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

[Chad Versace]

On 09/27/2011 09:29 AM, Ian Romanick wrote:
> On 09/26/2011 01:50 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>
>
> Other than the comment below and Brian's comment about the envvars.html description,
>
> Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>
>
>> ---
>> 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.
>> <li>MESA_GLSL -<a href="shading.html#envvars">shading language compiler options</a>
>> </ul>
>>
>> diff --git a/src/mesa/main/version.c b/src/mesa/main/version.c
>> index 80fa0c2..bd6feeb 100644
>> --- a/src/mesa/main/version.c
>> +++ b/src/mesa/main/version.c
>> @@ -27,7 +27,28 @@
>> #include "version.h"
>> #include "git_sha1.h"
>>
>> +/**
>> + * Override GL version by setting environment variable
>> + * MESA_GL_VERSION_OVERRIDE.
>> + */
>> +static void
>> +override_version(struct gl_context *ctx, GLuint *major, GLuint *minor)
>> +{
>> + const char *env_var = "MESA_GL_VERSION_OVERRIDE";
>> + const char *version;
>> + int n;
>> +
>> + version = getenv(env_var);
>> + if (!version) {
>> + return;
>> + }
>>
>> + n = sscanf(version, "%d.%d.", major, minor);
> ^
> Spurious period?

I've removed the period.

It was lucky chance that the extra period didn't alter any behavior.

>> + if (n != 2) {
>> + fprintf(stderr, "error: invalid value for %s: %s\n", env_var, version);
>> + return;
>> + }
>> +}
>>
>> /**
>> * Examine enabled GL extensions to determine GL version.
>> @@ -183,6 +204,9 @@ compute_version(struct gl_context *ctx)
>>
>> ctx->VersionMajor = major;
>> ctx->VersionMinor = minor;
>> +
>> + override_version(ctx,&ctx->VersionMajor,&ctx->VersionMinor);
>> +
>> ctx->VersionString = (char *) malloc(max);
>> if (ctx->VersionString) {
>> _mesa_snprintf(ctx->VersionString, max,

-- 
Chad Versace
chad at chad-versace.us