mirror of
https://github.com/godotengine/godot.git
synced 2024-12-15 10:12:40 +08:00
458 lines
12 KiB
C++
458 lines
12 KiB
C++
/*************************************************************************/
|
|
/* quick_hull.cpp */
|
|
/*************************************************************************/
|
|
/* This file is part of: */
|
|
/* GODOT ENGINE */
|
|
/* https://godotengine.org */
|
|
/*************************************************************************/
|
|
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
|
|
/* Copyright (c) 2014-2022 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 "quick_hull.h"
|
|
|
|
#include "core/templates/map.h"
|
|
|
|
uint32_t QuickHull::debug_stop_after = 0xFFFFFFFF;
|
|
|
|
Error QuickHull::build(const Vector<Vector3> &p_points, Geometry3D::MeshData &r_mesh) {
|
|
/* CREATE AABB VOLUME */
|
|
|
|
AABB aabb;
|
|
for (int i = 0; i < p_points.size(); i++) {
|
|
if (i == 0) {
|
|
aabb.position = p_points[i];
|
|
} else {
|
|
aabb.expand_to(p_points[i]);
|
|
}
|
|
}
|
|
|
|
if (aabb.size == Vector3()) {
|
|
return ERR_CANT_CREATE;
|
|
}
|
|
|
|
Vector<bool> valid_points;
|
|
valid_points.resize(p_points.size());
|
|
Set<Vector3> valid_cache;
|
|
|
|
for (int i = 0; i < p_points.size(); i++) {
|
|
Vector3 sp = p_points[i].snapped(Vector3(0.0001, 0.0001, 0.0001));
|
|
if (valid_cache.has(sp)) {
|
|
valid_points.write[i] = false;
|
|
} else {
|
|
valid_points.write[i] = true;
|
|
valid_cache.insert(sp);
|
|
}
|
|
}
|
|
|
|
/* CREATE INITIAL SIMPLEX */
|
|
|
|
int longest_axis = aabb.get_longest_axis_index();
|
|
|
|
//first two vertices are the most distant
|
|
int simplex[4] = { 0 };
|
|
|
|
{
|
|
real_t max = 0, min = 0;
|
|
|
|
for (int i = 0; i < p_points.size(); i++) {
|
|
if (!valid_points[i]) {
|
|
continue;
|
|
}
|
|
real_t d = p_points[i][longest_axis];
|
|
if (i == 0 || d < min) {
|
|
simplex[0] = i;
|
|
min = d;
|
|
}
|
|
|
|
if (i == 0 || d > max) {
|
|
simplex[1] = i;
|
|
max = d;
|
|
}
|
|
}
|
|
}
|
|
|
|
//third vertex is one most further away from the line
|
|
|
|
{
|
|
real_t maxd = 0;
|
|
Vector3 rel12 = p_points[simplex[0]] - p_points[simplex[1]];
|
|
|
|
for (int i = 0; i < p_points.size(); i++) {
|
|
if (!valid_points[i]) {
|
|
continue;
|
|
}
|
|
|
|
Vector3 n = rel12.cross(p_points[simplex[0]] - p_points[i]).cross(rel12).normalized();
|
|
real_t d = Math::abs(n.dot(p_points[simplex[0]]) - n.dot(p_points[i]));
|
|
|
|
if (i == 0 || d > maxd) {
|
|
maxd = d;
|
|
simplex[2] = i;
|
|
}
|
|
}
|
|
}
|
|
|
|
//fourth vertex is the one most further away from the plane
|
|
|
|
{
|
|
real_t maxd = 0;
|
|
Plane p(p_points[simplex[0]], p_points[simplex[1]], p_points[simplex[2]]);
|
|
|
|
for (int i = 0; i < p_points.size(); i++) {
|
|
if (!valid_points[i]) {
|
|
continue;
|
|
}
|
|
|
|
real_t d = Math::abs(p.distance_to(p_points[i]));
|
|
|
|
if (i == 0 || d > maxd) {
|
|
maxd = d;
|
|
simplex[3] = i;
|
|
}
|
|
}
|
|
}
|
|
|
|
//compute center of simplex, this is a point always warranted to be inside
|
|
Vector3 center;
|
|
|
|
for (int i = 0; i < 4; i++) {
|
|
center += p_points[simplex[i]];
|
|
}
|
|
|
|
center /= 4.0;
|
|
|
|
//add faces
