btOptimizedBvh.cpp

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/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2009 Erwin Coumans  http://bulletphysics.org

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"
#include "LinearMath/btIDebugDraw.h"


btOptimizedBvh::btOptimizedBvh()
{ 
}

btOptimizedBvh::~btOptimizedBvh()
{
}


void btOptimizedBvh::build(btStridingMeshInterface* triangles, bool useQuantizedAabbCompression, const btVector3& bvhAabbMin, const btVector3& bvhAabbMax)
{
        m_useQuantization = useQuantizedAabbCompression;


        // NodeArray    triangleNodes;

        struct  NodeTriangleCallback : public btInternalTriangleIndexCallback
        {

                NodeArray&      m_triangleNodes;

                NodeTriangleCallback& operator=(NodeTriangleCallback& other)
                {
                        m_triangleNodes.copyFromArray(other.m_triangleNodes);
                        return *this;
                }
                
                NodeTriangleCallback(NodeArray& triangleNodes)
                        :m_triangleNodes(triangleNodes)
                {
                }

                virtual void internalProcessTriangleIndex(btVector3* triangle,int partId,int  triangleIndex)
                {
                        btOptimizedBvhNode node;
                        btVector3       aabbMin,aabbMax;
                        aabbMin.setValue(btScalar(BT_LARGE_FLOAT),btScalar(BT_LARGE_FLOAT),btScalar(BT_LARGE_FLOAT));
                        aabbMax.setValue(btScalar(-BT_LARGE_FLOAT),btScalar(-BT_LARGE_FLOAT),btScalar(-BT_LARGE_FLOAT)); 
                        aabbMin.setMin(triangle[0]);
                        aabbMax.setMax(triangle[0]);
                        aabbMin.setMin(triangle[1]);
                        aabbMax.setMax(triangle[1]);
                        aabbMin.setMin(triangle[2]);
                        aabbMax.setMax(triangle[2]);

                        //with quantization?
                        node.m_aabbMinOrg = aabbMin;
                        node.m_aabbMaxOrg = aabbMax;

                        node.m_escapeIndex = -1;
        
                        //for child nodes
                        node.m_subPart = partId;
                        node.m_triangleIndex = triangleIndex;
                        m_triangleNodes.push_back(node);
                }
        };
        struct  QuantizedNodeTriangleCallback : public btInternalTriangleIndexCallback
        {
                QuantizedNodeArray&     m_triangleNodes;
                const btQuantizedBvh* m_optimizedTree; // for quantization

                QuantizedNodeTriangleCallback& operator=(QuantizedNodeTriangleCallback& other)
                {
                        m_triangleNodes.copyFromArray(other.m_triangleNodes);
                        m_optimizedTree = other.m_optimizedTree;
                        return *this;
                }

                QuantizedNodeTriangleCallback(QuantizedNodeArray&       triangleNodes,const btQuantizedBvh* tree)
                        :m_triangleNodes(triangleNodes),m_optimizedTree(tree)
                {
                }

                virtual void internalProcessTriangleIndex(btVector3* triangle,int partId,int  triangleIndex)
                {
                        // The partId and triangle index must fit in the same (positive) integer
                        btAssert(partId < (1<<MAX_NUM_PARTS_IN_BITS));
                        btAssert(triangleIndex < (1<<(31-MAX_NUM_PARTS_IN_BITS)));
                        //negative indices are reserved for escapeIndex
                        btAssert(triangleIndex>=0);

                        btQuantizedBvhNode node;
                        btVector3       aabbMin,aabbMax;
                        aabbMin.setValue(btScalar(BT_LARGE_FLOAT),btScalar(BT_LARGE_FLOAT),btScalar(BT_LARGE_FLOAT));
                        aabbMax.setValue(btScalar(-BT_LARGE_FLOAT),btScalar(-BT_LARGE_FLOAT),btScalar(-BT_LARGE_FLOAT)); 
                        aabbMin.setMin(triangle[0]);
                        aabbMax.setMax(triangle[0]);
                        aabbMin.setMin(triangle[1]);
                        aabbMax.setMax(triangle[1]);
                        aabbMin.setMin(triangle[2]);
                        aabbMax.setMax(triangle[2]);

