[CREATE] OpenRaster and filters

[Cyrille Berger]

Hello,

In the following monthes I am going to try to push OpenRaster forward, and 
from time to time will raise on the list one of the issue of [1] and ask for 
opinions on how to solve the issue, until we have been able to find a 
concensus on the subject.

The most urgent issue (even if it appears at the bottom of [1]) to solve is 
how to serialize filters:

We have three ways (at least) of doing this:
1) <filter name="standard:blur" type="standard:gaussianblur">
   <params>
     <param name="radius">10</param>
   </params>
 </filter>

2) <filter:standard:blur radius="10" />

3) <filter:standard:blur>
  <radius>10</radius>
 </filter:standard:blur>

The main weakness of 1) is that this doesn't allow DTD/RelaxNG checking and 
validation, but it makes easier to extend since you don't have to write the 
schema for your filter

While 2) and 3) have the advantage to allow DTD/RelaxNG validation, while 
still allowing extensability. 2) is similar to the SVG syntax.

3) and 1) have the advantage that you can easily pass more complex parameters 
to the filter, for instance, the mask on a layer could be serialize as:

<filter:standard:mask>
  <mask> <layer src="alphamask.png" /> </mask>
</filter:standard:mask>

I would like to hear your opinions on the subject, as well as other 
suggestions.

[1] http://create.freedesktop.org/wiki/index.php/OpenRaster/Open_for_comments
-- 
Cyrille Berger