Path: utzoo!mnetor!tmsoft!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!usc!ucsd!ucbvax!bloom-beacon!ZIA.AOC.NRAO.EDU!cflatter
From: cflatter@ZIA.AOC.NRAO.EDU (Chris Flatters)
Newsgroups: comp.windows.x
Subject: Re:  Zooming
Message-ID: <9011071852.AA01344@zia.aoc.nrao.edu>
Date: 7 Nov 90 18:52:12 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 16


> I am writing an application that must allow a user to zoom the image >
> displayed in a window.  How does one implement such a feature using X
> windows? Any ideas would be appreciated.  Thanks.

The only way I know of is to build the zoomed image in the client, using
either simple pixel replication or some form of interpolation, and then
XPutImage the zoomed image to the window.  Actually, it may be better to
load the zoomed image into a pixmap and then display that in a window. 
Providing that you have enough memory on the server side, this would speed
up redraws and scrolling operations since you wouldn't have to transfer
the image date to the server every time.

If there are better methods around, I would like to hear of them too.

			Chris Flatters