btQuantizedBvh.h

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/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans  https://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.
*/
 
#ifndef BT_QUANTIZED_BVH_H
#define BT_QUANTIZED_BVH_H
 
class btSerializer;
 
//#define DEBUG_CHECK_DEQUANTIZATION 1
#ifdef DEBUG_CHECK_DEQUANTIZATION
#ifdef __SPU__
#define printf spu_printf
#endif  //__SPU__
 
#include <stdio.h>
#include <stdlib.h>
#endif  //DEBUG_CHECK_DEQUANTIZATION
 
#include "LinearMath/btVector3.h"
#include "LinearMath/btAlignedAllocator.h"
 
#ifdef BT_USE_DOUBLE_PRECISION
#define btQuantizedBvhData btQuantizedBvhDoubleData
#define btOptimizedBvhNodeData btOptimizedBvhNodeDoubleData
#define btQuantizedBvhDataName "btQuantizedBvhDoubleData"
#else
#define btQuantizedBvhData btQuantizedBvhFloatData
#define btOptimizedBvhNodeData btOptimizedBvhNodeFloatData
#define btQuantizedBvhDataName "btQuantizedBvhFloatData"
#endif
 
//http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclang/html/vclrf__m128.asp
 
//Note: currently we have 16 bytes per quantized node
#define MAX_SUBTREE_SIZE_IN_BYTES 2048
 
// 10 gives the potential for 1024 parts, with at most 2^21 (2097152) (minus one
// 4 gives the potential for 16 parts, each with 2^27 triangles (134217728)
// actually) triangles each (since the sign bit is reserved
//#define MAX_NUM_PARTS_IN_BITS 10
#define MAX_NUM_PARTS_IN_BITS 4

ATTRIBUTE_ALIGNED16(struct)
btQuantizedBvhNode
{
        BT_DECLARE_ALIGNED_ALLOCATOR();
 
        //12 bytes
        unsigned short int m_quantizedAabbMin[3];
        unsigned short int m_quantizedAabbMax[3];
        //4 bytes
        int m_escapeIndexOrTriangleIndex;
 
        bool isLeafNode() const
        {
                //skipindex is negative (internal node), triangleindex >=0 (leafnode)
                return (m_escapeIndexOrTriangleIndex >= 0);
        }
        int getEscapeIndex() const
        {
                btAssert(!isLeafNode());
                return -m_escapeIndexOrTriangleIndex;
        }
        int getTriangleIndex() const
        {
                btAssert(isLeafNode());
                unsigned int x = 0;
                unsigned int y = (~(x & 0)) << (31 - MAX_NUM_PARTS_IN_BITS);
                // Get only the lower bits where the triangle index is stored
                return (m_escapeIndexOrTriangleIndex & ~(y));
        }
        int getPartId() const
        {
                btAssert(isLeafNode());
                // Get only the highest bits where the part index is stored
                return (m_escapeIndexOrTriangleIndex >> (31 - MAX_NUM_PARTS_IN_BITS));
        }
};

ATTRIBUTE_ALIGNED16(struct)
btOptimizedBvhNode
{
        BT_DECLARE_ALIGNED_ALLOCATOR();
 
        //32 bytes
        btVector3 m_aabbMinOrg;
        btVector3 m_aabbMaxOrg;
 
        //4
        int m_escapeIndex;
 
        //8
        //for child nodes
        int m_subPart;
        int m_triangleIndex;
 
        //pad the size to 64 bytes
        char m_padding[20];
};

ATTRIBUTE_ALIGNED16(class)
btBvhSubtreeInfo
{
public:
        BT_DECLARE_ALIGNED_ALLOCATOR();
 
