godot/scene/2d/navigation_2d.cpp
Rémi Verschelde a7f49ac9a1 Update copyright statements to 2020
Happy new year to the wonderful Godot community!

We're starting a new decade with a well-established, non-profit, free
and open source game engine, and tons of further improvements in the
pipeline from hundreds of contributors.

Godot will keep getting better, and we're looking forward to all the
games that the community will keep developing and releasing with it.
2020-01-01 11:16:22 +01:00

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/*************************************************************************/
/* navigation_2d.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2020 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 "navigation_2d.h"
#define USE_ENTRY_POINT
void Navigation2D::_navpoly_link(int p_id) {
ERR_FAIL_COND(!navpoly_map.has(p_id));
NavMesh &nm = navpoly_map[p_id];
ERR_FAIL_COND(nm.linked);
PoolVector<Vector2> vertices = nm.navpoly->get_vertices();
int len = vertices.size();
if (len == 0)
return;
PoolVector<Vector2>::Read r = vertices.read();
for (int i = 0; i < nm.navpoly->get_polygon_count(); i++) {
//build
List<Polygon>::Element *P = nm.polygons.push_back(Polygon());
Polygon &p = P->get();
p.owner = &nm;
Vector<int> poly = nm.navpoly->get_polygon(i);
int plen = poly.size();
const int *indices = poly.ptr();
bool valid = true;
p.edges.resize(plen);
Vector2 center;
float sum = 0;
for (int j = 0; j < plen; j++) {
int idx = indices[j];
if (idx < 0 || idx >= len) {
valid = false;
break;
}
Polygon::Edge e;
Vector2 ep = nm.xform.xform(r[idx]);
center += ep;
e.point = _get_point(ep);
p.edges.write[j] = e;
int idxn = indices[(j + 1) % plen];
if (idxn < 0 || idxn >= len) {
valid = false;
break;
}
Vector2 epn = nm.xform.xform(r[idxn]);
sum += (epn.x - ep.x) * (epn.y + ep.y);
}
p.clockwise = sum > 0;
if (!valid) {
nm.polygons.pop_back();
ERR_CONTINUE(!valid);
}
p.center = center / plen;
//connect
for (int j = 0; j < plen; j++) {
int next = (j + 1) % plen;
EdgeKey ek(p.edges[j].point, p.edges[next].point);
Map<EdgeKey, Connection>::Element *C = connections.find(ek);
if (!C) {
Connection c;
c.A = &p;
c.A_edge = j;
c.B = NULL;
c.B_edge = -1;
connections[ek] = c;
} else {
if (C->get().B != NULL) {
ConnectionPending pending;
pending.polygon = &p;
pending.edge = j;
p.edges.write[j].P = C->get().pending.push_back(pending);
continue;
}
C->get().B = &p;
C->get().B_edge = j;
C->get().A->edges.write[C->get().A_edge].C = &p;
C->get().A->edges.write[C->get().A_edge].C_edge = j;
p.edges.write[j].C = C->get().A;
p.edges.write[j].C_edge = C->get().A_edge;
//connection successful.
