message: expanded documentation on `check_update_time`
diff: @@ -206,6 +206,20 @@ pub fn time_since_start(ctx: &Context) -> time::Duration {
  /// Check whether or not the desired amount of time has elapsed
  /// since the last frame.
  +///
  +/// The intention is to use this in your `update` call to control
  +/// how often game logic is updated per frame (see [the astroblasto example](https://github.com/ggez/ggez/blob/30ea4a4ead67557d2ebb39550e17339323fc9c58/examples/05_astroblasto.rs#L438-L442)).
  +///
  +/// Calling this decreases a timer inside the context if the function returns true.
  +/// If called in a loop it may therefore return true once, twice or not at all, depending on
  +/// how much time elapsed since the last frame.
  +///
  +/// For more info on the idea behind this see <http://gafferongames.com/game-physics/fix-your-timestep/>.
  +///
  +/// Due to the global nature of this timer it's desirable to only use this function at one point
  +/// of your code. If you want to limit the frame rate in both game logic and drawing consider writing
  +/// your own event loop, or using a dirty bit for when to redraw graphics, which is set whenever the game
  +/// logic runs.
  pub fn check_update_time(ctx: &mut Context, target_fps: u32) -> bool {
  let timedata = &mut ctx.timer_context;
  