OpenSimMirror/libraries/ode-0.9/OPCODE/OPC_SweepAndPrune.cpp

665 lines
17 KiB
C++

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/*
* OPCODE - Optimized Collision Detection
* Copyright (C) 2001 Pierre Terdiman
* Homepage: http://www.codercorner.com/Opcode.htm
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Contains an implementation of the sweep-and-prune algorithm (moved from Z-Collide)
* \file OPC_SweepAndPrune.cpp
* \author Pierre Terdiman
* \date January, 29, 2000
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Precompiled Header
#include "Stdafx.h"
using namespace Opcode;
inline_ void Sort(udword& id0, udword& id1)
{
if(id0>id1) Swap(id0, id1);
}
class Opcode::SAP_Element
{
public:
inline_ SAP_Element() {}
inline_ SAP_Element(udword id, SAP_Element* next) : mID(id), mNext(next) {}
inline_ ~SAP_Element() {}
udword mID;
SAP_Element* mNext;
};
class Opcode::SAP_Box
{
public:
SAP_EndPoint* Min[3];
SAP_EndPoint* Max[3];
};
class Opcode::SAP_EndPoint
{
public:
float Value; // Min or Max value
SAP_EndPoint* Previous; // Previous EndPoint whose Value is smaller than ours (or null)
SAP_EndPoint* Next; // Next EndPoint whose Value is greater than ours (or null)
udword Data; // Parent box ID *2 | MinMax flag
inline_ void SetData(udword box_id, BOOL is_max) { Data = (box_id<<1)|is_max; }
inline_ BOOL IsMax() const { return Data & 1; }
inline_ udword GetBoxID() const { return Data>>1; }
inline_ void InsertAfter(SAP_EndPoint* element)
{
if(this!=element && this!=element->Next)
{
// Remove
if(Previous) Previous->Next = Next;
if(Next) Next->Previous = Previous;
// Insert
Next = element->Next;
if(Next) Next->Previous = this;
element->Next = this;
Previous = element;
}
}
inline_ void InsertBefore(SAP_EndPoint* element)
{
if(this!=element && this!=element->Previous)
{
// Remove
if(Previous) Previous->Next = Next;
if(Next) Next->Previous = Previous;
// Insert
Previous = element->Previous;
element->Previous = this;
Next = element;
if(Previous) Previous->Next = this;
}
}
};
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Constructor.
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
SAP_PairData::SAP_PairData() :
mNbElements (0),
mNbUsedElements (0),
mElementPool (null),
mFirstFree (null),
mNbObjects (0),
mArray (null)
{
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Destructor.
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
SAP_PairData::~SAP_PairData()
{
Release();
}
void SAP_PairData::Release()
{
mNbElements = 0;
mNbUsedElements = 0;
mNbObjects = 0;
DELETEARRAY(mElementPool);
DELETEARRAY(mArray);
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Initializes.
* \param nb_objects [in]
* \return true if success
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
bool SAP_PairData::Init(udword nb_objects)
{
// Make sure everything has been released
Release();
if(!nb_objects) return false;
mArray = new SAP_Element*[nb_objects];
CHECKALLOC(mArray);
ZeroMemory(mArray, nb_objects*sizeof(SAP_Element*));
mNbObjects = nb_objects;
return true;
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Remaps a pointer when pool gets resized.
* \param element [in/out] remapped element
* \param delta [in] offset in bytes
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
inline_ void Remap(SAP_Element*& element, size_t delta)
{
if(element) element = (SAP_Element*)(size_t(element) + delta);
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Gets a free element in the pool.
