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Re: [css3-transitions] Back-tracking transition-timing-function

From: Simon Fraser <smfr@me.com>
Date: Wed, 05 May 2010 23:46:01 -0700
Cc: Alex Meiburg <timeroot.alex@gmail.com>, www-style@w3.org
Message-id: <C6A50FD7-B923-471F-960D-A1081E4C659C@me.com>
To: Erik Arvidsson <arv@chromium.org>
We modeled transition/animation timing functions after SVG keySplines:
http://www.w3.org/TR/2001/REC-smil-animation-20010904/#KeySplinesAttribute

which limit the values between 0 and 1.

We'd be OK lifting this restriction for CSS (assuming people are happy with the divergence from SVG), but we'd have to make some rules about how properties like color get clamped when you go outside the 0->1 range.

Simon

On May 5, 2010, at 7:33 PM, Erik Arvidsson wrote:

> I modified my local build of webkit to remove the limitations on the timing function and everything just works (famous last words).
> 
> erik 
> 
> 
> On Wed, May 5, 2010 at 19:20, Alex Meiburg <timeroot.alex@gmail.com> wrote:
> Nice necro. ;-)
> 
> I thought about it, I suppose it wouldn't have to be invertible then, would it? Only single-valued as it stands, but bounce animations shouldn't break anything...
> 
> As was already meantioned, though, limiting the coordinates to the unit square prevent and bouncing. It seems that one could have legitimate functions, then, with the coordinates extended over the [0,1] range in the x or y direction.
> 
> ~6 out of 5 statisticians say that the number of statistics that either make no sense or use ridiculous timescales at all has dropped over 164% in the last 5.62474396842 years.
> 
> On Wed, May 5, 2010 at 5:20 PM, Erik Arvidsson <arv@chromium.org> wrote:
> On Thu, Apr 22, 2010 at 17:29, Tab Atkins Jr. <jackalmage@gmail.com> wrote:
> Within that range, you're guaranteed that the curve will be
> monotonically increasing (or maybe just non-decreasing?), and thus is
> invertible.
> 
> Why is that a requirement? Removing the limitation allows bounce like animations without the need to switch to using keyframes.
> 
> -- 
> erik
> 
> 
> 
Received on Thursday, 6 May 2010 06:46:57 GMT

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