/*************************************************************************/
/* bsp_tree.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2015 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 "bsp_tree.h"
#include "error_macros.h"
#include "print_string.h"
void BSP_Tree::from_aabb(const AABB& p_aabb) {
planes.clear();
for(int i=0;i<3;i++) {
Vector3 n;
n[i]=1;
planes.push_back(Plane(n,p_aabb.pos[i]+p_aabb.size[i]));
planes.push_back(Plane(-n,-p_aabb.pos[i]));
}
nodes.clear();
for(int i=0;i<6;i++) {
Node n;
n.plane=i;
n.under=(i==0)?UNDER_LEAF:i-1;
n.over=OVER_LEAF;
nodes.push_back(n);
}
aabb=p_aabb;
error_radius=0;
}
Vector<BSP_Tree::Node> BSP_Tree::get_nodes() const {
return nodes;
}
Vector<Plane> BSP_Tree::get_planes() const {
return planes;
}
AABB BSP_Tree::get_aabb() const {
return aabb;
}
int BSP_Tree::_get_points_inside(int p_node,const Vector3* p_points,int *p_indices, const Vector3& p_center,const Vector3& p_half_extents,int p_indices_count) const {
const Node *node =&nodes[p_node];
const Plane &p = planes[node->plane];
Vector3 min(
(p.normal.x>0) ? -p_half_extents.x : p_half_extents.x,
(p.normal.y>0) ? -p_half_extents.y : p_half_extents.y,
(p.normal.z>0) ? -p_half_extents.z : p_half_extents.z
);
Vector3 max=-min;
max+=p_center;
min+=p_center;
float dist_min = p.distance_to(min);
float dist_max = p.distance_to(max);
if ((dist_min * dist_max) < CMP_EPSILON ) { //intersection, test point by point
int under_count=0;
//sort points, so the are under first, over last
for(int i=0;i<p_indices_count;i++) {
int index=p_indices[i];
if (p.is_point_over(p_points[index])) {
// kind of slow (but cache friendly), should try something else,
// but this is a corner case most of the time
for(int j=index;j<p_indices_count-1;j++)
p_indices[j]=p_indices[j+1];
p_indices[p_indices_count-1]=index;
} else {
under_count++;
}
}
int total=0;
if (under_count>0) {
if (node->under==UNDER_LEAF) {
total+=under_count;
} else {
total+=_get_points_inside(node->under,p_points,p_indices,p_center,p_half_extents,under_count);
}
}
if (under_count!=p_indices_count) {
if (node->over==OVER_LEAF) {
//total+=0 //if they are over an OVER_LEAF, they are outside the model
} else {
total+=_get_points_inside(node->over,p_points,&p_indices[under_count],p_center,p_half_extents,p_indices_count-under_count);
}
}
return total;
} else if (dist_min > 0 ) { //all points over plane
if (node->over==OVER_LEAF) {
return 0; // all these points are not visible
}
return _get_points_inside(node->over,p_points,p_indices,p_center,p_half_extents,p_indices_count);
} else if (dist_min <= 0 ) { //all points behind plane
if (node->under==UNDER_LEAF) {
return p_indices_count; // all these points are visible
}
return _get_points_inside(node->under,p_points,p_indices,p_center,p_half_extents,p_indices_count);
}
return 0;
}
int BSP_Tree::get_points_inside(const Vector3* p_points,int p_point_count) const {
if (nodes.size()==0)
return 0;
#if 1
//this version is easier to debug, and and MUCH faster in real world cases
int pass_count = 0;
const Node *nodesptr=&nodes[0];
const Plane *planesptr=&planes[0];
int plane_count=planes.size();
int node_count=nodes.size();
if (node_count==0) // no nodes!
return 0;
for(int i=0;i<p_point_count;i++) {
const Vector3& point = p_points[i];
if (!aabb.has_point(point)) {
continue;
}
int idx=node_count-1;
bool pass=false;
while(true) {
if (idx==OVER_LEAF) {
pass=false;
break;
} else if (idx==UNDER_LEAF) {
pass=true;
break;
}
uint16_t plane=nodesptr[ idx ].plane;
#ifdef DEBUG_ENABLED
ERR_FAIL_INDEX_V( plane, plane_count, false );
#endif
idx = planesptr[ nodesptr[ idx ].plane ].is_point_over(point) ? nodes[ idx ].over : nodes[ idx ].under;
#ifdef DEBUG_ENABLED
ERR_FAIL_COND_V( idx<MAX_NODES && idx>=node_count, false );
#endif
}
if (pass)
pass_count++;
}
return pass_count;
#else
//this version scales better but it's slower for real world cases
int *indices = (int*)alloca(p_point_count*sizeof(int));
AABB bounds;
for(int i=0;i<p_point_count;i++) {
indices[i]=i;
if (i==0)
bounds.pos=p_points[i];
else
bounds.expand_to(p_points[i]);
}
Vector3 half_extents = bounds.size/2.0;
return _get_points_inside(nodes.size()+1,p_points,indices,bounds.pos+half_extents,half_extents,p_point_count);
#endif
}
bool BSP_Tree::point_is_inside(const Vector3& p_point) const {
if (!aabb.has_point(p_point)) {
return false;
}
int node_count=nodes.size();
if (node_count==0) // no nodes!
