Re: [w3c/gamepad] Should spec a buffering/refresh interval model of gamepad data? (#22)

Thanks for the great comments! I agree that any "superhuman" button presses that only occur for a single digit millisecond duration are of not concern. Not sure whether the OS itself would be registering these either.

Although the "all these thinking assumes that our polling is happening at 60Hz no matter what and the same about firing rAF which might always be the case (but we should be close to that for quality gaming experience anyway)." thought could be read a bit in a all bets are off type of scenario for the Gamepad API if one doesn't have 60fps. I think it's rather the hiccup/GC stutter cases and slow frame rates exactly that are the important consideration. We would not want to miss button presses in the event that for example the JS garbage collector decided to take a 500msec pause in a critical moment in a game.

I'm leaning to thinking that perhaps Gamepad API should add an event model which ensures best possible promise about no lost events. With this, if the OS buffers up gamepad events, then these could be naturally delivered. And .getGamepads() could always return the most recent data that browser has, which would be good for sampling analog signals when only most recent signal value is of interest. (e.g. racing car throttle position).

I would dislike having a snapshot model spec which would go and specify actual millisecond intervals when polling occurs or anything like that. That would feel brittle.

On the topic of theoretical vs concrete, and the superhuman question aside, the question of whether the second code snippet above has a danger of losing presses is a concrete issue. This is more rather a question of whether a browser implementation might be using a separate thread to receive gamepad api messages, and the polled data could change mid-flight when JavaScript code is executing. That could make the two code snippets behave differently. Does the spec (intend to) allow that?

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