        //12 bytes
        unsigned short int m_quantizedAabbMin[3];
        unsigned short int m_quantizedAabbMax[3];
        //4 bytes, points to the root of the subtree
        int m_rootNodeIndex;
        //4 bytes
        int m_subtreeSize;
        int m_padding[3];
 
        btBvhSubtreeInfo()
        {
                //memset(&m_padding[0], 0, sizeof(m_padding));
        }
 
        void setAabbFromQuantizeNode(const btQuantizedBvhNode& quantizedNode)
        {
                m_quantizedAabbMin[0] = quantizedNode.m_quantizedAabbMin[0];
                m_quantizedAabbMin[1] = quantizedNode.m_quantizedAabbMin[1];
                m_quantizedAabbMin[2] = quantizedNode.m_quantizedAabbMin[2];
                m_quantizedAabbMax[0] = quantizedNode.m_quantizedAabbMax[0];
                m_quantizedAabbMax[1] = quantizedNode.m_quantizedAabbMax[1];
                m_quantizedAabbMax[2] = quantizedNode.m_quantizedAabbMax[2];
        }
};
 
class btNodeOverlapCallback
{
public:
        virtual ~btNodeOverlapCallback(){};
 
        virtual void processNode(int subPart, int triangleIndex) = 0;
};
 
#include "LinearMath/btAlignedAllocator.h"
#include "LinearMath/btAlignedObjectArray.h"

typedef btAlignedObjectArray<btOptimizedBvhNode> NodeArray;
typedef btAlignedObjectArray<btQuantizedBvhNode> QuantizedNodeArray;
typedef btAlignedObjectArray<btBvhSubtreeInfo> BvhSubtreeInfoArray;

ATTRIBUTE_ALIGNED16(class)
btQuantizedBvh
{
public:
        enum btTraversalMode
        {
                TRAVERSAL_STACKLESS = 0,
                TRAVERSAL_STACKLESS_CACHE_FRIENDLY,
                TRAVERSAL_RECURSIVE
        };
 
protected:
        btVector3 m_bvhAabbMin;
        btVector3 m_bvhAabbMax;
        btVector3 m_bvhQuantization;
 
        int m_bulletVersion;  //for serialization versioning. It could also be used to detect endianess.
 
        int m_curNodeIndex;
        //quantization data
        bool m_useQuantization;
 
        NodeArray m_leafNodes;
        NodeArray m_contiguousNodes;
        QuantizedNodeArray m_quantizedLeafNodes;
        QuantizedNodeArray m_quantizedContiguousNodes;
 
        btTraversalMode m_traversalMode;
        BvhSubtreeInfoArray m_SubtreeHeaders;
 
        //This is only used for serialization so we don't have to add serialization directly to btAlignedObjectArray
        mutable int m_subtreeHeaderCount;

        void setInternalNodeAabbMin(int nodeIndex, const btVector3& aabbMin)
        {
                if (m_useQuantization)
                {
                        quantize(&m_quantizedContiguousNodes[nodeIndex].m_quantizedAabbMin[0], aabbMin, 0);
                }
                else
                {
                        m_contiguousNodes[nodeIndex].m_aabbMinOrg = aabbMin;
                }
        }
        void setInternalNodeAabbMax(int nodeIndex, const btVector3& aabbMax)
        {
                if (m_useQuantization)
                {
                        quantize(&m_quantizedContiguousNodes[nodeIndex].m_quantizedAabbMax[0], aabbMax, 1);
                }
                else
                {
                        m_contiguousNodes[nodeIndex].m_aabbMaxOrg = aabbMax;
                }
        }
 
        btVector3 getAabbMin(int nodeIndex) const
        {
                if (m_useQuantization)
                {
                        return unQuantize(&m_quantizedLeafNodes[nodeIndex].m_quantizedAabbMin[0]);
                }
                //non-quantized
                return m_leafNodes[nodeIndex].m_aabbMinOrg;
        }
        btVector3 getAabbMax(int nodeIndex) const
        {
                if (m_useQuantization)
                {
                        return unQuantize(&m_quantizedLeafNodes[nodeIndex].m_quantizedAabbMax[0]);
                }
                //non-quantized
                return m_leafNodes[nodeIndex].m_aabbMaxOrg;
        }
 
        void setInternalNodeEscapeIndex(int nodeIndex, int escapeIndex)
        {
                if (m_useQuantization)
                {
                        m_quantizedContiguousNodes[nodeIndex].m_escapeIndexOrTriangleIndex = -escapeIndex;
                }
                else
                {
                        m_contiguousNodes[nodeIndex].m_escapeIndex = escapeIndex;
                }
        }
 
        void mergeInternalNodeAabb(int nodeIndex, const btVector3& newAabbMin, const btVector3& newAabbMax)
        {
                if (m_useQuantization)
                {
                        unsigned short int quantizedAabbMin[3];
                        unsigned short int quantizedAabbMax[3];
                        quantize(quantizedAabbMin, newAabbMin, 0);
                        quantize(quantizedAabbMax, newAabbMax, 1);
                        for (int i = 0; i < 3; i++)
                        {
                                if (m_quantizedContiguousNodes[nodeIndex].m_quantizedAabbMin[i] > quantizedAabbMin[i])
                                        m_quantizedContiguousNodes[nodeIndex].m_quantizedAabbMin[i] = quantizedAabbMin[i];
 
