[Mesa-dev] and a random apitrace/gallium question..

[Jose Fonseca]

----- Original Message -----
> On Mon, Jun 3, 2013 at 10:41 AM, Jose Fonseca <jfonseca at vmware.com> wrote:
> > ----- Original Message -----
> >> On Fri, May 31, 2013 at 10:18 AM, José Fonseca <jose.r.fonseca at gmail.com>
> >> wrote:
> >> > I'd support such change. Be it through GL_GREMEDY_string_marker, or
> >> > ARB_debug_output's glDebugMessageInsertARB(DEBUG_SOURCE_THIRD_PARTY_ARB,
> >> > ...), or KHR_debug's glPushDebugGroup(). A Gallium interface change
> >> > would
> >> > be
> >> > necessary to pass these annotations to the drivers. This discussion
> >> > would
> >> > be
> >> > more appropriate in Mesa-dev mailing list though.
> >
> > I looked at the relevant specs (KHR_debug, ARB_debug_output), and I believe
> > the most natural / standard-compliant way of implementing this would be to
> > rely on glDebugMessageInsertARB(GL_DEBUG_SOURCE_THIRD_PARTY_ARB).
> 
> hmm, these look more about letting the gl driver send log msgs to the
> app.. 

Far from it. The spec is crystal clear on that regard, from http://www.opengl.org/registry/specs/KHR/debug.txt :

    [...]

    This extension also defines debug markers, a mechanism for the OpenGL 
    application to annotate the command stream with markers for discrete 
    events.

    [...]    

    5.5.1 - Debug Messages
    
    A debug message is uniquely identified by the source that generated
    it, a type within that source, and an unsigned integer ID
    identifying the message within that type.  The message source is
    one of the symbolic constants listed in Table 5.3.  The message
    type is one of the symbolic constants listed in Table 5.4.
    
    Debug Output Message Source           Messages Generated by
    ---------------------------           ---------------------
    DEBUG_SOURCE_API_ARB                  The GL

    DEBUG_SOURCE_SHADER_COMPILER_ARB      The GLSL shader compiler or compilers for
                                          other extension-provided languages
                                          
    DEBUG_SOURCE_WINDOW_SYSTEM_ARB        The window system, such as WGL or GLX
                                          
    DEBUG_SOURCE_THIRD_PARTY_ARB          External debuggers or third-party middleware
                                          libraries
                                          
    DEBUG_SOURCE_APPLICATION_ARB          The application
    
    DEBUG_SOURCE_OTHER_ARB                Sources that do not fit to any of the ones listed above
    ----------------------------------------------------------------------------
    Table 5.3: Sources of debug output messages.  Each message must originate
    from a source listed in this table.


> although maybe it is the best extension we have?

It seems to fit our needs quite well AFAICT.  KHR_debug is pretty much a superset of everything out there, plus it is part of core OpenGL 4.3.  And there is even a source for our needs -- DEBUG_SOURCE_THIRD_PARTY_ARB -- "External debuggers"...

Jose