* \param id [in] element id
* \param next [in] next element
* \param remap [out] possible remapping offset
* \return the new element
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
SAP_Element* SAP_PairData::GetFreeElem(udword id, SAP_Element* next, udword* remap)
{
if(remap) *remap = 0;
SAP_Element* FreeElem;
if(mFirstFree)
{
// Recycle
FreeElem = mFirstFree;
mFirstFree = mFirstFree->mNext; // First free = next free (or null)
}
else
{
if(mNbUsedElements==mNbElements)
{
// Resize
mNbElements = mNbElements ? (mNbElements<<1) : 2;
SAP_Element* NewElems = new SAP_Element[mNbElements];
if(mNbUsedElements) CopyMemory(NewElems, mElementPool, mNbUsedElements*sizeof(SAP_Element));
// Remap everything
{
size_t Delta = size_t(NewElems) - size_t(mElementPool);
for(udword i=0;i<mNbUsedElements;i++) Remap(NewElems[i].mNext, Delta);
for(udword i=0;i<mNbObjects;i++) Remap(mArray[i], Delta);
Remap(mFirstFree, Delta);
Remap(next, Delta);
if(remap) *remap = Delta;
}
DELETEARRAY(mElementPool);
mElementPool = NewElems;
}
FreeElem = &mElementPool[mNbUsedElements++];
}
FreeElem->mID = id;
FreeElem->mNext = next;
return FreeElem;
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Frees an element of the pool.
* \param elem [in] element to free/recycle
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
inline_ void SAP_PairData::FreeElem(SAP_Element* elem)
{
elem->mNext = mFirstFree; // Next free
mFirstFree = elem;
}
// Add a pair to the set.
void SAP_PairData::AddPair(udword id1, udword id2)
{
// Order the ids
Sort(id1, id2);
ASSERT(id1<mNbObjects);
if(id1>=mNbObjects) return;
// Select the right list from "mArray".
SAP_Element* Current = mArray[id1];
if(!Current)
{
// Empty slot => create new element
mArray[id1] = GetFreeElem(id2, null);
}
else if(Current->mID>id2)
{
// The list is not empty but all elements are greater than id2 => insert id2 in the front.
mArray[id1] = GetFreeElem(id2, mArray[id1]);
}
else
{
// Else find the correct location in the sorted list (ascending order) and insert id2 there.
while(Current->mNext)
{
if(Current->mNext->mID > id2) break;
Current = Current->mNext;
}
if(Current->mID==id2) return; // The pair already exists
// Current->mNext = GetFreeElem(id2, Current->mNext);
udword Delta;
SAP_Element* E = GetFreeElem(id2, Current->mNext, &Delta);
if(Delta) Remap(Current, Delta);
Current->mNext = E;
}
}
// Delete a pair from the set.
void SAP_PairData::RemovePair(udword id1, udword id2)
{
// Order the ids.
Sort(id1, id2);
// Exit if the pair doesn't exist in the set
if(id1>=mNbObjects) return;
// Otherwise, select the correct list.
SAP_Element* Current = mArray[id1];
// If this list is empty, the pair doesn't exist.
if(!Current) return;
// Otherwise, if id2 is the first element, delete it.
if(Current->mID==id2)
{
mArray[id1] = Current->mNext;
FreeElem(Current);
}
else
{
// If id2 is not the first element, start traversing the sorted list.
while(Current->mNext)
{
// If we have moved too far away without hitting id2, then the pair doesn't exist
if(Current->mNext->mID > id2) return;
// Otherwise, delete id2.
if(Current->mNext->mID == id2)
{
SAP_Element* Temp = Current->mNext;
Current->mNext = Temp->mNext;
FreeElem(Temp);
return;
}
Current = Current->mNext;
}
}
}
void SAP_PairData::DumpPairs(Pairs& pairs) const
{
// ### Ugly and slow
for(udword i=0;i<mNbObjects;i++)
{
SAP_Element* Current = mArray[i];
while(Current)
{
ASSERT(Current->mID<mNbObjects);
pairs.AddPair(i, Current->mID);
Current = Current->mNext;
}
}
}
void SAP_PairData::DumpPairs(PairCallback callback, void* user_data) const
{
if(!callback) return;
// ### Ugly and slow
for(udword i=0;i<mNbObjects;i++)
{
SAP_Element* Current = mArray[i];
while(Current)
{
ASSERT(Current->mID<mNbObjects);
if(!(callback)(i, Current->mID, user_data)) return;
Current = Current->mNext;
}
}
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Constructor.
