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Re: Specifying window.performance.now()

From: James Robinson <jamesr@google.com>
Date: Wed, 29 Feb 2012 13:59:42 -0800
Message-ID: <CAD73mdL5Nw_tPyyNr=wQo-bJYOLtKRyp46AyuaqQXmg0+qqdgQ@mail.gmail.com>
To: Boris Zbarsky <bzbarsky@mit.edu>
Cc: public-web-perf@w3.org
On Wed, Feb 29, 2012 at 1:55 PM, Boris Zbarsky <bzbarsky@mit.edu> wrote:

> On 2/29/12 4:52 PM, James Robinson wrote:
>> Technically speaking using the parameter to track animation progress is
>> OK, so long as the page isn't trying to compare the parameter to JS
>> Date.now()s.
> It's hard to track progress without comparing to "the time I started the
> animation".
> And that last is only available via Date.now in most UAs.  :(
>  My reading of the code that Google Maps is using for animations today is
>> that it's always using the value of Date.now() to update its internal
>> progress.
> Good!  Well, bad for the actual behavior of the animations, but good for
> making this backwards-incompatible change.  ;)

Agree on both points.  We need to change our behavior before authors get
their act together!

I think we're willing to make the change to requestAnimationFrame for
WebKit and see how it goes.  Would Mozilla and Microsoft be willing to try
it as well?

- James

> -Boris
Received on Wednesday, 29 February 2012 22:00:14 UTC

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