                                if (m_quantizedContiguousNodes[nodeIndex].m_quantizedAabbMax[i] < quantizedAabbMax[i])
                                        m_quantizedContiguousNodes[nodeIndex].m_quantizedAabbMax[i] = quantizedAabbMax[i];
                        }
                }
                else
                {
                        //non-quantized
                        m_contiguousNodes[nodeIndex].m_aabbMinOrg.setMin(newAabbMin);
                        m_contiguousNodes[nodeIndex].m_aabbMaxOrg.setMax(newAabbMax);
                }
        }
 
        void swapLeafNodes(int firstIndex, int secondIndex);
 
        void assignInternalNodeFromLeafNode(int internalNode, int leafNodeIndex);
 
protected:
        void buildTree(int startIndex, int endIndex);
 
        int calcSplittingAxis(int startIndex, int endIndex);
 
        int sortAndCalcSplittingIndex(int startIndex, int endIndex, int splitAxis);
 
        void walkStacklessTree(btNodeOverlapCallback * nodeCallback, const btVector3& aabbMin, const btVector3& aabbMax) const;
 
        void walkStacklessQuantizedTreeAgainstRay(btNodeOverlapCallback * nodeCallback, const btVector3& raySource, const btVector3& rayTarget, const btVector3& aabbMin, const btVector3& aabbMax, int startNodeIndex, int endNodeIndex) const;
        void walkStacklessQuantizedTree(btNodeOverlapCallback * nodeCallback, unsigned short int* quantizedQueryAabbMin, unsigned short int* quantizedQueryAabbMax, int startNodeIndex, int endNodeIndex) const;
        void walkStacklessTreeAgainstRay(btNodeOverlapCallback * nodeCallback, const btVector3& raySource, const btVector3& rayTarget, const btVector3& aabbMin, const btVector3& aabbMax, int startNodeIndex, int endNodeIndex) const;

        void walkStacklessQuantizedTreeCacheFriendly(btNodeOverlapCallback * nodeCallback, unsigned short int* quantizedQueryAabbMin, unsigned short int* quantizedQueryAabbMax) const;

        void walkRecursiveQuantizedTreeAgainstQueryAabb(const btQuantizedBvhNode* currentNode, btNodeOverlapCallback* nodeCallback, unsigned short int* quantizedQueryAabbMin, unsigned short int* quantizedQueryAabbMax) const;

        void walkRecursiveQuantizedTreeAgainstQuantizedTree(const btQuantizedBvhNode* treeNodeA, const btQuantizedBvhNode* treeNodeB, btNodeOverlapCallback* nodeCallback) const;
 
        void updateSubtreeHeaders(int leftChildNodexIndex, int rightChildNodexIndex);
 
public:
        BT_DECLARE_ALIGNED_ALLOCATOR();
 
        btQuantizedBvh();
 
        virtual ~btQuantizedBvh();

        void setQuantizationValues(const btVector3& bvhAabbMin, const btVector3& bvhAabbMax, btScalar quantizationMargin = btScalar(1.0));
        QuantizedNodeArray& getLeafNodeArray() { return m_quantizedLeafNodes; }
        void buildInternal();
 
        void reportAabbOverlappingNodex(btNodeOverlapCallback * nodeCallback, const btVector3& aabbMin, const btVector3& aabbMax) const;
        void reportRayOverlappingNodex(btNodeOverlapCallback * nodeCallback, const btVector3& raySource, const btVector3& rayTarget) const;
        void reportBoxCastOverlappingNodex(btNodeOverlapCallback * nodeCallback, const btVector3& raySource, const btVector3& rayTarget, const btVector3& aabbMin, const btVector3& aabbMax) const;
 
