Problems with libGL libraries and ROOT - swrast driver

[guido.fantini]

Hi all,

I am trying to plot a TH3D in root with a very simple macro:

void Draw(string inputFile)
{
  TFile* pf = new TFile(inputFile.c_str(),"READ");
  TH3D* h = (TH3D*)pf->Get("CUORE");                                                                
  gStyle->SetCanvasPreferGL(kTRUE);
  h->Draw("glcolz");
}

but as soon as I run it interactively from an SSH session

ssh -XY <myusername>@cuore-login.lngs.infn.it

I get this weird error. I tried googling that but didn’t get any useful info

root [0] .L CuoreRate3D.C 
root [1] Draw("../out/CuoreRate3D.root");
libGL error: failed to load driver: swrast
Info in <TCanvas::MakeDefCanvas>:  created default TCanvas with name c1
Error in <RootX11ErrorHandler>: GLXBadContext (XID: 6291743, XREQ: 149)

It looks also someone else on this forum had this kind of issues but when I was going through the other posts I couldn’t really understand what was the problem. Can someone explain me what’s happening?

Thanks a lot!
Cheers
Guido

---

ROOT Version: Not Provided
Platform: Not Provided
Compiler: Not Provided

---

[couet]

Is OpenGl properly installed on this machine ? can you run some standard app like “glxgears” ? I searched in google: “swrast opengl fail” and got several answers which might help you.

[Wile_E_Coyote]

On your “remote computer”, before you start ROOT or another OpenGL (GLX) application (e.g. “glxinfo” and/or “glxgears”), try:
[bash]$ export LIBGL_ALWAYS_INDIRECT=1
[tcsh]$ setenv LIBGL_ALWAYS_INDIRECT 1

See also:
CMSPublic -> OpenGL and X11 problems

[guido.fantini]

Ok, then:

1. openGL is installed (I don’t know if properly or not…) on the server, because

[gfantini@cuore-login1 gfantini]$ ls /usr/lib64 | grep libGL
libGL.so
libGL.so.1
libGL.so.1.2.0
libGLU.so
libGLU.so.1
libGLU.so.1.3.1
libGLw.so
libGLw.so.1
libGLw.so.1.0.0

but if I try glxgears, even after having set

[bash]$ export LIBGL_ALWAYS_INDIRECT=1

I get this:

[gfantini@cuore-login1 gfantini]$ glxgears
X Error of failed request:  BadValue (integer parameter out of range for operation)
  Major opcode of failed request:  149 (GLX)
  Minor opcode of failed request:  3 (X_GLXCreateContext)
  Value in failed request:  0x0
  Serial number of failed request:  21
  Current serial number in output stream:  23

I confess I need to check more carefully into here
https://twiki.cern.ch/twiki/bin/view/CMSPublic/WorkBookFireworksHowToFix#OpenGL_and_X11_problems
but I suspect it could be related to this suggestion (which I have to say I don’t really understand…):

This can be fixed by adding the +iglx option to the line that starts the X server on the local machine. There is currently no configuration file option (it will be added to xorg-1.19 and probably backported to older versions).

What do they mean by “the line that starts the X server on the local machine”?

Anyway, in my root macro I forgot to
gSystem->Load("libGL");
and that sent away the first two errors but I still get

Error in <RootX11ErrorHandler>: GLXBadContext (XID: 12583199, XREQ: 149)

Thank you very much for your suggestions. They really speed up my debug process!
And sorry if I ask dumb questions, I am sort of noob about this.

Best
Guido

[Wile_E_Coyote]

The “local machine” means the computer on which you actually display your graphics (i.e. the computer with the graphics card to which your monitor / screen is directly connected).

[guido.fantini]

Good then!

I think I got the solution. On mac OSX one should just kill the X server (go to activity monitor, look for the xquartz processes and kill them all), then open a shell and give

defaults write org.macosforge.xquartz.X11 enable_iglx -bool true

which would set the -iglx option (whatever it means).
Then restart the ssh -XY session, and run any GL-based application (such as glxgears).

Thank you all for your patience, suggestions and useful help!
Cheers!

Guido