/// <summary>
/// folds up unused quads by checking this node and it's parent, and on up if it keeps finding empty nodes
/// </summary>
private void Verify()
{
if (IsParent)
{
//if it's 0, collapse check parent
var children = ChildCount();
if (children == 0)
{
NW = SW = NE = SE = null;//ugly but it works better for this circumstance
parent.Verify();
}
else if (children == 1)
{
var objects = GatherAll()[0];
NW = SW = NE = SE = null;
containedObject = objects;
objects.CurrentQuad = this;
if (parent != null) //doh, forgot that the master quad doesn't have a parent...
{
parent.Verify();
}
}
//if it's more than 1, do nothing
}
else
{
if (parent != null) //temp bug fix not sure why this was null...
{
parent.Verify();
}
}
}
/// <summary>
/// if it's the very top one, set parent as null
/// </summary>
/// <param name="bounds">collidable area</param>
/// <param name="parent">parent of this node</param>
public ElasticQuadTree(RectangleFloat bounds, ElasticQuadTree parent)
{
this.parent = parent;
this.bounds = bounds;
this.queryBounds = bounds;
}
/// <summary>
/// splits this node into 4 quads and places it's held object into the appropriate child
/// </summary>
private void Split()
{
//build em up
//nw left top
NW = new ElasticQuadTree(new RectangleFloat(bounds.Left, bounds.Top, bounds.Width / 2, bounds.Height / 2), this);
//ne center, top
NE = new ElasticQuadTree(new RectangleFloat(bounds.Left + bounds.Width / 2, bounds.Top, bounds.Width / 2, bounds.Height / 2), this);
//sw left center
SW = new ElasticQuadTree(new RectangleFloat(bounds.Left, bounds.Top + bounds.Height / 2, bounds.Width / 2, bounds.Height / 2), this);
//se center center
SE = new ElasticQuadTree(new RectangleFloat(bounds.Left + bounds.Width / 2, bounds.Top + bounds.Height / 2, bounds.Width / 2, bounds.Height / 2), this);
//semi dangerous assumption that it contains an object at this point
var temp = containedObject;
containedObject = null;
if (NW.Insert(temp)) return;
else if (SW.Insert(temp)) return;
else if (NE.Insert(temp)) return;
else if (SE.Insert(temp)) return;
MasterInsert(temp);
}