return false;
const Node *nodesptr=&nodes[0];
const Plane *planesptr=&planes[0];
int plane_count=planes.size();
int idx=node_count-1;
int steps=0;
while(true) {
if (idx==OVER_LEAF) {
return false;
}
if (idx==UNDER_LEAF) {
return true;
}
uint16_t plane=nodesptr[ idx ].plane;
#ifdef DEBUG_ENABLED
ERR_FAIL_INDEX_V( plane, plane_count, false );
#endif
bool over = planesptr[ nodesptr[ idx ].plane ].is_point_over(p_point);
idx = over ? nodes[ idx ].over : nodes[ idx ].under;
#ifdef DEBUG_ENABLED
ERR_FAIL_COND_V( idx<MAX_NODES && idx>=node_count, false );
#endif
steps++;
}
return false;
}
static int _bsp_find_best_half_plane(const Face3* p_faces,const Vector<int>& p_indices,float p_tolerance) {
int ic = p_indices.size();
const int*indices=p_indices.ptr();
int best_plane = -1;
float best_plane_cost = 1e20;
// Loop to find the polygon that best divides the set.
for (int i=0;i<ic;i++) {
const Face3& f=p_faces[ indices[i] ];
Plane p = f.get_plane();
int num_over=0,num_under=0,num_spanning=0;
for(int j=0;j<ic;j++) {
if (i==j)
continue;
const Face3& g=p_faces[ indices[j] ];
int over=0,under=0;
for(int k=0;k<3;k++) {
float d = p.distance_to(g.vertex[j]);
if (Math::abs(d)>p_tolerance) {
if (d > 0)
over++;
else
under++;
}
}
if (over && under)
num_spanning++;
else if (over)
num_over++;
else
num_under++;
}
//double split_cost = num_spanning / (double) face_count;
double relation = Math::abs(num_over-num_under) / (double) ic;
// being honest, i never found a way to add split cost to the mix in a meaninguful way
// in this engine, also, will likely be ignored anyway
double plane_cost = /*split_cost +*/ relation;
//printf("plane %i, %i over, %i under, %i spanning, cost is %g\n",i,num_over,num_under,num_spanning,plane_cost);
if (plane_cost<best_plane_cost) {
best_plane=i;
best_plane_cost=plane_cost;
}
}
return best_plane;
}
static int _bsp_create_node(const Face3 *p_faces,const Vector<int>& p_indices,Vector<Plane> &p_planes, Vector<BSP_Tree::Node> &p_nodes,float p_tolerance) {
ERR_FAIL_COND_V( p_nodes.size() == BSP_Tree::MAX_NODES, -1 );
// should not reach here
ERR_FAIL_COND_V( p_indices.size() == 0, -1 )
int ic = p_indices.size();
const int*indices=p_indices.ptr();
int divisor_idx = _bsp_find_best_half_plane(p_faces,p_indices,p_tolerance);
// returned error
ERR_FAIL_COND_V( divisor_idx<0 , -1 );
Vector<int> faces_over;
Vector<int> faces_under;
Plane divisor_plane=p_faces[ indices[divisor_idx] ].get_plane();
for (int i=0;i<ic;i++) {
if (i==divisor_idx)
continue;
const Face3& f=p_faces[ indices[i] ];
//if (f.get_plane().is_almost_like(divisor_plane))
// continue;
int over_count=0;
int under_count=0;
for(int j=0;j<3;j++) {
float d = divisor_plane.distance_to(f.vertex[j]);
if (Math::abs(d)>p_tolerance) {
if (d > 0)
over_count++;
else
under_count++;
}
}
if (over_count)
faces_over.push_back( indices[i] );
if (under_count)
faces_under.push_back( indices[i] );
}
uint16_t over_idx=BSP_Tree::OVER_LEAF,under_idx=BSP_Tree::UNDER_LEAF;
if (faces_over.size()>0) { //have facess above?
int idx = _bsp_create_node( p_faces, faces_over, p_planes, p_nodes,p_tolerance );
if (idx>=0)
over_idx=idx;
}
if (faces_under.size()>0) { //have facess above?