}
}
}
nm.linked = true;
}
void Navigation2D::_navpoly_unlink(int p_id) {
ERR_FAIL_COND(!navpoly_map.has(p_id));
NavMesh &nm = navpoly_map[p_id];
ERR_FAIL_COND(!nm.linked);
for (List<Polygon>::Element *E = nm.polygons.front(); E; E = E->next()) {
Polygon &p = E->get();
int ec = p.edges.size();
Polygon::Edge *edges = p.edges.ptrw();
for (int i = 0; i < ec; i++) {
int next = (i + 1) % ec;
EdgeKey ek(edges[i].point, edges[next].point);
Map<EdgeKey, Connection>::Element *C = connections.find(ek);
ERR_CONTINUE(!C);
if (edges[i].P) {
C->get().pending.erase(edges[i].P);
edges[i].P = NULL;
} else if (C->get().B) {
//disconnect
C->get().B->edges.write[C->get().B_edge].C = NULL;
C->get().B->edges.write[C->get().B_edge].C_edge = -1;
C->get().A->edges.write[C->get().A_edge].C = NULL;
C->get().A->edges.write[C->get().A_edge].C_edge = -1;
if (C->get().A == &E->get()) {
C->get().A = C->get().B;
C->get().A_edge = C->get().B_edge;
}
C->get().B = NULL;
C->get().B_edge = -1;
if (C->get().pending.size()) {
//reconnect if something is pending
ConnectionPending cp = C->get().pending.front()->get();
C->get().pending.pop_front();
C->get().B = cp.polygon;
C->get().B_edge = cp.edge;
C->get().A->edges.write[C->get().A_edge].C = cp.polygon;
C->get().A->edges.write[C->get().A_edge].C_edge = cp.edge;
cp.polygon->edges.write[cp.edge].C = C->get().A;
cp.polygon->edges.write[cp.edge].C_edge = C->get().A_edge;
cp.polygon->edges.write[cp.edge].P = NULL;
}
} else {
connections.erase(C);
//erase
}
}
}
nm.polygons.clear();
nm.linked = false;
}
int Navigation2D::navpoly_add(const Ref<NavigationPolygon> &p_mesh, const Transform2D &p_xform, Object *p_owner) {
int id = last_id++;
NavMesh nm;
nm.linked = false;
nm.navpoly = p_mesh;
nm.xform = p_xform;
nm.owner = p_owner;
navpoly_map[id] = nm;
_navpoly_link(id);
return id;
}
void Navigation2D::navpoly_set_transform(int p_id, const Transform2D &p_xform) {
ERR_FAIL_COND(!navpoly_map.has(p_id));
NavMesh &nm = navpoly_map[p_id];
if (nm.xform == p_xform)
return; //bleh
_navpoly_unlink(p_id);
nm.xform = p_xform;
_navpoly_link(p_id);
}
void Navigation2D::navpoly_remove(int p_id) {
ERR_FAIL_COND(!navpoly_map.has(p_id));
_navpoly_unlink(p_id);
navpoly_map.erase(p_id);
}
Vector<Vector2> Navigation2D::get_simple_path(const Vector2 &p_start, const Vector2 &p_end, bool p_optimize) {
Polygon *begin_poly = NULL;
Polygon *end_poly = NULL;
Vector2 begin_point;
Vector2 end_point;
float begin_d = 1e20;
float end_d = 1e20;
//look for point inside triangle
for (Map<int, NavMesh>::Element *E = navpoly_map.front(); E; E = E->next()) {
if (!E->get().linked)
continue;
for (List<Polygon>::Element *F = E->get().polygons.front(); F; F = F->next()) {
Polygon &p = F->get();
if (begin_d || end_d) {
for (int i = 2; i < p.edges.size(); i++) {
if (begin_d > 0) {
if (Geometry::is_point_in_triangle(p_start, _get_vertex(p.edges[0].point), _get_vertex(p.edges[i - 1].point), _get_vertex(p.edges[i].point))) {
begin_poly = &p;
begin_point = p_start;
begin_d = 0;
if (end_d == 0)
break;
}
}
if (end_d > 0) {
if (Geometry::is_point_in_triangle(p_end, _get_vertex(p.edges[0].point), _get_vertex(p.edges[i - 1].point), _get_vertex(p.edges[i].point))) {
end_poly = &p;
end_point = p_end;
end_d = 0;
if (begin_d == 0)
break;
}
}
}
}
p.prev_edge = -1;
}
}
//start or end not inside triangle.. look for closest segment :|
