/// <summary>
/// Grow the octree to fit in all objects.
/// </summary>
/// <param name="direction">Direction to grow.</param>
public void Grow(Vector3 direction)
{
sbyte xDirection = direction.x >= 0 ? (sbyte)1 : (sbyte)-1;
sbyte yDirection = direction.y >= 0 ? (sbyte)1 : (sbyte)-1;
sbyte zDirection = direction.z >= 0 ? (sbyte)1 : (sbyte)-1;
PointOctreeNode <T> oldRoot = RootNode;
var half = RootNode.SideLength / 2;
var newLength = RootNode.SideLength * 2;
var newCenter = RootNode.Center + new Vector3(xDirection * half, yDirection * half, zDirection * half);
RootNode = new PointOctreeNode <T>(newLength, MinSize, newCenter);
// Create 7 new octree children to go with the old root as children of the new root...
var rootPos = GetRootPosIndex(xDirection, yDirection, zDirection);
PointOctreeNode <T>[] children = new PointOctreeNode <T> [8];
for (var i = 0; i < 8; i++)
{
if (i == rootPos)
{
children[i] = oldRoot;
}
else
{
xDirection = i % 2 == 0 ? (sbyte)-1 : (sbyte)1;
yDirection = i > 3 ? (sbyte)-1 : (sbyte)1;
zDirection = (i < 2 || (i > 3 && i < 6)) ? (sbyte)-1 : (sbyte)1;
children[i] = new PointOctreeNode <T>(RootNode.SideLength, MinSize, newCenter + new Vector3(xDirection * half,
yDirection * half,
zDirection * half));
}
}
RootNode.SetChildren(ref children);
}
/// <summary>
/// Shrink the octree if possible, else leave it the same.
/// </summary>
public void Shrink()
{
RootNode = RootNode.ShrinkIfPossible(InitialSize);
}
