-2;i++) {
wp[i]=points[i].pos;
pw[i]=points[i].penalty;
PoolVector<int> c;
c.resize(points[i].connections.size());
{
PoolVector<int>::Write cw=c.write();
int idx=0;
for (Set<int>::Element *E=points[i].connections.front();E;E=E->next()) {
cw[idx++]=E->get();
}
}
connections[i]=c;
}
}
{
PoolVector<int>::Write iw=ind.write();
int idx=0;
for (Set<Edge>::Element *E=edges.front();E;E=E->next()) {
iw[idx++]=E->get().points[0];
iw[idx++]=E->get().points[1];
}
}
d["bounds"]=bounds;
d["points"]=p;
d["penalties"]=penalties;
d["connections"]=connections;
d["segments"]=ind;
return d;
}
bool PolygonPathFinder::is_point_inside(const Vector2& p_point) const {
return _is_point_inside(p_point);
}
Vector2 PolygonPathFinder::get_closest_point(const Vector2& p_point) const {
float closest_dist=1e20;
Vector2 closest_point;
for (Set<Edge>::Element *E=edges.front();E;E=E->next()) {
const Edge& e=E->get();
Vector2 seg[2]={
points[e.points[0]].pos,
points[e.points[1]].pos
};
Vector2 closest = Geometry::get_closest_point_to_segment_2d(p_point,seg);
float d = p_point.distance_squared_to(closest);
if (d<closest_dist) {
closest_dist=d;
closest_point=closest;
}
}
ERR_FAIL_COND_V(closest_dist==1e20,Vector2());
return closest_point;
}
Vector<Vector2> PolygonPathFinder::get_intersections(const Vector2& p_from, const Vector2& p_to) const {
Vector<Vector2> inters;
for (Set<Edge>::Element *E=edges.front();E;E=E->next()) {
Vector2 a = points[E->get().points[0]].pos;
Vector2 b = points[E->get().points[1]].pos;
Vector2 res;
if (Geometry::segment_intersects_segment_2d(a,b,p_from,p_to,&res)) {
inters.push_back(res);
}
}
return inters;
}
Rect2 PolygonPathFinder::get_bounds() const {
return bounds;
}
void PolygonPathFinder::set_point_penalty(int p_point,float p_penalty) {
ERR_FAIL_INDEX(p_point,points.size()-2);
points[p_point].penalty=p_penalty;
}
float PolygonPathFinder::get_point_penalty(int p_point) const {
ERR_FAIL_INDEX_V(p_point,points.size()-2,0);
return points[p_point].penalty;
}
void PolygonPathFinder::_bind_methods() {
ClassDB::bind_method(_MD("setup","points","connections"),&PolygonPathFinder::setup);
ClassDB::bind_method(_MD("find_path","from","to"),&PolygonPathFinder::find_path);
ClassDB::bind_method(_MD("get_intersections","from","to"),&PolygonPathFinder::get_intersections);
ClassDB::bind_method(_MD("get_closest_point","point"),&PolygonPathFinder::get_closest_point);
ClassDB::bind_method(_MD("is_point_inside","point"),&PolygonPathFinder::is_point_inside);
ClassDB::bind_method(_MD("set_point_penalty","idx","penalty"),&PolygonPathFinder::set_point_penalty);
ClassDB::bind_method(_MD("get_point_penalty","idx"),&PolygonPathFinder::get_point_penalty);
ClassDB::bind_method(_MD("get_bounds"),&PolygonPathFinder::get_bounds);
ClassDB::bind_method(_MD("_set_data"),&PolygonPathFinder::_set_data);
ClassDB::bind_method(_MD("_get_data"),&PolygonPathFinder::_get_data);
ADD_PROPERTY(PropertyInfo(Variant::DICTIONARY,"data",PROPERTY_HINT_NONE,"",PROPERTY_USAGE_NOEDITOR),_SCS("_set_data"),_SCS("_get_data"));
}
PolygonPathFinder::PolygonPathFinder()
{
}