InitDebugContext

void InitDebugContext()
{
    // Set the debug output callback if the driver supports it.
    FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 1"));
    VERIFY_GL(__FUNCTION__);
    FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 2"));
    bool bDebugOutputInitialized = false;
    FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 3"));
#if !ENABLE_VERIFY_GL
    FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 4"));
    #if defined(GL_ARB_debug_output)
    FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 5"));
        if (glDebugMessageCallbackARB)
        {
            FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 6"));
            // Synchronous output can slow things down, but we'll get better callstack if breaking in or crashing in the callback. This is debug only after all.
            glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
            FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 7"));
            glDebugMessageCallbackARB(GLDEBUGPROCARB(OpenGLDebugMessageCallbackARB), /*UserParam=*/ NULL);
            FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 8"));
            bDebugOutputInitialized = (glGetError() == GL_NO_ERROR);
            FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 9"));
        }
    #elif defined(GL_KHR_debug)
    FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 10"));
        // OpenGLES names the debug functions differently, but they behave the same
        if (glDebugMessageCallbackKHR)
        {
            FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 11"));
            glDebugMessageCallbackKHR(GLDEBUGPROCKHR(OpenGLDebugMessageCallbackARB), /*UserParam=*/ NULL);
            FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 12"));
            bDebugOutputInitialized = (glGetError() == GL_NO_ERROR);
            FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 13"));
        }
    #endif // GL_ARB_debug_output / GL_KHR_debug
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 14"));
    #if defined(GL_AMD_debug_output)
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 15"));
        if (glDebugMessageCallbackAMD && !bDebugOutputInitialized)
        {
            FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 16"));
            glDebugMessageCallbackAMD(OpenGLDebugMessageCallbackAMD, /*UserParam=*/ NULL);
            FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 17"));
            bDebugOutputInitialized = (glGetError() == GL_NO_ERROR);
            FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 18"));
        }
    #endif // GL_AMD_debug_output
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 19"));
#endif // !ENABLE_VERIFY_GL
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 20"));
    if (!bDebugOutputInitialized && !PLATFORM_MAC)
    {
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 21"));
        UE_LOG(LogRHI,Warning,TEXT("OpenGL debug output extension not supported!"));
    }
    FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 22"));
    // this is to suppress feeding back of the debug markers and groups to the log, since those originate in the app anyways...
#if ENABLE_OPENGL_DEBUG_GROUPS && GL_ARB_debug_output && GL_KHR_debug && !OPENGL_ES31
    FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 23"));
    if(glDebugMessageControlARB && bDebugOutputInitialized)
    {
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 24"));
        glDebugMessageControlARB(GL_DEBUG_SOURCE_APPLICATION_ARB, GL_DEBUG_TYPE_MARKER, GL_DONT_CARE, 0, NULL, GL_FALSE);
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 25"));
        glDebugMessageControlARB(GL_DEBUG_SOURCE_APPLICATION_ARB, GL_DEBUG_TYPE_PUSH_GROUP, GL_DONT_CARE, 0, NULL, GL_FALSE);
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 26"));
        glDebugMessageControlARB(GL_DEBUG_SOURCE_APPLICATION_ARB, GL_DEBUG_TYPE_POP_GROUP, GL_DONT_CARE, 0, NULL, GL_FALSE);
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 27"));
#ifdef GL_KHR_debug
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 28"));
        glDebugMessageControlARB(GL_DEBUG_SOURCE_API_ARB, GL_DEBUG_TYPE_OTHER_ARB, GL_DEBUG_SEVERITY_NOTIFICATION, 0, NULL, GL_FALSE);
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 29"));
#endif
        UE_LOG(LogRHI,Verbose,TEXT("disabling reporting back of debug groups and markers to the OpenGL debug output callback"));
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 30"));
    }
    FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 31"));
#elif ENABLE_OPENGL_DEBUG_GROUPS && !defined(GL_ARB_debug_output) && GL_KHR_debug
    FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 32"));
    if(glDebugMessageControlKHR)
    {
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 33"));
        glDebugMessageControlKHR(GL_DEBUG_SOURCE_APPLICATION_KHR, GL_DEBUG_TYPE_MARKER, GL_DONT_CARE, 0, NULL, GL_FALSE);
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 34"));
        glDebugMessageControlKHR(GL_DEBUG_SOURCE_APPLICATION_KHR, GL_DEBUG_TYPE_PUSH_GROUP, GL_DONT_CARE, 0, NULL, GL_FALSE);
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 35"));
        glDebugMessageControlKHR(GL_DEBUG_SOURCE_APPLICATION_KHR, GL_DEBUG_TYPE_POP_GROUP, GL_DONT_CARE, 0, NULL, GL_FALSE);
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 36"));
        glDebugMessageControlKHR(GL_DEBUG_SOURCE_API_KHR, GL_DEBUG_TYPE_OTHER_KHR, GL_DEBUG_SEVERITY_NOTIFICATION, 0, NULL, GL_FALSE);
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 37"));
        UE_LOG(LogRHI,Verbose,TEXT("disabling reporting back of debug groups and markers to the OpenGL debug output callback"));
        FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 38"));
    }
    FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 39"));
#endif
    FPlatformMisc::LowLevelOutputDebugString(TEXT("Debug 40"));
}