OPC_BoxPruning.cpp

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/*
 *      OPCODE - Optimized Collision Detection
 *      Copyright (C) 2001 Pierre Terdiman
 *      Homepage: http://www.codercorner.com/Opcode.htm
 */



/*
        You could use a complex sweep-and-prune as implemented in I-Collide.
        You could use a complex hashing scheme as implemented in V-Clip or recently in ODE it seems.
        You could use a "Recursive Dimensional Clustering" algorithm as implemented in GPG2.

        Or you could use this.
        Faster ? I don't know. Probably not. It would be a shame. But who knows ?
        Easier ? Definitely. Enjoy the sheer simplicity.
*/


// Precompiled Header
#include "Stdafx.h"

using namespace Opcode;

        inline_ void FindRunningIndex(udword& index, float* array, udword* sorted, int last, float max)
        {
                int First=index;
                while(First<=last)
                {
                        index = (First+last)>>1;

                        if(max>array[sorted[index]])    First   = index+1;
                        else                                                    last    = index-1;
                }
        }
// ### could be log(n) !
// and maybe use cmp integers

// InsertionSort has better coherence, RadixSort is better for one-shot queries.
#define PRUNING_SORTER  RadixSort
//#define PRUNING_SORTER        InsertionSort

// Static for coherence
static PRUNING_SORTER* gCompletePruningSorter = null;
static PRUNING_SORTER* gBipartitePruningSorter0 = null;
static PRUNING_SORTER* gBipartitePruningSorter1 = null;
inline_ PRUNING_SORTER* GetCompletePruningSorter()
{
        if(!gCompletePruningSorter)     gCompletePruningSorter = new PRUNING_SORTER;
        return gCompletePruningSorter;
}
inline_ PRUNING_SORTER* GetBipartitePruningSorter0()
{
        if(!gBipartitePruningSorter0)   gBipartitePruningSorter0 = new PRUNING_SORTER;
        return gBipartitePruningSorter0;
}
inline_ PRUNING_SORTER* GetBipartitePruningSorter1()
{
        if(!gBipartitePruningSorter1)   gBipartitePruningSorter1 = new PRUNING_SORTER;
        return gBipartitePruningSorter1;
}
void ReleasePruningSorters()
{
        DELETESINGLE(gBipartitePruningSorter1);
        DELETESINGLE(gBipartitePruningSorter0);
        DELETESINGLE(gCompletePruningSorter);
}



bool Opcode::BipartiteBoxPruning(udword nb0, const AABB** array0, udword nb1, const AABB** array1, Pairs& pairs, const Axes& axes)
{
        // Checkings
        if(!nb0 || !array0 || !nb1 || !array1)  return false;

        // Catch axes
        udword Axis0 = axes.mAxis0;
        udword Axis1 = axes.mAxis1;
        udword Axis2 = axes.mAxis2;

        // Allocate some temporary data
        float* MinPosList0 = new float[nb0];
        float* MinPosList1 = new float[nb1];

        // 1) Build main lists using the primary axis
        for(udword i=0;i<nb0;i++)       MinPosList0[i] = array0[i]->GetMin(Axis0);
        for(udword i=0;i<nb1;i++)       MinPosList1[i] = array1[i]->GetMin(Axis0);

        // 2) Sort the lists
        PRUNING_SORTER* RS0 = GetBipartitePruningSorter0();
        PRUNING_SORTER* RS1 = GetBipartitePruningSorter1();
        const udword* Sorted0 = RS0->Sort(MinPosList0, nb0).GetRanks();
        const udword* Sorted1 = RS1->Sort(MinPosList1, nb1).GetRanks();

        // 3) Prune the lists
        udword Index0, Index1;

        const udword* const LastSorted0 = &Sorted0[nb0];
        const udword* const LastSorted1 = &Sorted1[nb1];
        const udword* RunningAddress0 = Sorted0;
        const udword* RunningAddress1 = Sorted1;

        while(RunningAddress1<LastSorted1 && Sorted0<LastSorted0)
        {
                Index0 = *Sorted0++;

                while(RunningAddress1<LastSorted1 && MinPosList1[*RunningAddress1]<MinPosList0[Index0]) RunningAddress1++;

                const udword* RunningAddress2_1 = RunningAddress1;

                while(RunningAddress2_1<LastSorted1 && MinPosList1[Index1 = *RunningAddress2_1++]<=array0[Index0]->GetMax(Axis0))
                {
                        if(array0[Index0]->Intersect(*array1[Index1], Axis1))
                        {
                                if(array0[Index0]->Intersect(*array1[Index1], Axis2))
                                {
                                        pairs.AddPair(Index0, Index1);
                                }
                        }
                }
        }


        while(RunningAddress0<LastSorted0 && Sorted1<LastSorted1)
        {
                Index0 = *Sorted1++;

                while(RunningAddress0<LastSorted0 && MinPosList0[*RunningAddress0]<=MinPosList1[Index0])        RunningAddress0++;

                const udword* RunningAddress2_0 = RunningAddress0;

                while(RunningAddress2_0<LastSorted0 && MinPosList0[Index1 = *RunningAddress2_0++]<=array1[Index0]->GetMax(Axis0))
                {
                        if(array0[Index1]->Intersect(*array1[Index0], Axis1))
                        {
                                if(array0[Index1]->Intersect(*array1[Index0], Axis2))
                                {
                                        pairs.AddPair(Index1, Index0);
                                }
                        }

