opc_lsscollider.cpp

opcode是功能强大

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/*
 *	OPCODE - Optimized Collision Detection
 *	Copyright (C) 2001 Pierre Terdiman
 *	Homepage: http://www.codercorner.com/Opcode.htm
 *
 *  OPCODE modifications for scaled model support (and other things)
 *  Copyright (C) 2004 Gilvan Maia (gilvan 'at' vdl.ufc.br)
 *	Check http://www.vdl.ufc.br/gilvan/coll/opcode/index.htm for updates.
 *
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Contains code for an LSS collider.
 *	\file		OPC_LSSCollider.cpp
 *	\author		Pierre Terdiman
 *	\date		December, 28, 2002
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Contains a lss-vs-tree collider.
 *
 *	\class		LSSCollider
 *	\author		Pierre Terdiman
 *	\version	1.3
 *	\date		December, 28, 2002
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Precompiled Header
#include "Opcode/Stdafx.h"

using namespace Opcode;

#include "Opcode/OPC_LSSAABBOverlap.h"
#include "Opcode/OPC_LSSTriOverlap.h"

#define SET_CONTACT(prim_index, flag)									\
	/* Set contact status */											\
	mFlags |= flag;														\
	mTouchedPrimitives->Add(prim_index);

//! LSS-triangle overlap test
#define LSS_PRIM(prim_index, flag)										\
	/* Request vertices from the app */									\
	VertexPointers VP;	mIMesh->GetTriangle(VP, prim_index);			\
																		\
	/* Perform LSS-tri overlap test */									\
	if(LSSTriOverlap(*VP.Vertex[0], *VP.Vertex[1], *VP.Vertex[2]))		\
	{																	\
		SET_CONTACT(prim_index, flag)									\
	}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Constructor.
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
LSSCollider::LSSCollider()
{
//	mCenter.Zero();
//	mRadius2 = 0.0f;
}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Destructor.
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
LSSCollider::~LSSCollider()
{
}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Generic collision query for generic OPCODE models. After the call, access the results:
 *	- with GetContactStatus()
 *	- with GetNbTouchedPrimitives()
 *	- with GetTouchedPrimitives()
 *
 *	\param		cache			[in/out] an lss cache
 *	\param		lss				[in] collision lss in local space
 *	\param		model			[in] Opcode model to collide with
 *	\param		worldl			[in] lss world matrix, or null
 *	\param		worldm			[in] model's world matrix, or null
 *	\return		true if success
 *	\warning	SCALE NOT SUPPORTED IN LSS WORLD MATRIX. The LSS matrix must contain rotation & translation parts only.
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
bool LSSCollider::Collide(LSSCache& cache, const IceMaths::LSS& lss, const Model& model, const IceMaths::Matrix4x4* worldl, const IceMaths::Matrix4x4* worldm)
{
	// Checkings
	if(!Setup(&model))	return false;

	// Init collision query
	if(InitQuery(cache, lss, worldl, worldm))	return true;

	if(!model.HasLeafNodes())
	{
		if(model.IsQuantized())
		{
			const AABBQuantizedNoLeafTree* Tree = (const AABBQuantizedNoLeafTree*)model.GetTree();

			// Setup dequantization coeffs
			mCenterCoeff	= Tree->mCenterCoeff;
			mExtentsCoeff	= Tree->mExtentsCoeff;

			// Perform collision query
			if(SkipPrimitiveTests())	_CollideNoPrimitiveTest(Tree->GetNodes());
			else						_Collide(Tree->GetNodes());
		}
		else
		{
			const AABBNoLeafTree* Tree = (const AABBNoLeafTree*)model.GetTree();

			// Perform collision query
			if(SkipPrimitiveTests())	_CollideNoPrimitiveTest(Tree->GetNodes());
			else						_Collide(Tree->GetNodes());
		}
	}
	else
	{
		if(model.IsQuantized())
		{
			const AABBQuantizedTree* Tree = (const AABBQuantizedTree*)model.GetTree();

