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Re: Motion animation freezing on a discontinuity in the path

From: Dr. Olaf Hoffmann <Dr.O.Hoffmann@gmx.de>
Date: Mon, 31 Jul 2006 11:34:55 +0200
To: www-svg@w3.org
Cc: cam@mcc.id.au
Message-Id: <200607311134.55991.Dr.O.Hoffmann@gmx.de>


I think, it has to do more with SMIL as with SVG.
The timing model of SMIL is applicable here 
(just my interpretation):
We have two intervals for the animation
without end ( '[' for an inclusion of the border,
')' for exclusion): [0s, 2s) and [2s, 4s).
On the other hand we have an interval
determined from begin, end and dur, this
is [0s, 2s).

This means, normally the circle is never at 
the position (200,100), but if frozen exactly
at 2s with end, it stops at (200,100), this is
mathematically a one-side limit. This can 
be seen for example with the adobe plugin or 
Opera - I think, they are correct.

Interesting testcase to see, if the SMIL
timing model is implemented correctly.
I already tried similar things with 
calcMode discrete.

The only problem with this interpretation
is, that SVG has not really an interval
model for paths and stroke-dasharray as
already mention in relation to slightly
different problems (even without animation).

>With this animation:
> <circle cx="0" cy="0" r="10">
>    <animateMotion dur="4s" end="2s" calcMode="paced" fill="freeze"
>                   path="M 100,100 L 200,100 M 100,200 L 200,200"/>
>  </circle>
>should the animation freeze with the position (200,100) or (100,200)?
Received on Monday, 31 July 2006 09:34:45 UTC

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