OpenSceneGraph/examples/osgkdtree/variabledivision.cpp

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/* OpenSceneGraph example, osgintersection.
*
* 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 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 "variabledivision.h"
namespace variabledivision
{
struct TriangleIndicesCollector
{
TriangleIndicesCollector():
_kdTree(0)
{
}
inline void operator () (unsigned int p1, unsigned int p2, unsigned int p3)
{
unsigned int i = _kdTree->_triangles.size();
_kdTree->_triangles.push_back(Triangle(p1,p2,p3));
osg::BoundingBox bb;
bb.expandBy((*(_kdTree->_vertices))[p1]);
bb.expandBy((*(_kdTree->_vertices))[p2]);
bb.expandBy((*(_kdTree->_vertices))[p3]);
_kdTree->_boundingBoxes.push_back(bb);
_kdTree->_centers.push_back(bb.center());
_kdTree->_primitiveIndices.push_back(i);
}
KDTree* _kdTree;
};
KDTree* KDTreeBuilder::createKDTree(osg::Geometry* geometry)
{
#ifdef VERBOSE_OUTPUT
osg::notify(osg::NOTICE)<<"osg::KDTreeBuilder::createKDTree()"<<std::endl;
#endif
osg::Vec3Array* vertices = dynamic_cast<osg::Vec3Array*>(geometry->getVertexArray());
if (!vertices) return 0;
if (vertices->size() <= _targetNumTrianglesPerLeaf) return 0;
osg::ref_ptr<KDTree> kdTree = new KDTree;
kdTree->_geometry = geometry;
kdTree->_bb = kdTree->_geometry->getBound();
kdTree->_vertices = vertices;
unsigned int estimatedSize = (unsigned int)(2.0*float(vertices->size())/float(_targetNumTrianglesPerLeaf));
#ifdef VERBOSE_OUTPUT
osg::notify(osg::NOTICE)<<"kdTree->_kdNodes.reserve()="<<estimatedSize<<std::endl<<std::endl;
#endif
kdTree->_kdNodes.reserve(estimatedSize);
kdTree->_kdLeaves.reserve(estimatedSize);
computeDivisions(*kdTree);
_numVerticesProcessed += vertices->size();
unsigned int estimatedNumTriangles = vertices->size()*2;
kdTree->_primitiveIndices.reserve(estimatedNumTriangles);
kdTree->_boundingBoxes.reserve(estimatedNumTriangles);
kdTree->_triangles.reserve(estimatedNumTriangles);
kdTree->_centers.reserve(estimatedNumTriangles);
osg::TriangleIndexFunctor<TriangleIndicesCollector> collectTriangleIndices;
collectTriangleIndices._kdTree = kdTree.get();
geometry->accept(collectTriangleIndices);
kdTree->_primitiveIndices.reserve(vertices->size());
KDLeaf leaf(0, kdTree->_primitiveIndices.size());
int leafNum = kdTree->addLeaf(leaf);
osg::BoundingBox bb = kdTree->_bb;
int nodeNum = divide(*kdTree, bb, leafNum, 0);
#ifdef VERBOSE_OUTPUT
osg::notify(osg::NOTICE)<<"Root nodeNum="<<nodeNum<<std::endl;
#endif
#ifdef VERBOSE_OUTPUT
KDTreeTraverser traverser;
traverser.traverse(*kdTree);
osg::notify(osg::NOTICE)<<"Final kdTree->_kdNodes.size()="<<kdTree->_kdNodes.size()<<std::endl;
osg::notify(osg::NOTICE)<<"Final kdTree->_kdLeaves.size()="<<kdTree->_kdLeaves.size()<<std::endl;
osg::notify(osg::NOTICE)<<"osg::KDTreeBuilder::createKDTree() completed"<<std::endl<<std::endl;
#endif
// osg::notify(osg::NOTICE)<<"kdTree->_kdNodes.size()="<<kdTree->_kdNodes.size()<<" estimated size = "<<estimatedSize<<std::endl;
// osg::notify(osg::NOTICE)<<"kdTree->_kdLeaves.size()="<<kdTree->_kdLeaves.size()<<" estimated size = "<<estimatedSize<<std::endl<<std::endl;
return kdTree.release();
}
void KDTreeBuilder::computeDivisions(KDTree& kdTree)
{
osg::Vec3 dimensions(kdTree._bb.xMax()-kdTree._bb.xMin(),
kdTree._bb.yMax()-kdTree._bb.yMin(),
kdTree._bb.zMax()-kdTree._bb.zMin());
#ifdef VERBOSE_OUTPUT
osg::notify(osg::NOTICE)<<"computeDivisions("<<_maxNumLevels<<") "<<dimensions<< " { "<<std::endl;
#endif
kdTree._axisStack.reserve(_maxNumLevels);
int level = 0;
for(unsigned int level=0; level<_maxNumLevels; ++level)
{
int axis = 0;
if (dimensions[0]>=dimensions[1])
{
if (dimensions[0]>=dimensions[2]) axis = 0;
else axis = 2;
}
else if (dimensions[1]>=dimensions[2]) axis = 1;
else axis = 2;
kdTree._axisStack.push_back(axis);
dimensions[axis] /= 2.0f;
#ifdef VERBOSE_OUTPUT
