OpenGl - enable debugging - runtime System.AccessViolationException

Question

I've been through multiple articles on enabling glDebugMessageCallback and I don't get any compile errors. However, when I run the program, I get a runtime System.AccessViolationException right on the glDebugMessageCallback call. I'm using GLEW and GLFW in my setup.

When I run GlewInfo, I can see that the debug is available:

GL_ARB_debug_output:                                           OK 
--------------------
- glDebugMessageCallbackARB:                                   OK
- glDebugMessageControlARB:                                    OK
- glDebugMessageInsertARB:                                     OK
- glGetDebugMessageLogARB:                                     OK

GL_KHR_debug:                                                  OK 
-------------
- glDebugMessageCallback:                                      OK
- glDebugMessageControl:                                       OK
- glDebugMessageInsert:                                        OK
- glGetDebugMessageLog:                                        OK
- GL_KHR_no_error:                                               MISSING

In my code, I set the glfw windows hint before creating the window:

if (get_debug_gl())
{
   glfwWindowHint(GLFW_OPENGL_DEBUG_CONTEXT, GL_TRUE);
}

I attempt to enable the debugging with this:

if (get_debug_gl())
    {
        glEnable(GL_DEBUG_OUTPUT);

        if (GLEW_KHR_debug)
        {
            gl_log_debug("KHR_debug extension found\n");
            GLDEBUGPROC p = &(debug_gl_callback);
            ///glDebugMessageCallback(p, NULL); /// @todo GRRRRR : this throws runtime System.AccessViolationException
            glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
            gl_log_debug("debug callback enabled\n");
        }
        else if(GL_ARB_debug_output)
        {
            gl_log_debug("GL_ARB_debug_output extension found\n");
            GLDEBUGPROC p = &(debug_gl_callback);
            glDebugMessageCallbackARB(p, NULL); /// @todo GRRRRR : this throws runtime System.AccessViolationException
            gl_log_debug("debug callback enabled\n");
            glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS_ARB);
        }
        else
        {
            gl_log_debug("KHR_debug extension NOT found\n");
        }
    }

Observations:

GLEW_KHR_debug is false, despite the glewinfo reporting that it should be true. If I bypass it, I get the runtime error
If I run the code through the glDebugMessageCallbackARB call, I get the same runtime error.

Can anyone out there give me a tip as to what I am missing? Writing OpenGl without messages is like driving a car with a blindfold.

Where do you initialize GLEW in relation to the code above? And are you using a current GLEW2 version, or still GLEW1.x which is broke in core profiles? — derhass, Nov 22 '19 at 14:58
@derhass You nailed it. I had the glewInit(); call below the attempt to set the call back. Thank you! — Jim, Nov 22 '19 at 16:59

score -1 · Answer 1 · answered Nov 22 '19 at 17:00

-1

glewInit();

must be called before

if (get_debug_gl())
    {
        glEnable(GL_DEBUG_OUTPUT);
...

answered Nov 22 '19 at 17:00

Jim

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OpenGl - enable debugging - runtime System.AccessViolationException

Observations:

1 Answers1