virtualx-engine/core/math/triangle_mesh.cpp
Rémi Verschelde c7bc44d5ad Welcome in 2017, dear changelog reader!
That year should bring the long-awaited OpenGL ES 3.0 compatible renderer
with state-of-the-art rendering techniques tuned to work as low as middle
end handheld devices - without compromising with the possibilities given
for higher end desktop games of course. Great times ahead for the Godot
community and the gamers that will play our games!
2017-01-01 22:03:33 +01:00

554 lines
12 KiB
C++

/*************************************************************************/
/* triangle_mesh.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur. */
/* */
/* 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 "sort.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.pos+aabb.size*0.5;
_new->face_index=-1;
_new->left=left;
_new->right=right;
return index;
}
void TriangleMesh::create(const DVector<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)
DVector<BVH>::Write bw = bvh.write();
{
//create faces and indices and base bvh
//except for the Set for repeated triangles, everything
//goes in-place.
DVector<Vector3>::Read r = p_faces.read();
DVector<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(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.pos=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.pos+bw[i].aabb.size*0.5;
}
vertices.resize(db.size());
DVector<Vector3>::Write vw = vertices.write();
for (Map<Vector3,int>::Element *E=db.front();E;E=E->next()) {
vw[E->get()]=E->key();
}
}
DVector<BVH*> bwptrs;
bwptrs.resize(fc);
DVector<BVH*>::Write bwp = bwptrs.write();
for(int i=0;i<fc;i++) {
bwp[i]=&bw[i];
}
max_depth=0;
int max_alloc=fc;
int max=_create_bvh(bw.ptr(),bwp.ptr(),0,fc,1,max_depth,max_alloc);
bw=DVector<BVH>::Write(); //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;
DVector<Triangle>::Read trianglesr = triangles.read();
DVector<Vector3>::Read verticesr=vertices.read();
DVector<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;
DVector<Triangle>::Read trianglesr = triangles.read();
DVector<Vector3>::Read verticesr=vertices.read();
DVector<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)) {
float 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;
DVector<Triangle>::Read trianglesr = triangles.read();
DVector<Vector3>::Read verticesr=vertices.read();
DVector<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)) {
float 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::is_valid() const {
return valid;
}
DVector<Face3> TriangleMesh::get_faces() const {
if (!valid)
return DVector<Face3>();
DVector<Face3> faces;
int ts = triangles.size();
faces.resize(triangles.size());
DVector<Face3>::Write w=faces.write();
DVector<Triangle>::Read r = triangles.read();
DVector<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 = DVector<Face3>::Write();
return faces;
}
TriangleMesh::TriangleMesh() {
valid=false;
max_depth=0;
}