Re: exposing CANVAS or something like it to Web Workers

On Mon, May 14, 2012 at 5:03 PM, Boris Zbarsky <bzbarsky@mit.edu> wrote:

> On 5/14/12 7:56 PM, Glenn Maynard wrote:
>
>> A tricky bit: you need to know which element to sync to, so the browser
>> knows which monitor's vsync to use.  According to [1] only WebKit's
>> requestAnimationFrame actually takes an element.  (That's surprising;
>> this seems obvious.
>>
>
> Does WebKit actually use the element to determine vsync?  How do they
> handle cases when the element spans monitors?


> As far as I know WebKit's implementation uses the element to optimize out
> callbacks when the element is not visible, but that's it.
>

The element isn't used for anything currently in WebKit.  "Which vsync" is
determined by the monitor the tab/window/whatever lands on.  When this
spans monitors, something random happens (there aren't many good options).

>
> Note that Gecko, for example, does not tie requestAnimationFrame callbacks
> to vsync.  I can't speak for other UAs.


I think you'll want to.

- James


>
>
>  I mention this because
>> this method would need to accept a context in lieu of an element
>>
>
> What would the context be used for?
>
> -Boris
>
>