                        //PCK: add these checks for zero dimensions of aabb
                        const btScalar MIN_AABB_DIMENSION = btScalar(0.002);
                        const btScalar MIN_AABB_HALF_DIMENSION = btScalar(0.001);
                        if (aabbMax.x() - aabbMin.x() < MIN_AABB_DIMENSION)
                        {
                                aabbMax.setX(aabbMax.x() + MIN_AABB_HALF_DIMENSION);
                                aabbMin.setX(aabbMin.x() - MIN_AABB_HALF_DIMENSION);
                        }
                        if (aabbMax.y() - aabbMin.y() < MIN_AABB_DIMENSION)
                        {
                                aabbMax.setY(aabbMax.y() + MIN_AABB_HALF_DIMENSION);
                                aabbMin.setY(aabbMin.y() - MIN_AABB_HALF_DIMENSION);
                        }
                        if (aabbMax.z() - aabbMin.z() < MIN_AABB_DIMENSION)
                        {
                                aabbMax.setZ(aabbMax.z() + MIN_AABB_HALF_DIMENSION);
                                aabbMin.setZ(aabbMin.z() - MIN_AABB_HALF_DIMENSION);
                        }

                        m_optimizedTree->quantize(&node.m_quantizedAabbMin[0],aabbMin,0);
                        m_optimizedTree->quantize(&node.m_quantizedAabbMax[0],aabbMax,1);

                        node.m_escapeIndexOrTriangleIndex = (partId<<(31-MAX_NUM_PARTS_IN_BITS)) | triangleIndex;

                        m_triangleNodes.push_back(node);
                }
        };
        


        int numLeafNodes = 0;

        
        if (m_useQuantization)
        {

                //initialize quantization values
                setQuantizationValues(bvhAabbMin,bvhAabbMax);

                QuantizedNodeTriangleCallback   callback(m_quantizedLeafNodes,this);

        
                triangles->InternalProcessAllTriangles(&callback,m_bvhAabbMin,m_bvhAabbMax);

                //now we have an array of leafnodes in m_leafNodes
                numLeafNodes = m_quantizedLeafNodes.size();


                m_quantizedContiguousNodes.resize(2*numLeafNodes);


        } else
        {
                NodeTriangleCallback    callback(m_leafNodes);

                btVector3 aabbMin(btScalar(-BT_LARGE_FLOAT),btScalar(-BT_LARGE_FLOAT),btScalar(-BT_LARGE_FLOAT));
                btVector3 aabbMax(btScalar(BT_LARGE_FLOAT),btScalar(BT_LARGE_FLOAT),btScalar(BT_LARGE_FLOAT));

                triangles->InternalProcessAllTriangles(&callback,aabbMin,aabbMax);

                //now we have an array of leafnodes in m_leafNodes
                numLeafNodes = m_leafNodes.size();

                m_contiguousNodes.resize(2*numLeafNodes);
        }

        m_curNodeIndex = 0;

        buildTree(0,numLeafNodes);

        if(m_useQuantization && !m_SubtreeHeaders.size())
        {
                btBvhSubtreeInfo& subtree = m_SubtreeHeaders.expand();
                subtree.setAabbFromQuantizeNode(m_quantizedContiguousNodes[0]);
                subtree.m_rootNodeIndex = 0;
                subtree.m_subtreeSize = m_quantizedContiguousNodes[0].isLeafNode() ? 1 : m_quantizedContiguousNodes[0].getEscapeIndex();
        }

        //PCK: update the copy of the size
        m_subtreeHeaderCount = m_SubtreeHeaders.size();

