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Re: animateTransform, underlying value and additive="sum"

From: Dr. Olaf Hoffmann <Dr.O.Hoffmann@gmx.de>
Date: Thu, 8 Feb 2007 19:44:57 +0100
To: www-svg@w3.org
Message-Id: <200702081944.58023.Dr.O.Hoffmann@gmx.de>


"If 'from' or 'to' attributes are not specified, the underlying value (see  
SMIL discussion of animation function values) is the corresponding  
identity transformation value."

I think the original intent of the author of this paragraph was to
clearify or simplify some complex behaviour for example to avoid
an implicite necessity of an animation of the matrix-attribute.
There are maybe additional problems with constructions like
transform="ref(svg)" as underlying value.
Anyway the result is a simple contradiction if values,
from-to, from-by or by animations are used and a logical analysis
of the meaning of this paragraph is hard work and does not cover
at the end a to-animation - this is the only case without any 
contradiction, but with the biggest problems for implementors. 
My estimate is, that just a small minority of readers of this paragraph
is able to get the correct meaning of it - to get the intended meaning
is maybe simpler, but not relevant ;o)
Therefore more problems are added with this paragraph as solved.

Because animateTransform is specific for SVG and not mentioned in
SMIL, the easiest simplification, if one is really needed, is to say, that
only the values attribute is allowed and no to, from or by for 
SVG Tiny 1.2 to avoid further problems in this specification. 
Received on Thursday, 8 February 2007 18:47:41 GMT

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