[Mesa-dev] [PATCH v2] mesa: Allow override of GL version with environment variable

[Brian Paul]

On 09/26/2011 02:50 PM, Chad Versace wrote:
> [idr and kwg, I see your point. I've removed the overrides for GLES1 and
> GLES2.]
>
> It is necessary to manually set the GL version to 3.0 in order to run
> Piglit tests using glGetUniform*().
>
> This patch allows one to override the version of the OpenGL context by
> setting the environment variable MESA_GL_VERSION_OVERRIDE.
>
> v2
> ---
> - [brianp] Change variable name to MESA_GL_VERSION_OVERRIDE.
> - [brianp] Document in envvars.html.
> - [idr, kwg] Remove overrides for GLES1 and GLES2.
>
> Reviewed-by: Brian Paul<brianp at vmware.com>
> Signed-off-by: Chad Versace<chad at chad-versace.us>
> ---
>   docs/envvars.html       |    2 ++
>   src/mesa/main/version.c |   24 ++++++++++++++++++++++++
>   2 files changed, 26 insertions(+), 0 deletions(-)
>
> diff --git a/docs/envvars.html b/docs/envvars.html
> index 986d2f8..7280f2b 100644
> --- a/docs/envvars.html
> +++ b/docs/envvars.html
> @@ -58,6 +58,8 @@ copied into a fixed-size buffer without truncating.
>   If the extension string is too long, the buffer overrun can cause the game
>   to crash.
>   This is a work-around for that.
> +<li>MESA_GL_VERSION_OVERRIDE - sets the GL version. For example, the value "3.0"
> +will enable support for GL 3.0.

The description is a little inaccurate.  I'd say something like 
"setting this variable changes the value returned by 
glGetString(GL_VERSION).  Mesa will not really implement all the 
features of the given version if it's higher than what's normally 
reported.

-Brian