Re: [Gegl-developer] enable a GEGL graph evolution log

[Jon Nordby <jononor gmail com>]

On 10 September 2016 at 23:12, Philip R. Dutton
<fooledbyprimes gmail com> wrote:
> I ran across much talk and some implementation of GEGL.  I can see how the
> Undo /History features would make great use of the DAG graph data structure
> used by GEGL.
>
> Q: How hard will it be to log the GEGL graph evolution to disk in real-time
> using perhaps a rolling log?   What is the best approach for an idea like
> this?

For the approach, pippin and I sketched together a basic spec a couple
of years back.
https://mail.gnome.org/archives/gegl-developer-list/2012-June/msg00004.html
https://git.gnome.org/browse/gegl/tree/docs/journal.txt

"How hard" is always a tricky question to answer... One would have to
implement such a Journal, including persistence and wiring up to
follow GEGL graph changes. These tasks would require one to be fairly
comfortable with C programming. Some GObject experience would be a
benefit.

*However*, I believe the GEGL graphs used in GIMP are still "short
lived" - used for the duration of one operation and then applied
destructively. Meaning that there is no one graph which represents the
entire document and thus the evolution of your artwork.
It may be possible to try to stich together a sort of journal from all
these , but probably there would be need for a significant amount of
GIMP specific logic in addition... Not sure of the feasibility here.


-- 
Jon Nordby - www.jonnor.com