osg::notify(osg::NOTICE)<<" "<<level<<", "<<dimensions<<", "<<axis<<std::endl;
#endif
}
#ifdef VERBOSE_OUTPUT
osg::notify(osg::NOTICE)<<"}"<<std::endl;
#endif
}
int KDTreeBuilder::divide(KDTree& kdTree, osg::BoundingBox& bb, int nodeIndex, unsigned int level)
{
if (kdTree._axisStack.size()<=level) return nodeIndex;
int axis = kdTree._axisStack[level];
#ifdef VERBOSE_OUTPUT
//osg::notify(osg::NOTICE)<<"divide("<<nodeIndex<<", "<<level<< "), axis="<<axis<<std::endl;
#endif
if (nodeIndex>=0)
{
#ifdef VERBOSE_OUTPUT
osg::notify(osg::NOTICE)<<" divide node"<<std::endl;
#endif
KDNode& node = kdTree.getNode(nodeIndex);
return nodeIndex;
}
else
{
if (kdTree.getLeaf(nodeIndex).second<=_targetNumTrianglesPerLeaf) return nodeIndex;
//osg::notify(osg::NOTICE)<<" divide leaf"<<std::endl;
int nodeNum = kdTree.addNode(KDNode());
float original_min = bb._min[axis];
float original_max = bb._max[axis];
float mid = (original_min+original_max)*0.5f;
{
KDLeaf& leaf = kdTree.getLeaf(nodeIndex);
//osg::Vec3Array* vertices = kdTree._vertices.get();
KDTree::CenterList& centers = kdTree._centers;
int end = leaf.first+leaf.second-1;
int left = leaf.first;
int right = leaf.first+leaf.second-1;
while(left<right)
{
while(left<right && (centers[kdTree._primitiveIndices[left]][axis]<=mid)) { ++left; }
while(left<right && (centers[kdTree._primitiveIndices[right]][axis]>mid)) { --right; }
while(left<right && (centers[kdTree._primitiveIndices[right]][axis]>mid)) { --right; }
if (left<right)
{
std::swap(kdTree._primitiveIndices[left], kdTree._primitiveIndices[right]);
++left;
--right;
}
}
if (left==right)
{
if (centers[kdTree._primitiveIndices[left]][axis]<=mid) ++left;
else --right;
}
KDLeaf leftLeaf(leaf.first, (right-leaf.first)+1);
KDLeaf rightLeaf(left, (end-left)+1);
#if 0
osg::notify(osg::NOTICE)<<"In leaf.first ="<<leaf.first <<" leaf.second ="<<leaf.second<<std::endl;
osg::notify(osg::NOTICE)<<" leftLeaf.first ="<<leftLeaf.first <<" leftLeaf.second ="<<leftLeaf.second<<std::endl;
osg::notify(osg::NOTICE)<<" rightLeaf.first="<<rightLeaf.first<<" rightLeaf.second="<<rightLeaf.second<<std::endl;
osg::notify(osg::NOTICE)<<" left="<<left<<" right="<<right<<std::endl;
if (leaf.second != (leftLeaf.second +rightLeaf.second))
{
osg::notify(osg::NOTICE)<<"*** Error in size, leaf.second="<<leaf.second
<<", leftLeaf.second="<<leftLeaf.second
<<", rightLeaf.second="<<rightLeaf.second<<std::endl;
}
else
{
osg::notify(osg::NOTICE)<<"Size OK, leaf.second="<<leaf.second
<<", leftLeaf.second="<<leftLeaf.second
<<", rightLeaf.second="<<rightLeaf.second<<std::endl;
}
#endif
if (leftLeaf.second<=0)
{
//osg::notify(osg::NOTICE)<<"LeftLeaf empty"<<std::endl;
kdTree.getNode(nodeNum).first = 0;
kdTree.getNode(nodeNum).second = kdTree.replaceLeaf(nodeIndex, rightLeaf);
}
else if (rightLeaf.second<=0)
{
//osg::notify(osg::NOTICE)<<"RightLeaf empty"<<std::endl;
kdTree.getNode(nodeNum).first = kdTree.replaceLeaf(nodeIndex, leftLeaf);
kdTree.getNode(nodeNum).second = 0;
}
else
{
kdTree.getNode(nodeNum).first = kdTree.replaceLeaf(nodeIndex, leftLeaf);
kdTree.getNode(nodeNum).second = kdTree.addLeaf(rightLeaf);
}
}
int originalLeftChildIndex = kdTree.getNode(nodeNum).first;
int originalRightChildIndex = kdTree.getNode(nodeNum).second;
float restore = bb._max[axis];
bb._max[axis] = mid;
//osg::notify(osg::NOTICE)<<" divide leftLeaf "<<kdTree.getNode(nodeNum).first<<std::endl;
int leftChildIndex = divide(kdTree, bb, originalLeftChildIndex, level+1);
bb._max[axis] = restore;
restore = bb._min[axis];
bb._min[axis] = mid;
//osg::notify(osg::NOTICE)<<" divide rightLeaf "<<kdTree.getNode(nodeNum).second<<std::endl;
int rightChildIndex = divide(kdTree, bb, originalRightChildIndex, level+1);
bb._min[axis] = restore;
kdTree.getNode(nodeNum).first = leftChildIndex;
kdTree.getNode(nodeNum).second = rightChildIndex;
return nodeNum;
}
}
}