while let Some(e) = window.next() {
    window.draw_2d(&e, |c, g, d| {
      let fps = 22;
      let transform = c.transform.trans(10.0, 100.0);
      text::Text::new_color([0.0, 1.0, 0.0, 1.0], 32).draw(
        format!("FPS {}", fps).as_str(),
        &mut glyphs,
        &c.draw_state,
        transform,
        g
      ).unwrap();
      glyphs.factory.encoder.flush(d);
    });
  };