Re: [Gegl-developer] Journal for changes to a GEGL graph

[Jon Nordby <jononor gmail com>]

On 11 June 2012 09:39, Jasper van de Gronde <th v d gronde hccnet nl> wrote:
> On 08-06-12 23:43, Jon Nordby wrote:
> > ...
> > For instance adding a layer in GIMP may result in 5, 10 or even more
> > changes to the GEGL graph. Grouping these into one transaction then
> > allows GIMP to treat them as one logical change.
> > ...
> > > Which cool things do you think of?
> >
> > - Sharing the undo/redo history across applications using GEGL
> > - Allowing the undo/redo history to be saved together with a document.
> > When you open an old file, you have all the history of it, since it
> > started existing.
> > - Working on the same document from two different applications at the same time.
> > - Preserving non-linear histories
> > - Browsing through the entire timeline of a document
>
> This would imply that the GEGL "model" would have to be translatable
> (ideally one-on-one) to the document model. Or where you just referring
> to the case when people are actually editing GEGL graphs, rather than
> some other image format?

Yes, this implies that a mapping between the GEGL graph and the
internal document model is possible.
That same problem comes up when talking about structured import/export
of documents (ref: "[Gegl-developer] Possible strategy for improving
file format support in GEGL" thread).

How feasible this is for actual applications out there remains to be
seen. I think it should be doable for MyPaint at least, and more
GEGL/graph centric applications like a node-based compositor or apps
that just do "operation stacking" will likely be simpler.

Once we get some real-life experience in this problem area we can
hopefully establish some best practices.

-- 
Jon Nordby - www.jonnor.com