Sigsev during shader/program creation

[haukehil...@web.de]

I get s sigsev when trying to create a shader or program

SIGSEGV: segmentation violation
PC=0x0
signal arrived during cgo execution

runtime.cgocall(0x4003ec0, 0x45cfed8)
    /usr/local/go/src/pkg/runtime/cgocall.c:149 +0x11b fp=0x45cfec0
github.com/go-gl/gl._Cfunc_glCreateProgram(0x3f80000000000000)
[...]

Calls to set the clear color and clear the buffer, for eample, work. I have added the runtime.LockOSThread() to my program.

I am on OSX 10.9 using Go 1.2.1, glfw 3.0.4 and glew-1.10.0.

Any ideas what might be going wrong?

Thanks,
Hauke

[Dmitri Shuralyov]

I have a few ideas of what could be wrong, but it'd be much easier if I could see the source code and try to confirm...

Are you forgetting to do gl.Init() or glew.Init()? Is glew even neccessary?

Are you not requesting a recent enough version of OpenGL context?

That error message basically means the gl.glCreateProgram function pointer is null (it wasn't set to a correct value due to some reason).

You can take a look at this working sample that indirectly uses gl.CreateProgram (via "github.com/Ysgard/GoGLutils" package) successfully for reference: https://gist.github.com/shurcooL/5816852

[hawk]

Thanks! Yes, I forgot to call gl.Init(), wasn't aware of that method since that doesn't exist in "naked" OpenGL.

Now I am fighting with sigsevs, I guess due to goroutines switching threads. Everything works fine when I call everything from the main method (which has its goroutine locked), but I'd like to bundle graphics calls in a static library. But I'll try a little longer before I call for help.. :-)

Thanks again,
Hauke