let mut window = GlfwWindow::new(
    shader_version::opengl::OpenGL_3_2,
    WindowSettings {
        title: "My application".to_string(),
        size: [640, 480],
        fullscreen: false,
        exit_on_esc: true,
        samples: 4,
    }
);

let mut device = gfx::GlDevice::new(|s|
    self.window.get_proc_address(s)
);
let (w, h) = window.get_size();
let frame = gfx::Frame::new(w as u16, h as u16);