godot/scene/3d/navigation.cpp
DualMatrix 0b5c694b74 Better heuristic for the shortest path algorithm for navigation2D and navigation.
Better heuristic for the shortest path algorithm for navigation2D and navigation.
It now will use the shortest distance to the polygon as cost instead of the distance to the center.
2018-09-20 21:23:17 +02:00

741 lines
19 KiB
C++

/*************************************************************************/
/* navigation.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2018 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.*/
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/*************************************************************************/
#include "navigation.h"
#define USE_ENTRY_POINT
void Navigation::_navmesh_link(int p_id) {
ERR_FAIL_COND(!navmesh_map.has(p_id));
NavMesh &nm = navmesh_map[p_id];
ERR_FAIL_COND(nm.linked);
ERR_FAIL_COND(nm.navmesh.is_null());
PoolVector<Vector3> vertices = nm.navmesh->get_vertices();
int len = vertices.size();
if (len == 0)
return;
PoolVector<Vector3>::Read r = vertices.read();
for (int i = 0; i < nm.navmesh->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.navmesh->get_polygon(i);
int plen = poly.size();
const int *indices = poly.ptr();
bool valid = true;
p.edges.resize(plen);
Vector3 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;
Vector3 ep = nm.xform.xform(r[idx]);
center += ep;
e.point = _get_point(ep);
p.edges.write[j] = e;
if (j >= 2) {
Vector3 epa = nm.xform.xform(r[indices[j - 2]]);
Vector3 epb = nm.xform.xform(r[indices[j - 1]]);
sum += up.dot((epb - epa).cross(ep - epa));
}
}
p.clockwise = sum > 0;
if (!valid) {
nm.polygons.pop_back();
ERR_CONTINUE(!valid);
continue;
}
p.center = center;
if (plen != 0) {
p.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 Navigation::_navmesh_unlink(int p_id) {
ERR_FAIL_COND(!navmesh_map.has(p_id));
NavMesh &nm = navmesh_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 Navigation::navmesh_add(const Ref<NavigationMesh> &p_mesh, const Transform &p_xform, Object *p_owner) {
int id = last_id++;
NavMesh nm;
nm.linked = false;
nm.navmesh = p_mesh;
nm.xform = p_xform;
nm.owner = p_owner;
navmesh_map[id] = nm;
_navmesh_link(id);
return id;
}
void Navigation::navmesh_set_transform(int p_id, const Transform &p_xform) {
ERR_FAIL_COND(!navmesh_map.has(p_id));
NavMesh &nm = navmesh_map[p_id];
if (nm.xform == p_xform)
return; //bleh
_navmesh_unlink(p_id);
nm.xform = p_xform;
_navmesh_link(p_id);
}
void Navigation::navmesh_remove(int p_id) {
ERR_FAIL_COND(!navmesh_map.has(p_id));
_navmesh_unlink(p_id);
navmesh_map.erase(p_id);
}
void Navigation::_clip_path(Vector<Vector3> &path, Polygon *from_poly, const Vector3 &p_to_point, Polygon *p_to_poly) {
Vector3 from = path[path.size() - 1];
if (from.distance_to(p_to_point) < CMP_EPSILON)
return;
Plane cut_plane;
cut_plane.normal = (from - p_to_point).cross(up);
if (cut_plane.normal == Vector3())
return;
cut_plane.normal.normalize();
cut_plane.d = cut_plane.normal.dot(from);
while (from_poly != p_to_poly) {
int pe = from_poly->prev_edge;
Vector3 a = _get_vertex(from_poly->edges[pe].point);
Vector3 b = _get_vertex(from_poly->edges[(pe + 1) % from_poly->edges.size()].point);
from_poly = from_poly->edges[pe].C;
ERR_FAIL_COND(!from_poly);
if (a.distance_to(b) > CMP_EPSILON) {
Vector3 inters;
if (cut_plane.intersects_segment(a, b, &inters)) {
if (inters.distance_to(p_to_point) > CMP_EPSILON && inters.distance_to(path[path.size() - 1]) > CMP_EPSILON) {
path.push_back(inters);
}
}
}
}
}
Vector<Vector3> Navigation::get_simple_path(const Vector3 &p_start, const Vector3 &p_end, bool p_optimize) {
Polygon *begin_poly = NULL;
Polygon *end_poly = NULL;
Vector3 begin_point;
Vector3 end_point;
float begin_d = 1e20;
float end_d = 1e20;
for (Map<int, NavMesh>::Element *E = navmesh_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++) {
