GODOT IS OPEN SOURCE
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Juan Linietsky
628
core/math/bsp_tree.cpp
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628
core/math/bsp_tree.cpp
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/*************************************************************************/
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/* bsp_tree.cpp */
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/*************************************************************************/
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/* This file is part of: */
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/* GODOT ENGINE */
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/* http://www.godotengine.org */
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/*************************************************************************/
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/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
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/* */
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/* Permission is hereby granted, free of charge, to any person obtaining */
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/* a copy of this software and associated documentation files (the */
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/* "Software"), to deal in the Software without restriction, including */
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/* without limitation the rights to use, copy, modify, merge, publish, */
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/* distribute, sublicense, and/or sell copies of the Software, and to */
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/* permit persons to whom the Software is furnished to do so, subject to */
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/* the following conditions: */
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/* */
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/* The above copyright notice and this permission notice shall be */
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/* included in all copies or substantial portions of the Software. */
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/* */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
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/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
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/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
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/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
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/*************************************************************************/
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#include "bsp_tree.h"
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#include "error_macros.h"
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#include "print_string.h"
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void BSP_Tree::from_aabb(const AABB& p_aabb) {
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planes.clear();
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for(int i=0;i<3;i++) {
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Vector3 n;
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n[i]=1;
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planes.push_back(Plane(n,p_aabb.pos[i]+p_aabb.size[i]));
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planes.push_back(Plane(-n,-p_aabb.pos[i]));
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}
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nodes.clear();
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for(int i=0;i<6;i++) {
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Node n;
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n.plane=i;
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n.under=(i==0)?UNDER_LEAF:i-1;
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n.over=OVER_LEAF;
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nodes.push_back(n);
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}
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aabb=p_aabb;
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error_radius=0;
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}
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Vector<BSP_Tree::Node> BSP_Tree::get_nodes() const {
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return nodes;
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}
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Vector<Plane> BSP_Tree::get_planes() const {
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return planes;
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}
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AABB BSP_Tree::get_aabb() const {
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return aabb;
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}
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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 {
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const Node *node =&nodes[p_node];
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const Plane &p = planes[node->plane];
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Vector3 min(
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(p.normal.x>0) ? -p_half_extents.x : p_half_extents.x,
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(p.normal.y>0) ? -p_half_extents.y : p_half_extents.y,
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(p.normal.z>0) ? -p_half_extents.z : p_half_extents.z
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);
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Vector3 max=-min;
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max+=p_center;
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min+=p_center;
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float dist_min = p.distance_to(min);
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float dist_max = p.distance_to(max);
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if ((dist_min * dist_max) < CMP_EPSILON ) { //intersection, test point by point
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int under_count=0;
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//sort points, so the are under first, over last
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for(int i=0;i<p_indices_count;i++) {
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int index=p_indices[i];
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if (p.is_point_over(p_points[index])) {
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// kind of slow (but cache friendly), should try something else,
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// but this is a corner case most of the time
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for(int j=index;j<p_indices_count-1;j++)
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p_indices[j]=p_indices[j+1];
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p_indices[p_indices_count-1]=index;
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} else {
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under_count++;
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}
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}
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int total=0;
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if (under_count>0) {
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if (node->under==UNDER_LEAF) {
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total+=under_count;
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} else {
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total+=_get_points_inside(node->under,p_points,p_indices,p_center,p_half_extents,under_count);
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}
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}
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if (under_count!=p_indices_count) {
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if (node->over==OVER_LEAF) {
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//total+=0 //if they are over an OVER_LEAF, they are outside the model
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} else {
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total+=_get_points_inside(node->over,p_points,&p_indices[under_count],p_center,p_half_extents,p_indices_count-under_count);
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}
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}
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return total;
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} else if (dist_min > 0 ) { //all points over plane
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if (node->over==OVER_LEAF) {
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return 0; // all these points are not visible
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}
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return _get_points_inside(node->over,p_points,p_indices,p_center,p_half_extents,p_indices_count);
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} else if (dist_min <= 0 ) { //all points behind plane
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if (node->under==UNDER_LEAF) {
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return p_indices_count; // all these points are visible
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}
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return _get_points_inside(node->under,p_points,p_indices,p_center,p_half_extents,p_indices_count);
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}
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return 0;
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}
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int BSP_Tree::get_points_inside(const Vector3* p_points,int p_point_count) const {
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if (nodes.size()==0)
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return 0;
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#if 1
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//this version is easier to debug, and and MUCH faster in real world cases
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int pass_count = 0;
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const Node *nodesptr=&nodes[0];
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const Plane *planesptr=&planes[0];
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int plane_count=planes.size();
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int node_count=nodes.size();
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if (node_count==0) // no nodes!