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
SweepAndPrune::SweepAndPrune()
{
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Destructor.
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
SweepAndPrune::~SweepAndPrune()
{
}
void SweepAndPrune::GetPairs(Pairs& pairs) const
{
mPairs.DumpPairs(pairs);
}
void SweepAndPrune::GetPairs(PairCallback callback, void* user_data) const
{
mPairs.DumpPairs(callback, user_data);
}
bool SweepAndPrune::Init(udword nb_objects, const AABB** boxes)
{
// 1) Create sorted lists
mNbObjects = nb_objects;
mBoxes = new SAP_Box[nb_objects];
// for(udword i=0;i<nb_objects;i++) mBoxes[i].Box = *boxes[i];
float* Data = new float[nb_objects*2];
for(udword Axis=0;Axis<3;Axis++)
{
mList[Axis] = new SAP_EndPoint[nb_objects*2];
for(udword i=0;i<nb_objects;i++)
{
Data[i*2+0] = boxes[i]->GetMin(Axis);
Data[i*2+1] = boxes[i]->GetMax(Axis);
}
RadixSort RS;
const udword* Sorted = RS.Sort(Data, nb_objects*2).GetRanks();
SAP_EndPoint* PreviousEndPoint = null;
for(udword i=0;i<nb_objects*2;i++)
{
udword SortedIndex = *Sorted++;
float SortedCoord = Data[SortedIndex];
udword BoxIndex = SortedIndex>>1;
ASSERT(BoxIndex<nb_objects);
SAP_EndPoint* CurrentEndPoint = &mList[Axis][SortedIndex];
CurrentEndPoint->Value = SortedCoord;
// CurrentEndPoint->IsMax = SortedIndex&1; // ### could be implicit ?
// CurrentEndPoint->ID = BoxIndex; // ### could be implicit ?
CurrentEndPoint->SetData(BoxIndex, SortedIndex&1); // ### could be implicit ?
CurrentEndPoint->Previous = PreviousEndPoint;
CurrentEndPoint->Next = null;
if(PreviousEndPoint) PreviousEndPoint->Next = CurrentEndPoint;
if(CurrentEndPoint->IsMax()) mBoxes[BoxIndex].Max[Axis] = CurrentEndPoint;
else mBoxes[BoxIndex].Min[Axis] = CurrentEndPoint;
PreviousEndPoint = CurrentEndPoint;
}
}
DELETEARRAY(Data);
CheckListsIntegrity();
// 2) Quickly find starting pairs
mPairs.Init(nb_objects);
{
Pairs P;
CompleteBoxPruning(nb_objects, boxes, P, Axes(AXES_XZY));
for(udword i=0;i<P.GetNbPairs();i++)
{
const Pair* PP = P.GetPair(i);
udword id0 = PP->id0;
udword id1 = PP->id1;
if(id0!=id1 && boxes[id0]->Intersect(*boxes[id1]))
{
mPairs.AddPair(id0, id1);
}
else ASSERT(0);
}
}
return true;
}
bool SweepAndPrune::CheckListsIntegrity()
{
for(udword Axis=0;Axis<3;Axis++)
{
// Find list head
SAP_EndPoint* Current = mList[Axis];
while(Current->Previous) Current = Current->Previous;
udword Nb = 0;
SAP_EndPoint* Previous = null;
while(Current)
{
Nb++;
if(Previous)
{
ASSERT(Previous->Value <= Current->Value);
if(Previous->Value > Current->Value) return false;
}
ASSERT(Current->Previous==Previous);
if(Current->Previous!=Previous) return false;
Previous = Current;
Current = Current->Next;
}
ASSERT(Nb==mNbObjects*2);
}
return true;
}
