opc_raycollider.cpp

opcode是功能强大

	// Checkings
	if(!Setup(&model))	return false;

	// Init collision query
	float maxDistanceBkp = mMaxDist;	
	Point originBkp = mOrigin;
	Point dirBkp = mDir;

	if(InitQuery(world_ray, world, cache))
	{
		mMaxDist = maxDistanceBkp;
		mDir = dirBkp;
		mOrigin = originBkp;
		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 stabbing query
			if(IR(mMaxDist)!=IEEE_MAX_FLOAT)	_SegmentStab(Tree->GetNodes());
			else								_RayStab(Tree->GetNodes());
		}
		else
		{
			const AABBNoLeafTree* Tree = (const AABBNoLeafTree*)model.GetTree();

			// Perform stabbing query
			if(IR(mMaxDist)!=IEEE_MAX_FLOAT)	_SegmentStab(Tree->GetNodes());
			else								_RayStab(Tree->GetNodes());
		}
	}
	else
	{
		if(model.IsQuantized())
		{
			const AABBQuantizedTree* Tree = (const AABBQuantizedTree*)model.GetTree();

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

			// Perform stabbing query
			if(IR(mMaxDist)!=IEEE_MAX_FLOAT)	_SegmentStab(Tree->GetNodes());
			else								_RayStab(Tree->GetNodes());
		}
		else
		{
			const AABBCollisionTree* Tree = (const AABBCollisionTree*)model.GetTree();

			// Perform stabbing query
			if(IR(mMaxDist)!=IEEE_MAX_FLOAT)	_SegmentStab(Tree->GetNodes());
			else								_RayStab(Tree->GetNodes());
		}
	}

        // reverts max distance, etc
	mMaxDist = maxDistanceBkp;
	mDir = dirBkp;
	mOrigin = originBkp;

	// Update cache if needed
	UPDATE_CACHE
	return true;
}


///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Initializes a stabbing query :
 *	- reset stats & contact status
 *	- compute ray in local space
 *	- check temporal coherence
 *
 *	\param		world_ray	[in] stabbing ray in world space
 *	\param		world		[in] object's world matrix, or null
 *	\param		face_id		[in] index of previously stabbed triangle
 *	\return		TRUE if we can return immediately
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
BOOL RayCollider::InitQuery(const IceMaths::Ray& world_ray, const IceMaths::Matrix4x4* world, udword* face_id)
{
	// Reset stats & contact status
	Collider::InitQuery();

	mNbRayBVTests		= 0;
	mNbRayPrimTests		= 0;
	mNbIntersections	= 0;

#ifndef OPC_RAYHIT_CALLBACK
	if(mStabbedFaces)	mStabbedFaces->Reset();
#endif

	// Compute ray in local space
	// The (Origin/Dir) form is needed for the ray-triangle test anyway (even for segment tests)
	if(world)
	{
#ifdef OPC_RAYCOLLIDER_SCALE_BEFORE_OVERLAP
		// Matrix normalization & scaling stripping		
		Matrix4x4 normWorldm;
		NormalizePRSMatrix( normWorldm, mLocalScale, *world );
		
		// Invert model matrix
		Matrix3x3 InvWorld = normWorldm;
		mDir = InvWorld * world_ray.mDir;

		Matrix4x4 World;
		InvertPRMatrix(World, normWorldm);
		mOrigin = world_ray.mOrig * World;
#else
		// Now we are a much better code to get the ray in local space.
		// Some notes about this new code:
		//	- faster, because we don't need to compute square roots anymore;
		//  - faster yet, because the number of divisions is even smaller now;
		//  - the intersection tests are robust enough to handle rays with non-unit direction vectors;
		//  - matrices are less subject to FPU errors, because I don't like square root;
		//	 (it seems to introduce errors, because it cuts number precision by a half when
		//	  stripping the matrix scale off)
		//  - the code is shorter and easier to maintain;  :P
		#pragma message(" >> Using new code for ray collision")		

		// first, invert the world matrix and transform the ray's origin
		Matrix4x4 World;
		InvertPRSMatrix(World, *world);
		mOrigin = world_ray.mOrig * World;

