Re: GTK+ GLArea widget and GIMP problems

[Carlos Pereira <carlos pehoe civil ist utl pt>]

> > > Whenever I run an application that uses the GTK+ GLArea widget, GIMP's
> > > screen grab function stops working. I tried getting a particular window
> > > and getting the entire screen, I hear a beep and then nothing happens.

> > > I tried using XV and it says something about `cannot get Window' and
> > > that's it.

Hi,
I fully confirm what you said regarding 
Gimp, this is the exact message I get:

xwd: Warning. Error in XWD-color-structure (flag)
xwd: EOF encountered on reading
xwd: load_image (xwd): XWD-file /home/carlos/.gimp/tmp/gimp_temp.294110.xwd has format 2, depth 24
and bits per pixel 24.
Currently this is not supported.

However, XV works for me, I have been doing screenshots
from my GTK-GTKGLArea-Mesa app using XV. I save these images
as .gif, .png whatever, and THEN handle them with Gimp.

I am using GTKGLArea 1.2.1 and Mesa 3.0/3.4, both Gimp and XV
versions are rather old, the ones that came with RH5.2

> > Because the OpenGL API does not contain any platform or window system
> > specific calls, a mechanism for integrating OpenGL calls with your
> > platform is required.  With X, that mechanism is the GLX server
> > extensions.  GLX generally works behind the scenes, keeping
> > OpenGL-specific state associated with otherwise "normal" X resources
> > like visuals, windows, etc.  What's being suggested is that that's
> > somehow interfering internally with XGetImage().  You might explore
> > upgrading your GLX and/or OpenGL implementations.
>
> I'm currently using the latest Mesa3D 3.5
>
> Should I notify the author of Mesa3D about this problem?

I don't think so. I suggest installing the latest version
of Gimp and if that does not work, notify the Gimp team.

Try again with XV. The message that you get "cannot get Window"
is probably due to a different thing. I just do:

xv<return>
Grab<Click> /* Grab dialog comes up */
Grab<Click> /* on the Grab dialog */
pointer over the screenshot window and <Click>

Carlos