Method InitQuery

Engine/lib/opcode/OPC_PlanesCollider.cpp:176–256

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// * 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] lis

 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
BOOL PlanesCollider::InitQuery(PlanesCache& cache, const Plane* planes, udword nb_planes, const Matrix4x4* worldm)
{
	// 1) Call the base method
	VolumeCollider::InitQuery();

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

	if(worldm)
	{
		Matrix4x4 InvWorldM;
		InvertPRMatrix(InvWorldM, *worldm);

//		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 CopyMemory(mPlanes, planes, nb_planes*sizeof(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