Hi,

  I have an ati 9800pro card on my computer which is double-boot with
both linux and windows. I compiled my program on both linux and
windows sides. With exact same souce code, I got pretty different
rendering results. On Windows side, it is much slower. I installed the
driver from ati on both linux and windows side.

  My assumption about the performance difference is that, ati linux
driver directly replaced system opengl libraries, like libGL.so.1,
etc. But on windows side, a new dll (atioglxx.dll) was placed in
system32 directory. The microsoft opengl32.dll is still used in my
program linking. I could replace every opengl32.dll with atioglxx.dll,
but I don't have opengl32.lib to link against.

  What do I missed for windows opengl programming using ati (or
nvidia) opengl library?

  Thanks.

-Feng

"Feng Ma" <mafeng@gmail.com> wrote in message
news:1ede493d.0407160939.797fd2ca@posting.google.com...

>   What do I missed for windows opengl programming using ati (or
> nvidia) opengl library?

Have you disabled "wait for vertical sync" on your
Windows machine?

--
Dave Eberly
http://www.magic-software.com

Feng Ma wrote:
> 
>   My assumption about the performance difference is that, ati linux
> driver directly replaced system opengl libraries, like libGL.so.1,
> etc. But on windows side, a new dll (atioglxx.dll) was placed in
> system32 directory. The microsoft opengl32.dll is still used in my
> program linking. I could replace every opengl32.dll with atioglxx.dll,
> but I don't have opengl32.lib to link against.
> 

Opengl32.dll is never replaced, it's just a bridge to
the underlying drivers. It's not the source of your
problem.

What difference in speed are you seeing? Actual numbers
would help...

>   What do I missed for windows opengl programming using ati (or
> nvidia) opengl library?
> 

Nothing, that's the way it works on Windows.


-- 
<\___/>
/ O O \
\_____/  FTB.    For email, remove my socks.

Governments, like diapers, should be changed often,
and for the same reason.

Feng Ma wrote:
> Hi,
> 
>   I have an ati 9800pro card on my computer which is double-boot with
> both linux and windows. I compiled my program on both linux and
> windows sides. With exact same souce code, I got pretty different
> rendering results. On Windows side, it is much slower. I installed the
> driver from ati on both linux and windows side.
> 
>   My assumption about the performance difference is that, ati linux
> driver directly replaced system opengl libraries, like libGL.so.1,
> etc. But on windows side, a new dll (atioglxx.dll) was placed in
> system32 directory. The microsoft opengl32.dll is still used in my
> program linking. I could replace every opengl32.dll with atioglxx.dll,
> but I don't have opengl32.lib to link against.
> 
>   What do I missed for windows opengl programming using ati (or
> nvidia) opengl library?
> 
>   Thanks.
> 
> -Feng

Two things to check :

1. As noted by a previous poster, check your Display Properties in 
windows to see if 'wait for vertical sync' is enabled. If it is, you 
should be getting somethign like 60 FPS (or whatever the refresh 
frequency of your monitor is).

2. A little bit more obscure but, are you running Windows on 16 bit 
depth? I've had a case where I was requesting a 24 bit depth buffer and 
8 bit stencil, but I was running at 16bit color. I think the library I 
was using (SDL) didn't give an error, but emulated the depth/stencil in 
software....resulting in very poor performance!