Face3 f(_get_vertex(p.edges[0].point), _get_vertex(p.edges[i - 1].point), _get_vertex(p.edges[i].point));
Vector3 spoint = f.get_closest_point_to(p_start);
float dpoint = spoint.distance_to(p_start);
if (dpoint < begin_d) {
begin_d = dpoint;
begin_poly = &p;
begin_point = spoint;
}
spoint = f.get_closest_point_to(p_end);
dpoint = spoint.distance_to(p_end);
if (dpoint < end_d) {
end_d = dpoint;
end_poly = &p;
end_point = spoint;
}
}
p.prev_edge = -1;
}
}
if (!begin_poly || !end_poly) {
return Vector<Vector3>(); //no path
}
if (begin_poly == end_poly) {
Vector<Vector3> path;
path.resize(2);
path.write[0] = begin_point;
path.write[1] = end_point;
return path;
}
bool found_route = false;
List<Polygon *> open_list;
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
Vector3 edge[2] = {
_get_vertex(begin_poly->edges[i].point),
_get_vertex(begin_poly->edges[(i + 1) % begin_poly->edges.size()].point)
};
Vector3 entry = Geometry::get_closest_point_to_segment(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;
Vector3 edge[2] = {
_get_vertex(p->edges[i].point),
_get_vertex(p->edges[(i + 1) % es].point)
};
Vector3 edge_point = Geometry::get_closest_point_to_segment(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
for (int i = 0; i < p->edges.size(); i++) {
Polygon::Edge &e = p->edges.write[i];
if (!e.C)
continue;
float distance = p->center.distance_to(e.C->center) + p->distance;
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;
}
} else {
//add to open neighbours
e.C->prev_edge = e.C_edge;
e.C->distance = distance;
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<Vector3> path;
if (p_optimize) {
//string pulling
Polygon *apex_poly = end_poly;
Vector3 apex_point = end_point;
Vector3 portal_left = apex_point;
Vector3 portal_right = apex_point;
Polygon *left_poly = end_poly;
Polygon *right_poly = end_poly;
Polygon *p = end_poly;
path.push_back(end_point);
while (p) {
Vector3 left;
Vector3 right;
#define CLOCK_TANGENT(m_a, m_b, m_c) (((m_a) - (m_c)).cross((m_a) - (m_b)))
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 (CLOCK_TANGENT(apex_point,left,(left+right)*0.5).dot(up) < 0){
if (p->clockwise) {
SWAP(left, right);
}
}
bool skip = false;
if (CLOCK_TANGENT(apex_point, portal_left, left).dot(up) >= 0) {
//process
if (portal_left == apex_point || CLOCK_TANGENT(apex_point, left, portal_right).dot(up) > 0) {
left_poly = p;
portal_left = left;
} else {
_clip_path(path, apex_poly, portal_right, right_poly);
apex_point = portal_right;
p = right_poly;
left_poly = p;
apex_poly = p;
portal_left = apex_point;
portal_right = apex_point;
path.push_back(apex_point);
skip = true;
}
}
if (!skip && CLOCK_TANGENT(apex_point, portal_right, right).dot(up) <= 0) {
//process
if (portal_right == apex_point || CLOCK_TANGENT(apex_point, right, portal_left).dot(up) < 0) {
right_poly = p;
portal_right = right;
} else {
_clip_path(path, apex_poly, portal_left, left_poly);
apex_point = portal_left;
p = left_poly;
right_poly = p;
apex_poly = p;
portal_right = apex_point;
portal_left = apex_point;
path.push_back(apex_point);
}
}
if (p != begin_poly)
p = p->edges[p->prev_edge].C;
else
p = NULL;
}
if (path[path.size() - 1] != begin_point)
path.push_back(begin_point);
path.invert();
} else {
//midpoints
Polygon *p = end_poly;
path.push_back(end_point);
while (true) {
int prev = p->prev_edge;
int prev_n = (p->prev_edge + 1) % p->edges.size();
Vector3 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;
}
path.push_back(begin_point);
path.invert();
}
return path;
}
return Vector<Vector3>();
}
Vector3 Navigation::get_closest_point_to_segment(const Vector3 &p_from, const Vector3 &p_to, const bool &p_use_collision) {
bool use_collision = p_use_collision;
Vector3 closest_point;
float closest_point_d = 1e20;
NavMesh *closest_navmesh = NULL;
for (Map<int, NavMesh>::Element *E = navmesh_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++) {
Face3 f(_get_vertex(p.edges[0].point), _get_vertex(p.edges[i - 1].point), _get_vertex(p.edges[i].point));
