private void ExpandRecursively(QtNode <T> node, ref int i)
{
if (node.Depth == MaxDepth)
{
return;
}
int depth = node.Depth + 1;
float size = node.Size / 2f;
for (int x = 0; x < 2; x++)
{
for (int y = 0; y < 2; y++)
{
var childCoord = node.Coord * 2 + new IntVector2(x, y);
var childPosition = node.Position + new Vector2(size * x, size * y);
var child = CreateNode(ref i, depth, childCoord, childPosition, size);
int localChildIndex = x * 2 + y;
node.Children[localChildIndex] = i - 1;
ExpandRecursively(child, ref i);
}
}
}
public QuadTree(Vector2 posMin, int size, int patchSize, Func <QtNode <T>, T> constructor)
{
//log2(1024*8/32)
int numPatchesAtLod0 = size / patchSize;
if (!Mathf.IsPowerOfTwo(numPatchesAtLod0))
{
throw new ArgumentException("Ratio of size/patchSize must be power-of-two");
}
MaxDepth = (int)Math.Log(numPatchesAtLod0, 2);
_constructor = constructor;
int totalNodes = CalculateNumNodes(MaxDepth);
Debug.Log(
"QuadTree || Depth: " + MaxDepth +
", Total Nodes: " + totalNodes +
", Total Mem: " + totalNodes * QtNode <T> .SizeBytes / 1024 + "KB");
_nodes = new QtNode <T> [totalNodes];
int i = 0;
QtNode <T> root = CreateNode(ref i, 0, IntVector2.Zero, posMin, size);
ExpandRecursively(root, ref i);
}
private QtNode <T> CreateNode(ref int i, int depth, IntVector2 childCoord, Vector2 childPosition, float size)
{
var child = new QtNode <T>(depth, childCoord, childPosition, size);
child.Value = _constructor(child);
_nodes[i++] = child;
return(child);
}