OpenSceneGraph/examples/osgkdtree/osgkdtree.cpp
2008-06-05 18:52:29 +00:00

501 lines
15 KiB
C++

/* 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 <osgDB/ReadFile>
#define _GLIBCXX_DEBUG
#include <osg/ArgumentParser>
#include <osg/ApplicationUsage>
#include <osg/Timer>
#include <osg/CoordinateSystemNode>
#include <osg/Notify>
#include <osg/io_utils>
#include <osg/Geometry>
#include <osgUtil/IntersectionVisitor>
#include <osgUtil/LineSegmentIntersector>
#include <osgSim/LineOfSight>
#include <osgSim/HeightAboveTerrain>
#include <osgSim/ElevationSlice>
#include <iostream>
namespace osg
{
class KDNode
{
public:
KDNode():
_leftChild(0),
_rightChild(0) {}
KDNode(const KDNode& rhs):
_leftChild(rhs._leftChild),
_rightChild(rhs._rightChild) {}
KDNode& operator = (const KDNode& rhs)
{
_leftChild = rhs._leftChild;
_rightChild = rhs._rightChild;
return *this;
}
typedef short value_type;
value_type _leftChild;
value_type _rightChild;
};
class KDLeaf : public osg::Referenced
{
public:
KDLeaf() {}
typedef unsigned int index_type;
typedef std::vector< index_type > Indices;
Indices _vertexIndices;
protected:
virtual ~KDLeaf() {}
};
class KDTree : public osg::Shape
{
public:
KDTree() {}
KDTree(const KDTree& rhs, const CopyOp& copyop=CopyOp::SHALLOW_COPY):
Shape(rhs,copyop) {}
META_Shape(osg, KDTree)
typedef std::vector< unsigned int > AxisStack;
typedef std::vector< KDNode > KDNodeList;
typedef std::vector< osg::ref_ptr<KDLeaf> > KDLeafList;
/// note, leafNum is negative to distinguish from nodeNum
int addLeaf(KDLeaf* leaf) { int num = _kdLeaves.size(); _kdLeaves.push_back(leaf); return -(num+1); }
int replaceLeaf(int leafNum, KDLeaf* leaf)
{
int num = -leafNum-1;
if (num>_kdLeaves.size()-1)
{
osg::notify(osg::NOTICE)<<"Warning: replaceChild("<<leafNum<<", leaf), num = "<<num<<" _kdLeaves.size()="<<_kdLeaves.size()<<std::endl;
return leafNum;
}
_kdLeaves[num] = leaf; return leafNum;
}
/// note, leafNum is negative to distinguish from nodeNum
KDLeaf* getLeaf(int leafNum)
{
int num = -leafNum-1;
if (num<0 || num>_kdLeaves.size()-1)
{
osg::notify(osg::NOTICE)<<"Warning: getLeaf("<<leafNum<<", num = "<<num<<") _kdLeaves.size()="<<_kdLeaves.size()<<std::endl;
return 0;
}
return _kdLeaves[num].get();
}
int addNode(const KDNode& node)
{
int num = _kdNodes.size();
_kdNodes.push_back(node);
return num;
}
/// note, nodeNum is positive to distinguish from leftNum
KDNode& getNode(int nodeNum)
{
if (nodeNum<0 || nodeNum>_kdNodes.size()-1)
{
osg::notify(osg::NOTICE)<<"Warning: getNode("<<nodeNum<<") _kdNodes.size()="<<_kdNodes.size()<<std::endl;
}
return _kdNodes[nodeNum];
}
osg::observer_ptr<osg::Geometry> _geometry;
osg::BoundingBox _bb;
AxisStack _axisStack;
KDNodeList _kdNodes;
KDLeafList _kdLeaves;
};
class KDTreeTraverser
{
public:
std::ostream& output(unsigned int level)
{
for(unsigned int i=0; i<level; ++i)
{
osg::notify(osg::NOTICE)<<" ";
}
return osg::notify(osg::NOTICE);
}
void traverse(KDLeaf& leaf, unsigned int level)
{
output(level)<<"leaf("<<level<<") { ";
for(unsigned int i=0; i<leaf._vertexIndices.size(); ++i)
{
if (i==0) osg::notify(osg::NOTICE)<<leaf._vertexIndices[i];
else osg::notify(osg::NOTICE)<<", "<<leaf._vertexIndices[i];
}
osg::notify(osg::NOTICE)<<"}"<<std::endl;;