        SIMD_FORCE_INLINE void quantize(unsigned short* out, const btVector3& point, int isMax) const
        {
                btAssert(m_useQuantization);
 
                btAssert(point.getX() <= m_bvhAabbMax.getX());
                btAssert(point.getY() <= m_bvhAabbMax.getY());
                btAssert(point.getZ() <= m_bvhAabbMax.getZ());
 
                btAssert(point.getX() >= m_bvhAabbMin.getX());
                btAssert(point.getY() >= m_bvhAabbMin.getY());
                btAssert(point.getZ() >= m_bvhAabbMin.getZ());
 
                btVector3 v = (point - m_bvhAabbMin) * m_bvhQuantization;
                if (isMax)
                {
                        out[0] = (unsigned short)(((unsigned short)(v.getX() + btScalar(1.)) | 1));
                        out[1] = (unsigned short)(((unsigned short)(v.getY() + btScalar(1.)) | 1));
                        out[2] = (unsigned short)(((unsigned short)(v.getZ() + btScalar(1.)) | 1));
                }
                else
                {
                        out[0] = (unsigned short)(((unsigned short)(v.getX()) & 0xfffe));
                        out[1] = (unsigned short)(((unsigned short)(v.getY()) & 0xfffe));
                        out[2] = (unsigned short)(((unsigned short)(v.getZ()) & 0xfffe));
                }
 
#ifdef DEBUG_CHECK_DEQUANTIZATION
                btVector3 newPoint = unQuantize(out);
                if (isMax)
                {
                        if (newPoint.getX() < point.getX())
                        {
                                printf("unconservative X, diffX = %f, oldX=%f,newX=%f\n", newPoint.getX() - point.getX(), newPoint.getX(), point.getX());
                        }
                        if (newPoint.getY() < point.getY())
                        {
                                printf("unconservative Y, diffY = %f, oldY=%f,newY=%f\n", newPoint.getY() - point.getY(), newPoint.getY(), point.getY());
                        }
                        if (newPoint.getZ() < point.getZ())
                        {
                                printf("unconservative Z, diffZ = %f, oldZ=%f,newZ=%f\n", newPoint.getZ() - point.getZ(), newPoint.getZ(), point.getZ());
                        }
                }
                else
                {
                        if (newPoint.getX() > point.getX())
                        {
                                printf("unconservative X, diffX = %f, oldX=%f,newX=%f\n", newPoint.getX() - point.getX(), newPoint.getX(), point.getX());
                        }
                        if (newPoint.getY() > point.getY())
                        {
                                printf("unconservative Y, diffY = %f, oldY=%f,newY=%f\n", newPoint.getY() - point.getY(), newPoint.getY(), point.getY());
                        }
                        if (newPoint.getZ() > point.getZ())
                        {
                                printf("unconservative Z, diffZ = %f, oldZ=%f,newZ=%f\n", newPoint.getZ() - point.getZ(), newPoint.getZ(), point.getZ());
                        }
                }
#endif  //DEBUG_CHECK_DEQUANTIZATION
        }
 
        SIMD_FORCE_INLINE void quantizeWithClamp(unsigned short* out, const btVector3& point2, int isMax) const
        {
                btAssert(m_useQuantization);
 
                btVector3 clampedPoint(point2);
                clampedPoint.setMax(m_bvhAabbMin);
                clampedPoint.setMin(m_bvhAabbMax);
 
                quantize(out, clampedPoint, isMax);
        }
 
        SIMD_FORCE_INLINE btVector3 unQuantize(const unsigned short* vecIn) const
        {
                btVector3 vecOut;
                vecOut.setValue(
                        (btScalar)(vecIn[0]) / (m_bvhQuantization.getX()),
                        (btScalar)(vecIn[1]) / (m_bvhQuantization.getY()),
                        (btScalar)(vecIn[2]) / (m_bvhQuantization.getZ()));
                vecOut += m_bvhAabbMin;
                return vecOut;
        }

        void setTraversalMode(btTraversalMode traversalMode)
        {
                m_traversalMode = traversalMode;
        }
 
        SIMD_FORCE_INLINE QuantizedNodeArray& getQuantizedNodeArray()
        {
                return m_quantizedContiguousNodes;
        }
 
