diamondTree (from Falre)

/**
 * from Flare demo
 * Demos/uutils/GraphUtils.as
 */

/**
 * Create a diamond tree, with a given branching factor at
 * each level, and depth levels for the two main branches.
 * @param b the number of children of each branch node
 * @param d1 the length of the first (left) branch
 * @param d2 the length of the second (right) branch
 * @return the generated Tree
 */

public static function diamondTree(b:int, d1:int, d2:int) : Tree
{
	var tree:Tree = new Tree();
	var n:NodeSprite = tree.addRoot();
	var l:NodeSprite = tree.addChild(n);
	var r:NodeSprite = tree.addChild(n);
            
        deepHelper(tree, l, b, d1-2, true);
        deepHelper(tree, r, b, d1-2, false);
        
	while (l.firstChildNode != null)
		l = l.firstChildNode;
	while (r.lastChildNode != null)
		r = r.lastChildNode;
        	
        deepHelper(tree, l, b, d2-1, false);
        deepHelper(tree, r, b, d2-1, true);
        		
        return tree;
}
    
private static function deepHelper(t:Tree, n:NodeSprite,
		breadth:int, depth:int, left:Boolean) : void
{
	var c:NodeSprite = t.addChild(n);
	if (left && depth > 0)
		deepHelper(t, c, breadth, depth-1, left);
			
	for (var i:uint = 1; i<breadth; ++i) {
		c = t.addChild(n);
	}
			
	if (!left && depth > 0)
		deepHelper(t, c, breadth, depth-1, left);
	}
}