[CREATE] OpenRaster fallbacks (proposal/RFC)

[Martin Renold]

Sorry for replying to myself again ;-)

On Sun, Aug 09, 2009 at 10:45:41PM +0200, Martin Renold wrote:
> Two OpenRaster loaders should probably be supported: the OpenRaster
> importer, and the native OpenRaster application that keeps XML in memory. 
> 
> The native application uses all caches and allows the user to navigate and
> selectively edit the stack.

Actually, such a "native openraster" application is a rather high goal that
nobody seems to be working towards at the moment.  Let's focus on supporting
only "OpenRaster importer" applications.

An importer only uses fallbacks of <render> tags, because those can be
composited without removing other elements.  This includes text, svg and
pattern generators, but not fallbacks for missing layer modes or filters.

So, let's not bother saving filter/layermode fallbacks at all.


Two possible exceptions. 1) An application that does not support nested
layer stacks will be forced to collapse them somehow.  If a <stack> is
composited OVER, then it's no problem.  But if it uses some compositing
mode, the importer might be better off by using its fallback instead of
loading the elements below it.  2) A fully-rendered "fallback" of the image,
according to http://create.freedesktop.org/wiki/OpenRaster#Likely_Problems

bye,
Martin