opengl in 1.7 on Win7 again

[Luke J. West]

Hi,

I forgot to mention in my previous email that glxgears works fine - even
though my sample opengl program bombs out like this...

sh-3.2$ ./sample.bin
freeglut (./sample.bin):  ERROR:
Internal error <Visual with necessary capabilities not found> in
function fgOpenWindow
Segmentation fault (core dumped)

Where's the first place you would check if you had this problem? *any*
help appreciated. any suggestions as to where to look or what to check
will be most helpful.

Thanks again,

Luke

-- previous msg...

Hi,

I've just installed Cygwin 1.7 (Win7 Hmoe Premium) and am trying to get
started with OpenGL.

I have a sample OpenGL program (sample.c) and I get the following.

sh-3.2$ gcc -o sample.bin sample.c -lglut -lglu -lgl

sh-3.2$ ./sample.bin
freeglut (./sample.bin):  ERROR:  Internal error <Visual with necessary
capabilities not found> in function fgOpenWindow
Segmentation fault (core dumped)

sh-3.2$ glxinfo
name of display: :0.0
display: :0  screen: 0
direct rendering: Yes
server glx vendor string: Brian Paul
...
64 GLX Visuals
   visual  x  bf lv rg d st colorbuffer ax dp st accumbuffer  ms  cav
 id dep cl sp sz l  ci b ro  r  g  b  a bf th cl  r  g  b  a ns b eat
----------------------------------------------------------------------
0x21 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16 16  0 0 None
0xc2 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16 16  0 0 None
0xc3 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16 16  0 0 None
0xc4 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16 16  0 0 None
....


Any advice or suggestions would be very much appreciated

Luke

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[Jon TURNEY]

On 05/11/2009 11:32, Luke J. West wrote:

> I forgot to mention in my previous email that glxgears works fine - even
> though my sample opengl program bombs out like this...
>
> sh-3.2$ ./sample.bin
> freeglut (./sample.bin):  ERROR:
> Internal error<Visual with necessary capabilities not found>  in
> function fgOpenWindow
> Segmentation fault (core dumped)
>
> Where's the first place you would check if you had this problem?

Although you probably will not consider this helpful, the first place to look
is: in your sample.c

You haven't shown any evidence that the error message reported isn't correct
i.e. your sample code is causing freeglut to ask for a visual which the server
can't give it.

> *any*
> help appreciated. any suggestions as to where to look or what to check
> will be most helpful.

Looking at the source code for fgOpenWindow and fgChooseVisual [1], the
specification of glXChooseVisual, the set of visuals available as listed by
glxinfo and how your sample code configures freeglut would probably be
informative...

[1]
http://freeglut.svn.sourceforge.net/viewvc/freeglut/trunk/freeglut/freeglut/src/freeglut_window.c?view

> I've just installed Cygwin 1.7 (Win7 Hmoe Premium) and am trying to get
> started with OpenGL.
>
> I have a sample OpenGL program (sample.c) and I get the following.
>
> sh-3.2$ gcc -o sample.bin sample.c -lglut -lglu -lgl
>
> sh-3.2$ ./sample.bin
> freeglut (./sample.bin):  ERROR:  Internal error<Visual with necessary
> capabilities not found>  in function fgOpenWindow
> Segmentation fault (core dumped)
>
> sh-3.2$ glxinfo
> name of display: :0.0
> display: :0  screen: 0
> direct rendering: Yes
> server glx vendor string: Brian Paul
> ...
> 64 GLX Visuals
>     visual  x  bf lv rg d st colorbuffer ax dp st accumbuffer  ms  cav
>   id dep cl sp sz l  ci b ro  r  g  b  a bf th cl  r  g  b  a ns b eat
> ----------------------------------------------------------------------
> 0x21 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16 16  0 0 None
> 0xc2 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16 16  0 0 None
> 0xc3 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16 16  0 0 None
> 0xc4 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16 16  0 0 None
> ....

--
Jon TURNEY
Volunteer Cygwin/X X Server maintainer

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[Luke J. West]

Thanks Jon,

On the contrary - it turned out to be very helpful. I tried again using
this exceedingly minimal glut app:-

#include <GL/glut.h>

void func() {}

int main(int argc, char* argv[]) {
 glutInit(&argc, argv);
 glutCreateWindow("Jon rocks!");
 glutDisplayFunc(func);
 glutMainLoop();
 return 0;
}

Once I supplied "-display 127.0.0.1:0.0" as cmdline args it ran a treat.
I may not be out of the woods, but I now have a positive result and a
negative one, and that's enough to go hunting on my own. It just goes to
show that even after (more than) 3 decades of coding, you can still miss
the blindingly obvious!

Thanks again,

Luke


On Thu, 05 Nov 2009 23:43:07 +0000, "Jon TURNEY"
<jon.turney@...> said:

> On 05/11/2009 11:32, Luke J. West wrote:
> > I forgot to mention in my previous email that glxgears works fine - even
> > though my sample opengl program bombs out like this...
> >
> > sh-3.2$ ./sample.bin
> > freeglut (./sample.bin):  ERROR:
> > Internal error<Visual with necessary capabilities not found>  in
> > function fgOpenWindow
> > Segmentation fault (core dumped)
> >
> > Where's the first place you would check if you had this problem?
>
> Although you probably will not consider this helpful, the first place to
> look
> is: in your sample.c
>
> You haven't shown any evidence that the error message reported isn't
> correct
> i.e. your sample code is causing freeglut to ask for a visual which the
> server
> can't give it.
>
> > *any*
> > help appreciated. any suggestions as to where to look or what to check
> > will be most helpful.
>
> Looking at the source code for fgOpenWindow and fgChooseVisual [1], the
> specification of glXChooseVisual, the set of visuals available as listed
> by
> glxinfo and how your sample code configures freeglut would probably be
> informative...
>
> [1]
> http://freeglut.svn.sourceforge.net/viewvc/freeglut/trunk/freeglut/freeglut/src/freeglut_window.c?view
>
> > I've just installed Cygwin 1.7 (Win7 Hmoe Premium) and am trying to get
> > started with OpenGL.
> >
> > I have a sample OpenGL program (sample.c) and I get the following.
> >
> > sh-3.2$ gcc -o sample.bin sample.c -lglut -lglu -lgl
> >
> > sh-3.2$ ./sample.bin
> > freeglut (./sample.bin):  ERROR:  Internal error<Visual with necessary
> > capabilities not found>  in function fgOpenWindow
> > Segmentation fault (core dumped)
> >
> > sh-3.2$ glxinfo
> > name of display: :0.0
> > display: :0  screen: 0
> > direct rendering: Yes
> > server glx vendor string: Brian Paul
> > ...
> > 64 GLX Visuals
> >     visual  x  bf lv rg d st colorbuffer ax dp st accumbuffer  ms  cav
> >   id dep cl sp sz l  ci b ro  r  g  b  a bf th cl  r  g  b  a ns b eat
> > ----------------------------------------------------------------------
> > 0x21 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16 16  0 0 None
> > 0xc2 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16 16  0 0 None
> > 0xc3 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16 16  0 0 None
> > 0xc4 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16 16  0 0 None
> > ....
>
> --
> Jon TURNEY
> Volunteer Cygwin/X X Server maintainer

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