int idx = _bsp_create_node( p_faces,faces_under, p_planes, p_nodes,p_tolerance );
if (idx>=0)
under_idx=idx;
}
/* Create the node */
// find existing divisor plane
int divisor_plane_idx=-1;
for (int i=0;i<p_planes.size();i++) {
if (p_planes[i].is_almost_like( divisor_plane )) {
divisor_plane_idx=i;
break;
}
}
if (divisor_plane_idx==-1) {
ERR_FAIL_COND_V( p_planes.size() == BSP_Tree::MAX_PLANES, -1 );
divisor_plane_idx=p_planes.size();
p_planes.push_back( divisor_plane );
}
BSP_Tree::Node node;
node.plane=divisor_plane_idx;
node.under=under_idx;
node.over=over_idx;
p_nodes.push_back(node);
return p_nodes.size()-1;
}
BSP_Tree::operator Variant() const {
Dictionary d;
d["error_radius"]=error_radius;
Vector<float> plane_values;
plane_values.resize(planes.size()*4);
for(int i=0;i<planes.size();i++) {
plane_values[i*4+0]=planes[i].normal.x;
plane_values[i*4+1]=planes[i].normal.y;
plane_values[i*4+2]=planes[i].normal.z;
plane_values[i*4+3]=planes[i].d;
}
d["planes"]=plane_values;
DVector<int> dst_nodes;
dst_nodes.resize(nodes.size()*3);
for(int i=0;i<nodes.size();i++) {
dst_nodes.set(i*3+0,nodes[i].over);
dst_nodes.set(i*3+1,nodes[i].under);
dst_nodes.set(i*3+2,nodes[i].plane);
}
d["nodes"]=dst_nodes;
d["aabb"] = aabb;
return Variant(d);
}
BSP_Tree::BSP_Tree() {
}
BSP_Tree::BSP_Tree(const Variant& p_variant) {
Dictionary d=p_variant;
ERR_FAIL_COND(!d.has("nodes"));
ERR_FAIL_COND(!d.has("planes"));
ERR_FAIL_COND(!d.has("aabb"));
ERR_FAIL_COND(!d.has("error_radius"));
DVector<int> src_nodes = d["nodes"];
ERR_FAIL_COND(src_nodes.size()%3);
if (d["planes"].get_type()==Variant::REAL_ARRAY) {
DVector<float> src_planes=d["planes"];
int plane_count=src_planes.size();
ERR_FAIL_COND(plane_count%4);
planes.resize(plane_count/4);
if (plane_count) {
DVector<float>::Read r = src_planes.read();
for(int i=0;i<plane_count/4;i++) {
planes[i].normal.x=r[i*4+0];
planes[i].normal.y=r[i*4+1];
planes[i].normal.z=r[i*4+2];
planes[i].d=r[i*4+3];
}
}
} else {
planes = d["planes"];
}
error_radius = d["error"];
aabb = d["aabb"];
// int node_count = src_nodes.size();
nodes.resize(src_nodes.size()/3);
DVector<int>::Read r = src_nodes.read();
for(int i=0;i<nodes.size();i++) {
nodes[i].over=r[i*3+0];
nodes[i].under=r[i*3+1];
nodes[i].plane=r[i*3+2];
}
}
BSP_Tree::BSP_Tree(const DVector<Face3>& p_faces,float p_error_radius) {
// compute aabb
int face_count=p_faces.size();
DVector<Face3>::Read faces_r=p_faces.read();
const Face3 *facesptr = faces_r.ptr();
bool first=true;
Vector<int> indices;
for (int i=0;i<face_count;i++) {
const Face3& f=facesptr[i];
if (f.is_degenerate())
continue;
for (int j=0;j<3;j++) {
if (first) {
aabb.pos=f.vertex[0];
first=false;
} else {
aabb.expand_to(f.vertex[j]);
}
}
indices.push_back(i);
}
ERR_FAIL_COND( aabb.has_no_area() );
int top = _bsp_create_node(faces_r.ptr(),indices,planes,nodes,aabb.get_longest_axis_size()*0.0001);
if (top<0) {
nodes.clear();
planes.clear();
ERR_FAIL_COND( top < 0 );
}
error_radius=p_error_radius;
}
BSP_Tree::BSP_Tree(const Vector<Node> &p_nodes, const Vector<Plane> &p_planes, const AABB& p_aabb,float p_error_radius) {
nodes=p_nodes;
planes=p_planes;
aabb=p_aabb;
error_radius=p_error_radius;
}
BSP_Tree::~BSP_Tree() {
}