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

From: Dr. Olaf Hoffmann <Dr.O.Hoffmann@gmx.de>
Date: Tue, 8 Mar 2011 13:20:20 +0100
To: www-svg@w3.org
Message-Id: <201103081320.20582.Dr.O.Hoffmann@gmx.de>
Hello,

well, with the behaviour defined in SMIL the discrete to-animation
is comparable to a set-animation. Is it confusing too, that set sets
the value at the begin of the active duration and not in the middle?
And it is comparable with a values-animation, if values contains
only one list item. Is it confusing too, that this type of animation
sets the value at the begin of the active duration and not in the
middle? 

I think, because it is defined in all SMIL versions in the same way,
there should be no inconsistent change in  SVG 1.1 Second Edition,
resulting mainly in even more complications.

Because SMIL defines specific rules for to-animations in general,
it is obvious, that keyTimes have no effect for to-animations, as
attributes additive, accumulate, keySplines etc. The situation for
keyTimes is therefore not specific. 
(Interpretation of keyTimes is interesting as well,
of course for a  values-animation, if there is only on list item 
in values ;o)

It is nice, that to-animations are implemented better in
Mozilla/Gecko than in most other viewers, this indicates, that
a useful feature is implementable, and maybe one time, bugs
in other viewers are fixed, it will really become usable for authors ;o)

But there is indeed one thing, that can be improved in SVG 1.1 Second Edition,
we haven't seen before. 
Because discrete to-animations for animateTransform are not affected
by the postmultiplication problem, one should reduced the related paragraph
of undefinedness to continuous to-animations for animateTransform.
It is defined anyway in the first edition, there is no real problem, therefore
no need to undefine it for the second edition ;o)
Because set-animations are not applicable for the transform attribute,
discrete to-animations could be really useful. For most other attributes
however, discrete to-animation are typically not very interesting, because
single-item-values-animations or set-animations can be used.

Olaf
Received on Tuesday, 8 March 2011 12:20:58 GMT

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