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-rw-r--r--scene/resources/polygon_path_finder.cpp413
1 files changed, 413 insertions, 0 deletions
diff --git a/scene/resources/polygon_path_finder.cpp b/scene/resources/polygon_path_finder.cpp
new file mode 100644
index 0000000000..9f7b6d5b9e
--- /dev/null
+++ b/scene/resources/polygon_path_finder.cpp
@@ -0,0 +1,413 @@
+#include "polygon_path_finder.h"
+#include "geometry.h"
+
+
+bool PolygonPathFinder::_is_point_inside(const Vector2& p_point) {
+
+ 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);
+
+ for(int i=0;i<p_points.size();i++) {
+
+ points[i].pos=p_points[i];
+
+ 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 ));
+ }
+
+ 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;
+ if (!_is_point_inside(p_from))
+ return path;
+ if (!_is_point_inside(p_to))
+ return path;
+
+ //test direct connection
+ {
+
+ bool can_see_eachother=true;
+
+ 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_from,p_to,NULL)) {
+ can_see_eachother=false;
+ break;
+ }
+
+ }
+
+ if (can_see_eachother) {
+
+ path.push_back(p_from);
+ path.push_back(p_to);
+ return path;
+ }
+ }
+
+ //add to graph
+
+ int aidx = points.size()-2;
+ int bidx = points.size()-1;
+ points[aidx].pos=p_from;
+ points[bidx].pos=p_to;
+ points[aidx].distance=0;
+ points[bidx].distance=0;
+ points[aidx].distance=0;
+ points[bidx].distance=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;
+
+ 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 (Geometry::segment_intersects_segment_2d(a,b,p_from,points[i].pos,NULL)) {
+ valid_a=false;
+ }
+ }
+
+ if (valid_b) {
+
+ if (Geometry::segment_intersects_segment_2d(a,b,p_to,points[i].pos,NULL)) {
+ valid_b=false;
+ }
+ }
+
+ if (!valid_a && !valid_b)
+ continue;
+
+ }
+
+ 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=p_from.distance_to(points[E->get()].pos);
+ points[E->get()].prev=aidx;
+
+ }
+
+
+ bool found_route=false;
+
+ while(true) {
+
+ if (open_list.size()==0) {
+ 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(p_to);
+ 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"));
+
+ DVector<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);
+
+ DVector<Vector2>::Read pr=p.read();
+ for(int i=0;i<pc;i++) {
+ points[i].pos=pr[i];
+ DVector<int> con=c[i];
+ DVector<int>::Read cr=con.read();
+ int cc=con.size();
+ for(int j=0;j<cc;j++) {
+
+ points[i].connections.insert(cr[j]);
+ }
+
+ }
+
+ DVector<int> segs=p_data["segments"];
+ int sc=segs.size();
+ ERR_FAIL_COND(sc&1);
+ DVector<int>::Read sr = segs.read();
+ for(int i=0;i<sc;i+=2) {
+
+ Edge e(sr[i],sr[i+1]);
+ edges.insert(e);
+ }
+
+}
+
+Dictionary PolygonPathFinder::_get_data() const{
+
+ Dictionary d;
+ DVector<Vector2> p;
+ DVector<int> ind;
+ Array connections;
+ p.resize(points.size()-2);
+ connections.resize(points.size()-2);
+ ind.resize(edges.size()*2);
+ {
+ DVector<Vector2>::Write wp=p.write();
+ for(int i=0;i<points.size()-2;i++) {
+ wp[i]=points[i].pos;
+ DVector<int> c;
+ c.resize(points[i].connections.size());
+ {
+ DVector<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;
+ }
+ }
+ {
+
+ DVector<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["points"]=p;
+ d["connections"]=connections;
+ d["segments"]=ind;
+
+ return d;
+
+}
+
+void PolygonPathFinder::_bind_methods() {
+
+ ObjectTypeDB::bind_method(_MD("setup","points","connections"),&PolygonPathFinder::setup);
+ ObjectTypeDB::bind_method(_MD("find_path","from","to"),&PolygonPathFinder::find_path);
+ ObjectTypeDB::bind_method(_MD("_set_data"),&PolygonPathFinder::_set_data);
+ ObjectTypeDB::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()
+{
+}
+
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-02 13:45:25 +0000