[Mesa-users] Question about support for OpenGL 3.2 Core context

[Ken Martin]

Thanks! Seems the system in question was using llvmpipe which passes ~95%
of our tests when we tell it be a 3.2 context using the environment
variables. For some reason I was thinking llvmpipe was full 3.2 Core.  I
tried playing with softpipe to see if that had better results but it had
significantly more failures. I think the Intel SWR is at the 99% or so mark
now on our tests so that may be a good bet for our pure software rendering.

Thanks Again!
Ken


On Thu, Nov 26, 2015 at 6:41 AM, Albert Freeman <albertwdfreeman at gmail.com>
wrote:

> On 26 November 2015 at 11:37, Albert Freeman <albertwdfreeman at gmail.com>
> wrote:
> > On 25 November 2015 at 22:45, Ken Martin <ken.martin at kitware.com> wrote:
> >>
> >> Noob question incoming... I have an application that requests a 3.2 core
> >> context from Mesa.  I tell folks to make sure they have mesa version
> 10.6.5
> >> or later which I thought supported OpenGL 3.2.  Usually this works but
> now
> >> and then I get users who's Mesa (including version 11) fails to provide
> a
> >> 3.2 Core context. I tell them to set
> >>
> >> MESA_GL_VERSION_OVERRIDE=3.2
> >>
> >> and
> >>
> >> MESA_GLSL_VERSION_OVERRIDE=150 (or something like that)
> >>
> >> and it generally works. But I'm not sure why the original request for
> 3.2
> >> Core is failing on some systems (drivers?).  Looking at
> >>
> >> http://mesamatrix.net/
> >>
> >> leads me to think that all drivers with a recent mesa should be fine
> with
> >> 3.2 Core but obviously I am missing something. Do I need to be telling
> them
> >> to use a specific driver? Is there a list of drivers that do not
> support 3.2
> >> I should tell them to avoid? Anything else come to mind?
> >>
> >> I just want to try to provide a bit more help to folks to get them up
> and
> >> running with Mesa and even better get our code to handle it
> automatically if
> >> we could.
> >>
> >> Any pointers appreciated. The application is vtk.
> >>
> >> Thanks
> >> Ken
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >> --
> >> Ken Martin PhD
> >> Chairman & CFO
> >> Kitware Inc.
> >> 28 Corporate Drive
> >> Clifton Park NY 12065
> >> 518 371 3971
> >>
> >> This communication, including all attachments, contains confidential and
> >> legally privileged information, and it is intended only for the use of
> the
> >> addressee.  Access to this email by anyone else is unauthorized. If you
> are
> >> not the intended recipient, any disclosure, copying, distribution or any
> >> action taken in reliance on it is prohibited and may be unlawful. If you
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> >>
> >> _______________________________________________
> >> mesa-users mailing list
> >> mesa-users at lists.freedesktop.org
> >> http://lists.freedesktop.org/mailman/listinfo/mesa-users
> >>
> > Not all mesa drivers support gl 3.2, e.g. the r300 gallium driver in
> > the git mesa supports only glsl 1.20:
> >         case PIPE_CAP_GLSL_FEATURE_LEVEL:
> >             return 120;
> >
> > That website is based on gl3.txt. It does not list all drivers mesa
> > supports (as gl3.txt dosen't). They are both only meant to be a rough
> > guide. The svga driver apparently supports gl 3.3 and it isn't even
> > mentioned in gl3.txt. So I think some of the vtk users have really old
> > gpus that don't support gl 3.2. Some gl versions already have software
> > emulated components for gl features not supported by the hardware on
> > older gpus and some older gpus simply don't have support.
> As those environment variables you use simply fake the gl version to
> the application. If the application then uses say a gl 3.2 feature
> that isn't supported by that driver, the behavior is undefined (e.g.
> application can crash).
>



-- 
Ken Martin PhD
Chairman & CFO
Kitware Inc.
28 Corporate Drive
Clifton Park NY 12065
518 371 3971

This communication, including all attachments, contains confidential and
legally privileged information, and it is intended only for the use of the
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not the intended recipient, any disclosure, copying, distribution or any
action taken in reliance on it is prohibited and may be unlawful. If you
received this communication in error please notify us immediately and
destroy the original message.  Thank you.
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