Problem with gl surface (seg-fault)

Hi, I’d like to use the opengl option to draw 2D histograms, so I’m trying gltf3.C and glsurfaces.C tutorials but seems that somethings don’t work: the images in canvas are black or in general not appears like images in release notes (in attachment there are the snapshots) and when the pointer pass over the pad in the root shell appears the message:

*** Break *** segmentation violation

Where is the problem?

I’m using root 5.10, compiled from sources, on a laptop with kubuntu dapper installed and a nvidia card.

Other tutorials like glViewerExercise.C and glViewerLOD.C work well.




Hello.

I do not have “kubuntu dapper” (I even do no know what it is :slight_smile: ).
Can you modify the source code of ROOT and recompile? I can send you modifications for gl module to try fix the problem.

[quote=“tpochep”]Hello.

I do not have “kubuntu dapper” (I even do no know what it is :slight_smile: ).
Can you modify the source code of ROOT and recompile? I can send you modifications for gl module to try fix the problem.[/quote]

Great, I cite my distribution to describe the environment, is not something to eat :laughing:

For the code: great, send to me the patch.

many thanks, guido

It was a joke :slight_smile:))

To say the truth, I do not remember what was in version 5-10-00.
In your $ROOTSYS/gl/src/TX11GL.cxx -
if your version has function TX11GLManager::ReadGLBuffer, please, try the following:
before the line

add

glPixelStorei(GL_PACK_ALIGNMENT, 1);.

I’m not shure, if it helps, but at least we can try (recently, I have some problems with incorrect alignment - overwriteen memory).

uhm… don’t work :confused:

I add the line code but the results are the same.

If you are interested the problem there is in 5-11-02 version too.

Excuse me for stupid question :slight_smile: Did you recompile after addition?

TX11GL code seem to be the same in version 5-11-02 (differences are small).

Yes, I’m interested but I do not have kubuntu to fix the bug. After seg fault message, what is in stack trace?

[quote][quote]
I add the line code but the results are the same.
[/quote]

Excuse me for stupid question :slight_smile: Did you recompile after addition?
[/quote]
yes, yes I recompiled and reinstalled ROOT :wink:

[quote]

TX11GL code seem to be the same in version 5-11-02 (differences are small).

Yes, I’m interested but I do not have kubuntu to fix the bug. After seg fault message, what is in stack trace?[/quote]

For the glsurfaces.C example the erro messages are:

 *** Break *** segmentation violating
Root>  Error: class,struct,union or type RootCsg not defined /opt/root/tutorial/glsurfaces.C:41

 *** Break *** segmentation violating
Root>
 *** Break *** segmentation violating
Root>
... 
error message repeated any time I'm over the pad

in the gltf3.C there is only a sequence of segment violation (no seg-fault I was wrong)

What if you try to start ROOT under gdb?

There is a problem… How I can start ROOT in gdb?

if I try with

receive an usr1 signal and ROOT seems stopped, what is the method?

Please, try

gdb root.exeand after that press r in command line to start ROOT.

the answer of root.exe (now work in gdb :smiley:) in my opnioni is not very long, now I have some network problem and cannot send to you the bt report (in any case 6 lines).

The 2nd line cite an address in: glXChannelRecSyncSGIX from /usr/lib/libGL.so.1

so seems the the problem depends on my libGL :frowning:

Hello.

[quote]the answer of root.exe (now work in gdb :smiley:) in my opnioni is not very long, now I have some network problem and cannot send to you the bt report (in any case 6 lines).
The 2nd line cite an address in: glXChannelRecSyncSGIX from /usr/lib/libGL.so.1
so seems the the problem depends on my libGL :frowning:[/quote]

Thank you very much for your help. I’m afraid, it’s difficult to fix such a problem :frowning: