X11 speed (was Re: Interested in starting some basic development)

[Jorrit Tyberghein <Jorrit.Tyberghein@uz.kuleuven.ac.be>]

Borko Jandras wrote:

> On Wed, Nov 18, 1998 at 07:33:37PM +0100, Magnus Norddahl wrote:
> > I'm getting quite borred of hearing GGI people bla bla about their stupid
> > project. Let's talk about what GGI can do TODAY. Nothing is the keyword.
>
> Let's talk about what can you do TODAY with what you have. Nothing!
>
> > Give me direct access to the frame buffer? Great! This is also possible with
> > svgalib, Xfree86 and /dev/fb.
>
> X? I did a very simple test. Opened up a 640x480 window and drawed a rectangle
> across it, using Mesa. It took cca. 150 milliseconds for each frame.
> Let me spare you the calculation, that's 6.6 fps. Can you live with that?
> Oh yes, the machine was K6-2 333. X just isn't made for such things.

Crystal Space (yes that ugly C++ library of mine :-) runs with the following
speeds in X with a 640x480 window (16-bit display mode):
    My old pentium 90: 10 FPS
    My new P-II 400: 27 FPS

And you have to keep in mind that it also has to do some rendering instead
of only blitting to the screen.

You just have to use the SHM extension (shared memory extension).
This helps a VERY GREAT deal. With that extension you get almost the
same speeds as with svgalib but without the suid problems.


> I don't know if GGI will or will not have a future, I just know that something
> has to be done. The current situation holds no future for games under Linux.

X11 with the SHM extension is pretty good.

Greetings,

--
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Jorrit.Tyberghein@uz.kuleuven.ac.be, University Hospitals KU Leuven BELGIUM

Brother Preptil, the master of the music, had described Brutha's voice as
putting him in mind of a disappointed vulture arriving too late at the dead
donkey.
        -- (Terry Pratchett, Small Gods)
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