Re: GlxGears

On Tuesday 16 March 2004 2:09 am, Sven Panne wrote:
> Shawn P. Garbett wrote:
> > [...]
> > Haskell Version on my laptop, FPS = 103
> > C Version on my laptop, FPS = 192
> > [...]
>
> I just gave your example a quick try on my PC, the results do not
> differ that much for my setup (SuSE x86 Linux 8.2, 3GHz P4, NVIDIA FX
> 5900):
>
>     Haskell version: 6000 FPS
>     C version: 7165 FPS

That's even better. The actual difference isn't x2 on a fast box, but 
much closer. So for a performing box, the speed difference is quite 
acceptable given the gains of working in Haskell. Good job to the 
HOpenGL folks. 

>
> Curiously, using -O for the Haskell compilation doesn't make any
> difference. I'll take a closer look with GHC's profiler and the
> ltrace tool when I get some time.
>
> Thanks for the conversion BTW, I'd like to place this example into
> GLUT'S "Misc" example directory, with a BSD-like license. Would that
> be OK?

That was the intent of the copyright at the top. Maybe I got it wrong, 
but it's supposed to be a BSD style license. I really don't care how 
it's used, but I just wanted to show my support for the BSD code 
sharing method.

I suspect that data marshalling is most of the speed difference. As I 
understand when a program misses a frame refresh window, OpenGL put's 
it in the next frame refresh window, so the actual speed difference may 
be quite small and it occasionally misses the refresh window.

Shawn