virtualx-engine/core/math/triangle_mesh.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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/*************************************************************************/
/* triangle_mesh.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 "triangle_mesh.h"
#include "core/sort_array.h"
int TriangleMesh::_create_bvh(BVH *p_bvh, BVH **p_bb, int p_from, int p_size, int p_depth, int &max_depth, int &max_alloc) {
if (p_depth > max_depth) {
max_depth = p_depth;
}
if (p_size == 1) {
return p_bb[p_from] - p_bvh;
} else if (p_size == 0) {
return -1;
}
AABB aabb;
aabb = p_bb[p_from]->aabb;
for (int i = 1; i < p_size; i++) {
aabb.merge_with(p_bb[p_from + i]->aabb);
}
int li = aabb.get_longest_axis_index();
switch (li) {
case Vector3::AXIS_X: {
SortArray<BVH *, BVHCmpX> sort_x;
sort_x.nth_element(0, p_size, p_size / 2, &p_bb[p_from]);
//sort_x.sort(&p_bb[p_from],p_size);
} break;
case Vector3::AXIS_Y: {
SortArray<BVH *, BVHCmpY> sort_y;
sort_y.nth_element(0, p_size, p_size / 2, &p_bb[p_from]);
//sort_y.sort(&p_bb[p_from],p_size);
} break;
case Vector3::AXIS_Z: {
SortArray<BVH *, BVHCmpZ> sort_z;
sort_z.nth_element(0, p_size, p_size / 2, &p_bb[p_from]);
//sort_z.sort(&p_bb[p_from],p_size);
} break;
}
int left = _create_bvh(p_bvh, p_bb, p_from, p_size / 2, p_depth + 1, max_depth, max_alloc);
int right = _create_bvh(p_bvh, p_bb, p_from + p_size / 2, p_size - p_size / 2, p_depth + 1, max_depth, max_alloc);
int index = max_alloc++;
BVH *_new = &p_bvh[index];
_new->aabb = aabb;
_new->center = aabb.position + aabb.size * 0.5;
_new->face_index = -1;
_new->left = left;
_new->right = right;
return index;
}
void TriangleMesh::get_indices(PoolVector<int> *r_triangles_indices) const {
if (!valid)
return;
const int triangles_num = triangles.size();
// Parse vertices indices
PoolVector<Triangle>::Read triangles_read = triangles.read();
r_triangles_indices->resize(triangles_num * 3);
PoolVector<int>::Write r_indices_write = r_triangles_indices->write();
for (int i = 0; i < triangles_num; ++i) {
r_indices_write[3 * i + 0] = triangles_read[i].indices[0];
r_indices_write[3 * i + 1] = triangles_read[i].indices[1];
r_indices_write[3 * i + 2] = triangles_read[i].indices[2];
}
}
void TriangleMesh::create(const PoolVector<Vector3> &p_faces) {
valid = false;
int fc = p_faces.size();
ERR_FAIL_COND(!fc || ((fc % 3) != 0));
fc /= 3;
triangles.resize(fc);
bvh.resize(fc * 3); //will never be larger than this (todo make better)
PoolVector<BVH>::Write bw = bvh.write();
{
//create faces and indices and base bvh
//except for the Set for repeated triangles, everything
//goes in-place.
