[Mesa3d-users] OpenGL version Restriction of Mesa

[정준영 <rh...@hl...>]

Hi, all Mesa users.

I have heard that the Mesa is the software implementation of OpenGL. So 
it acts as OpenGL emulation.
But I found that Mesa also supports DRI and applied DRI to the X Window 
System I use.

However while the X Window system uses DRI,
the version of OpenGL provided by Mesa is restricted to the version of 
OpenGL which graphics hardware driver supports.

glxinfo ouput when DRI is used.
      direct rendering: Yes
      OpenGL vendor string: Tungsten Graphics, Inc
      OpenGL renderer string: Mesa DRI Intel(R) 852GM/855GM 20061017 
x86/MMX/SSE2
      OpenGL version string: 1.3 Mesa 7.0.3

glxinfo output when DRI is not used.
      direct rendering: No (If you want to find out why, try setting 
LIBGL_DEBUG=verbose)
      OpenGL vendor string: Mesa project: www.mesa3d.org
      OpenGL renderer string: Mesa GLX Indirect
      OpenGL version string: 1.4 (2.1 Mesa 7.0.2)

(I attach the full outputs of both glxinfo executions)

The OpenGL commands belonging to OpenGL 2.1 is not available when DRI is 
used, but it is available when DRI is not used.


I wonder that it is possible to use OpenGL emulation in case of the 
OpenGL command is beyond the OpenGL version supported by graphics 
hardware driver. Whilst the OpenGL commands provided by graphics 
hardware driver are processed by DRI.

Thank you.