        SIMD_FORCE_INLINE BvhSubtreeInfoArray& getSubtreeInfoArray()
        {
                return m_SubtreeHeaders;
        }


        unsigned calculateSerializeBufferSize() const;

        virtual bool serialize(void* o_alignedDataBuffer, unsigned i_dataBufferSize, bool i_swapEndian) const;

        static btQuantizedBvh* deSerializeInPlace(void* i_alignedDataBuffer, unsigned int i_dataBufferSize, bool i_swapEndian);
 
        static unsigned int getAlignmentSerializationPadding();
 
        virtual int calculateSerializeBufferSizeNew() const;

        virtual const char* serialize(void* dataBuffer, btSerializer* serializer) const;
 
        virtual void deSerializeFloat(struct btQuantizedBvhFloatData & quantizedBvhFloatData);
 
        virtual void deSerializeDouble(struct btQuantizedBvhDoubleData & quantizedBvhDoubleData);

 
        SIMD_FORCE_INLINE bool isQuantized()
        {
                return m_useQuantization;
        }
 
private:
        // Special "copy" constructor that allows for in-place deserialization
        // Prevents btVector3's default constructor from being called, but doesn't inialize much else
        // ownsMemory should most likely be false if deserializing, and if you are not, don't call this (it also changes the function signature, which we need)
        btQuantizedBvh(btQuantizedBvh & other, bool ownsMemory);
};
 
// clang-format off
// parser needs * with the name
struct btBvhSubtreeInfoData
{
        int m_rootNodeIndex;
        int m_subtreeSize;
        unsigned short m_quantizedAabbMin[3];
        unsigned short m_quantizedAabbMax[3];
};
 
struct btOptimizedBvhNodeFloatData
{
        btVector3FloatData m_aabbMinOrg;
        btVector3FloatData m_aabbMaxOrg;
        int m_escapeIndex;
        int m_subPart;
        int m_triangleIndex;
        char m_pad[4];
};
 
struct btOptimizedBvhNodeDoubleData
{
        btVector3DoubleData m_aabbMinOrg;
        btVector3DoubleData m_aabbMaxOrg;
        int m_escapeIndex;
        int m_subPart;
        int m_triangleIndex;
        char m_pad[4];
};
 
 
struct btQuantizedBvhNodeData
{
        unsigned short m_quantizedAabbMin[3];
        unsigned short m_quantizedAabbMax[3];
        int     m_escapeIndexOrTriangleIndex;
};
 
struct  btQuantizedBvhFloatData
{
        btVector3FloatData                    m_bvhAabbMin;
        btVector3FloatData                    m_bvhAabbMax;
        btVector3FloatData                    m_bvhQuantization;
        int                                     m_curNodeIndex;
        int                                     m_useQuantization;
        int                                     m_numContiguousLeafNodes;
        int                                     m_numQuantizedContiguousNodes;
        btOptimizedBvhNodeFloatData  *m_contiguousNodesPtr;
        btQuantizedBvhNodeData            *m_quantizedContiguousNodesPtr;
        btBvhSubtreeInfoData        *m_subTreeInfoPtr;
        int                                     m_traversalMode;
        int                                     m_numSubtreeHeaders;
        
};
 
struct  btQuantizedBvhDoubleData
{
        btVector3DoubleData                  m_bvhAabbMin;
        btVector3DoubleData                  m_bvhAabbMax;
        btVector3DoubleData                  m_bvhQuantization;
        int                                                     m_curNodeIndex;
        int                                                     m_useQuantization;
        int                                                     m_numContiguousLeafNodes;
        int                                                     m_numQuantizedContiguousNodes;
        btOptimizedBvhNodeDoubleData        *m_contiguousNodesPtr;
        btQuantizedBvhNodeData                    *m_quantizedContiguousNodesPtr;
 
        int                                                     m_traversalMode;
        int                                                     m_numSubtreeHeaders;
        btBvhSubtreeInfoData                *m_subTreeInfoPtr;
};
// clang-format on
 
SIMD_FORCE_INLINE int btQuantizedBvh::calculateSerializeBufferSizeNew() const
{
        return sizeof(btQuantizedBvhData);
}
 
#endif  //BT_QUANTIZED_BVH_H