Questions about VNC

[Benjamin Vierck]

Each client gets a client object on the server which in turn gets a
buffer object which in turn owns the buffers and desktop object. The
desktop object has a method CaptureScreen(RECT &rect, BYTE *scrBuff,
UINT scrBuffSize) which is called by the buffer's method GrabRect(RECT
&rect) which is called by the client object's method
GrabRegion(vncRegion &rgn) which is called by the client's method
SendUpdate(). The client object then sacrifices a chicken, does a little
rectangle arithmetic to grind out some rects that may not be necessary,
then calls its method CheckRects(vncRegion &rgn, rectlist &rects) which
in turn calls the buffer's method GetChangedRegion(vncRegion &rgn, RECT
&rect) which does a pixel by pixel comparison for changes. Later the
region is sent without compression.

The process is actually alot messier. But thats the quickie answer.

Benjamin Vierck
RioLogic

-----Original Message-----
From: tsw "at" shuwei.pl.my [mailto:tsw "at" shuwei.pl.my]
Sent: Tuesday, June 01, 1999 10:35 AM
To: vnc-list "at" uk.research.att.com
Subject: Questions about VNC


How is Windows VNC implemented? Is it through screen 
capturing? If it is, are the images compressed before being sent, 
and is the whole screen transmitted or only the area that has 
changed?

Thanks

Shu Wei


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