}
void traverse(KDTree& tree, KDNode::value_type nodeIndex, unsigned int level)
{
output(level)<<"traverse("<<nodeIndex<<", "<< level<<") { "<<std::endl;
if (nodeIndex>=0)
{
KDNode& node = tree._kdNodes[nodeIndex];
if (node._leftChild) traverse(tree,node._leftChild,level+1);
else output(level+1)<<"empty left child()"<<std::endl;
if (node._rightChild) traverse(tree,node._rightChild,level+1);
else output(level+1)<<"empty right child()"<<std::endl;
}
else
{
KDNode::value_type leafIndex = -nodeIndex-1;
KDLeaf& leaf = *(tree._kdLeaves[leafIndex]);
traverse(leaf, level);
}
output(level)<<"}"<<std::endl;;
}
void traverse(KDTree& tree)
{
osg::notify(osg::NOTICE)<<"traverse(tree)"<<std::endl;
if (!tree._kdNodes.empty())
{
traverse(tree,0,0);
}
else if (!tree._kdLeaves.empty())
{
traverse(*tree._kdLeaves.front(), 0);
}
}
};
class KDTreeBuilder : public osg::NodeVisitor
{
public:
KDTreeBuilder():
osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN),
_maxNumLevels(24),
_targetNumVerticesPerLeaf(8),
_numVerticesProcessed(0)
{
}
void apply(osg::Geode& geode)
{
for(unsigned int i=0; i<geode.getNumDrawables(); ++i)
{
osg::Geometry* geom = geode.getDrawable(i)->asGeometry();
if (geom)
{
geom->setShape(createKDTree(geom));
}
}
}
KDTree* createKDTree(osg::Geometry* geometry);
void computeDivisions(KDTree& kdTree);
int divide(KDTree& kdTree, osg::BoundingBox& bb, int nodeIndex, unsigned int level);
unsigned int _maxNumLevels;
unsigned int _targetNumVerticesPerLeaf;
unsigned int _numVerticesProcessed;
};
KDTree* KDTreeBuilder::createKDTree(osg::Geometry* geometry)
{
#if 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;
osg::ref_ptr<KDTree> kdTree = new KDTree;
kdTree->_geometry = geometry;
kdTree->_bb = kdTree->_geometry->getBound();
unsigned int estimatedSize = (unsigned int)(float(vertices->size())/float(_targetNumVerticesPerLeaf)*1.5);
#if 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();
// create initial leaf list
KDLeaf* leaf = new KDLeaf;
leaf->_vertexIndices.reserve(vertices->size());
for(unsigned int i=0; i<vertices->size(); ++i)
{
leaf->_vertexIndices.push_back(i);
}
osg::BoundingBox bb = kdTree->_bb;
int leafNum = kdTree->addLeaf(leaf);
int nodeNum = divide(*kdTree, bb, leafNum, 0);
#if VERBOSE_OUTPUT
osg::notify(osg::NOTICE)<<"Root nodeNum="<<nodeNum<<std::endl;
#endif
#if 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
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());
#if 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;
#if VERBOSE_OUTPUT
osg::notify(osg::NOTICE)<<" "<<level<<", "<<dimensions<<", "<<axis<<std::endl;
#endif
}
#if 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];
#if VERBOSE_OUTPUT
//osg::notify(osg::NOTICE)<<"divide("<<nodeIndex<<", "<<level<< "), axis="<<axis<<std::endl;
#endif
if (nodeIndex>=0)
{
#if VERBOSE_OUTPUT
osg::notify(osg::NOTICE)<<" divide node"<<std::endl;
#endif
KDNode& node = kdTree.getNode(nodeIndex);
return nodeIndex;
}
else
{
if (kdTree.getLeaf(nodeIndex)->_vertexIndices.size()<=_targetNumVerticesPerLeaf) 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;
{
osg::ref_ptr<KDLeaf> leaf = kdTree.getLeaf(nodeIndex);
// create new node, and add two leaves to it.