                }
        }

        DELETEARRAY(MinPosList1);
        DELETEARRAY(MinPosList0);

        return true;
}

#define ORIGINAL_VERSION
//#define JOAKIM


bool Opcode::CompleteBoxPruning(udword nb, const AABB** array, Pairs& pairs, const Axes& axes)
{
        // Checkings
        if(!nb || !array)       return false;

        // Catch axes
        udword Axis0 = axes.mAxis0;
        udword Axis1 = axes.mAxis1;
        udword Axis2 = axes.mAxis2;

#ifdef ORIGINAL_VERSION
        // Allocate some temporary data
//      float* PosList = new float[nb];
        float* PosList = new float[nb+1];

        // 1) Build main list using the primary axis
        for(udword i=0;i<nb;i++)        PosList[i] = array[i]->GetMin(Axis0);
PosList[nb++] = MAX_FLOAT;

        // 2) Sort the list
        PRUNING_SORTER* RS = GetCompletePruningSorter();
        const udword* Sorted = RS->Sort(PosList, nb).GetRanks();

        // 3) Prune the list
        const udword* const LastSorted = &Sorted[nb];
        const udword* RunningAddress = Sorted;
        udword Index0, Index1;
        while(RunningAddress<LastSorted && Sorted<LastSorted)
        {
                Index0 = *Sorted++;

//              while(RunningAddress<LastSorted && PosList[*RunningAddress++]<PosList[Index0]);
                while(PosList[*RunningAddress++]<PosList[Index0]);

                if(RunningAddress<LastSorted)
                {
                        const udword* RunningAddress2 = RunningAddress;

//                      while(RunningAddress2<LastSorted && PosList[Index1 = *RunningAddress2++]<=array[Index0]->GetMax(Axis0))
                        while(PosList[Index1 = *RunningAddress2++]<=array[Index0]->GetMax(Axis0))
                        {
//                              if(Index0!=Index1)
//                              {
                                        if(array[Index0]->Intersect(*array[Index1], Axis1))
                                        {
                                                if(array[Index0]->Intersect(*array[Index1], Axis2))
                                                {
                                                        pairs.AddPair(Index0, Index1);
                                                }
                                        }
//                              }
                        }
                }
        }

        DELETEARRAY(PosList);
#endif

#ifdef JOAKIM
        // Allocate some temporary data
//      float* PosList = new float[nb];
        float* MinList = new float[nb+1];

        // 1) Build main list using the primary axis
        for(udword i=0;i<nb;i++)        MinList[i] = array[i]->GetMin(Axis0);
        MinList[nb] = MAX_FLOAT;

        // 2) Sort the list
        PRUNING_SORTER* RS = GetCompletePruningSorter();
        udword* Sorted = RS->Sort(MinList, nb+1).GetRanks();

        // 3) Prune the list
//      const udword* const LastSorted = &Sorted[nb];
//      const udword* const LastSorted = &Sorted[nb-1];
        const udword* RunningAddress = Sorted;
        udword Index0, Index1;

//      while(RunningAddress<LastSorted && Sorted<LastSorted)
//      while(RunningAddress<LastSorted)
        while(RunningAddress<&Sorted[nb])
//      while(Sorted<LastSorted)
        {
//              Index0 = *Sorted++;
                Index0 = *RunningAddress++;

//              while(RunningAddress<LastSorted && PosList[*RunningAddress++]<PosList[Index0]);
//              while(PosList[*RunningAddress++]<PosList[Index0]);
//RunningAddress = Sorted;
//              if(RunningAddress<LastSorted)
                {
                        const udword* RunningAddress2 = RunningAddress;

//                      while(RunningAddress2<LastSorted && PosList[Index1 = *RunningAddress2++]<=array[Index0]->GetMax(Axis0))

//                      float CurrentMin = array[Index0]->GetMin(Axis0);
                        float CurrentMax = array[Index0]->GetMax(Axis0);

                        while(MinList[Index1 = *RunningAddress2] <= CurrentMax)
//                      while(PosList[Index1 = *RunningAddress] <= CurrentMax)
                        {
//                              if(Index0!=Index1)
//                              {
                                        if(array[Index0]->Intersect(*array[Index1], Axis1))
                                        {
                                                if(array[Index0]->Intersect(*array[Index1], Axis2))
                                                {
                                                        pairs.AddPair(Index0, Index1);
                                                }
                                        }
//                              }

                                RunningAddress2++;
//                              RunningAddress++;
                        }
                }
        }

        DELETEARRAY(MinList);
#endif

        return true;
}

// Brute-force versions are kept:
// - to check the optimized versions return the correct list of intersections
// - to check the speed of the optimized code against the brute-force one


bool Opcode::BruteForceBipartiteBoxTest(udword nb0, const AABB** array0, udword nb1, const AABB** array1, Pairs& pairs)
{
        // Checkings
        if(!nb0 || !array0 || !nb1 || !array1)  return false;

        // Brute-force nb0*nb1 overlap tests
        for(udword i=0;i<nb0;i++)
        {
                for(udword j=0;j<nb1;j++)
                {
                        if(array0[i]->Intersect(*array1[j]))    pairs.AddPair(i, j);
                }
        }
        return true;
}


bool Opcode::BruteForceCompleteBoxTest(udword nb, const AABB** array, Pairs& pairs)
{
        // Checkings
        if(!nb || !array)       return false;

        // Brute-force n(n-1)/2 overlap tests
        for(udword i=0;i<nb;i++)
        {
                for(udword j=i+1;j<nb;j++)
                {
                        if(array[i]->Intersect(*array[j]))      pairs.AddPair(i, j);
                }
        }
        return true;
}