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Re: [css3-transitions]

From: Dean Jackson <dino@apple.com>
Date: Wed, 1 Apr 2009 07:24:56 +1100
Cc: www-style@w3.org
Message-Id: <6AFD5FCD-1307-476A-A940-9FB180B4DE32@apple.com>
To: Dr. Olaf Hoffmann <Dr.O.Hoffmann@gmx.de>

On 31/03/2009, at 11:30 PM, Dr. Olaf Hoffmann wrote:

>>
>>> 5. in section 4. it is not noted, how to animate
>>> between keywords (they are mentioned
>>> in 5. too). This will be the same as for
>>> 'visibility'? Or are the keywords always
>>> converted into numbers for the current
>>> animatable properties (seems to apply
>>> only to vertical-align).
>>
>> We'll have to define this for every keyword-based property. I'm not a
>> big fan of these properties being animated anyway.
>>
>
> For transitions - as I understand it now - it does not look
> very useful, indeed. For animations (well discrete animations
> are not really available in the CSS animation draft) this is
> different.
> Therefore the list of transitionable properties could be much
> more restrictive than the list of animatable properties.

No. Transitions and animations are fundamentally very similar. The  
difference is how they are triggered (one via style changes, the other  
is declarative).

>
>>> About paint-server - how to interpolate
>>> between a radial and linear gradient?
>>> Is the direction vector for linear gradients
>>> interpolated too if different? Respectively
>>> the cx, cy, fx, fy, r for a radial gradient?
>>> What about gradientUnits, gradientTransform,
>>> spreadMethod, xlink:href? Or is the interpolation
>>> done for each pixel of the output separately?
>>> I think, it needs some more explanations
>>> how this should work.
>>
>> It's still up in the air how gradients should transition. For regular
>> images, like background, they should probably crossfade (with the
>> opacity used in the transition calculated by the timing function..  
>> and
>> the reverse for the outgoing image).
>
> - more fun, if width or height of the two images differ, with and  
> without
> background repetition and and implications on positioning and all
> those complications would require a quite long prose to define the
> same effect for all implementations unambiguously for such complex
> issues ...

No. This is all defined by CSS. We animate the property values.

Dean
Received on Tuesday, 31 March 2009 20:25:40 GMT

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