[9fans] X device

[Digby Tarvin digbyt@acm.org]

>
>I did this for Inferno, which has a different graphics protocol but
>the same overall architecture, so it can be done.  I don't wish the
>job on anyone; it's a nasty mess to get two unrelated graphics models
>to function together.
>
Hi Rob,

Thanks for the quick and detailed insights.

Did your work make it into the Inferno distribution?
Have you any idea if the VNC model (http://www.orl.co.uk/vnc/)
is any more compatible with Plan9? I have used it to get
a Windows machine console in a window on my X-Terminal
(and vice versa), although performance does suffer when
using the Internet to access a remote machine in Sydney
when using a display in London...

Is the Inferno implementation an improvement, as in a re-design
incorportating lessons learnt from Plan 9, or is there some
sort of trade off whereby both have merits?

>I did it by..
>
You have convinced me that it isn't a good learners project :-)

>Getting all this to go fast involved much trickery and analysis of X
>internals.  The result is barely satisfactory.  Plus, a huge piece of
>the code deals with the psychotic pas de deux of allocating a screen
>and color map in X. When it came to 16-bit X screens, we cut bait; it
>wasn't worth any more time.
>
Mine is a 24-bit 1600x1200 NCD - hence my preference for it over
the SPARCstation 2 screen. It seemed preferable to share
one good display amoungst all of my machines, rather than trying
to equip then all with usable displays. Even if I could afford
the latter, I would have nowhere to put them all. Of course that
relies on everything supporting the same network graphics protocol,
which fortunately most do, with the exception of Windows (and who cares!)
and Plan 9 :-(.

>Similar games can be done on Windows, but it's much easier there, at
>least conceptually, because you can write code that runs on (in X
>terminology) the server and also just paint data on the screen, in
>other words, decode the Plan 9 protocol on the machine with the frame
>buffer.
>
Would it be more practical to play with the X server extensions
mechanism, to decode the Plan 9 protocol, the same way postscript
etc is added to some X servers?

Is the reverse easier to achieve - translating X protocol
into Plan 9 or Inferno protocol?

It would be nice if the Plan 9 and Inferno protocols could converge,
and perhaps gain a wider acceptance as an alternate protocol
for networking graphics.

Regards,
DigbyT
-- 
Digby R. S. Tarvin                                              digbyt@acm.org
http://www.cthulhu.dircon.co.uk