[Mesa-dev] State of llvmpipe geometry shaders?

[Brian Paul]

On 07/19/2014 09:16 AM, Paul wrote:
> Brian Paul <brianp <at> vmware.com> writes:
>
>>
>> On 07/11/2014 01:47 AM, Florian Link wrote:
>>> Hi everyone,
>>>
>>> I read a post from 2012 that MESA supports geometry shaders. I tried a
>>> current MESA 10.2.x release, but MESA GL_VERSION returns OpenGL version
>>> 3.0 (not 3.2) and the
>>> GL_ARB_geometry_shader4 extension is not reported in the MESA
> extensions.
>>> The function lookup for the functions of GL_ARB_geometry_shader4 works,
>>> though.
>>> When I run a shader program with a geometry shader, the MESA linker
>>> complains that the varying that is used in the fragment shader is not
>>> emitted from the vertex shader, which indicates that the geometry shader
>>> is not detected/used.
>>>
>>> Should geometry shaders work in the current MESA llvm pipe release, or
>>> do I need to enable/compile in some code?
>>>
>>> regards,
>>> Florian
>>>
>>> P.S. My geometry shader works on non-MESA native ATI/NVidia/Intel OpenGL
>>> drivers, so I don't think it is a problem of my shader code, especially
>>> the ATI drivers are quite strict.
>>
>> llvmpipe supports GS, but only in core profiles.  With glxinfo, use the
>> -c option to see core profile version/extension info.
>>
>> -Brian
>>
>
> Hi.
>
> I was also wondering about geometry shaders and the core profile with
> llvmpipe. I have cross compiled Mesa for Windows following the steps at qt-
> project, then tested the DLL with OpenGL Extensions Viewer. All I get is
> OpenGL 3.0, and no core profiles. I have tested versions 10.2.2, 10.2.3 and
> 10.3.0-devel with no luck so far. This message is as close as I have gotten
> to an answer, but it only seems to indicate that in Linux it just works (if
> you ask for a core profile).
>
> Is it supported in Windows? If so, is there something that needs to be done
> to enable the core profile?

Yeah, we probably do need some extra changes to get this to work on 
Windows.  I just don't have any time right now to look into this.  If 
you can debug it further that'd be great.

-Brian