        //PCK: clear m_quantizedLeafNodes and m_leafNodes, they are temporary
        m_quantizedLeafNodes.clear();
        m_leafNodes.clear();
}




void    btOptimizedBvh::refit(btStridingMeshInterface* meshInterface,const btVector3& aabbMin,const btVector3& aabbMax)
{
        if (m_useQuantization)
        {

                setQuantizationValues(aabbMin,aabbMax);

                updateBvhNodes(meshInterface,0,m_curNodeIndex,0);


                int i;
                for (i=0;i<m_SubtreeHeaders.size();i++)
                {
                        btBvhSubtreeInfo& subtree = m_SubtreeHeaders[i];
                        subtree.setAabbFromQuantizeNode(m_quantizedContiguousNodes[subtree.m_rootNodeIndex]);
                }

        } else
        {

        }
}




void    btOptimizedBvh::refitPartial(btStridingMeshInterface* meshInterface,const btVector3& aabbMin,const btVector3& aabbMax)
{
        //incrementally initialize quantization values
        btAssert(m_useQuantization);

        btAssert(aabbMin.getX() > m_bvhAabbMin.getX());
        btAssert(aabbMin.getY() > m_bvhAabbMin.getY());
        btAssert(aabbMin.getZ() > m_bvhAabbMin.getZ());

        btAssert(aabbMax.getX() < m_bvhAabbMax.getX());
        btAssert(aabbMax.getY() < m_bvhAabbMax.getY());
        btAssert(aabbMax.getZ() < m_bvhAabbMax.getZ());

        
        unsigned short  quantizedQueryAabbMin[3];
        unsigned short  quantizedQueryAabbMax[3];

        quantize(&quantizedQueryAabbMin[0],aabbMin,0);
        quantize(&quantizedQueryAabbMax[0],aabbMax,1);

        int i;
        for (i=0;i<this->m_SubtreeHeaders.size();i++)
        {
                btBvhSubtreeInfo& subtree = m_SubtreeHeaders[i];

                //PCK: unsigned instead of bool
                unsigned overlap = testQuantizedAabbAgainstQuantizedAabb(quantizedQueryAabbMin,quantizedQueryAabbMax,subtree.m_quantizedAabbMin,subtree.m_quantizedAabbMax);
                if (overlap != 0)
                {
                        updateBvhNodes(meshInterface,subtree.m_rootNodeIndex,subtree.m_rootNodeIndex+subtree.m_subtreeSize,i);

                        subtree.setAabbFromQuantizeNode(m_quantizedContiguousNodes[subtree.m_rootNodeIndex]);
                }
        }
        
}

void    btOptimizedBvh::updateBvhNodes(btStridingMeshInterface* meshInterface,int firstNode,int endNode,int index)
{
        (void)index;

        btAssert(m_useQuantization);

        int curNodeSubPart=-1;

        //get access info to trianglemesh data
                const unsigned char *vertexbase = 0;
                int numverts = 0;
                PHY_ScalarType type = PHY_INTEGER;
                int stride = 0;
                const unsigned char *indexbase = 0;
                int indexstride = 0;
                int numfaces = 0;
                PHY_ScalarType indicestype = PHY_INTEGER;

                btVector3       triangleVerts[3];
                btVector3       aabbMin,aabbMax;
                const btVector3& meshScaling = meshInterface->getScaling();
                
                int i;
                for (i=endNode-1;i>=firstNode;i--)
                {


                        btQuantizedBvhNode& curNode = m_quantizedContiguousNodes[i];
                        if (curNode.isLeafNode())
                        {
                                //recalc aabb from triangle data
                                int nodeSubPart = curNode.getPartId();
                                int nodeTriangleIndex = curNode.getTriangleIndex();
                                if (nodeSubPart != curNodeSubPart)
                                {
                                        if (curNodeSubPart >= 0)
                                                meshInterface->unLockReadOnlyVertexBase(curNodeSubPart);
                                        meshInterface->getLockedReadOnlyVertexIndexBase(&vertexbase,numverts,   type,stride,&indexbase,indexstride,numfaces,indicestype,nodeSubPart);