PoolVector<Vector3>::Read r = p_faces.read();
PoolVector<Triangle>::Write w = triangles.write();
Map<Vector3, int> db;
for (int i = 0; i < fc; i++) {
Triangle &f = w[i];
const Vector3 *v = &r[i * 3];
for (int j = 0; j < 3; j++) {
int vidx = -1;
Vector3 vs = v[j].snapped(Vector3(0.0001, 0.0001, 0.0001));
Map<Vector3, int>::Element *E = db.find(vs);
if (E) {
vidx = E->get();
} else {
vidx = db.size();
db[vs] = vidx;
}
f.indices[j] = vidx;
if (j == 0)
bw[i].aabb.position = vs;
else
bw[i].aabb.expand_to(vs);
}
f.normal = Face3(r[i * 3 + 0], r[i * 3 + 1], r[i * 3 + 2]).get_plane().get_normal();
bw[i].left = -1;
bw[i].right = -1;
bw[i].face_index = i;
bw[i].center = bw[i].aabb.position + bw[i].aabb.size * 0.5;
}
vertices.resize(db.size());
PoolVector<Vector3>::Write vw = vertices.write();
for (Map<Vector3, int>::Element *E = db.front(); E; E = E->next()) {
vw[E->get()] = E->key();
}
}
PoolVector<BVH *> bwptrs;
bwptrs.resize(fc);
PoolVector<BVH *>::Write bwp = bwptrs.write();
for (int i = 0; i < fc; i++) {
bwp[i] = &bw[i];
}
max_depth = 0;
int max_alloc = fc;
_create_bvh(bw.ptr(), bwp.ptr(), 0, fc, 1, max_depth, max_alloc);
bw.release(); //clearup
bvh.resize(max_alloc); //resize back
valid = true;
}
Vector3 TriangleMesh::get_area_normal(const AABB &p_aabb) const {
uint32_t *stack = (uint32_t *)alloca(sizeof(int) * max_depth);
enum {
TEST_AABB_BIT = 0,
VISIT_LEFT_BIT = 1,
VISIT_RIGHT_BIT = 2,
VISIT_DONE_BIT = 3,
VISITED_BIT_SHIFT = 29,
NODE_IDX_MASK = (1 << VISITED_BIT_SHIFT) - 1,
VISITED_BIT_MASK = ~NODE_IDX_MASK,
};
int n_count = 0;
Vector3 n;
int level = 0;
PoolVector<Triangle>::Read trianglesr = triangles.read();
PoolVector<Vector3>::Read verticesr = vertices.read();
PoolVector<BVH>::Read bvhr = bvh.read();
const Triangle *triangleptr = trianglesr.ptr();
int pos = bvh.size() - 1;
const BVH *bvhptr = bvhr.ptr();
stack[0] = pos;
while (true) {
uint32_t node = stack[level] & NODE_IDX_MASK;
const BVH &b = bvhptr[node];
bool done = false;
switch (stack[level] >> VISITED_BIT_SHIFT) {
case TEST_AABB_BIT: {
bool valid = b.aabb.intersects(p_aabb);
if (!valid) {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
if (b.face_index >= 0) {
const Triangle &s = triangleptr[b.face_index];
n += s.normal;
n_count++;
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
stack[level] = (VISIT_LEFT_BIT << VISITED_BIT_SHIFT) | node;
}
}
continue;
}
case VISIT_LEFT_BIT: {
stack[level] = (VISIT_RIGHT_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.left | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_RIGHT_BIT: {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.right | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_DONE_BIT: {
if (level == 0) {
done = true;
break;
} else
level--;
continue;
}
}
if (done)
break;
}
if (n_count > 0)
n /= n_count;
return n;
}
bool TriangleMesh::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_point, Vector3 &r_normal) const {
uint32_t *stack = (uint32_t *)alloca(sizeof(int) * max_depth);
enum {
TEST_AABB_BIT = 0,
VISIT_LEFT_BIT = 1,
VISIT_RIGHT_BIT = 2,
VISIT_DONE_BIT = 3,
VISITED_BIT_SHIFT = 29,
NODE_IDX_MASK = (1 << VISITED_BIT_SHIFT) - 1,
VISITED_BIT_MASK = ~NODE_IDX_MASK,
};
Vector3 n = (p_end - p_begin).normalized();
real_t d = 1e10;
bool inters = false;
int level = 0;
PoolVector<Triangle>::Read trianglesr = triangles.read();
PoolVector<Vector3>::Read verticesr = vertices.read();
PoolVector<BVH>::Read bvhr = bvh.read();
const Triangle *triangleptr = trianglesr.ptr();
const Vector3 *vertexptr = verticesr.ptr();
int pos = bvh.size() - 1;
const BVH *bvhptr = bvhr.ptr();
stack[0] = pos;
while (true) {
uint32_t node = stack[level] & NODE_IDX_MASK;
const BVH &b = bvhptr[node];
bool done = false;
switch (stack[level] >> VISITED_BIT_SHIFT) {
case TEST_AABB_BIT: {
bool valid = b.aabb.intersects_segment(p_begin, p_end);
//bool valid = b.aabb.intersects(ray_aabb);
