Method prepareData

physx/source/lowlevelaabb/src/BpBroadPhaseABP.cpp:1335–1746

PX_COMPILE_TIME_ASSERT(sizeof(BpHandle)==sizeof(float));
void BoxManager::prepareData(RadixSortBuffered& /*rs*/, ABP_Object* PX_RESTRICT objects, PxU32 objectsCapacity, ABP_MM& memoryManager)
{
	PX_UNUSED(objectsCapacity);

	// PT: mNbUpdated = number of objects in the updated buffer, could have been updated this frame or previous frame
	const PxU32 size = mNbUpdated;
	if(!size)
	{
		if(mNbRemovedSleeping)
		{
			// PT: benchmark for this codepath: MBP.RemoveHalfSleeping
			purgeRemovedFromSleeping(objects, objectsCapacity);
		}
		return;
	}

	PX_ASSERT(mAABBManagerBounds);
	PX_ASSERT(mAABBManagerDistances);
	PX_ASSERT(mInToOut_Updated);

	// Prepare new/updated objects
	const ABP_Index* PX_RESTRICT remap = mInToOut_Updated;
	const PxBounds3* PX_RESTRICT bounds = mAABBManagerBounds;
	const float* PX_RESTRICT distances = mAABBManagerDistances;

	float* PX_RESTRICT keys = NULL;

	// newOrUpdatedIDs: *userIDs* of objects that have been added or updated this frame.
	// sleepingIndices: *indices* (not userIDs) of non-updated objects within mInToOut_Updated
	PxU32* tempBuffer = NULL;
	PxU32* newOrUpdatedIDs = tempBuffer;
	PxU32* sleepingIndices = tempBuffer;

	// PT: mNbUpdated / mInToOut_Updated contains:
	// 1) objects added this frame (from addObject(s))
	// 2) objects updated this frame (from updateObject(s))
	// 3) objects updated the frame before, not updated this frame, i.e. they are now "sleeping"
	// 4) objects updated the frame before, then removed (from removeObject(s))
	//
	// We split the current array into separate groups:
	// - 1) & 2) go to "temp", count is "nbUpdated"
	// - 3) go to "temp2", count is "nbSleeping"
	// - 4) are filtered out. No special processing is needed because the updated data is always parsed/recreated here anyway.
	//   So if we don't actively add removed objects to the new buffers, they get removed as a side-effect.

	PxU32 nbUpdated = 0;	// PT: number of objects updated this frame
	PxU32 nbSleeping = 0;
	PxU32 nbRemoved = 0;	// PT: number of removed objects that were previously located in the udpated array

	// PT: TODO: could we do the work within mInToOut_Updated?
	// - updated objects have invalidated bounds so we don't need to preserve their order
	// - we need to preserve the order of sleeping objects to avoid re-sorting them
	// - we cannot use MTF since it breaks the order
	// - parse backward and move sleeping objects to the back? but then we might have to move the sleeping boxes at the same time

	for(PxU32 i=0;i<size;i++)
	{
		PX_ASSERT(i<mMaxNbUpdated);