inline_ BOOL Intersect(const AABB& a, const SAP_Box& b)
{
if(b.Max[0]->Value < a.GetMin(0) || a.GetMax(0) < b.Min[0]->Value
|| b.Max[1]->Value < a.GetMin(1) || a.GetMax(1) < b.Min[1]->Value
|| b.Max[2]->Value < a.GetMin(2) || a.GetMax(2) < b.Min[2]->Value) return FALSE;
return TRUE;
}
bool SweepAndPrune::UpdateObject(udword i, const AABB& box)
{
for(udword Axis=0;Axis<3;Axis++)
{
// udword Base = (udword)&mList[Axis][0];
// Update min
{
SAP_EndPoint* const CurrentMin = mBoxes[i].Min[Axis];
ASSERT(!CurrentMin->IsMax());
const float Limit = box.GetMin(Axis);
if(Limit == CurrentMin->Value)
{
}
else if(Limit < CurrentMin->Value)
{
CurrentMin->Value = Limit;
// Min is moving left:
SAP_EndPoint* NewPos = CurrentMin;
ASSERT(NewPos);
SAP_EndPoint* tmp;
while((tmp = NewPos->Previous) && tmp->Value > Limit)
{
NewPos = tmp;
if(NewPos->IsMax())
{
// Our min passed a max => start overlap
//udword SortedIndex = (udword(CurrentMin) - Base)/sizeof(NS_EndPoint);
const udword id0 = CurrentMin->GetBoxID();
const udword id1 = NewPos->GetBoxID();
if(id0!=id1 && Intersect(box, mBoxes[id1])) mPairs.AddPair(id0, id1);
}
}
CurrentMin->InsertBefore(NewPos);
}
else// if(Limit > CurrentMin->Value)
{
CurrentMin->Value = Limit;
// Min is moving right:
SAP_EndPoint* NewPos = CurrentMin;
ASSERT(NewPos);
SAP_EndPoint* tmp;
while((tmp = NewPos->Next) && tmp->Value < Limit)
{
NewPos = tmp;
if(NewPos->IsMax())
{
// Our min passed a max => stop overlap
const udword id0 = CurrentMin->GetBoxID();
const udword id1 = NewPos->GetBoxID();
if(id0!=id1) mPairs.RemovePair(id0, id1);
}
}
CurrentMin->InsertAfter(NewPos);
}
}
// Update max
{
SAP_EndPoint* const CurrentMax = mBoxes[i].Max[Axis];
ASSERT(CurrentMax->IsMax());
const float Limit = box.GetMax(Axis);
if(Limit == CurrentMax->Value)
{
}
else if(Limit > CurrentMax->Value)
{
CurrentMax->Value = Limit;
// Max is moving right:
SAP_EndPoint* NewPos = CurrentMax;
ASSERT(NewPos);
SAP_EndPoint* tmp;
while((tmp = NewPos->Next) && tmp->Value < Limit)
{
NewPos = tmp;
if(!NewPos->IsMax())
{
// Our max passed a min => start overlap
const udword id0 = CurrentMax->GetBoxID();
const udword id1 = NewPos->GetBoxID();
if(id0!=id1 && Intersect(box, mBoxes[id1])) mPairs.AddPair(id0, id1);
}
}
CurrentMax->InsertAfter(NewPos);
}
else// if(Limit < CurrentMax->Value)
{
CurrentMax->Value = Limit;
// Max is moving left:
SAP_EndPoint* NewPos = CurrentMax;
ASSERT(NewPos);
SAP_EndPoint* tmp;
while((tmp = NewPos->Previous) && tmp->Value > Limit)
{
NewPos = tmp;
if(!NewPos->IsMax())
{
// Our max passed a min => stop overlap
const udword id0 = CurrentMax->GetBoxID();
const udword id1 = NewPos->GetBoxID();
if(id0!=id1) mPairs.RemovePair(id0, id1);
}
}
CurrentMax->InsertBefore(NewPos);
}
}
}
return true;
}