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Re: frozen value for discrete animation

From: Dr. Olaf Hoffmann <Dr.O.Hoffmann@gmx.de>
Date: Fri, 6 Apr 2007 16:42:42 +0200
To: www-smil@w3.org
Message-Id: <200704061642.42980.Dr.O.Hoffmann@gmx.de>

Hello,

I think there is another problem concerning frozen animation,
maybe just a wording problem. I discussed this with several 
people, but the result was always the same, but from my point of
view somehow useless for animation, but maybe I am wrong with this.

For 'Freezing animations' (SMIL 2.1, 3.3.5) it is noted:

'If AD is an even multiple of d, i.e. AD = d*i for some positive 
 integer i , and the animation is non-cumulative, f_f(t) = f(d).'

There a two remarkable points about this - why only 'some' and not
'any' or 'a' positive integer and why only even multiples, why not 
odd multiples too?
Ok, if odd multiples are excluded by this rule, this means that
some integers are only even integers, but then it should be much
more precise to write:
'AD = d*2*i for a positive integer i'

Of course 'even' can have several meanings, therefore
I looked for another interpretation for 'even multiple'
in wikipedia and other resources, but all I could find is 
really:
'AD = d*2*i for a positive integer i'.
I cannot see, why to distinguish between odd and even
multiples? Is there any reason?

This causes another problem for odd multiples, because then
the following has to be applied:

'If AD is not an even multiple of the simple duration d, 
 f_f(t) = f_i(t), where i = floor(t/d).'
 
For example with AD=d (odd multiple) we get 1 = floor(d/d)
f_f(t=AD) = f_1(t=0)
if the animation is repeated (and stopped for example with
an end attribute) and an undefined value, if the animation 
is not repeated. Is this correct?


Thanks in advance for a clarification

Olaf Hoffmann
Received on Friday, 6 April 2007 15:02:07 GMT

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