osg::ref_ptr<KDLeaf> leftLeaf = new KDLeaf;
osg::ref_ptr<KDLeaf> rightLeaf = new KDLeaf;
osg::Vec3Array* vertices = dynamic_cast<osg::Vec3Array*>(kdTree._geometry->getVertexArray());
//osg::notify(osg::NOTICE)<<" divide leaf->_vertexIndices.size()="<<leaf->_vertexIndices.size()<<std::endl;
unsigned int estimatedSize = leaf->_vertexIndices.size();
leftLeaf->_vertexIndices.reserve(estimatedSize);
rightLeaf->_vertexIndices.reserve(estimatedSize);
for(unsigned int i=0; i<leaf->_vertexIndices.size(); ++i)
{
unsigned int vi = leaf->_vertexIndices[i];
osg::Vec3& v = (*vertices)[vi];
if (v[axis] <= mid) leftLeaf->_vertexIndices.push_back(vi);
else rightLeaf->_vertexIndices.push_back(vi);
}
if (leftLeaf->_vertexIndices.empty())
{
//osg::notify(osg::NOTICE)<<"LeftLeaf empty"<<std::endl;
kdTree.getNode(nodeNum)._leftChild = 0;
kdTree.getNode(nodeNum)._rightChild = kdTree.replaceLeaf(nodeIndex, rightLeaf.get());
}
else if (rightLeaf->_vertexIndices.empty())
{
//osg::notify(osg::NOTICE)<<"RightLeaf empty"<<std::endl;
kdTree.getNode(nodeNum)._leftChild = kdTree.replaceLeaf(nodeIndex, leftLeaf.get());
kdTree.getNode(nodeNum)._rightChild = 0;
}
else
{
kdTree.getNode(nodeNum)._leftChild = kdTree.replaceLeaf(nodeIndex, leftLeaf.get());
kdTree.getNode(nodeNum)._rightChild = kdTree.addLeaf(rightLeaf.get());
}
}
int originalLeftChildIndex = kdTree.getNode(nodeNum)._leftChild;
int originalRightChildIndex = kdTree.getNode(nodeNum)._rightChild;
float restore = bb._max[axis];
bb._max[axis] = mid;
//osg::notify(osg::NOTICE)<<" divide leftLeaf "<<kdTree.getNode(nodeNum)._leftChild<<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)._rightChild<<std::endl;
int rightChildIndex = divide(kdTree, bb, originalRightChildIndex, level+1);
bb._min[axis] = restore;
kdTree.getNode(nodeNum)._leftChild = leftChildIndex;
kdTree.getNode(nodeNum)._rightChild = rightChildIndex;
return nodeNum;
}
}
}
int main(int argc, char **argv)
{
// use an ArgumentParser object to manage the program arguments.
osg::ArgumentParser arguments(&argc,argv);
osg::ref_ptr<osg::Node> scene = osgDB::readNodeFiles(arguments);
if (!scene)
{
std::cout<<"No model loaded, please specify a valid model on the command line."<<std::endl;
return 0;
}
osg::Timer_t start = osg::Timer::instance()->tick();
osg::KDTreeBuilder builder;
scene->accept(builder);
osg::Timer_t end = osg::Timer::instance()->tick();
double time = osg::Timer::instance()->delta_s(start,end);
osg::notify(osg::NOTICE)<<"Time to build "<<time*1000.0<<"ms "<<builder._numVerticesProcessed<<std::endl;
osg::notify(osg::NOTICE)<<"build speed "<<(double(builder._numVerticesProcessed)/time)/1000000.0<<"M vertices per second"<<std::endl;
return 0;
}