/* Bullet Continuous Collision Detection and Physics Library Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/ This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software. Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions: 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 3. This notice may not be removed or altered from any source distribution. */ #include "btOptimizedBvh.h" #include "btStridingMeshInterface.h" #include "LinearMath/btAabbUtil2.h" btOptimizedBvh::btOptimizedBvh() :m_rootNode1(0), m_numNodes(0) { } void btOptimizedBvh::build(btStridingMeshInterface* triangles) { //int countTriangles = 0; // NodeArray triangleNodes; struct NodeTriangleCallback : public btInternalTriangleIndexCallback { NodeArray& m_triangleNodes; NodeTriangleCallback(NodeArray& triangleNodes) :m_triangleNodes(triangleNodes) { } virtual void internalProcessTriangleIndex(btVector3* triangle,int partId,int triangleIndex) { btOptimizedBvhNode node; node.m_aabbMin = btVector3(btScalar(1e30),btScalar(1e30),btScalar(1e30)); node.m_aabbMax = btVector3(btScalar(-1e30),btScalar(-1e30),btScalar(-1e30)); node.m_aabbMin.setMin(triangle[0]); node.m_aabbMax.setMax(triangle[0]); node.m_aabbMin.setMin(triangle[1]); node.m_aabbMax.setMax(triangle[1]); node.m_aabbMin.setMin(triangle[2]); node.m_aabbMax.setMax(triangle[2]); node.m_escapeIndex = -1; node.m_leftChild = 0; node.m_rightChild = 0; //for child nodes node.m_subPart = partId; node.m_triangleIndex = triangleIndex; m_triangleNodes.push_back(node); } }; NodeTriangleCallback callback(m_leafNodes); btVector3 aabbMin(btScalar(-1e30),btScalar(-1e30),btScalar(-1e30)); btVector3 aabbMax(btScalar(1e30),btScalar(1e30),btScalar(1e30)); triangles->InternalProcessAllTriangles(&callback,aabbMin,aabbMax); //now we have an array of leafnodes in m_leafNodes m_contiguousNodes = new btOptimizedBvhNode[2*m_leafNodes.size()]; m_curNodeIndex = 0; m_rootNode1 = buildTree(m_leafNodes,0,m_leafNodes.size()); ///create the leafnodes first // btOptimizedBvhNode* leafNodes = new btOptimizedBvhNode; } btOptimizedBvh::~btOptimizedBvh() { if (m_contiguousNodes) delete []m_contiguousNodes; } #ifdef DEBUG_TREE_BUILDING int gStackDepth = 0; int gMaxStackDepth = 0; #endif //DEBUG_TREE_BUILDING btOptimizedBvhNode* btOptimizedBvh::buildTree (NodeArray& leafNodes,int startIndex,int endIndex) { #ifdef DEBUG_TREE_BUILDING gStackDepth++; if (gStackDepth > gMaxStackDepth) gMaxStackDepth = gStackDepth; #endif //DEBUG_TREE_BUILDING btOptimizedBvhNode* internalNode; int splitAxis, splitIndex, i; int numIndices =endIndex-startIndex; int curIndex = m_curNodeIndex; assert(numIndices>0); if (numIndices==1) { #ifdef DEBUG_TREE_BUILDING gStackDepth--; #endif //DEBUG_TREE_BUILDING return new (&m_contiguousNodes[m_curNodeIndex++]) btOptimizedBvhNode(leafNodes[startIndex]); } //calculate Best Splitting Axis and where to split it. Sort the incoming 'leafNodes' array within range 'startIndex/endIndex'. splitAxis = calcSplittingAxis(leafNodes,startIndex,endIndex); splitIndex = sortAndCalcSplittingIndex(leafNodes,startIndex,endIndex,splitAxis); internalNode = &m_contiguousNodes[m_curNodeIndex++]; internalNode->m_aabbMax.setValue(btScalar(-1e30),btScalar(-1e30),btScalar(-1e30)); internalNode->m_aabbMin.setValue(btScalar(1e30),btScalar(1e30),btScalar(1e30)); for (i=startIndex;im_aabbMax.setMax(leafNodes[i].m_aabbMax); internalNode->m_aabbMin.setMin(leafNodes[i].m_aabbMin); } //internalNode->m_escapeIndex; internalNode->m_leftChild = buildTree(leafNodes,startIndex,splitIndex); internalNode->m_rightChild = buildTree(leafNodes,splitIndex,endIndex); #ifdef DEBUG_TREE_BUILDING gStackDepth--; #endif //DEBUG_TREE_BUILDING internalNode->m_escapeIndex = m_curNodeIndex - curIndex; return internalNode; } int btOptimizedBvh::sortAndCalcSplittingIndex(NodeArray& leafNodes,int startIndex,int endIndex,int splitAxis) { int i; int splitIndex =startIndex; int numIndices = endIndex - startIndex; btScalar splitValue; btVector3 means(btScalar(0.),btScalar(0.),btScalar(0.)); for (i=startIndex;i splitValue) { //swap btOptimizedBvhNode tmp = leafNodes[i]; leafNodes[i] = leafNodes[splitIndex]; leafNodes[splitIndex] = tmp; splitIndex++; } } //if the splitIndex causes unbalanced trees, fix this by using the center in between startIndex and endIndex //otherwise the tree-building might fail due to stack-overflows in certain cases. //unbalanced1 is unsafe: it can cause stack overflows //bool unbalanced1 = ((splitIndex==startIndex) || (splitIndex == (endIndex-1))); //unbalanced2 should work too: always use center (perfect balanced trees) //bool unbalanced2 = true; //this should be safe too: int rangeBalancedIndices = numIndices/3; bool unbalanced = ((splitIndex<=(startIndex+rangeBalancedIndices)) || (splitIndex >=(endIndex-1-rangeBalancedIndices))); if (unbalanced) { splitIndex = startIndex+ (numIndices>>1); } bool unbal = (splitIndex==startIndex) || (splitIndex == (endIndex)); btAssert(!unbal); return splitIndex; } int btOptimizedBvh::calcSplittingAxis(NodeArray& leafNodes,int startIndex,int endIndex) { int i; btVector3 means(btScalar(0.),btScalar(0.),btScalar(0.)); btVector3 variance(btScalar(0.),btScalar(0.),btScalar(0.)); int numIndices = endIndex-startIndex; for (i=startIndex;im_aabbMin,rootNode->m_aabbMax); if (aabbOverlap) { isLeafNode = (!rootNode->m_leftChild && !rootNode->m_rightChild); if (isLeafNode) { nodeCallback->processNode(rootNode); } else { walkTree(rootNode->m_leftChild,nodeCallback,aabbMin,aabbMax); walkTree(rootNode->m_rightChild,nodeCallback,aabbMin,aabbMax); } } } int maxIterations = 0; void btOptimizedBvh::walkStacklessTree(btOptimizedBvhNode* rootNode,btNodeOverlapCallback* nodeCallback,const btVector3& aabbMin,const btVector3& aabbMax) const { int escapeIndex, curIndex = 0; int walkIterations = 0; bool aabbOverlap, isLeafNode; while (curIndex < m_curNodeIndex) { //catch bugs in tree data assert (walkIterations < m_curNodeIndex); walkIterations++; aabbOverlap = TestAabbAgainstAabb2(aabbMin,aabbMax,rootNode->m_aabbMin,rootNode->m_aabbMax); isLeafNode = (!rootNode->m_leftChild && !rootNode->m_rightChild); if (isLeafNode && aabbOverlap) { nodeCallback->processNode(rootNode); } if (aabbOverlap || isLeafNode) { rootNode++; curIndex++; } else { escapeIndex = rootNode->m_escapeIndex; rootNode += escapeIndex; curIndex += escapeIndex; } } if (maxIterations < walkIterations) maxIterations = walkIterations; } void btOptimizedBvh::reportSphereOverlappingNodex(btNodeOverlapCallback* nodeCallback,const btVector3& aabbMin,const btVector3& aabbMax) const { }