func (r Rect) Draw(out *op.Iterator) {
out.Start()
*out.MoveTo() = op.MoveTo{r.X, r.Y}
*out.LineTo() = op.LineTo{r.X + r.W, r.Y}
*out.LineTo() = op.LineTo{r.X + r.W, r.Y + r.H}
*out.LineTo() = op.LineTo{r.X, r.Y + r.H}
out.Close()
}
func (r Rect) Render(out *op.Iterator) {
r.Draw(out)
out.Fill()
out.Stroke()
}