From: Andreas Beck <becka@rz.uni-duesseldorf.de>
  To  : Mark Vojkovich <mvojkovi@ucsd.edu>
  Date: Fri, 6 Aug 1999 10:26:32 +0200

Re: Regarding GGI and Xfree 4.0, Forwarded.

Hi Mark !

It's nice to see, that we are finally on one track. Thanks for the kind
reply.

> > Is that right ? I.e. the full graphics driver is in the module now ?
>     Yes everything is in a module.  The fbdev driver is just
> a module. 

This is very good. That will make it much easier for us to make a
module-wrapper that will wrap around a KGI driver and eventually 
even one that wraps around LibGGI.

The developer for the latter is on vacation right now, but I'll notify him
as soon as he's back. In the meantime I'll try to collect some information
for him to get him running easier when he's back. So may I ask you a few
things ?

While KGI only cares about the graphics card, LibGGI as well covers input
devices via LibGII, as input devices vary with the "target" (the thing we
render on, i.e. an fbdev device, an X window, ...).

Does XFree as well modularize the input subsystem, so that we could as well
make an LibGGI input module ?

You can probably see that this is needed for making XFree-with-LibGGI-
rendering-module a substitute for XGGI (which is a "bad hack" in some 
areas).

> Scitech is writing a driver that works with their "nucleus."

*grin*. Should make our job easier. I reviewed their specs several times,
while they were in the design phase :-).

> There can be a GGI driver that would allow all
> hardware access to go through GGI. 

Great.

> > This is in deed problematic in userspace. You will need at least a bit of
> > kernel help, as you will want to use DMA and IRQs for full performance of
> > the whole system.

>    3D in XFree86 4.0 is based on Direct Rendering (client libraries
> write to the graphics pipeline directly) 

Yes. That is very reasonable, especially for 3D.

> with PI's kernel module providing the sychronization and DMA services 
> required to do this.

O.K. - I'll have to review this one again. I liked it a lot I read it the
last time.

> > But there are times, when you want to do graphics, but you don't want to
> > start X for it. Games are one example, file viewers often as well.

>    Our target for games is Direct Rendered OpenGL, in windowed
> or DGA mode.   

Yes, that's where the industry is heading, and that's the area, where
performance is really critical.

> > Thus compiling the graphics drivers into the X server was IMHO not a very 
> > good idea. O.K. you had a great X server, but what about the other tasks ?

>    It is our goal to give you everything you need in the Xserver.
> People really don't want to quit X to play their games.

That is a matter of taste. I agree with you, that if you are running X
all time anyway, quitting it to run a game is nonsense.
However I'm a console-die-hard, so I don't like to enter X just to play a
game or quickly view a graphics file from my mail client or something.

LibGGI is based on that philosophy. It will detect the environment it is
running in, and redirect output as appropriate (unless manually overridden,
which is of course possible). This system gives both worlds what they want.

If we can manage to somehow load your driver modules in the LibGGI
environment, we can probably provide your excellent drivers even to
console-freaks. We'll see if that is possible.

> > Could you tell me whom you talked to ? 
>    It was Steffen Seeger.
Ooops sorry. I learned that in the meantime.

> I invited him to join and write a driver for 4.0 and he declined.

Yes. He explained that in the meantime. He is working on a new version of
KGI, which takes all of his time. I'll try to talk Marcus into doing it.

> You guys could have had a driver in the recently released 3.9.15 
> snapshot had you joined back then.  This was several months ago.

Probably. I'll see that we can set things straight now.

>    Contact Dirk (hohndel@XFree86.org) and he can set your developer
> up with a membership. 

O.K. - will do as soon as I have the developers back and convinced.

Thanks again, ANdy

P.S.: To the GGI people on the list:

O.K. I need 3 volunteers for the three tasks that are upcoming:

1. Someone to write a LibGGI rendering module for XFree. I suppose Marcus
will take that job. But don't hesitate to yell anyway. He will need help.

2. Someone to write a KGI wrapper module for XFree. That is a KGI OS-layer
that will make a KGI driver look like an XFree driver. I offer my personal
assistance on that topic, as I have experience with the OS-layer stuff.

3. Someone to write a XFree wrapper module for KGI or LibGGI. From what I
heard of the XFree module design, it will probably be for LibGGI. As this
would be similar to the suidkgi target, I again offer my assistance.

O.K. - volunteers step forward !
And please think well, if you have the time and motivation. These are
serious tasks, and I don't want to hurt the now seemingly good relations
to the XFree people again by doing a bad job on those.

CU, ANdy

-- 
= Andreas Beck                    |  Email :  <andreas.beck@ggi-project.org> =