                                        curNodeSubPart = nodeSubPart;
                                        btAssert(indicestype==PHY_INTEGER||indicestype==PHY_SHORT);
                                }
                                //triangles->getLockedReadOnlyVertexIndexBase(vertexBase,numVerts,

                                unsigned int* gfxbase = (unsigned int*)(indexbase+nodeTriangleIndex*indexstride);
                                
                                
                                for (int j=2;j>=0;j--)
                                {
                                        
                                        int graphicsindex = indicestype==PHY_SHORT?((unsigned short*)gfxbase)[j]:gfxbase[j];
                                        if (type == PHY_FLOAT)
                                        {
                                                float* graphicsbase = (float*)(vertexbase+graphicsindex*stride);
                                                triangleVerts[j] = btVector3(
                                                        graphicsbase[0]*meshScaling.getX(),
                                                        graphicsbase[1]*meshScaling.getY(),
                                                        graphicsbase[2]*meshScaling.getZ());
                                        }
                                        else
                                        {
                                                double* graphicsbase = (double*)(vertexbase+graphicsindex*stride);
                                                triangleVerts[j] = btVector3( btScalar(graphicsbase[0]*meshScaling.getX()), btScalar(graphicsbase[1]*meshScaling.getY()), btScalar(graphicsbase[2]*meshScaling.getZ()));
                                        }
                                }


                                
                                aabbMin.setValue(btScalar(BT_LARGE_FLOAT),btScalar(BT_LARGE_FLOAT),btScalar(BT_LARGE_FLOAT));
                                aabbMax.setValue(btScalar(-BT_LARGE_FLOAT),btScalar(-BT_LARGE_FLOAT),btScalar(-BT_LARGE_FLOAT)); 
                                aabbMin.setMin(triangleVerts[0]);
                                aabbMax.setMax(triangleVerts[0]);
                                aabbMin.setMin(triangleVerts[1]);
                                aabbMax.setMax(triangleVerts[1]);
                                aabbMin.setMin(triangleVerts[2]);
                                aabbMax.setMax(triangleVerts[2]);

                                quantize(&curNode.m_quantizedAabbMin[0],aabbMin,0);
                                quantize(&curNode.m_quantizedAabbMax[0],aabbMax,1);
                                
                        } else
                        {
                                //combine aabb from both children

                                btQuantizedBvhNode* leftChildNode = &m_quantizedContiguousNodes[i+1];
                                
                                btQuantizedBvhNode* rightChildNode = leftChildNode->isLeafNode() ? &m_quantizedContiguousNodes[i+2] :
                                        &m_quantizedContiguousNodes[i+1+leftChildNode->getEscapeIndex()];
                                

                                {
                                        for (int i=0;i<3;i++)
                                        {
                                                curNode.m_quantizedAabbMin[i] = leftChildNode->m_quantizedAabbMin[i];
                                                if (curNode.m_quantizedAabbMin[i]>rightChildNode->m_quantizedAabbMin[i])
                                                        curNode.m_quantizedAabbMin[i]=rightChildNode->m_quantizedAabbMin[i];

                                                curNode.m_quantizedAabbMax[i] = leftChildNode->m_quantizedAabbMax[i];
                                                if (curNode.m_quantizedAabbMax[i] < rightChildNode->m_quantizedAabbMax[i])
                                                        curNode.m_quantizedAabbMax[i] = rightChildNode->m_quantizedAabbMax[i];
                                        }
                                }
                        }

                }

                if (curNodeSubPart >= 0)
                        meshInterface->unLockReadOnlyVertexBase(curNodeSubPart);

                
}

btOptimizedBvh* btOptimizedBvh::deSerializeInPlace(void *i_alignedDataBuffer, unsigned int i_dataBufferSize, bool i_swapEndian)
{
        btQuantizedBvh* bvh = btQuantizedBvh::deSerializeInPlace(i_alignedDataBuffer,i_dataBufferSize,i_swapEndian);
        
        //we don't add additional data so just do a static upcast
        return static_cast<btOptimizedBvh*>(bvh);
}