if (!valid) {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
if (b.face_index >= 0) {
const Triangle &s = triangleptr[b.face_index];
Face3 f3(vertexptr[s.indices[0]], vertexptr[s.indices[1]], vertexptr[s.indices[2]]);
Vector3 res;
if (f3.intersects_segment(p_begin, p_end, &res)) {
real_t nd = n.dot(res);
if (nd < d) {
d = nd;
r_point = res;
r_normal = f3.get_plane().get_normal();
inters = true;
}
}
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
stack[level] = (VISIT_LEFT_BIT << VISITED_BIT_SHIFT) | node;
}
}
continue;
}
case VISIT_LEFT_BIT: {
stack[level] = (VISIT_RIGHT_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.left | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_RIGHT_BIT: {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.right | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_DONE_BIT: {
if (level == 0) {
done = true;
break;
} else
level--;
continue;
}
}
if (done)
break;
}
if (inters) {
if (n.dot(r_normal) > 0)
r_normal = -r_normal;
}
return inters;
}
bool TriangleMesh::intersect_ray(const Vector3 &p_begin, const Vector3 &p_dir, Vector3 &r_point, Vector3 &r_normal) const {
uint32_t *stack = (uint32_t *)alloca(sizeof(int) * max_depth);
enum {
TEST_AABB_BIT = 0,
VISIT_LEFT_BIT = 1,
VISIT_RIGHT_BIT = 2,
VISIT_DONE_BIT = 3,
VISITED_BIT_SHIFT = 29,
NODE_IDX_MASK = (1 << VISITED_BIT_SHIFT) - 1,
VISITED_BIT_MASK = ~NODE_IDX_MASK,
};
Vector3 n = p_dir;
real_t d = 1e20;
bool inters = false;
int level = 0;
PoolVector<Triangle>::Read trianglesr = triangles.read();
PoolVector<Vector3>::Read verticesr = vertices.read();
PoolVector<BVH>::Read bvhr = bvh.read();
const Triangle *triangleptr = trianglesr.ptr();
const Vector3 *vertexptr = verticesr.ptr();
int pos = bvh.size() - 1;
const BVH *bvhptr = bvhr.ptr();
stack[0] = pos;
while (true) {
uint32_t node = stack[level] & NODE_IDX_MASK;
const BVH &b = bvhptr[node];
bool done = false;
switch (stack[level] >> VISITED_BIT_SHIFT) {
case TEST_AABB_BIT: {
bool valid = b.aabb.intersects_ray(p_begin, p_dir);
if (!valid) {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
if (b.face_index >= 0) {
const Triangle &s = triangleptr[b.face_index];
Face3 f3(vertexptr[s.indices[0]], vertexptr[s.indices[1]], vertexptr[s.indices[2]]);
Vector3 res;
if (f3.intersects_ray(p_begin, p_dir, &res)) {
real_t nd = n.dot(res);
if (nd < d) {
d = nd;
r_point = res;
r_normal = f3.get_plane().get_normal();
inters = true;
}
}
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
stack[level] = (VISIT_LEFT_BIT << VISITED_BIT_SHIFT) | node;
}
}
continue;
}
case VISIT_LEFT_BIT: {
stack[level] = (VISIT_RIGHT_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.left | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_RIGHT_BIT: {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.right | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_DONE_BIT: {
if (level == 0) {
done = true;
break;
} else
level--;
continue;
}
}
if (done)
break;
}
if (inters) {
if (n.dot(r_normal) > 0)
r_normal = -r_normal;
}
return inters;
}
bool TriangleMesh::intersect_convex_shape(const Plane *p_planes, int p_plane_count) const {
uint32_t *stack = (uint32_t *)alloca(sizeof(int) * max_depth);
//p_fully_inside = true;
enum {
TEST_AABB_BIT = 0,
VISIT_LEFT_BIT = 1,
VISIT_RIGHT_BIT = 2,
VISIT_DONE_BIT = 3,
VISITED_BIT_SHIFT = 29,
NODE_IDX_MASK = (1 << VISITED_BIT_SHIFT) - 1,
VISITED_BIT_MASK = ~NODE_IDX_MASK,
};
int level = 0;
PoolVector<Triangle>::Read trianglesr = triangles.read();
PoolVector<Vector3>::Read verticesr = vertices.read();
PoolVector<BVH>::Read bvhr = bvh.read();
const Triangle *triangleptr = trianglesr.ptr();
const Vector3 *vertexptr = verticesr.ptr();
int pos = bvh.size() - 1;
const BVH *bvhptr = bvhr.ptr();
stack[0] = pos;
while (true) {
uint32_t node = stack[level] & NODE_IDX_MASK;
const BVH &b = bvhptr[node];
bool done = false;
switch (stack[level] >> VISITED_BIT_SHIFT) {
case TEST_AABB_BIT: {
