Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!execu!sequoia!uudell!bigtex!texsun!male!newstop!exodus!Sun.COM!price
From: price@Sun.COM (Chuck Price)
Newsgroups: comp.windows.x
Subject: Re: Questions about cursors (large crosshairs)
Message-ID: <4012@exodus.Eng.Sun.COM>
Date: 5 Dec 90 23:52:55 GMT
References: <1124@cvbnetPrime.COM> <3083@gazette.bcm.tmc.edu>
Sender: news@exodus.Eng.Sun.COM
Reply-To: price@Sun.COM (Chuck Price)
Distribution: usa
Organization: Sun Laboratories
Lines: 15

You are not guaranteed that a particular X server will support arbitrary
cursor sizes. (And I bet those that do support cursors the size of your  window
are not likely to move them around as quickly as you would hope).

You will get quite reasonable performance on most systems by simulating
a crosshair cursor on the client side. First, set an invisible cursor (makes
any lag less noticable...). Next, be sure you are getting motion hints, not
every mouse motion the server generates. Then listen for motion events,
drawing and undrawing the lines with the appropriate graphics functions.

This conference and the sources contain many examples of each step described
above (check out most any window manager source). Also, using zero width lines
frequently speeds things up quite a bit.

-chuck