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return 0;
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for(int i=0;i<p_point_count;i++) {
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const Vector3& point = p_points[i];
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if (!aabb.has_point(point)) {
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continue;
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}
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int idx=node_count-1;
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bool pass=false;
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while(true) {
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if (idx==OVER_LEAF) {
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pass=false;
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break;
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} else if (idx==UNDER_LEAF) {
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pass=true;
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break;
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}
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uint16_t plane=nodesptr[ idx ].plane;
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#ifdef DEBUG_ENABLED
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ERR_FAIL_INDEX_V( plane, plane_count, false );
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#endif
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idx = planesptr[ nodesptr[ idx ].plane ].is_point_over(point) ? nodes[ idx ].over : nodes[ idx ].under;
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#ifdef DEBUG_ENABLED
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ERR_FAIL_COND_V( idx<MAX_NODES && idx>=node_count, false );
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#endif
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}
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if (pass)
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pass_count++;
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}
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return pass_count;
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#else
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//this version scales better but it's slower for real world cases
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int *indices = (int*)alloca(p_point_count*sizeof(int));
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AABB bounds;
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for(int i=0;i<p_point_count;i++) {
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indices[i]=i;
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if (i==0)
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bounds.pos=p_points[i];
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else
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bounds.expand_to(p_points[i]);
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}
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Vector3 half_extents = bounds.size/2.0;
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return _get_points_inside(nodes.size()+1,p_points,indices,bounds.pos+half_extents,half_extents,p_point_count);
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#endif
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}
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bool BSP_Tree::point_is_inside(const Vector3& p_point) const {
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if (!aabb.has_point(p_point)) {
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return false;
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}
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int node_count=nodes.size();
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if (node_count==0) // no nodes!
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return false;
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const Node *nodesptr=&nodes[0];
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const Plane *planesptr=&planes[0];
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int plane_count=planes.size();
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int idx=node_count-1;
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int steps=0;
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while(true) {
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if (idx==OVER_LEAF) {
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return false;
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}
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if (idx==UNDER_LEAF) {
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return true;
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}
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uint16_t plane=nodesptr[ idx ].plane;
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#ifdef DEBUG_ENABLED
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ERR_FAIL_INDEX_V( plane, plane_count, false );
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#endif
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bool over = planesptr[ nodesptr[ idx ].plane ].is_point_over(p_point);
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idx = over ? nodes[ idx ].over : nodes[ idx ].under;
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#ifdef DEBUG_ENABLED
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ERR_FAIL_COND_V( idx<MAX_NODES && idx>=node_count, false );
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#endif
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steps++;
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}
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return false;
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}
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static int _bsp_find_best_half_plane(const Face3* p_faces,const Vector<int>& p_indices,float p_tolerance) {
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int ic = p_indices.size();
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const int*indices=p_indices.ptr();
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int best_plane = -1;
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float best_plane_cost = 1e20;
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// Loop to find the polygon that best divides the set.
