Biggest beef with game loops

Question

What do you hate most about the modern game loop? Can the game loop be improved or is there just a better alternative, such as an event-driven architecture?

Answer 1

It seems like this really ought to be a CW...

I'm taking a grad-level game engine programming course right now and they're sticking with the game loop approach. Granted, that doesn't mean it's the only/best solution but it's certainly logical. Using a loop allows you to ensure that all game systems get their turn to run without requesting their own timed interrupts or something else. Control can be centralized: in my current project, I have a GameManager class that, each frame, loops through the Update(float deltaTime) function for every registered object in turn. I don't have to debug an event system or set up timed signals, I just use a loop to call a series of functions. No muss, no fuss.

To answer your question of what do I hate most, the loop approach does logically lend itself to liberal use of inheritance and polymorphism which can bloat the size/complexity of your objects. If you're not careful, this can be a mild-to-horrible pitfall. If you are careful, it may not be a problem at all.

Answer 2

To be fully event based you could spawn an extra thread that does nothing but put a CPUTick event into your event queue every x milliseconds.

In JavaScript this is usually the more natural route, because you can so easily create an extra 'thread' that sends you the events with setInterval().

Or, if you already have a loop in the framework containing your game - like JS has in the browser, or python has with twisted - you can tell that looper to call you back at fixed intervals. e.g.:

function gameLoop() {
   // update, draw...
}
window.setInterval(gameLoop, 1000/fps);

Answer 3

No matter there is any event in the game or not, game is supposed to draw itself and update it at a fixed rate, so I don't think dropping the game loop is possible. Still I would be wondered if anyone can think of any other alternative of game loop.

Answer 4

Usually the event driven architectures work best for games (only do something if the user wants something done). BUT, you'll still always need to have a thread constantly redrawing the world.