Vector3 inters;
if (f.intersects_segment(p_from, p_to, &inters)) {
if (!use_collision) {
closest_point = inters;
use_collision = true;
closest_point_d = p_from.distance_to(inters);
closest_navmesh = p.owner;
} else if (closest_point_d > inters.distance_to(p_from)) {
closest_point = inters;
closest_point_d = p_from.distance_to(inters);
closest_navmesh = p.owner;
}
}
}
if (!use_collision) {
for (int i = 0; i < p.edges.size(); i++) {
Vector3 a, b;
Geometry::get_closest_points_between_segments(p_from, p_to, _get_vertex(p.edges[i].point), _get_vertex(p.edges[(i + 1) % p.edges.size()].point), a, b);
float d = a.distance_to(b);
if (d < closest_point_d) {
closest_point_d = d;
closest_point = b;
closest_navmesh = p.owner;
}
}
}
}
}
return closest_point;
}
Vector3 Navigation::get_closest_point(const Vector3 &p_point) {
Vector3 closest_point;
float closest_point_d = 1e20;
for (Map<int, NavMesh>::Element *E = navmesh_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++) {
Face3 f(_get_vertex(p.edges[0].point), _get_vertex(p.edges[i - 1].point), _get_vertex(p.edges[i].point));
Vector3 inters = f.get_closest_point_to(p_point);
float d = inters.distance_to(p_point);
if (d < closest_point_d) {
closest_point = inters;
closest_point_d = d;
}
}
}
}
return closest_point;
}
Vector3 Navigation::get_closest_point_normal(const Vector3 &p_point) {
Vector3 closest_point;
Vector3 closest_normal;
float closest_point_d = 1e20;
for (Map<int, NavMesh>::Element *E = navmesh_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++) {
Face3 f(_get_vertex(p.edges[0].point), _get_vertex(p.edges[i - 1].point), _get_vertex(p.edges[i].point));
Vector3 inters = f.get_closest_point_to(p_point);
float d = inters.distance_to(p_point);
if (d < closest_point_d) {
closest_point = inters;
closest_point_d = d;
closest_normal = f.get_plane().normal;
}
}
}
}
return closest_normal;
}
Object *Navigation::get_closest_point_owner(const Vector3 &p_point) {
Vector3 closest_point;
Object *owner = NULL;
float closest_point_d = 1e20;
for (Map<int, NavMesh>::Element *E = navmesh_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++) {
Face3 f(_get_vertex(p.edges[0].point), _get_vertex(p.edges[i - 1].point), _get_vertex(p.edges[i].point));
Vector3 inters = f.get_closest_point_to(p_point);
float d = inters.distance_to(p_point);
if (d < closest_point_d) {
closest_point = inters;
closest_point_d = d;
owner = E->get().owner;
}
}
}
}
return owner;
}
void Navigation::set_up_vector(const Vector3 &p_up) {
up = p_up;
}
Vector3 Navigation::get_up_vector() const {
return up;
}
void Navigation::_bind_methods() {
ClassDB::bind_method(D_METHOD("navmesh_add", "mesh", "xform", "owner"), &Navigation::navmesh_add, DEFVAL(Variant()));
ClassDB::bind_method(D_METHOD("navmesh_set_transform", "id", "xform"), &Navigation::navmesh_set_transform);
ClassDB::bind_method(D_METHOD("navmesh_remove", "id"), &Navigation::navmesh_remove);
ClassDB::bind_method(D_METHOD("get_simple_path", "start", "end", "optimize"), &Navigation::get_simple_path, DEFVAL(true));
ClassDB::bind_method(D_METHOD("get_closest_point_to_segment", "start", "end", "use_collision"), &Navigation::get_closest_point_to_segment, DEFVAL(false));
ClassDB::bind_method(D_METHOD("get_closest_point", "to_point"), &Navigation::get_closest_point);
ClassDB::bind_method(D_METHOD("get_closest_point_normal", "to_point"), &Navigation::get_closest_point_normal);
ClassDB::bind_method(D_METHOD("get_closest_point_owner", "to_point"), &Navigation::get_closest_point_owner);
ClassDB::bind_method(D_METHOD("set_up_vector", "up"), &Navigation::set_up_vector);
ClassDB::bind_method(D_METHOD("get_up_vector"), &Navigation::get_up_vector);
ADD_PROPERTY(PropertyInfo(Variant::VECTOR3, "up_vector"), "set_up_vector", "get_up_vector");
}
Navigation::Navigation() {
ERR_FAIL_COND(sizeof(Point) != 8);
cell_size = 0.01; //one centimeter
last_id = 1;
up = Vector3(0, 1, 0);
}