unsafe void PairTest(int workerIndex)
{
Debug.Assert(!disposed);
int nextNodePairIndex;
//To minimize the number of worker overlap lists, perform direct load balancing by manually grabbing the next indices.
while ((nextNodePairIndex = Interlocked.Increment(ref NextNodePair)) < NodePairsToTest.Count)
{
var overlap = NodePairsToTest[nextNodePairIndex];
if (overlap.A >= 0)
{
if (overlap.A == overlap.B)
{
//Same node.
Tree.GetOverlapsInNode2(Tree.nodes + overlap.A, ref WorkerOverlaps[workerIndex]);
}
else if (overlap.B >= 0)
{
//Different nodes.
Tree.GetOverlapsBetweenDifferentNodes2(Tree.nodes + overlap.A, Tree.nodes + overlap.B, ref WorkerOverlaps[workerIndex]);
}
else
{
//A is an internal node, B is a leaf.
var leafIndex = Tree.Encode(overlap.B);
var leaf = Tree.leaves + leafIndex;
Tree.TestLeafAgainstNode2(leafIndex, ref (&Tree.nodes[leaf->NodeIndex].A)[leaf->ChildIndex], overlap.A, ref WorkerOverlaps[workerIndex]);
}
}
else
{
//A is a leaf, B is internal.
var leafIndex = Tree.Encode(overlap.A);
var leaf = Tree.leaves + leafIndex;
Tree.TestLeafAgainstNode2(leafIndex, ref (&Tree.nodes[leaf->NodeIndex].A)[leaf->ChildIndex], overlap.B, ref WorkerOverlaps[workerIndex]);
//NOTE THAT WE DO NOT HANDLE THE CASE THAT BOTH A AND B ARE LEAVES HERE.
//The collection routine should take care of that, since it has more convenient access to bounding boxes and because a single test isn't worth an atomic increment.
}
}
}
unsafe void RefitAndMark(int workerIndex)
{
int refitIndex;
while ((refitIndex = Interlocked.Increment(ref RefitNodeIndex)) < RefitNodes.Count)
{
var nodeIndex = RefitNodes.Elements[refitIndex];
bool shouldUseMark;
if (nodeIndex < 0)
{
//Node was already marked as a wavefront. Should proceed with a RefitAndMeasure instead of RefitAndMark.
nodeIndex = Tree.Encode(nodeIndex);
shouldUseMark = false;
}
else
{
shouldUseMark = true;
}
var node = Tree.nodes + nodeIndex;
Debug.Assert(node->Parent >= 0, "The root should not be marked for refit.");
var parent = Tree.nodes + node->Parent;
var boundingBoxInParent = &parent->A + node->IndexInParent;
if (shouldUseMark)
{
var costChange = Tree.RefitAndMark(nodeIndex, LeafCountThreshold, ref RefinementCandidates.Elements[workerIndex], ref *boundingBoxInParent);
node->LocalCostChange = costChange;
}
else
{
var costChange = Tree.RefitAndMeasure(nodeIndex, ref *boundingBoxInParent);
node->LocalCostChange = costChange;
}
//int foundLeafCount;
//Tree.Validate(RefitNodes.Elements[refitNodeIndex], node->Parent, node->IndexInParent, ref *boundingBoxInParent, out foundLeafCount);
//Walk up the tree.
node = parent;
while (true)
{
if (Interlocked.Decrement(ref node->RefineFlag) == 0)
{
//Compute the child contributions to this node's volume change.
var children = &node->ChildA;
node->LocalCostChange = 0;
for (int i = 0; i < node->ChildCount; ++i)
{
if (children[i] >= 0)
{
var child = Tree.nodes + children[i];
node->LocalCostChange += child->LocalCostChange;
//Clear the refine flag (unioned).
child->RefineFlag = 0;
}
}
//This thread is the last thread to visit this node, so it must handle this node.
//Merge all the child bounding boxes into one.
if (node->Parent < 0)
{
//Root node.
//Don't bother including the root's change in volume.
//Refinement can't change the root's bounds, so the fact that the world got bigger or smaller
//doesn't really have any bearing on how much refinement should be done.
//We do, however, need to divide by root volume so that we get the change in cost metric rather than volume.
var merged = new BoundingBox {
Min = new Vector3(float.MaxValue), Max = new Vector3(float.MinValue)
};
var bounds = &node->A;
for (int i = 0; i < node->ChildCount; ++i)
{
BoundingBox.Merge(ref bounds[i], ref merged, out merged);
}
var postmetric = ComputeBoundsMetric(ref merged);
if (postmetric > 1e-9f)
{
RefitCostChange = node->LocalCostChange / postmetric;
}
else
{
RefitCostChange = 0;
}
//Clear the root's refine flag (unioned).
node->RefineFlag = 0;
break;
}
else
{
parent = Tree.nodes + node->Parent;
boundingBoxInParent = &parent->A + node->IndexInParent;
var premetric = ComputeBoundsMetric(ref *boundingBoxInParent);
* boundingBoxInParent = new BoundingBox {
Min = new Vector3(float.MaxValue), Max = new Vector3(float.MinValue)
};
var bounds = &node->A;
for (int i = 0; i < node->ChildCount; ++i)
{
BoundingBox.Merge(ref bounds[i], ref *boundingBoxInParent, out *boundingBoxInParent);
}
var postmetric = ComputeBoundsMetric(ref *boundingBoxInParent);
node->LocalCostChange += postmetric - premetric;
node = parent;
}
}
else
{
//This thread wasn't the last to visit this node, so it should die. Some other thread will handle it later.
break;
}
}
}
}