internal override bool Remove(BroadPhaseEntry entry, out LeafNode leafNode, out Node replacementNode)
{
replacementNode = null;
if (element == entry)
{
leafNode = this;
return(true);
}
leafNode = null;
return(false);
}
internal override bool RemoveFast(BroadPhaseEntry entry, out LeafNode leafNode, out Node replacementNode)
{
//The fastremove leaf node procedure is identical to the brute force approach.
//We don't need to perform any bounding box test here; if they're equal, they're equal!
replacementNode = null;
if (element == entry)
{
leafNode = this;
return(true);
}
leafNode = null;
return(false);
}
internal override bool TryToInsert(LeafNode node, out Node treeNode)
{
var newTreeNode = InternalNode.nodePool.Take();
BoundingBox.CreateMerged(ref BoundingBox, ref node.BoundingBox, out newTreeNode.BoundingBox);
Vector3 offset;
Vector3.Subtract(ref newTreeNode.BoundingBox.Max, ref newTreeNode.BoundingBox.Min, out offset);
newTreeNode.currentVolume = offset.X * offset.Y * offset.Z;
//newTreeNode.maximumVolume = newTreeNode.currentVolume * InternalNode.MaximumVolumeScale;
newTreeNode.childA = this;
newTreeNode.childB = node;
treeNode = newTreeNode;
return(true);
}
internal override bool RemoveFast(BroadPhaseEntry entry, out LeafNode leafNode, out Node replacementNode)
{
//Only bother checking deeper in the path if the entry and child have overlapping bounding boxes.
bool intersects;
childA.BoundingBox.Intersects(ref entry.boundingBox, out intersects);
if (intersects && childA.RemoveFast(entry, out leafNode, out replacementNode))
{
if (childA.IsLeaf)
{
replacementNode = childB;
}
else
{
//It was not a leaf node, but a child found the leaf.
//Change the child to the replacement node.
childA = replacementNode;
replacementNode = this; //We don't need to be replaced!
}
return(true);
}
childB.BoundingBox.Intersects(ref entry.boundingBox, out intersects);
if (intersects && childB.RemoveFast(entry, out leafNode, out replacementNode))
{
if (childB.IsLeaf)
{
replacementNode = childA;
}
else
{
//It was not a leaf node, but a child found the leaf.
//Change the child to the replacement node.
childB = replacementNode;
replacementNode = this; //We don't need to be replaced!
}
return(true);
}
replacementNode = this;
leafNode = null;
return(false);
}
internal abstract bool RemoveFast(BroadPhaseEntry entry, out LeafNode leafNode, out Node replacementNode);
internal abstract bool TryToInsert(LeafNode node, out Node treeNode);
internal override bool TryToInsert(LeafNode node, out Node treeNode)
{
//Since we are an internal node, we know we have two children.
//Regardless of what kind of nodes they are, figure out which would be a better choice to merge the new node with.
//Use the path which produces the smallest 'volume.'
BoundingBox mergedA, mergedB;
BoundingBox.CreateMerged(ref childA.BoundingBox, ref node.BoundingBox, out mergedA);
BoundingBox.CreateMerged(ref childB.BoundingBox, ref node.BoundingBox, out mergedB);
Vector3 offset;
float originalAVolume, originalBVolume;
Vector3.Subtract(ref childA.BoundingBox.Max, ref childA.BoundingBox.Min, out offset);
originalAVolume = offset.X * offset.Y * offset.Z;
Vector3.Subtract(ref childB.BoundingBox.Max, ref childB.BoundingBox.Min, out offset);
originalBVolume = offset.X * offset.Y * offset.Z;
float mergedAVolume, mergedBVolume;
Vector3.Subtract(ref mergedA.Max, ref mergedA.Min, out offset);
mergedAVolume = offset.X * offset.Y * offset.Z;
Vector3.Subtract(ref mergedB.Max, ref mergedB.Min, out offset);
mergedBVolume = offset.X * offset.Y * offset.Z;
//Could use factor increase or absolute difference
if (mergedAVolume - originalAVolume < mergedBVolume - originalBVolume)
{
//merging A produces a better result.
if (childA.IsLeaf)
{
var newChildA = nodePool.Take();
newChildA.BoundingBox = mergedA;
newChildA.childA = this.childA;
newChildA.childB = node;
newChildA.currentVolume = mergedAVolume;
//newChildA.maximumVolume = newChildA.currentVolume * MaximumVolumeScale;
childA = newChildA;
treeNode = null;
return(true);
}
else
{
childA.BoundingBox = mergedA;
var internalNode = (InternalNode)childA;
internalNode.currentVolume = mergedAVolume;
//internalNode.maximumVolume = internalNode.currentVolume * MaximumVolumeScale;
treeNode = childA;
return(false);
}
}
else
{
//merging B produces a better result.
if (childB.IsLeaf)
{
//Target is a leaf! Return.
var newChildB = nodePool.Take();
newChildB.BoundingBox = mergedB;
newChildB.childA = node;
newChildB.childB = this.childB;
newChildB.currentVolume = mergedBVolume;
//newChildB.maximumVolume = newChildB.currentVolume * MaximumVolumeScale;
childB = newChildB;
treeNode = null;
return(true);
}
else
{
childB.BoundingBox = mergedB;
treeNode = childB;
var internalNode = (InternalNode)childB;
internalNode.currentVolume = mergedBVolume;
//internalNode.maximumVolume = internalNode.currentVolume * MaximumVolumeScale;
return(false);
}
}
}