Protocol Changes (was: Zoom / Scaling in VNC)

[rich@annexia.org]

On Wed, Mar 01, 2000 at 12:06:22PM +0000, cjsmith "at" btinternet.com wrote:
> Hi,
[...]
> The question I have now is how to add these to the public protocol - we=
 don't
> want to force all servers to implement this, so increasing the protocol=
 version
> number isn't ideal. I was thinking of changing the "pad2" field of the =
rfbPixelFormat
> into a "display features" bit-mask, so that bit 0 would indicate that t=
he current
> server and desktop settings support the scaling functions.

The problem is that the VNC protocol isn't really very
extensible as it stands. I've been thinking about
this a lot too since I also need a way to be able
to extend the protocol for my own purposes.

Things which are missing, and could usefully be added
if you decide to overhaul the protocol are:

* Server -> client and client -> server negotiated
  `features'. Note that there are features to be negotiated
  in both directions.
   =20
* Add a message length to each message so that you can
  easily add extra fields to messages. This allows servers
  and clients to synchronize with the message flow, even
  if they have to ignore the extra fields.

> Is it guaranteed that *all* VNC servers will set the "pad2" field to ZE=
RO? Does
> anyone have a better idea on how to implement this protocol change?

Doesn't seem likely.

Rich.

--=20
rich "at" annexia.org | Is your school part of http://www.schoolmaster.net ?
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Copyright =A9 2000 Richard Jones | GnuPG/PGP key from www.annexia.org

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