Re: Proposal: Fix discrete to animation in SVG 1.1 Second Edition

Hi Cameron,

Thanks for looking into this.

On 28 March 2011 07:18, Cameron McCormack <[email protected]> wrote:
>> =A0 In order to provide intuitive and consistent behavior when the start=
ing
>> =A0 value of an animation is explicitly specified by a "from" attribute =
(e.g.
>> =A0 "from-to animation") and when the underlying value is used (e.g. "to
>> =A0 animation") the behavior of discrete to-animation in SVG deviates fr=
om the
>> =A0 definition in SMIL Animation.
>
> This paragraph confused me on first read. =A0I think it would be slightly
> clearer like this:
>
> =A0In order to provide behavior that is intuitive and consistent between
> =A0discrete animations with an explicitly specified "from" attribute
> =A0(e.g. "from-to animation") and those where the underlying value is
> =A0used (e.g. "to animation"), the behavior of discrete to-animation in
> =A0SVG deviates from the definition in SMIL Animation.

Sounds great.

> I made a simple test, too:
>
> =A0http://dev.w3.org/SVG/profiles/1.1F2/test/svg/animate-elem-92-t.svg
>
> I would prefer to make this change only if we test it (by approving the
> above test) and if we have at least two passing implementations of it.
> As you mention, Opera and WebKit ignore keyTimes on discrete to-
> animations, so of the above implementations (which are the only ones I
> currently have access to that implement animation) only Batik passes the
> test.

Oh, that's a shame. Fixing Gecko should hopefully be as simple as
backing out the patch where we "fixed" this (bug 544855). I'm happy to
do that if you're confident we can get this changed in the spec.
Otherwise, I wonder what Abbra does?

Of course, that depends on resolving the issue about whether keyTimes
should affect to animations that Erik raised. I believe SMIL
explicitly says that it does:

  The keyTimes and keySplines attributes may also be used with the
from/to/by shorthand forms for specifying values[1]

Best regards,

Brian

[1] http://www.w3.org/TR/SMIL/smil-animation.html#animationNS-Interpolation=
Keysplines