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Re: [SMIL30 FWD] calcMode, keyTimes and examples

From: Sjoerd Mullender <sjoerd@acm.org>
Date: Tue, 29 May 2007 10:20:37 +0200
Message-ID: <465BE255.9010706@acm.org>
To: "Dr. Olaf Hoffmann" <Dr.O.Hoffmann@gmx.de>
CC: www-smil@w3.org, Patrick Schmitz <cogit@ludicrum.org>
This is indeed an inconsistency which should be fixed.

Patrick, any ideas?  I'm referring to the first problem reported here
since I already have a tentative resolution for the second (fix both
example and accompanying text--see the other thread).

Dr. Olaf Hoffmann wrote:
> Hello,
> 
> I would like to (re)report a problem in the working draft
> of SMIL 3 (already reported for previous versions or
> working drafts of SMIL, but not corrected or discussed
> yet).
> 
> In 3.9.1 SMIL 3.0 SplineAnimation Module Attributes
> (Calculation mode attributes)
> it is noted about keyTimes:
> 
> ' 
>   For linear and spline animation, the first time value in the list must be 0, 
>   and the last time value in the list must be 1.
> '
> 
>  Later in the section "Interpolation with keySplines" we find the example:
>  
> ' 
>   <animate attributeName="foo" from="10" to="20" 
>      dur="10s" keyTimes="0.0; 0.7"
>      calcMode="spline" keySplines=".5 0 .5 1" />
> 
>    The value will change from 10 to 20, using an "ease-in/ease-out" curve 
> specified 
>    by the keySplines values. The keyTimes values cause the value of 20 to be 
> reached 
>    at 7 seconds, and to hold there for the remainder of the 10 second simple 
> duration.
> '
> 
> Well the behaviour described for the examples sounds useful, but because
> the first cited section specified the last value has to be 1, this does not 
> fit together. 
> Is it possible to change the 'the last time value in the list must be 1' or
> the example?
> 
> 
> Another problem occurs with this example in the section "Examples of advanced 
> uses of calcMode"
> 
> '
>   <animateColor attributeName="color" dur="10s" calcMode="discrete"
>      values="green; yellow; red" keyTimes="0.0; 0.8;" />
> '
> 
> One time value is missing or invalid, because it is specified for keyTimes:
> '
> Each time value in the keyTimes list is specified as a floating point 
> value between 0 and 1 (inclusive), representing a proportional offset 
> into the simple duration of the animation element.
> '
> and 
> '
> If a list of keyTimes is specified, there must be exactly as many values in 
> the keyTimes list as in the values list.
> '
> and
> '
> Each successive time value must be greater than or equal to the preceding 
> time value.
> '
> 
> Well the last time value '' is no floating point value between 0 and 1 and '' 
> is not greater or equal to the preceding value '0.8'.
> Therefore this example does not fit to the description of the keyTimes 
> attribute, too.
> 
> 
> 
> 
> Best wishes...
> 
> 


-- 
Sjoerd Mullender


Received on Tuesday, 29 May 2007 08:20:50 GMT

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