public void toggleIntersectionColor(int x, int y, boolean b)
    {
        Intersection i = findIntersectionAtCanvasLocation(x, y);
        if (i != null)
        {
            if ((i.open && !b) || (!i.open && b))
            {
                i.setOpen(b);
                i.setOpen(!b);
            }
        }
    }