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Re: Specifying window.performance.now()

From: Nat Duca <nduca@chromium.org>
Date: Thu, 23 Feb 2012 13:50:20 -0800
Message-ID: <CAAMsTOuObigSL_ExsG2xX+vo89q4cNaNLM8QWcjgwaSki_u0SQ@mail.gmail.com>
To: Jatinder Mann <jmann@microsoft.com>
Cc: Tony Gentilcore <tonyg@google.com>, "public-web-perf@w3.org" <public-web-perf@w3.org>, James Robinson <jamesr@google.com>, "dmandelin@mozilla.com" <dmandelin@mozilla.com>
On a related note, as it stands now, the requestAnimationFrame callback
takes a DOM timestamp:

callback FrameRequestCallback = void (DOMTimeStamp
<http://www.w3.org/TR/WebIDL/#common-DOMTimeStamp> time);

In an ideal world, it be cool if the "time" parameter was instead a high
resolution time --- without it, 60hz animations would look like either 58
or 62hz. E.g.:

requesAnimationFrame(function(frame0_time) {
   requestAnimationFrame(function(frame1_time) {
      displayRefreshRate = 1000 / frame1_time - frame0_time;
   };
});



On Thu, Feb 23, 2012 at 8:31 AM, Jatinder Mann <jmann@microsoft.com> wrote:

> We spoke about specifying it in the High Resolution Time spec. I will have
> a draft of that spec available for next week's conference call. It aligns
> very closely with what James has described in his proposal:
> http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2011-July/032343.html.
>
> Jatinder
>
> -----Original Message-----
> From: Tony Gentilcore [mailto:tonyg@google.com]
> Sent: Thursday, February 23, 2012 5:33 AM
> To: public-web-perf@w3.org
> Cc: James Robinson; dmandelin@mozilla.com
> Subject: Specifying window.performance.now()
>
> Last July, James Robinson proposed[1] window.performance.now() to the
> whatwg. We've talked about it several times in this group, but as far as
> I'm aware no one has created a draft spec yet.
>
> WebKit is ready to move forward with an implementation[2] and David
> Mandelin informs me Mozilla is ready as well[3]. Just so those initial
> prefixed versions line up as much as possible, I think it makes sense to
> have a draft spec somewhere before we start landing. So my questions are:
> 1. Does it make sense to add it to this group's charter[4]?
> 2. If so, who would like to edit it? James?
>
> -Tony
>
> [1]
> http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2011-July/032343.html
> [2] https://bugs.webkit.org/show_bug.cgi?id=66684
> [3] https://bugzilla.mozilla.org/show_bug.cgi?id=539095#c29
> [4] http://www.w3.org/2011/04/webperf
>
>
>
>
>
Received on Friday, 24 February 2012 13:31:00 GMT

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