[Haskell-beginners] Performance problem with Haskell/OpenGL/GLFW

[Hollister Herhold]

I'm building glfw now on 10.7.5 and I'll try your test code. 

I've been learning haskell (still very much a beginner) but I know OpenGL, so I'm very interested in how this turns out.

-Hollister


On Mar 10, 2013, at 4:38 AM, Jesper Särnesjö wrote:

> On Sun, Mar 10, 2013 at 4:46 PM, Jesper Särnesjö <sarnesjo at gmail.com> wrote:
>> I've figured out what the problem is: the Haskell program is using a
>> software implementation of OpenGL, so rendering *does* in fact happen
>> on the CPU.
>> 
>> It would appear that there is in fact some relevant difference between
>> the Haskell and C versions of my program, or possibly some way
>> in which the bindings from the GLFW-b package are different from the C
>> library.
> 
> To remove any possibility of the problem being in GLFW-b or OpenGLRaw,
> I created two new programs, one in Haskell [1] and one in C [2], that
> don't import or include anything related to OpenGL, and that simply
> create a context, check if it is hardware accelerated, and then exit.
> That is all. And still, the Haskell program receives a software
> renderer, while the C program receives a hardware one:
> 
>    $ ghc -O2 Test2.hs -lglfw -framework OpenGL -fforce-recomp && ./Test2
>    [1 of 1] Compiling Main             ( Test2.hs, Test2.o )
>    Linking Test2 ...
>    software
>    (2,7,7)
>    (3,2,0)
>    $ gcc -O2 test2.c -lglfw -framework OpenGL && ./a.out
>    hardware
>    2.7.7
>    3.2.0
> 
> I haven't had the chance to run these programs on any OS other than
> Mac OS X 10.8.2, so I don't know if this problem is Mac-specific.
> Still, it's really weird that the system would differentiate between
> Haskell and C programs in this way.
> 
> If anyone has any ideas about what's going on here, I'd very much like
> to hear them.
> 
> -- 
> Jesper Särnesjö
> http://jesper.sarnesjo.org/
> 
> [1] https://gist.github.com/sarnesjo/5116084#file-test2-hs
> [2] https://gist.github.com/sarnesjo/5116084#file-test2-c
> 
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