func (w *Window) FramebufferSize() (width, height int) {
var wid, hei C.int
C.glfwGetFramebufferSize(w.w, &wid, &hei)
return int(wid), int(hei)
}
//GetFramebufferSize retrieves the size, in pixels, of the framebuffer of the
//specified window.
func (w *Window) GetFramebufferSize() (width, height int) {
var wi, h C.int
C.glfwGetFramebufferSize(w.data, &wi, &h)
return int(wi), int(h)
}