if (begin_d || end_d) {
for (Map<int, NavMesh>::Element *E = navpoly_map.front(); E; E = E->next()) {
if (!E->get().linked)
continue;
for (List<Polygon>::Element *F = E->get().polygons.front(); F; F = F->next()) {
Polygon &p = F->get();
int es = p.edges.size();
for (int i = 0; i < es; i++) {
Vector2 edge[2] = {
_get_vertex(p.edges[i].point),
_get_vertex(p.edges[(i + 1) % es].point)
};
if (begin_d > 0) {
Vector2 spoint = Geometry::get_closest_point_to_segment_2d(p_start, edge);
float d = spoint.distance_to(p_start);
if (d < begin_d) {
begin_poly = &p;
begin_point = spoint;
begin_d = d;
}
}
if (end_d > 0) {
Vector2 spoint = Geometry::get_closest_point_to_segment_2d(p_end, edge);
float d = spoint.distance_to(p_end);
if (d < end_d) {
end_poly = &p;
end_point = spoint;
end_d = d;
}
}
}
}
}
}
if (!begin_poly || !end_poly) {
return Vector<Vector2>(); //no path
}
if (begin_poly == end_poly) {
Vector<Vector2> path;
path.resize(2);
path.write[0] = begin_point;
path.write[1] = end_point;
return path;
}
bool found_route = false;
List<Polygon *> open_list;
begin_poly->entry = p_start;
for (int i = 0; i < begin_poly->edges.size(); i++) {
if (begin_poly->edges[i].C) {
begin_poly->edges[i].C->prev_edge = begin_poly->edges[i].C_edge;
#ifdef USE_ENTRY_POINT
Vector2 edge[2] = {
_get_vertex(begin_poly->edges[i].point),
_get_vertex(begin_poly->edges[(i + 1) % begin_poly->edges.size()].point)
};
Vector2 entry = Geometry::get_closest_point_to_segment_2d(begin_poly->entry, edge);
begin_poly->edges[i].C->distance = begin_poly->entry.distance_to(entry);
begin_poly->edges[i].C->entry = entry;
#else
begin_poly->edges[i].C->distance = begin_poly->center.distance_to(begin_poly->edges[i].C->center);
#endif
open_list.push_back(begin_poly->edges[i].C);
if (begin_poly->edges[i].C == end_poly) {
found_route = true;
}
}
}
while (!found_route) {
if (open_list.size() == 0) {
break;
}
//check open list
List<Polygon *>::Element *least_cost_poly = NULL;
float least_cost = 1e30;
//this could be faster (cache previous results)
for (List<Polygon *>::Element *E = open_list.front(); E; E = E->next()) {
Polygon *p = E->get();
float cost = p->distance;
#ifdef USE_ENTRY_POINT
int es = p->edges.size();
float shortest_distance = 1e30;
for (int i = 0; i < es; i++) {
Polygon::Edge &e = p->edges.write[i];
if (!e.C)
continue;
Vector2 edge[2] = {
_get_vertex(p->edges[i].point),
_get_vertex(p->edges[(i + 1) % es].point)
};
Vector2 edge_point = Geometry::get_closest_point_to_segment_2d(p->entry, edge);
float dist = p->entry.distance_to(edge_point);
if (dist < shortest_distance)
shortest_distance = dist;
}
cost += shortest_distance;
#else
cost += p->center.distance_to(end_point);
#endif
if (cost < least_cost) {
least_cost_poly = E;
least_cost = cost;
}
}
Polygon *p = least_cost_poly->get();
//open the neighbours for search
int es = p->edges.size();
for (int i = 0; i < es; i++) {
Polygon::Edge &e = p->edges.write[i];
if (!e.C)
continue;
#ifdef USE_ENTRY_POINT
Vector2 edge[2] = {
_get_vertex(p->edges[i].point),
_get_vertex(p->edges[(i + 1) % es].point)
};
Vector2 edge_entry = Geometry::get_closest_point_to_segment_2d(p->entry, edge);
float distance = p->entry.distance_to(edge_entry) + p->distance;
#else
float distance = p->center.distance_to(e.C->center) + p->distance;
#endif
if (e.C->prev_edge != -1) {
//oh this was visited already, can we win the cost?
