[SDL] how to know if (direct render) hardware accelerated is available

[David Roguin]

I'm working in a graphic library for making games, I want to use
OpenGL and SDL in case that accel hardware is not available; that's
why I need to check before rendering anything in screen.

I was thinking, if I test if the GL_RENDER is Mesa, I'm sure that not
hardware accel is present. But is there another soft OpenGL
implementation besides Mesa?

David.

On Nov 16, 2007 3:35 PM, Bob Pendleton <bob at pendleton.com> wrote:
>
> On Fri, 2007-11-16 at 09:44 -0300, David Roguin wrote:
> > With 'direct render' I was meaning "hardware accelerated".
> > Is there any way to be sure that hardware accelerated is available?
> >
> > I was thinking that maybe with GL_VENDOR and GL_RENDER I could
> > determine that, but I'm not really sure if that is the best way to do
> > it.
>
> That will work, but it requires that you have a list of valid vendor
> names which can be a real pain to generate. The simple way is to run a
> simple test and measure the performance. Just put a spinning logo at
> load time for maybe 10 seconds. If you don't get a high enough frame
> rate you know that you do not have accelerated graphics. If you do get a
> good frame rate you know a little more. You can even just measure the
> frame rate of the main application and if it is too slow, you can
> politely quit.
>
> Bob Pendleton
>
> >
> > The SDL_SysWMinfo has de Display, but I'm missing the GLXContext.
> >
> > David.
> >
> >
> > On Nov 16, 2007 3:49 AM, Solra Bizna <sbizna at tejat.net> wrote:
> > >
> > > On Nov 15, 2007 6:55 PM, David Roguin <nesdavid at gmail.com> wrote:
> > > > I want to know for a program running in linux if direct rendering is abailable.
> > > > I believe glXIsDirect does the trick.
> > > > The question is, can I call this function within a SDL context?
> > > SDL under X11 uses GLX internally for OpenGL, so I would assume so. I
> > > can think of two caveats, though.
> > > 1) You'll need a Display and a GLXContext to pass to the function, and
> > > I'm not sure how you'd get your hands on those.
> > > 2) If you're taking "direct rendering" to mean "hardware accelerated,"
> > > remember that indirect rendering can be accelerated too. For example,
> > > if X11 forwarding is in effect, rendering may be hardware accelerated
> > > (and reasonably fast) but glXIsDirect will return False. (I'm not sure
> > > how AIGLX fits in.)
> > > -:sigma.SB
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> > >
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> >
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