Re: [Gimp-developer] Cage transform and Warp transform

[Elle Stone <ellestone ninedegreesbelow com>]

On 11/28/2017 10:32 AM, Jehan Pagès wrote:
> Hi!
>
> On Tue, Nov 28, 2017 at 3:54 PM, Elle Stone
> <ellestone ninedegreesbelow com> wrote:

> > I wanted to somewhat reshape some curved lines in a drawing, and tried the
> > Cage transform, which I remember using a long time ago. After selecting the
> > points, it took a long time for the cage transform to calculate the cage.
> > But when trying to move a point on the cage, nothing happened. During all of
> > this calculating plus "nothing happened", these lines were printed over and
> > over to the terminal:
> >
> > (gimp-2.9:30657): GEGL-CRITICAL **: gegl_buffer_get: assertion
> > 'GEGL_IS_BUFFER (buffer)' failed
> >
> > Is there a bug?
>
> Well if it doesn't work and if there is a GEGL-critical, yes there is
> definitely a bug. ;-)
> You should run gimp with --gtk-g-fatal-warnings to force it to crash
> when it gets a warning. Doing this inside gdb will get you a
> stacktrace which led to this warning so that you can copy-paste it in
> a bug report. :-)

Hi Jehan,

What is the actual command to type to get GIMP to run with 
--gtk-g-fatal-warnings? I kept getting terminal output that indicated 
that GIMP couldn't find the file "--gtk-g-fatal-warnings".

Though in this case it really doesn't matter as I haven't been able to 
produce the same terminal output as before. Sorry for the noise!

I still think I'm not doing something correctly with Cage transform. But 
as Warp worked perfectly for the task at hand, I'm very glad that the 
cage transform didn't work as expected, because otherwise I wouldn't 
have tried the Warp tool.

> > Jehan, is there any possibility that this warp transform could be made to
> > work symmetrically, perhaps via the symmetric painting dialog? Or maybe it
> > already does, but somehow I did something wrong?
>
> No. The symmetries work for paint tools (children of GimpPaintTool
> class), but the warp transform is not a paint tool (I mean, not in our
> code; it is derived directly from GimpDrawTool, which is lower level
> class).
> Of course, in theory, that could be changed. But this is not how it is
> implemented currently.

Thanks! for letting me know. I had a feeling the Warp tool wasn't 
code-wise related to the Paint tools, but wanted to ask to make sure. 
Whhether it can work symmetrically or not, it's a wonderful way to 
transform portions of an image.

Best,
Elle