opc_planescollider.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 a planes collider.
 *	\file		OPC_PlanesCollider.cpp
 *	\author		Pierre Terdiman
 *	\date		January, 1st, 2002
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Contains a Planes-vs-tree collider.
 *
 *	\class		PlanesCollider
 *	\author		Pierre Terdiman
 *	\version	1.3
 *	\date		January, 1st, 2002
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

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

using namespace Opcode;
using namespace IceMaths;

#include "Opcode/OPC_PlanesAABBOverlap.h"
#include "Opcode/OPC_PlanesTriOverlap.h"

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

//! Planes-triangle test
#define PLANES_PRIM(prim_index, flag)		\
	/* Request vertices from the app */		\
	mIMesh->GetTriangle(mVP, prim_index);	\
	/* Perform triangle-box overlap test */	\
	if(PlanesTriOverlap(clip_mask))			\
	{										\
		SET_CONTACT(prim_index, flag)		\
	}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Constructor.
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
PlanesCollider::PlanesCollider() :
	mPlanes		(null),
	mNbPlanes	(0)
{
}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Destructor.
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
PlanesCollider::~PlanesCollider()
{
	DELETEARRAY(mPlanes);
}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Validates current settings. You should call this method after all the settings and callbacks have been defined.
 *	\return		null if everything is ok, else a string describing the problem
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
const char* PlanesCollider::ValidateSettings()
{
	if(TemporalCoherenceEnabled() && !FirstContactEnabled())	return "Temporal coherence only works with ""First contact"" mode!";

	return VolumeCollider::ValidateSettings();
}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Generic collision query for generic OPCODE models. After the call, access the results:
 *	- with GetContactStatus()
 *	- with GetNbTouchedPrimitives()
 *	- with GetTouchedPrimitives()
 *
 *	\param		cache		[in/out] a planes cache
 *	\param		planes		[in] list of planes in world space
 *	\param		nb_planes	[in] number of planes
 *	\param		model		[in] Opcode model to collide with
 *	\param		worldm		[in] model's world matrix, or null
 *	\return		true if success
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
bool PlanesCollider::Collide(PlanesCache& cache, const IceMaths::Plane* planes, udword nb_planes, const Model& model, const IceMaths::Matrix4x4* worldm)
{
	// Checkings
	if(!Setup(&model))	return false;

	// Init collision query
	if(InitQuery(cache, planes, nb_planes, worldm))	return true;

	udword PlaneMask = (1<<nb_planes)-1;

	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(), PlaneMask);
			else						_Collide(Tree->GetNodes(), PlaneMask);
		}
		else
		{
			const AABBNoLeafTree* Tree = (const AABBNoLeafTree*)model.GetTree();

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

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

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Initializes a collision query :
 *	- reset stats & contact status
 *	- compute planes in model space
 *	- check temporal coherence
 *
 *	\param		cache		[in/out] a planes cache
 *	\param		planes		[in] list of planes
 *	\param		nb_planes	[in] number of planes
 *	\param		worldm		[in] model's world matrix, or null
 *	\return		TRUE if we can return immediately
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
BOOL PlanesCollider::InitQuery(PlanesCache& cache, const IceMaths::Plane* planes, udword nb_planes, const IceMaths::Matrix4x4* worldm)
{
	// 1) Call the base method
	VolumeCollider::InitQuery();

	// 2) Compute planes in model space
	if(nb_planes>mNbPlanes)
	{
		DELETEARRAY(mPlanes);
		mPlanes = new IceMaths::Plane[nb_planes];
	}
	mNbPlanes = nb_planes;

	if(worldm)
	{
		// Matrix normalization & scaling stripping
		IceMaths::Matrix4x4 normWorldm;
		NormalizePRSMatrix( normWorldm, mLocalScale, *worldm );

		IceMaths::Matrix4x4 InvWorldM;
		InvertPRMatrix(InvWorldM, normWorldm);

//		for(udword i=0;i<nb_planes;i++)	mPlanes[i] = planes[i] * InvWorldM;
		for(udword i=0;i<nb_planes;i++)	TransformPlane(mPlanes[i], planes[i], InvWorldM);
	}
	else
	{
		mLocalScale.Set(1.0,1.0,1.0);
		CopyMemory(mPlanes, planes, nb_planes*sizeof(IceMaths::Plane));
	}

	// 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 planes (and set contact status if needed)
			udword clip_mask = (1<<mNbPlanes)-1;
			PLANES_PRIM(udword(0), OPC_CONTACT)

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

	// 4) 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 planes (and set contact status if needed)
				udword clip_mask = (1<<mNbPlanes)-1;
				PLANES_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 mTouchedPrimitives->Reset();
	}
	else
	{
		// Here we don't use temporal coherence => do a normal query
		mTouchedPrimitives->Reset();
	}

	return FALSE;
}

#define TEST_CLIP_MASK																					\
	/* If the box is completely included, so are its children. We don't need to do extra tests, we */	\
	/* can immediately output a list of visible children. Those ones won't need to be clipped. */		\
	if(!OutClipMask)																					\
	{																									\
		/* Set contact status */																		\
		mFlags |= OPC_CONTACT;																			\
		_Dump(node);																					\
		return;																							\
	}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Recursive collision query for normal AABB trees.
 *	\param		node	[in] current collision node
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void PlanesCollider::_Collide(const AABBCollisionNode* node, udword clip_mask)
{
	// Test the box against the planes. If the box is completely culled, so are its children, hence we exit.
	udword OutClipMask;
	if(!PlanesAABBOverlap(node->mAABB.mCenter, node->mAABB.mExtents, OutClipMask, clip_mask))	return;

	TEST_CLIP_MASK

	// Else the box straddles one or several planes, so we need to recurse down the tree.
	if(node->IsLeaf())
	{
		PLANES_PRIM(node->GetPrimitive(), OPC_CONTACT)
	}
	else
	{
		_Collide(node->GetPos(), OutClipMask);

		if(ContactFound()) return;

		_Collide(node->GetNeg(), OutClipMask);
	}
}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Recursive collision query for normal AABB trees.
 *	\param		node	[in] current collision node
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void PlanesCollider::_CollideNoPrimitiveTest(const AABBCollisionNode* node, udword clip_mask)
{
	// Test the box against the planes. If the box is completely culled, so are its children, hence we exit.
	udword OutClipMask;
	if(!PlanesAABBOverlap(node->mAABB.mCenter, node->mAABB.mExtents, OutClipMask, clip_mask))	return;

	TEST_CLIP_MASK

	// Else the box straddles one or several planes, so we need to recurse down the tree.
	if(node->IsLeaf())
	{
		SET_CONTACT(node->GetPrimitive(), OPC_CONTACT)
	}
	else
	{
		_CollideNoPrimitiveTest(node->GetPos(), OutClipMask);