I'm trying to run an opengl application on a remote computing cluster. I'm using osmesa as I intend to execute off-screen software rendering (no x11 forwarding etc). I want to use glew (to make life dealing with shaders and other extension related calls easier), and I seem to have built and linked both mesa and glew fine.
When I call mesa-create-context, glewinit gives a OPENGL Version not available output, which probably means the context has not been created. When I call glGetString(GL_EXTENSIONS) i dont get any output, which confirms this. This also shows that glew is working fine on its own. (Other glew commands like glew version etc also work).
Now when I (as shown below), add the mesa-make-context-current function, glewinit crashes with a segfault. Running glGetString(GL_EXTENSIONS) gives me a list of extensions now however (which means context creation is successful!)
I've spent hours trying to figure this out, tried tinkering but nothing works. Would greatly appreciate any help on this. Maybe some of you has experienced something similar before?? Thanks again!
int Height = 1; int Width = 1;
OSMesaContext ctx; void *buffer;
ctx = OSMesaCreateContext( OSMESA_RGBA, NULL );
buffer = malloc( Width * Height * 4 * sizeof(GLfloat) );
if (!OSMesaMakeCurrent( ctx, buffer, GL_UNSIGNED_BYTE, Width, Height )) {
printf("OSMesaMakeCurrent failed!\n");
return 0;
}
-- glewinit() crashes after this.
Just to add, osmesa and glew actually did not compile initially. Because glew undefines GLAPI in it's last line and since osmesa will not include gl.h again, GLAPI remains undefined and causes an error in osmesa.h (119). I got around this by adding an extern to GLAPI, not sure if this is relevant though.