|
|
|
|
List<Face> faces;
|
|
|
|
for (int i = 0; i < 4; i++) {
|
|
static const int face_order[4][3] = {
|
|
{ 0, 1, 2 },
|
|
{ 0, 1, 3 },
|
|
{ 0, 2, 3 },
|
|
{ 1, 2, 3 }
|
|
};
|
|
|
|
Face f;
|
|
for (int j = 0; j < 3; j++) {
|
|
f.vertices[j] = simplex[face_order[i][j]];
|
|
}
|
|
|
|
Plane p(p_points[f.vertices[0]], p_points[f.vertices[1]], p_points[f.vertices[2]]);
|
|
|
|
if (p.is_point_over(center)) {
|
|
//flip face to clockwise if facing inwards
|
|
SWAP(f.vertices[0], f.vertices[1]);
|
|
p = -p;
|
|
}
|
|
|
|
f.plane = p;
|
|
|
|
faces.push_back(f);
|
|
}
|
|
|
|
real_t over_tolerance = 3 * UNIT_EPSILON * (aabb.size.x + aabb.size.y + aabb.size.z);
|
|
|
|
/* COMPUTE AVAILABLE VERTICES */
|
|
|
|
for (int i = 0; i < p_points.size(); i++) {
|
|
if (i == simplex[0]) {
|
|
continue;
|
|
}
|
|
if (i == simplex[1]) {
|
|
continue;
|
|
}
|
|
if (i == simplex[2]) {
|
|
continue;
|
|
}
|
|
if (i == simplex[3]) {
|
|
continue;
|
|
}
|
|
if (!valid_points[i]) {
|
|
continue;
|
|
}
|
|
|
|
for (Face &E : faces) {
|
|
if (E.plane.distance_to(p_points[i]) > over_tolerance) {
|
|
E.points_over.push_back(i);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
faces.sort(); // sort them, so the ones with points are in the back
|
|
|
|
/* BUILD HULL */
|
|
|
|
//poop face (while still remain)
|
|
//find further away point
|
|
//find lit faces
|
|
//determine horizon edges
|
|
//build new faces with horizon edges, them assign points side from all lit faces
|
|
//remove lit faces
|
|
|
|
uint32_t debug_stop = debug_stop_after;
|
|
|
|
while (debug_stop > 0 && faces.back()->get().points_over.size()) {
|
|
debug_stop--;
|
|
Face &f = faces.back()->get();
|
|
|
|
//find vertex most outside
|
|
int next = -1;
|
|
real_t next_d = 0;
|
|
|
|
for (int i = 0; i < f.points_over.size(); i++) {
|
|
real_t d = f.plane.distance_to(p_points[f.points_over[i]]);
|
|
|
|
if (d > next_d) {
|
|
next_d = d;
|
|
next = i;
|
|
}
|
|
}
|
|
|
|
ERR_FAIL_COND_V(next == -1, ERR_BUG);
|
|
|
|
Vector3 v = p_points[f.points_over[next]];
|
|
|
|
//find lit faces and lit edges
|
|
List<List<Face>::Element *> lit_faces; //lit face is a death sentence
|
|
|
|
Map<Edge, FaceConnect> lit_edges; //create this on the flight, should not be that bad for performance and simplifies code a lot
|
|
|
|
for (List<Face>::Element *E = faces.front(); E; E = E->next()) {
|
|
if (E->get().plane.distance_to(v) > 0) {
|
|
lit_faces.push_back(E);
|
|
|
|
for (int i = 0; i < 3; i++) {
|
|
uint32_t a = E->get().vertices[i];
|
|
uint32_t b = E->get().vertices[(i + 1) % 3];
|
|
Edge e(a, b);
|
|
|
|
Map<Edge, FaceConnect>::Element *F = lit_edges.find(e);
|
|
if (!F) {
|
|
F = lit_edges.insert(e, FaceConnect());
|
|
}
|
|
if (e.vertices[0] == a) {
|
|
//left
|
|
F->get().left = E;
|
|
} else {
|
|
F->get().right = E;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
//create new faces from horizon edges
|
|
List<List<Face>::Element *> new_faces; //new faces
|
|
|
|
for (KeyValue<Edge, FaceConnect> &E : lit_edges) {
|
|
FaceConnect &fc = E.value;
|
|
if (fc.left && fc.right) {
|
|
continue; //edge is uninteresting, not on horizon
|
|
}
|
|
|
|
//create new face!
|
|
|
|
Face face;
|
|
face.vertices[0] = f.points_over[next];
|
|
face.vertices[1] = E.key.vertices[0];
|
|
face.vertices[2] = E.key.vertices[1];
|
|
|
|
Plane p(p_points[face.vertices[0]], p_points[face.vertices[1]], p_points[face.vertices[2]]);
|
|
|
|
if (p.is_point_over(center)) {
|
|
//flip face to clockwise if facing inwards
|
|
SWAP(face.vertices[0], face.vertices[1]);
|
|
p = -p;
|
|
}
|
|
|
|
face.plane = p;
|
|
new_faces.push_back(faces.push_back(face));
|
|
}
|
|
|
|
//distribute points into new faces
|
|
|
|
for (List<Face>::Element *&F : lit_faces) {
|
|
Face &lf = F->get();
|
|
|
|
for (int i = 0; i < lf.points_over.size(); i++) {
|
|
if (lf.points_over[i] == f.points_over[next]) { //do not add current one
|
|
continue;
|
|
}
|
|
|
|
Vector3 p = p_points[lf.points_over[i]];
|
|
for (List<Face>::Element *&E : new_faces) {
|
|
Face &f2 = E->get();
|
|
if (f2.plane.distance_to(p) > over_tolerance) {
|
|
f2.points_over.push_back(lf.points_over[i]);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
//erase lit faces
|
|
|
|
while (lit_faces.size()) {
|
|
faces.erase(lit_faces.front()->get());
|
|
lit_faces.pop_front();
|
|
}
|
|
|
|
//put faces that contain no points on the front
|
|
|
|
for (List<Face>::Element *&E : new_faces) {
|
|
Face &f2 = E->get();
|
|
if (f2.points_over.size() == 0) {
|
|
faces.move_to_front(E);
|
|
}
|
|
}
|
|
|
|
//whew, done with iteration, go next
|
|
}
|
|
|
|
/* CREATE MESHDATA */
|
|
|
|
//make a map of edges again
|
|
Map<Edge, RetFaceConnect> ret_edges;
|
|
List<Geometry3D::MeshData::Face> ret_faces;
|
|
|
|
for (const Face &E : faces) {
|
|
Geometry3D::MeshData::Face f;
|
|
f.plane = E.plane;
|
|
|
|
for (int i = 0; i < 3; i++) {
|
|
f.indices.push_back(E.vertices[i]);
|
|
}
|
|
|
|
List<Geometry3D::MeshData::Face>::Element *F = ret_faces.push_back(f);
|
|
|
|
for (int i = 0; i < 3; i++) {
|
|
uint32_t a = E.vertices[i];
|
|
uint32_t b = E.vertices[(i + 1) % 3];
|
|
Edge e(a, b);
|
|
|
|
Map<Edge, RetFaceConnect>::Element *G = ret_edges.find(e);
|
|
if (!G) {
|
|
G = ret_edges.insert(e, RetFaceConnect());
|
|
}
|
|
if (e.vertices[0] == a) {
|
|
//left
|
|
G->get().left = F;
|
|
} else {
|
|
G->get().right = F;
|
|
}
|
|
}
|
|
}
|
|
|
|
//fill faces
|
|
|
|
for (List<Geometry3D::MeshData::Face>::Element *E = ret_faces.front(); E; E = E->next()) {
|
|
Geometry3D::MeshData::Face &f = E->get();
|
|
|
|
for (int i = 0; i < f.indices.size(); i++) {
|
|
int a = E->get().indices[i];
|
|
int b = E->get().indices[(i + 1) % f.indices.size()];
|
|
Edge e(a, b);
|
|
|
|
Map<Edge, RetFaceConnect>::Element *F = ret_edges.find(e);
|
|
|
|
ERR_CONTINUE(!F);
|
|
List<Geometry3D::MeshData::Face>::Element *O = F->get().left == E ? F->get().right : F->get().left;
|
|
ERR_CONTINUE(O == E);
|
|
ERR_CONTINUE(O == nullptr);
|
|
|
|
if (O->get().plane.is_equal_approx(f.plane)) {
|
|
//merge and delete edge and contiguous face, while repointing edges (uuugh!)
|
|
int ois = O->get().indices.size();
|
|
int merged = 0;
|
|
|
|
for (int j = 0; j < ois; j++) {
|
|
//search a
|
|
if (O->get().indices[j] == a) {
|
|
//append the rest
|
|
for (int k = 0; k < ois; k++) {
|
|
int idx = O->get().indices[(k + j) % ois];
|
|
int idxn = O->get().indices[(k + j + 1) % ois];
|
|
if (idx == b && idxn == a) { //already have b!
|
|
break;
|
|
}
|
|
if (idx != a) {
|
|
f.indices.insert(i + 1, idx);
|
|
i++;
|
|
merged++;
|
|
}
|
|
Edge e2(idx, idxn);
|
|
|
|
Map<Edge, RetFaceConnect>::Element *F2 = ret_edges.find(e2);
|
|
ERR_CONTINUE(!F2);
|
|
//change faceconnect, point to this face instead
|
|
if (F2->get().left == O) {
|
|
F2->get().left = E;
|
|
} else if (F2->get().right == O) {
|
|
F2->get().right = E;
|
|
}
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
// remove all edge connections to this face
|
|
for (KeyValue<Edge, RetFaceConnect> &G : ret_edges) {
|
|
if (G.value.left == O) {
|
|
G.value.left = nullptr;
|
|
}
|
|
|
|
if (G.value.right == O) {
|
|
G.value.right = nullptr;
|
|
}
|
|
}
|
|
|
|
ret_edges.erase(F); //remove the edge
|
|
ret_faces.erase(O); //remove the face
|
|
}
|
|
}
|
|
}
|
|
|
|
//fill mesh
|
|
r_mesh.faces.clear();
|
|
r_mesh.faces.resize(ret_faces.size());
|
|
|
|
int idx = 0;
|
|
for (const Geometry3D::MeshData::Face &E : ret_faces) {
|
|
r_mesh.faces.write[idx++] = E;
|
|
}
|
|
r_mesh.edges.resize(ret_edges.size());
|
|
idx = 0;
|
|
for (const KeyValue<Edge, RetFaceConnect> &E : ret_edges) {
|
|
Geometry3D::MeshData::Edge e;
|
|
e.a = E.key.vertices[0];
|
|
e.b = E.key.vertices[1];
|
|
r_mesh.edges.write[idx++] = e;
|
|
}
|
|
|
|
r_mesh.vertices = p_points;
|
|
|
|
return OK;
|
|
}
|