/// <summary>
/// Gets the leaf nodes that touch the given AABB. (Same as
/// <see cref="GetOverlaps(Shapes.Aabb)"/> except we directly return the AABB tree node.
/// </summary>
/// <param name="aabb">The axis-aligned bounding box.</param>
/// <returns>All items that touch the given AABB.</returns>
/// <remarks>
/// Filtering (see <see cref="Filter"/>) is not applied.
/// </remarks>
private IEnumerable <Node> GetLeafNodes(Aabb aabb)
{
// Note: This methods is the same as GetOverlaps(Aabb), but instead of returning items we
// return the nodes directly. This is used in tree vs. tree tests, so we do not have to
// recompute the AABBs of each leaf node.
Update(false);
#if !POOL_ENUMERABLES
if (_numberOfItems == 0)
{
yield break;
}
// Stackless traversal of tree.
// The AABB tree nodes are stored in preorder traversal order. We can visit them in linear
// order. The EscapeOffset of each node can be used to skip a subtree.
int index = 0;
while (index < _nodes.Length)
{
Node node = _nodes[index];
bool haveContact = GeometryHelper.HaveContact(GetAabb(node), aabb);
if (haveContact && node.IsLeaf)
{
yield return(node);
}
if (haveContact || node.IsLeaf)
{
// Given AABB intersects the internal AABB tree node or the node is a leaf.
// Continue with next item in preorder traversal order.
index++;
}
else
{
// Given AABB does not touch the internal AABB tree node.
// --> Skip the subtree.
index += node.EscapeOffset;
}
}
#else
// Avoiding garbage:
return(GetLeafNodesWork.Create(this, ref aabb));
#endif
}
///// <summary>
///// Gets the items that touch the given leaf node.
///// </summary>
///// <param name="leaf">The axis-aligned bounding box.</param>
///// <returns>All items that touch the given AABB.</returns>
///// <remarks>
///// Filtering (see <see cref="BasePartition{T}.Filter"/>) is not applied.
///// </remarks>
//private IEnumerable<T> GetOverlaps(Node leaf)
//{
// // Note: This method is the same as GetOverlaps(Aabb), except that before checking
// // the AABBs we compare the nodes. This removes some unnecessary AABB checks when
// // computing self-overlaps.
// Debug.Assert(leaf.IsLeaf);
// Update(false);
// if (_root == null)
// yield break;
// var stack = DigitalRune.ResourcePools<Node>.Stacks.Obtain();
// stack.Push(_root);
// while (stack.Count > 0)
// {
// Node node = stack.Pop();
// node.IsActive = true;
// if (node != leaf && GeometryHelper.HaveContact(node.Aabb, leaf.Aabb))
// {
// if (node.IsLeaf)
// {
// yield return node.Item;
// }
// else
// {
// SplitIfNecessary(node);
// stack.Push(node.RightChild);
// stack.Push(node.LeftChild);
// }
// }
// }
// DigitalRune.ResourcePools<Node>.Stacks.Recycle(stack);
//}
/// <summary>
/// Gets the leaf nodes that touch the given AABB. (Same as <see cref="GetOverlaps(Aabb)"/>
/// except we directly return the AABB tree node.)
/// </summary>
/// <param name="aabb">The axis-aligned bounding box.</param>
/// <returns>All leaf nodes that touch the given AABB.</returns>
/// <remarks>
/// Filtering (see <see cref="BasePartition{T}.Filter"/>) is not applied.
/// </remarks>
private IEnumerable <Node> GetLeafNodes(Aabb aabb)
{
// Note: This methods is the same as GetOverlaps(Aabb), but instead of returning items we
// return the nodes directly. This is used in tree vs. tree tests, so we do not have to
// recompute the AABBs of each leaf node.
UpdateInternal();
#if !POOL_ENUMERABLES
if (_root == null)
{
yield break;
}
var stack = DigitalRune.ResourcePools <Node> .Stacks.Obtain();
stack.Push(_root);
while (stack.Count > 0)
{
Node node = stack.Pop();
node.IsActive = true;
if (GeometryHelper.HaveContact(node.Aabb, aabb))
{
if (node.IsLeaf)
{
yield return(node);
}
else
{
SplitIfNecessary(node);
stack.Push(node.RightChild);
stack.Push(node.LeftChild);
}
}
}
DigitalRune.ResourcePools <Node> .Stacks.Recycle(stack);
#else
// Avoiding garbage:
return(GetLeafNodesWork.Create(this, ref aabb));
#endif
}