		// second, transform the ray's direction
		Matrix3x3 InvWorld = World;
		mDir = world_ray.mDir * InvWorld;
#endif
	}
	else
	{
          	mLocalScale.Set(1.0f,1.0f,1.0f);
		mDir	= world_ray.mDir;
		mOrigin	= world_ray.mOrig;
	}

	// 4) Special case: 1-triangle meshes [Opcode 1.3]
	if(mCurrentModel && mCurrentModel->HasSingleNode())
	{
		// We simply perform the BV-Prim overlap test each time. We assume single triangle has index 0.
		if(!SkipPrimitiveTests())
		{
			// Perform overlap test between the unique triangle and the ray (and set contact status if needed)
			SEGMENT_PRIM(udword(0), OPC_CONTACT)

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

	// Check temporal coherence :

	// Test previously colliding primitives first
	if(TemporalCoherenceEnabled() && FirstContactEnabled() && face_id && *face_id!=INVALID_ID)
	{
#ifdef OLD_CODE
#ifndef OPC_RAYHIT_CALLBACK
		if(!mClosestHit)
#endif
		{
			// Request vertices from the app
			VertexPointers VP;
			mIMesh->GetTriangle(VP, *face_id);
			// Perform ray-cached tri overlap test
			if(RayTriOverlap(*VP.Vertex[0], *VP.Vertex[1], *VP.Vertex[2]))
			{
				// Intersection point is valid if:
				// - distance is positive (else it can just be a face behind the orig point)
				// - distance is smaller than a given max distance (useful for shadow feelers)
//				if(mStabbedFace.mDistance>0.0f && mStabbedFace.mDistance<mMaxDist)
				if(IR(mStabbedFace.mDistance)<IR(mMaxDist))	// The other test is already performed in RayTriOverlap
				{
					// Set contact status
					mFlags |= OPC_TEMPORAL_CONTACT;

					mStabbedFace.mFaceID = *face_id;

#ifndef OPC_RAYHIT_CALLBACK
					if(mStabbedFaces)	mStabbedFaces->AddFace(mStabbedFace);
#endif
					return TRUE;
				}
			}
		}
#else
		// New code
		// We handle both Segment/ray queries with the same segment code, and a possible infinite limit
		SEGMENT_PRIM(*face_id, OPC_TEMPORAL_CONTACT)

		// Return immediately if possible
		if(GetContactStatus())	return TRUE;
#endif
	}

	// Precompute data (moved after temporal coherence since only needed for ray-AABB)
	if(IR(mMaxDist)!=IEEE_MAX_FLOAT)
	{
		// For Segment-AABB overlap
		mData = 0.5f * mDir * mMaxDist;
		mData2 = mOrigin + mData;

		// Precompute mFDir;
		mFDir.x = fabsf(mData.x);
		mFDir.y = fabsf(mData.y);
		mFDir.z = fabsf(mData.z);
	}
	else
	{
		// For Ray-AABB overlap
//		udword x = SIR(mDir.x)-1;
//		udword y = SIR(mDir.y)-1;
//		udword z = SIR(mDir.z)-1;
//		mData.x = FR(x);
//		mData.y = FR(y);
//		mData.z = FR(z);

		// Precompute mFDir;
		mFDir.x = fabsf(mDir.x);
		mFDir.y = fabsf(mDir.y);
		mFDir.z = fabsf(mDir.z);
	}

	return FALSE;
}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Stabbing query for vanilla AABB trees.
 *	\param		world_ray		[in] stabbing ray in world space
 *	\param		tree			[in] AABB tree
 *	\param		box_indices		[out] indices of stabbed boxes
 *	\return		true if success
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
bool RayCollider::Collide(const IceMaths::Ray& world_ray, const AABBTree* tree, Container& box_indices)
{
	// ### bad design here

	// 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
	// Basically this is only called to initialize precomputed data
	if(InitQuery(world_ray))	return true;

	// Perform stabbing query
	if(IR(mMaxDist)!=IEEE_MAX_FLOAT)	_SegmentStab(tree, box_indices);
	else								_RayStab(tree, box_indices);

	return true;
}


///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 *	Recursive stabbing query for normal AABB trees.
 *	\param		node	[in] current collision node
 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////