protected PointList calculateDiamondPoints(Rectangle r)
{
PointList points = new PointList(4);
points.addPoint(new Point(r.x + (r.width-1)/2, r.y));
points.addPoint(new Point(r.x + (r.width-1), r.y + (r.height-1)/2));
points.addPoint(new Point(r.x + (r.width-1)/2, r.y + (r.height-1)));
points.addPoint(new Point(r.x, r.y + (r.height-1)/2));
return points;