			// Setup dequantization coeffs
			mCenterCoeff	= Tree->mCenterCoeff;
			mExtentsCoeff	= Tree->mExtentsCoeff;

			// Perform collision query
			if(SkipPrimitiveTests())	_CollideNoPrimitiveTest(Tree->GetNodes());
			else						_Collide(Tree->GetNodes());
		}
		else
		{
			const AABBCollisionTree* Tree = (const AABBCollisionTree*)model.GetTree();

			// Perform collision query
			if(SkipPrimitiveTests())	_CollideNoPrimitiveTest(Tree->GetNodes());
			else						_Collide(Tree->GetNodes());
		}
	}

	return true;
}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Initializes a collision query :
 *	- reset stats & contact status
 *	- setup matrices
 *	- check temporal coherence
 *
 *	\param		cache		[in/out] an lss cache
 *	\param		lss			[in] lss in local space
 *	\param		worldl		[in] lss world matrix, or null
 *	\param		worldm		[in] model's world matrix, or null
 *	\return		TRUE if we can return immediately
 *	\warning	SCALE NOT SUPPORTED IN LSS WORLD MATRIX. The matrix must contain rotation & translation parts only.
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
BOOL LSSCollider::InitQuery(LSSCache& cache, const IceMaths::LSS& lss, const IceMaths::Matrix4x4* worldl, const IceMaths::Matrix4x4* worldm)
{
	// 1) Call the base method
	VolumeCollider::InitQuery();

	// 2) Compute LSS in model space:
	// - Precompute R^2
	mRadius2 = lss.mRadius * lss.mRadius;
	// - Compute segment
	mSeg.mP0 = lss.mP0;
	mSeg.mP1 = lss.mP1;
	// -> to world space
	if(worldl)
	{
		mSeg.mP0 *= *worldl;
		mSeg.mP1 *= *worldl;
	}
	// -> to model space
	if(worldm)
	{
		// Matrix normalization & scaling stripping
		IceMaths::Matrix4x4 normWorldm;
		IceMaths::NormalizePRSMatrix( normWorldm, mLocalScale, *worldm );
		
		// Invert model matrix
		IceMaths::Matrix4x4 InvWorldM;
		IceMaths::InvertPRMatrix(InvWorldM, normWorldm); 

		mSeg.mP0 *= InvWorldM;
		mSeg.mP1 *= InvWorldM;
	}else
	{
		mLocalScale.Set(1.0,1.0,1.0);
	}

	// 3) Setup destination pointer
	mTouchedPrimitives = &cache.TouchedPrimitives;

	// 4) Special case: 1-triangle meshes [Opcode 1.3]
	if(mCurrentModel && mCurrentModel->HasSingleNode())
	{
		if(!SkipPrimitiveTests())
		{
			// We simply perform the BV-Prim overlap test each time. We assume single triangle has index 0.
			mTouchedPrimitives->Reset();

			// Perform overlap test between the unique triangle and the LSS (and set contact status if needed)
			LSS_PRIM(udword(0), OPC_CONTACT)

			// Return immediately regardless of status
			return TRUE;
		}
	}

	// 5) Check temporal coherence :
	if(TemporalCoherenceEnabled())
	{
		// Here we use temporal coherence
		// => check results from previous frame before performing the collision query
		if(FirstContactEnabled())
		{
			// We're only interested in the first contact found => test the unique previously touched face
			if(mTouchedPrimitives->GetNbEntries())
			{
				// Get index of previously touched face = the first entry in the array
				udword PreviouslyTouchedFace = mTouchedPrimitives->GetEntry(0);

				// Then reset the array:
				// - if the overlap test below is successful, the index we'll get added back anyway
				// - if it isn't, then the array should be reset anyway for the normal query
				mTouchedPrimitives->Reset();

