private KdTreeNode BuildSubTree(KdTreeNode parentNode, ArrayList <IdxDat <Vector2D> > points, int level)
{
if (points.Count <= mMaxPtsPerLeaf) // terminal node
{
KdTreeNodeTerminal terminalNode = new KdTreeNodeTerminal(points);
terminalNode.ParentNode = parentNode;
return(terminalNode);
}
else // non-terminal node
{
ArrayList <IdxDat <Vector2D> > pointsRight = null;
double bound = ComputeBound(points, ref pointsRight, level % 2);
KdTreeNodeNonTerminal node = new KdTreeNodeNonTerminal(bound);
node.ParentNode = parentNode;
node.LeftNode = BuildSubTree(node, points, level + 1);
node.RightNode = BuildSubTree(node, pointsRight, level + 1);
return(node);
}
}
//public bool RemovePoint(int idx, Vector2D point)
//{
// ArrayList<KdTreeNode> terminalNodes = new ArrayList<KdTreeNode>();
// GetTreeNodes(point, new Vector2D(), mRootNode, 0, terminalNodes);
// bool success = false;
// foreach (KdTreeNodeTerminal terminalNode in terminalNodes)
// {
// int oldCount = terminalNode.Points.Count;
// terminalNode.Points.Remove(new IdxDat<Vector2D>(idx));
// success = oldCount > terminalNode.Points.Count;
// if (success)
// {
// mNumChanges++;
// // *** the index is not updated here; it should be rebuilt manually after enough points have been removed/inserted
// break;
// }
// }
// return success;
//}
//public void InsertPoint(int idx, Vector2D point)
//{
// ArrayList<KdTreeNode> terminalNodes = new ArrayList<KdTreeNode>();
// GetTreeNodes(point, new Vector2D(), mRootNode, 0, terminalNodes);
// int min = int.MaxValue;
// int minIdx = -1;
// int i = 0;
// foreach (KdTreeNodeTerminal terminalNode in terminalNodes)
// {
// if (terminalNode.Points.Count < min) { minIdx = i; min = terminalNode.Points.Count; }
// i++;
// }
// ((KdTreeNodeTerminal)terminalNodes[minIdx]).Points.Add(new IdxDat<Vector2D>(idx, point));
// mNumChanges++;
// // *** the index is not updated here; it should be rebuilt manually after enough points have been removed/inserted
//}
private void GetTreeNodes(Vector2D refPoint, Vector2D size, KdTreeNode node, int level, ArrayList <KdTreeNode> treeNodes) // refPoint and size define a rectangle
{
int dim = level % 2;
if (node is KdTreeNodeNonTerminal)
{
KdTreeNodeNonTerminal nonTerminalNode = (KdTreeNodeNonTerminal)node;
double bound = nonTerminalNode.Bound;
double refPointCoord = GetVectCoord(refPoint, dim);
double sizeCoord = GetVectCoord(size, dim);
if (bound < refPointCoord)
{
GetTreeNodes(refPoint, size, nonTerminalNode.RightNode, level + 1, treeNodes);
}
else if (bound > refPointCoord + sizeCoord)
{
GetTreeNodes(refPoint, size, nonTerminalNode.LeftNode, level + 1, treeNodes);
}
else
{
// split the rectangle at the bound
Vector2D rightRefPoint = refPoint;
Vector2D rightSize = size;
SetVectCoord(ref size, dim, bound - refPointCoord);
GetTreeNodes(refPoint, size, nonTerminalNode.LeftNode, level + 1, treeNodes);
double rightRefPointCoord = GetVectCoord(rightRefPoint, dim);
double rightSizeCoord = GetVectCoord(rightSize, dim);
SetVectCoord(ref rightSize, dim, rightRefPointCoord + rightSizeCoord - bound);
SetVectCoord(ref rightRefPoint, dim, bound);
GetTreeNodes(rightRefPoint, rightSize, nonTerminalNode.RightNode, level + 1, treeNodes);
}
}
else
{
treeNodes.Add(node);
}
}