/// <summary>Attempts to add a rectangle of the given size to this node. The X and Y offsets keep track of the
/// offset of this node from the origin.
/// </summary>
public Point?TryAdd(int width, int height, int spacing)
{
if (width > this.Width || height > this.Height)
{
return(null);
}
if (RectangleStored)
{
// if this node has a rectangle stored here already, delegate to the children
if (Child1 != null) // try adding it to the right first
{
Point?pt = Child1.TryAdd(width, height, spacing);
// as an optimization, we'll prevent degenerate subtrees (linked lists) from forming by replacing this
// child with our grandchild if it's an only child, or removing this child if we have no grandchildren
if (pt.HasValue && (Child1.Child1 == null || Child1.Child2 == null))
{
Child1 = Child1.Child1 == null ? Child1.Child2 : Child1.Child1;
if (Child1 != null)
{
Child1.Parent = this;
}
}
if (pt.HasValue || Child2 == null)
{
return(pt);
}
}
if (Child2 != null) // if we couldn't add it to the first child, try adding it to the second
{
Point?pt = Child2.TryAdd(width, height, spacing);
if (pt.HasValue)
{
// prevent degenerate subtrees (linked lists) from forming (see comment above for details)
if (Child2.Child1 == null || Child2.Child2 == null)
{
Child2 = Child2.Child1 == null ? Child2.Child2 : Child2.Child1;
if (Child2 != null)
{
Child2.Parent = this;
}
}
}
return(pt);
}
return(null);
}
else // this node does not have a rectangle stored here yet, so store it here and subdivide this space
{
// only add children if they'd have a non-empty area
if (this.Width > width + spacing)
{
Child1 = new Node(this, X + (width + spacing), Y, this.Width - (width + spacing), height);
}
if (this.Height > height + spacing)
{
Child2 = new Node(this, X, Y + (height + spacing), this.Width, this.Height - (height + spacing));
}
RectangleStored = true;
return(new Point(X, Y));
}
}