game loop

no-reply@allegro.cc (mentalDisorder) — Sat, 03 Sep 2011 03:22:24 +0000

How should a good game loop looks like ?
I mean I've got something like:

#SelectExpand
  1   while(1)
  2   {
  3      ALLEGRO_EVENT ev;
  4      bool get_event = al_wait_for_event_timed(event_queue, &ev, 0.05f);
  5 
  6      if(get_event && ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE) {
  7         break;
  8
  9parseEvent(ev);
 10
 11// game logic and stuff
 12      }

but let's assume that game logic takes time, lets say 1/4 second. If in that time user press a button or generate any other event it'll be missed ?
Or the event will be generated and will set get_event on true next time al_wait_for_event will be executed?

no-reply@allegro.cc (kazzmir) — Sat, 03 Sep 2011 03:30:11 +0000

mentalDisorder said:

lets say 1/4 second

That is an extremely long time for most game loops. Most likely your game loop will take less than 10ms to execute.

Quote:

Or the event will be generated and will set get_event on true next time al_wait_for_event will be executed?

The events will sit in the queue until you get them out, so to answer your question, yes.

no-reply@allegro.cc (mentalDisorder) — Sat, 03 Sep 2011 03:38:00 +0000

after testing couple of function I guess that al_wait_for_event_until(...) is best option, right?

no-reply@allegro.cc (Edgar Reynaldo) — Sat, 03 Sep 2011 06:23:15 +0000

There is an example on the wiki somewhere, but this is better than using a timed wait because it always waits until there is an event, processes all the remaining events, and draws when the timer goes off :

#SelectExpand
  1
  2while (!quit) {
 do {
    ALLEGRO_EVENT ev;
    al_wait_for_event(queue , &ev);
  6
    game.ProcessInput(&ev);
    if (ev.type == ALLEGRO_EVENT_TIMER) {
       game.UpdateLogic(1.0/FRAMES_PER_SECOND);
       redraw = true;
    }
    else if (ev.type == ALLEGRO_EVENT_BLAH2) {
       // do other stuff
    }
 } while (!al_is_event_queue_empty(queue));
 if (redraw) {
    redraw = false;
    game.Display();
 }
 20}