if (e.C->distance > distance) {
e.C->prev_edge = e.C_edge;
e.C->distance = distance;
#ifdef USE_ENTRY_POINT
e.C->entry = edge_entry;
#endif
}
} else {
//add to open neighbours
e.C->prev_edge = e.C_edge;
e.C->distance = distance;
#ifdef USE_ENTRY_POINT
e.C->entry = edge_entry;
#endif
open_list.push_back(e.C);
if (e.C == end_poly) {
//oh my reached end! stop algorithm
found_route = true;
break;
}
}
}
if (found_route)
break;
open_list.erase(least_cost_poly);
}
if (found_route) {
Vector<Vector2> path;
if (p_optimize) {
//string pulling
Vector2 apex_point = end_point;
Vector2 portal_left = apex_point;
Vector2 portal_right = apex_point;
Polygon *left_poly = end_poly;
Polygon *right_poly = end_poly;
Polygon *p = end_poly;
while (p) {
Vector2 left;
Vector2 right;
//#define CLOCK_TANGENT(m_a,m_b,m_c) ( ((m_a)-(m_c)).cross((m_a)-(m_b)) )
#define CLOCK_TANGENT(m_a, m_b, m_c) ((((m_a).x - (m_c).x) * ((m_b).y - (m_c).y) - ((m_b).x - (m_c).x) * ((m_a).y - (m_c).y)))
if (p == begin_poly) {
left = begin_point;
right = begin_point;
} else {
int prev = p->prev_edge;
int prev_n = (p->prev_edge + 1) % p->edges.size();
left = _get_vertex(p->edges[prev].point);
right = _get_vertex(p->edges[prev_n].point);
if (p->clockwise) {
SWAP(left, right);
}
/*if (CLOCK_TANGENT(apex_point,left,(left+right)*0.5) < 0){
SWAP(left,right);
}*/
}
bool skip = false;
/*
print_line("-----\nAPEX: "+(apex_point-end_point));
print_line("LEFT:");
print_line("\tPortal: "+(portal_left-end_point));
print_line("\tPoint: "+(left-end_point));
print_line("\tLeft Tangent: "+rtos(CLOCK_TANGENT(apex_point,portal_left,left)));
print_line("\tLeft Distance: "+rtos(portal_left.distance_squared_to(apex_point)));
print_line("\tLeft Test: "+rtos(CLOCK_TANGENT(apex_point,left,portal_right)));
print_line("RIGHT:");
print_line("\tPortal: "+(portal_right-end_point));
print_line("\tPoint: "+(right-end_point));
print_line("\tRight Tangent: "+rtos(CLOCK_TANGENT(apex_point,portal_right,right)));
print_line("\tRight Distance: "+rtos(portal_right.distance_squared_to(apex_point)));
print_line("\tRight Test: "+rtos(CLOCK_TANGENT(apex_point,right,portal_left)));
*/
if (CLOCK_TANGENT(apex_point, portal_left, left) >= 0) {
//process
if (portal_left.is_equal_approx(apex_point) || CLOCK_TANGENT(apex_point, left, portal_right) > 0) {
left_poly = p;
portal_left = left;
} else {
apex_point = portal_right;
p = right_poly;
left_poly = p;
portal_left = apex_point;
portal_right = apex_point;
if (!path.size() || !path[path.size() - 1].is_equal_approx(apex_point))
path.push_back(apex_point);
skip = true;
}
}
if (!skip && CLOCK_TANGENT(apex_point, portal_right, right) <= 0) {
//process
if (portal_right.is_equal_approx(apex_point) || CLOCK_TANGENT(apex_point, right, portal_left) < 0) {
right_poly = p;
portal_right = right;
} else {
apex_point = portal_left;
p = left_poly;
right_poly = p;
portal_right = apex_point;
portal_left = apex_point;
if (!path.size() || !path[path.size() - 1].is_equal_approx(apex_point))
path.push_back(apex_point);
}
}
if (p != begin_poly)
p = p->edges[p->prev_edge].C;
else
p = NULL;
}
} else {
//midpoints
Polygon *p = end_poly;
while (true) {
int prev = p->prev_edge;
int prev_n = (p->prev_edge + 1) % p->edges.size();
Vector2 point = (_get_vertex(p->edges[prev].point) + _get_vertex(p->edges[prev_n].point)) * 0.5;
path.push_back(point);
p = p->edges[prev].C;
if (p == begin_poly)
break;
}
}
if (!path.size() || !path[path.size() - 1].is_equal_approx(begin_point)) {
path.push_back(begin_point); // Add the begin point
} else {
