public static void BuildTree(OctCell root, BoundingSphere bounds, Action<OctCell> forLeaves, float leafSize)
{
if (bounds.Intersects(root.box))
{
if ((root.box.Max.X - root.box.Min.X) <= leafSize)
{
if (root.contents == null) root.contents = new List<OctNode>();
forLeaves(root);
}
else
{
if (root.children == null) root.children = splitCell(root);
foreach (var child in root.children) BuildTree(child, bounds, forLeaves, leafSize);
}
}
}
public static void VisitTree(OctCell root, BoundingSphere bounds, Action<OctCell> callback)
{
if (bounds.Intersects(root.box))
{
if (root.Leaf) callback(root);
else foreach (var child in root.children) VisitTree(child, bounds, callback);
}
}
public static void RemoveNode(OctCell root, OctNode node)
{
VisitTree(root, node.bounds, (cell) => { if (cell.contents != null) cell.contents.Remove(node); });
}
public static void InsertNode(OctCell root, OctNode node, float leafSize)
{
BuildTree(root, node.bounds, (cell) => { cell.contents.Add(node); }, leafSize);
}
private static OctCell[] splitCell(OctCell root)
{
var into = new OctCell[8];
var dims = (root.box.Max - root.box.Min) / 2;
var min = root.box.Min;
into[0] = new OctCell(makeBox(min.X, min.Y, min.Z, dims.X, dims.Y, dims.Z));
into[1] = new OctCell(makeBox(min.X + dims.X, min.Y, min.Z, dims.X, dims.Y, dims.Z));
into[2] = new OctCell(makeBox(min.X, min.Y + dims.Y, min.Z, dims.X, dims.Y, dims.Z));
into[3] = new OctCell(makeBox(min.X + dims.X, min.Y + dims.Y, min.Z, dims.X, dims.Y, dims.Z));
into[4] = new OctCell(makeBox(min.X, min.Y, min.Z + dims.Z, dims.X, dims.Y, dims.Z));
into[5] = new OctCell(makeBox(min.X + dims.X, min.Y, min.Z + dims.Z, dims.X, dims.Y, dims.Z));
into[6] = new OctCell(makeBox(min.X, min.Y + dims.Y, min.Z + dims.Z, dims.X, dims.Y, dims.Z));
into[7] = new OctCell(makeBox(min.X + dims.X, min.Y + dims.Y, min.Z + dims.Z, dims.X, dims.Y, dims.Z));
return into;
}
public static void VisitTree(OctCell root, Ray ray, Action<OctCell> callback)
{
if (ray.Intersects(root.box).HasValue)
{
if (root.Leaf) callback(root);
else foreach (var child in root.children) VisitTree(child, ray, callback);
}
}
public static void VisitTree(OctCell root, BoundingFrustum frustum, Action<OctCell> callback)
{
if (frustum.Intersects(root.box))
{
if (root.Leaf) callback(root);
else foreach (var child in root.children) VisitTree(child, frustum, callback);
}
}