[9fans] X device

[miller@hamnavoe.demon.co.uk miller@hamnavoe.demon.co.uk]

"Russ Cox" <rsc@plan9.bell-labs.com> wrote:

> I think that writing a VNC server for Plan 9 could be done
> quite easily, actually: write something to translate /dev/bitblt
> commands into a VNC transcript of sorts, and then send whatever
> part of the transcript the client hasn't seen yet. 

Yes, this could be done.  Most of the work would be in compressing
the data to compensate for the key difference between the VNC and
Plan 9 protocols: VNC doesn't maintain any bitmaps on the viewer
machine other than the frame buffer itself (not even font images),
so there can be a lot of redundant transmissions.  But you could
borrow compression code from existing VNC servers.

> It seems like a Plan 9 VNC client would be even simpler: I'm
> guessing five to ten pages of code at most.

Mine is 685 lines of C.

> The real question is whether VNC actually feels decent enough
> to use. 

It is for my purposes: occasionally I need to access an X-based
program on a remote machine (e.g. the graphical debugging system
on a Cray T3E).  VNC lets me do this without having to leave
Plan 9.  If I had to look at it all day, though, I would want
to make it a bit quicker and smoother.

-- Richard Miller