				// Perform overlap test between the cached triangle and the LSS (and set contact status if needed)
				LSS_PRIM(PreviouslyTouchedFace, OPC_TEMPORAL_CONTACT)

				// Return immediately if possible
				if(GetContactStatus())	return TRUE;
			}
			// else no face has been touched during previous query
			// => we'll have to perform a normal query
		}
		else
		{
			// We're interested in all contacts =>test the new real LSS N(ew) against the previous fat LSS P(revious):

			// ### rewrite this

			IceMaths::LSS Test(mSeg, lss.mRadius);	// in model space
			IceMaths::LSS Previous(cache.Previous, sqrtf(cache.Previous.mRadius));

//			if(cache.Previous.Contains(Test))
			if(IsCacheValid(cache) && Previous.Contains(Test))
			{
				// - if N is included in P, return previous list
				// => we simply leave the list (mTouchedFaces) unchanged

				// Set contact status if needed
				if(mTouchedPrimitives->GetNbEntries())	mFlags |= OPC_TEMPORAL_CONTACT;

				// In any case we don't need to do a query
				return TRUE;
			}
			else
			{
				// - else do the query using a fat N

				// Reset cache since we'll about to perform a real query
				mTouchedPrimitives->Reset();

				// Make a fat sphere so that coherence will work for subsequent frames
				mRadius2 *= cache.FatCoeff;
//				mRadius2 = (lss.mRadius * cache.FatCoeff)*(lss.mRadius * cache.FatCoeff);


				// Update cache with query data (signature for cached faces)
				cache.Previous.mP0 = mSeg.mP0;
				cache.Previous.mP1 = mSeg.mP1;
				cache.Previous.mRadius = mRadius2;
			}
		}
	}
	else
	{
		// Here we don't use temporal coherence => do a normal query
		mTouchedPrimitives->Reset();
	}

	return FALSE;
}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Collision query for vanilla AABB trees.
 *	\param		cache		[in/out] an lss cache
 *	\param		lss			[in] collision lss in world space
 *	\param		tree		[in] AABB tree
 *	\return		true if success
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
bool LSSCollider::Collide(LSSCache& cache, const IceMaths::LSS& lss, const AABBTree* tree)
{
	// This is typically called for a scene tree, full of -AABBs-, not full of triangles.
	// So we don't really have "primitives" to deal with. Hence it doesn't work with
	// "FirstContact" + "TemporalCoherence".
	ASSERT( !(FirstContactEnabled() && TemporalCoherenceEnabled()) );

	// Checkings
	if(!tree)	return false;

	// Init collision query
	if(InitQuery(cache, lss))	return true;

	// Perform collision query
	_Collide(tree);

	return true;
}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Checks the LSS completely contains the box. In which case we can end the query sooner.
 *	\param		bc	[in] box center
 *	\param		be	[in] box extents
 *	\return		true if the LSS contains the whole box
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
inline_ BOOL LSSCollider::LSSContainsBox(const IceMaths::Point& bc, const IceMaths::Point& be)
{
	// Not implemented
	return FALSE;
}

#define TEST_BOX_IN_LSS(center, extents)	\
	if(LSSContainsBox(center, extents))		\
	{										\
		/* Set contact status */			\
		mFlags |= OPC_CONTACT;				\
		_Dump(node);						\
		return;								\
	}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Recursive collision query for normal AABB trees.
 *	\param		node	[in] current collision node
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void LSSCollider::_Collide(const AABBCollisionNode* node)
{
	// Perform LSS-AABB overlap test
	if(!LSSAABBOverlap(node->mAABB.mCenter, node->mAABB.mExtents))	return;

	TEST_BOX_IN_LSS(node->mAABB.mCenter, node->mAABB.mExtents)

	if(node->IsLeaf())
	{
		LSS_PRIM(node->GetPrimitive(), OPC_CONTACT)
	}
	else
	{
		_Collide(node->GetPos());