opc_spherecollider.cpp

opcode是功能强大

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/*
 *	OPCODE - Optimized Collision Detection
 *	Copyright (C) 2001 Pierre Terdiman
 *	Homepage: http://www.codercorner.com/Opcode.htm
 */
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///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Contains code for a sphere collider.
 *	\file		OPC_SphereCollider.cpp
 *	\author		Pierre Terdiman
 *	\date		June, 2, 2001
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Contains a sphere-vs-tree collider.
 *	This class performs a collision test between a sphere and an AABB tree. You can use this to do a standard player vs world collision,
 *	in a Nettle/Telemachos way. It doesn't suffer from all reported bugs in those two classic codes - the "new" one by Paul Nettle is a
 *	debuggued version I think. Collision response can be driven by reported collision data - it works extremely well for me. In sake of
 *	efficiency, all meshes (that is, all AABB trees) should of course also be kept in an extra hierarchical structure (octree, whatever).
 *
 *	\class		SphereCollider
 *	\author		Pierre Terdiman
 *	\version	1.3
 *	\date		June, 2, 2001
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

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

using namespace Opcode;
using namespace IceMaths;

#include "Opcode/OPC_SphereAABBOverlap.h"
#include "Opcode/OPC_SphereTriOverlap.h"



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

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

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

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

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

	// Init collision query
	if(InitQuery(cache, sphere, worlds, 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] a sphere cache
 *	\param		sphere		[in] sphere in local space
 *	\param		worlds		[in] sphere's 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 SPHERE WORLD MATRIX. The matrix must contain rotation & translation parts only.
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
BOOL SphereCollider::InitQuery(SphereCache& cache, const IceMaths::Sphere& sphere, const IceMaths::Matrix4x4* worlds, const IceMaths::Matrix4x4* worldm)
{
	// 1) Call the base method
	VolumeCollider::InitQuery();

	// 2) Compute sphere in model space:
	// - Precompute R^2
	mRadius2 = sphere.mRadius * sphere.mRadius;
	// - Compute center position
	mCenter = sphere.mCenter;
	// -> to world space
	if(worlds)	mCenter *= *worlds;
	// -> to model space
	if(worldm)
	{
		// Matrix normalization & scaling stripping
		IceMaths::Matrix4x4 normWorldm;
		NormalizePRSMatrix( normWorldm, mLocalScale, *worldm );
		
		// Invert model matrix
		IceMaths::Matrix4x4 InvWorldM;
		InvertPRMatrix(InvWorldM, normWorldm); // OLD:		//InvertPRMatrix(InvWorldM, *worldm);

		mCenter *= 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 sphere (and set contact status if needed)
			SPHERE_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 sphere (and set contact status if needed)
				SPHERE_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 sphere N(ew) against the previous fat sphere P(revious):
			float r = sqrtf(cache.FatRadius2) - sphere.mRadius;
			if(IsCacheValid(cache) && cache.Center.SquareDistance(mCenter) < r*r)
			{
				// - 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 = (sphere.mRadius * cache.FatCoeff)*(sphere.mRadius * cache.FatCoeff);

				// Update cache with query data (signature for cached faces)
				cache.Center = mCenter;
				cache.FatRadius2 = 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] a sphere cache
 *	\param		sphere		[in] collision sphere in world space
 *	\param		tree		[in] AABB tree
 *	\return		true if success
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
bool SphereCollider::Collide(SphereCache& cache, const IceMaths::Sphere& sphere, 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, sphere))	return true;

	// Perform collision query
	_Collide(tree);

	return true;
}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Checks the sphere 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 sphere contains the whole box
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
inline_ BOOL SphereCollider::SphereContainsBox(const IceMaths::Point& bc_, const IceMaths::Point& be_)
{
	// I assume if all 8 box vertices are inside the sphere, so does the whole box.
	// Sounds ok but maybe there's a better way?
	IceMaths::Point p;

	// scaling freak
	IceMaths::Point bc = bc_*mLocalScale;
	IceMaths::Point be = be_*mLocalScale;

	p.x=bc.x+be.x; p.y=bc.y+be.y; p.z=bc.z+be.z;	if(mCenter.SquareDistance(p)>=mRadius2)	return FALSE;
	p.x=bc.x-be.x;									if(mCenter.SquareDistance(p)>=mRadius2)	return FALSE;
	p.x=bc.x+be.x; p.y=bc.y-be.y;					if(mCenter.SquareDistance(p)>=mRadius2)	return FALSE;
	p.x=bc.x-be.x;									if(mCenter.SquareDistance(p)>=mRadius2)	return FALSE;
	p.x=bc.x+be.x; p.y=bc.y+be.y; p.z=bc.z-be.z;	if(mCenter.SquareDistance(p)>=mRadius2)	return FALSE;
	p.x=bc.x-be.x;									if(mCenter.SquareDistance(p)>=mRadius2)	return FALSE;
	p.x=bc.x+be.x; p.y=bc.y-be.y;					if(mCenter.SquareDistance(p)>=mRadius2)	return FALSE;
	p.x=bc.x-be.x;									if(mCenter.SquareDistance(p)>=mRadius2)	return FALSE;

	return TRUE;
}

#define TEST_BOX_IN_SPHERE(center, extents)	\
	if(SphereContainsBox(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 SphereCollider::_Collide(const AABBCollisionNode* node)
{
	// Perform Sphere-AABB overlap test
	if(!SphereAABBOverlap(node->mAABB.mCenter, node->mAABB.mExtents))	return;

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

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