bool valid = b.aabb.intersects_convex_shape(p_planes, p_plane_count);
if (!valid) {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
if (b.face_index >= 0) {
const Triangle &s = triangleptr[b.face_index];
for (int j = 0; j < 3; ++j) {
const Vector3 &point = vertexptr[s.indices[j]];
const Vector3 &next_point = vertexptr[s.indices[(j + 1) % 3]];
Vector3 res;
bool over = true;
for (int i = 0; i < p_plane_count; i++) {
const Plane &p = p_planes[i];
if (p.intersects_segment(point, next_point, &res)) {
bool inisde = true;
for (int k = 0; k < p_plane_count; k++) {
if (k == i) continue;
const Plane &pp = p_planes[k];
if (pp.is_point_over(res)) {
inisde = false;
break;
}
}
if (inisde) return true;
}
if (p.is_point_over(point)) {
over = false;
break;
}
}
if (over) return true;
}
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
stack[level] = (VISIT_LEFT_BIT << VISITED_BIT_SHIFT) | node;
}
}
continue;
}
case VISIT_LEFT_BIT: {
stack[level] = (VISIT_RIGHT_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.left | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_RIGHT_BIT: {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.right | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_DONE_BIT: {
if (level == 0) {
done = true;
break;
} else
level--;
continue;
}
}
if (done)
break;
}
return false;
}
bool TriangleMesh::inside_convex_shape(const Plane *p_planes, int p_plane_count, Vector3 p_scale) const {
uint32_t *stack = (uint32_t *)alloca(sizeof(int) * max_depth);
enum {
TEST_AABB_BIT = 0,
VISIT_LEFT_BIT = 1,
VISIT_RIGHT_BIT = 2,
VISIT_DONE_BIT = 3,
VISITED_BIT_SHIFT = 29,
NODE_IDX_MASK = (1 << VISITED_BIT_SHIFT) - 1,
VISITED_BIT_MASK = ~NODE_IDX_MASK,
};
int level = 0;
PoolVector<Triangle>::Read trianglesr = triangles.read();
PoolVector<Vector3>::Read verticesr = vertices.read();
PoolVector<BVH>::Read bvhr = bvh.read();
Transform scale(Basis().scaled(p_scale));
const Triangle *triangleptr = trianglesr.ptr();
const Vector3 *vertexptr = verticesr.ptr();
int pos = bvh.size() - 1;
const BVH *bvhptr = bvhr.ptr();
stack[0] = pos;
while (true) {
uint32_t node = stack[level] & NODE_IDX_MASK;
const BVH &b = bvhptr[node];
bool done = false;
switch (stack[level] >> VISITED_BIT_SHIFT) {
case TEST_AABB_BIT: {
bool intersects = scale.xform(b.aabb).intersects_convex_shape(p_planes, p_plane_count);
if (!intersects) return false;
bool inside = scale.xform(b.aabb).inside_convex_shape(p_planes, p_plane_count);
if (inside) {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
if (b.face_index >= 0) {
const Triangle &s = triangleptr[b.face_index];
for (int j = 0; j < 3; ++j) {
Vector3 point = scale.xform(vertexptr[s.indices[j]]);
for (int i = 0; i < p_plane_count; i++) {
const Plane &p = p_planes[i];
if (p.is_point_over(point)) return false;
}
}
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
stack[level] = (VISIT_LEFT_BIT << VISITED_BIT_SHIFT) | node;
}
}
continue;
}
case VISIT_LEFT_BIT: {
stack[level] = (VISIT_RIGHT_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.left | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_RIGHT_BIT: {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = b.right | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_DONE_BIT: {
if (level == 0) {
done = true;
break;
} else
level--;
continue;
}
}
if (done)
break;
}
return true;
}
bool TriangleMesh::is_valid() const {
return valid;
}
PoolVector<Face3> TriangleMesh::get_faces() const {
if (!valid)
return PoolVector<Face3>();
PoolVector<Face3> faces;
int ts = triangles.size();
faces.resize(triangles.size());
PoolVector<Face3>::Write w = faces.write();
PoolVector<Triangle>::Read r = triangles.read();
PoolVector<Vector3>::Read rv = vertices.read();
for (int i = 0; i < ts; i++) {
for (int j = 0; j < 3; j++) {
w[i].vertex[j] = rv[r[i].indices[j]];
}
}
w.release();
return faces;
}
TriangleMesh::TriangleMesh() {
valid = false;
max_depth = 0;
}