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for (int i=0;i<ic;i++) {
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const Face3& f=p_faces[ indices[i] ];
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Plane p = f.get_plane();
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int num_over=0,num_under=0,num_spanning=0;
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for(int j=0;j<ic;j++) {
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if (i==j)
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continue;
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const Face3& g=p_faces[ indices[j] ];
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int over=0,under=0;
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for(int k=0;k<3;k++) {
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float d = p.distance_to(g.vertex[j]);
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if (Math::abs(d)>p_tolerance) {
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if (d > 0)
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over++;
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else
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under++;
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}
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}
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if (over && under)
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num_spanning++;
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else if (over)
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num_over++;
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else
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num_under++;
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}
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//double split_cost = num_spanning / (double) face_count;
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double relation = Math::abs(num_over-num_under) / (double) ic;
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// being honest, i never found a way to add split cost to the mix in a meaninguful way
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// in this engine, also, will likely be ignored anyway
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double plane_cost = /*split_cost +*/ relation;
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//printf("plane %i, %i over, %i under, %i spanning, cost is %g\n",i,num_over,num_under,num_spanning,plane_cost);
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if (plane_cost<best_plane_cost) {
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best_plane=i;
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best_plane_cost=plane_cost;
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}
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}
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return best_plane;
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}
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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) {
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ERR_FAIL_COND_V( p_nodes.size() == BSP_Tree::MAX_NODES, -1 );
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// should not reach here
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ERR_FAIL_COND_V( p_indices.size() == 0, -1 )
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int ic = p_indices.size();
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const int*indices=p_indices.ptr();
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int divisor_idx = _bsp_find_best_half_plane(p_faces,p_indices,p_tolerance);
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// returned error
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ERR_FAIL_COND_V( divisor_idx<0 , -1 );
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Vector<int> faces_over;
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Vector<int> faces_under;
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Plane divisor_plane=p_faces[ indices[divisor_idx] ].get_plane();
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for (int i=0;i<ic;i++) {
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if (i==divisor_idx)
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continue;
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const Face3& f=p_faces[ indices[i] ];
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//if (f.get_plane().is_almost_like(divisor_plane))
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// continue;
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int over_count=0;
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int under_count=0;
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for(int j=0;j<3;j++) {
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float d = divisor_plane.distance_to(f.vertex[j]);
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if (Math::abs(d)>p_tolerance) {
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if (d > 0)
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over_count++;
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else
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under_count++;
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}
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}
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if (over_count)
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faces_over.push_back( indices[i] );
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if (under_count)
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faces_under.push_back( indices[i] );
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}
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uint16_t over_idx=BSP_Tree::OVER_LEAF,under_idx=BSP_Tree::UNDER_LEAF;
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if (faces_over.size()>0) { //have facess above?
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int idx = _bsp_create_node( p_faces, faces_over, p_planes, p_nodes,p_tolerance );
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if (idx>=0)
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over_idx=idx;
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}
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if (faces_under.size()>0) { //have facess above?
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int idx = _bsp_create_node( p_faces,faces_under, p_planes, p_nodes,p_tolerance );
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if (idx>=0)
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under_idx=idx;
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}
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/* Create the node */
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// find existing divisor plane
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int divisor_plane_idx=-1;
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for (int i=0;i<p_planes.size();i++) {
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if (p_planes[i].is_almost_like( divisor_plane )) {
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divisor_plane_idx=i;
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break;
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}
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}
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if (divisor_plane_idx==-1) {
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ERR_FAIL_COND_V( p_planes.size() == BSP_Tree::MAX_PLANES, -1 );
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divisor_plane_idx=p_planes.size();
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p_planes.push_back( divisor_plane );
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}
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BSP_Tree::Node node;
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node.plane=divisor_plane_idx;
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node.under=under_idx;
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node.over=over_idx;
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p_nodes.push_back(node);
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return p_nodes.size()-1;
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}
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BSP_Tree::operator Variant() const {
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Dictionary d;
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d["error_radius"]=error_radius;
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Vector<float> plane_values;
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plane_values.resize(planes.size()*4);
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for(int i=0;i<planes.size();i++) {
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plane_values[i*4+0]=planes[i].normal.x;
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plane_values[i*4+1]=planes[i].normal.y;
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plane_values[i*4+2]=planes[i].normal.z;
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plane_values[i*4+3]=planes[i].d;
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}
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d["planes"]=plane_values;
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DVector<int> dst_nodes;
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dst_nodes.resize(nodes.size()*3);
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for(int i=0;i<nodes.size();i++) {
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dst_nodes.set(i*3+0,nodes[i].over);
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dst_nodes.set(i*3+1,nodes[i].under);
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dst_nodes.set(i*3+2,nodes[i].plane);
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}
|
||||
|
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d["nodes"]=dst_nodes;
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d["aabb"] = aabb;
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return Variant(d);
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}
|
||||
|
||||
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() {
|
||||
|
||||
|
||||
}
|
||||
Reference in New Issue
Block a user