Method InitQuery

Engine/lib/opcode/OPC_AABBCollider.cpp:155–249

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// * Initializes a collision query : * - reset stats & contact status * - check temporal coherence * * \param cache [in/out] a box cache * \param box [in] AABB in world space * \return TRUE if we

 */
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
BOOL AABBCollider::InitQuery(AABBCache& cache, const CollisionAABB& box)
{
	// 1) Call the base method
	VolumeCollider::InitQuery();

	// 2) Keep track of the query box
	mBox = box;

	// 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 box (and set contact status if needed)
			AABB_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 box (and set contact status if needed)
				AABB_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 box N(ew) against the previous fat box P(revious):
			if(IsCacheValid(cache) && mBox.IsInside(cache.FatBox))