- From: Doug Schepers <schepers@w3.org>
- Date: Fri, 17 Oct 2008 21:41:13 -0400
- To: "Dr. Olaf Hoffmann" <Dr.O.Hoffmann@gmx.de>
- CC: www-svg@w3.org
Hi, Dr. Olaf- Dr. Olaf Hoffmann wrote (on 10/1/08 10:07 AM): > > in 16.2.9 it is mentioned: > > ## > If a 'by' value is used on a non-scalar data type ( such as color or > transform ), the starting 0 delta value is to be conceptually > considered as 'identity'. > ## > > If this is to be interpreted within some algebraic relation, it is required to > define or to specify the binary operation a value is considered the > 'identity' for. Luckily already in SMIL is defined, that this type of > animation is only available, if additive animation is supported. > The SMIL 3 CR already explains in more detail, that the starting '0' is > "the neutral element for addition for the domain of the target attribute". > Therefore the binary operation must be the addition (even or especially > because not explictly mentioned), this means if X is a value, then > X + 'identity' = X, with '+' beeing an additive operation for the space > X belongs to. > For example for RGB-colors this means the 'identity' is black, #000, > rgb(0,0,0) etc; > for vector like types this is the origin (zero length, any direction); > for lists of numbers (lengths etc) it might be a list of zeros > - right? Yes, that is the idea. In our offlist exchange, you seemed to indicate that this is already clarified in SMIL3. Is there any need for a change in SVG 1.2 Tiny, in that case? If there is a contradiction, we will certainly look at changing it, so please give us the details. If there is no need for a change and your comment is satisfied, please let us know. Regards- -Doug
Received on Saturday, 18 October 2008 01:41:22 UTC