/// <summary> This method splits the node into four branch, and disperses
/// the items into the branch. The split only happens if the
/// boundary size of the node is larger than the minimum size (if
/// we care). The items in this node are cleared after they are put
/// into the branch.
/// </summary>
protected internal void split()
{
// Make sure we're bigger than the minimum, if we care,
if (minSize != NO_MIN_SIZE)
if (Math.Abs(bounds.Top - bounds.Bottom) < minSize &&
Math.Abs(bounds.Right - bounds.Left) < minSize &&
Math.Abs(bounds.Front - bounds.Back) < minSize)
return;
float nsHalf = (float)(bounds.Top - (bounds.Top - bounds.Bottom) * 0.5);
float ewHalf = (float)(bounds.Right - (bounds.Right - bounds.Left) * 0.5);
float fbHalf = (float)(bounds.Front - (bounds.Front - bounds.Back) * 0.5);
branch = new OctreeNode[8];
branch[0] = new OctreeNode(ewHalf, bounds.Left, bounds.Front, fbHalf, bounds.Top, nsHalf, maxItems); //left-front-top
branch[1] = new OctreeNode(bounds.Right, ewHalf, bounds.Front, fbHalf, bounds.Top, nsHalf, maxItems);
branch[2] = new OctreeNode(ewHalf, bounds.Left, bounds.Front, fbHalf, nsHalf, bounds.Bottom, maxItems);
branch[3] = new OctreeNode(bounds.Right, ewHalf, bounds.Front, fbHalf, nsHalf, bounds.Bottom, maxItems);
branch[4] = new OctreeNode(ewHalf, bounds.Left, fbHalf, bounds.Back, bounds.Top, nsHalf, maxItems); //left-back-top
branch[5] = new OctreeNode(bounds.Right, ewHalf, fbHalf, bounds.Back, bounds.Top, nsHalf, maxItems);
branch[6] = new OctreeNode(ewHalf, bounds.Left, fbHalf, bounds.Back, nsHalf, bounds.Bottom, maxItems);
branch[7] = new OctreeNode(bounds.Right, ewHalf, fbHalf, bounds.Back, nsHalf, bounds.Bottom, maxItems);
ArrayList temp = (ArrayList)items.Clone();
items.Clear();
IEnumerator things = temp.GetEnumerator();
while (things.MoveNext())
{
AddNode((OctreeLeaf)things.Current);
}
}
public Octree(float xMax, float xMin, float yMax, float yMin, float zMax, float zMin, int maxItems, float minSize)
{
top = new OctreeNode(xMax, xMin, yMax, yMin, zMax, zMin, maxItems, minSize);
}