path.write[path.size() - 1] = begin_point; // Replace first midpoint by the exact begin point
}
path.invert();
if (path.size() <= 1 || !path[path.size() - 1].is_equal_approx(end_point)) {
path.push_back(end_point); // Add the end point
} else {
path.write[path.size() - 1] = end_point; // Replace last midpoint by the exact end point
}
return path;
}
return Vector<Vector2>();
}
Vector2 Navigation2D::get_closest_point(const Vector2 &p_point) {
Vector2 closest_point = Vector2();
float closest_point_d = 1e20;
for (Map<int, NavMesh>::Element *E = navpoly_map.front(); E; E = E->next()) {
if (!E->get().linked)
continue;
for (List<Polygon>::Element *F = E->get().polygons.front(); F; F = F->next()) {
Polygon &p = F->get();
for (int i = 2; i < p.edges.size(); i++) {
if (Geometry::is_point_in_triangle(p_point, _get_vertex(p.edges[0].point), _get_vertex(p.edges[i - 1].point), _get_vertex(p.edges[i].point))) {
return p_point; //inside triangle, nothing else to discuss
}
}
}
}
for (Map<int, NavMesh>::Element *E = navpoly_map.front(); E; E = E->next()) {
if (!E->get().linked)
continue;
for (List<Polygon>::Element *F = E->get().polygons.front(); F; F = F->next()) {
Polygon &p = F->get();
int es = p.edges.size();
for (int i = 0; i < es; i++) {
Vector2 edge[2] = {
_get_vertex(p.edges[i].point),
_get_vertex(p.edges[(i + 1) % es].point)
};
Vector2 spoint = Geometry::get_closest_point_to_segment_2d(p_point, edge);
float d = spoint.distance_squared_to(p_point);
if (d < closest_point_d) {
closest_point = spoint;
closest_point_d = d;
}
}
}
}
return closest_point;
}
Object *Navigation2D::get_closest_point_owner(const Vector2 &p_point) {
Object *owner = NULL;
Vector2 closest_point = Vector2();
float closest_point_d = 1e20;
for (Map<int, NavMesh>::Element *E = navpoly_map.front(); E; E = E->next()) {
if (!E->get().linked)
continue;
for (List<Polygon>::Element *F = E->get().polygons.front(); F; F = F->next()) {
Polygon &p = F->get();
for (int i = 2; i < p.edges.size(); i++) {
if (Geometry::is_point_in_triangle(p_point, _get_vertex(p.edges[0].point), _get_vertex(p.edges[i - 1].point), _get_vertex(p.edges[i].point))) {
return E->get().owner;
}
}
}
}
for (Map<int, NavMesh>::Element *E = navpoly_map.front(); E; E = E->next()) {
if (!E->get().linked)
continue;
for (List<Polygon>::Element *F = E->get().polygons.front(); F; F = F->next()) {
Polygon &p = F->get();
int es = p.edges.size();
for (int i = 0; i < es; i++) {
Vector2 edge[2] = {
_get_vertex(p.edges[i].point),
_get_vertex(p.edges[(i + 1) % es].point)
};
Vector2 spoint = Geometry::get_closest_point_to_segment_2d(p_point, edge);
float d = spoint.distance_squared_to(p_point);
if (d < closest_point_d) {
closest_point = spoint;
closest_point_d = d;
owner = E->get().owner;
}
}
}
}
return owner;
}
void Navigation2D::_bind_methods() {
ClassDB::bind_method(D_METHOD("navpoly_add", "mesh", "xform", "owner"), &Navigation2D::navpoly_add, DEFVAL(Variant()));
ClassDB::bind_method(D_METHOD("navpoly_set_transform", "id", "xform"), &Navigation2D::navpoly_set_transform);
ClassDB::bind_method(D_METHOD("navpoly_remove", "id"), &Navigation2D::navpoly_remove);
ClassDB::bind_method(D_METHOD("get_simple_path", "start", "end", "optimize"), &Navigation2D::get_simple_path, DEFVAL(true));
ClassDB::bind_method(D_METHOD("get_closest_point", "to_point"), &Navigation2D::get_closest_point);
ClassDB::bind_method(D_METHOD("get_closest_point_owner", "to_point"), &Navigation2D::get_closest_point_owner);
}
Navigation2D::Navigation2D() {
ERR_FAIL_COND(sizeof(Point) != 8);
cell_size = 1; // one pixel
last_id = 1;
}