If fixed timesteps are unreliable across web platforms, what can I use in my game loop?

Question

As I have found out in my previous question, window.setInterval is not the best choice for a cross-platform game loop. What is my alternative for a game loop in Javascript that will (attempt to) run at the same speed on all devices?

Also, you'll want to look into using requestAnimationFrame over something like setInterval() — XNargaHuntress, Dec 05 '14 at 13:09
You shouldn't assume your timesteps are fixed for a local game either. Always measure your time step and make sure only the appearance of the game is affected by a non standard interval — Richard Tingle, Dec 06 '14 at 17:33

score 2 · Accepted Answer · answered Dec 05 '14 at 11:26

2

You shouldn't use equal intervals for game loop. Instead of this use time_delta (current_time - last_update_time). Send time_delta to game object's update method and update position and other parameters depending on time_delta. For example, simple object moving with const velocity will be:

function update(time_delta) {
    position = position + velocity * time_delta;
}

In this case, you don't need to set fixed frame per second and allow game to update state as fast as possible.

answered Dec 05 '14 at 11:26

Kostya Regent

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7

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Good but rather incomplete answer. I'll just leave this here: http://gafferongames.com/game-physics/fix-your-timestep/
In sum, use fixed step delta times, it gives better accuracy for physics integration and is more predictable.
– Grimshaw Dec 05 '14 at 15:44
you could simplify this to position += velocity * time_delta – ndugger Dec 17 '14 at 14:36

If fixed timesteps are unreliable across web platforms, what can I use in my game loop?

1 Answers1