/**
* Inserts a new GameObject into the DBVH. The node bounds are supposed to be up to date.
*/
public bool Insert(ObiActor actor)
{
// If no gameobject at all, we can't insert it.
if (actor == null) return false;
// Create a new node.
DBVHNode node = new DBVHNode(actor);
node.UpdateBounds(nodes);
// If there are no nodes in the tree, this is the root.
if (nodes.Count == 0){
node.Index = 0;
nodes.Add(node);
}else{
InsertNode(node,nodes[0]);
}
return true;
}
/**
* Reursively inserts a node into the tree, starting at the provided parent node.
*/
private void InsertNode(DBVHNode node, DBVHNode parent)
{
if (parent.content != null){ //parent is a leaf.
// create a new parent for both the old leaf and the new leaf.
DBVHNode branch = new DBVHNode();
// our branch node is the new parent.
PutNode(branch,parent.Index);
PutNode(parent,branch.Left);
PutNode(node,branch.Right);
parent = branch;
}else{ // parent is a branch node, go down the child that will suffer less volume increase.
Bounds bL = nodes[parent.Left].bounds;
Bounds bR = nodes[parent.Right].bounds;
bL.Encapsulate(node.bounds);
bR.Encapsulate(node.bounds);
float volumeDiffL = bL.Volume() - nodes[parent.Left].bounds.Volume();
float volumeDiffR = bR.Volume() - nodes[parent.Right].bounds.Volume();
if (volumeDiffL < volumeDiffR)
InsertNode(node,nodes[parent.Left]);
else
InsertNode(node,nodes[parent.Right]);
}
// Update parent bounds on our way up the recursion stack.
parent.UpdateBounds(nodes);
}
