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From: fritzke@immd2.informatik.uni-erlangen.de (B. Fritzke)
Newsgroups: comp.windows.x
Subject: help needed: quick exchange of window contents (animation)
Keywords: line drawing
Message-ID: <3090@medusa.informatik.uni-erlangen.de>
Date: 3 Sep 90 16:40:56 GMT
Sender: root@medusa.informatik.uni-erlangen.de
Organization: Universitaet Erlangen, CS-Dep. IMMD II
Lines: 26

Hi there,
I want to display complicated, slowly changing line drawings in an
X-Window. The problem is, that the screen starts flickering very much,
if I

  1) make a drawing    (1 long call to XDrawSegments)
  2) flush the screen  (XFlush)
  3) clear the window  (XClearWindow)
  4) goto 1)

Is there a possibility to build up the new drawing somewhere in the
background while showing the old one and then switching to the new
drawing with one (quick) command?

I'm aware of pixmaps and the possibility of copying them into the 
window, but I would like to avoid copying because of performance
reasons.


Thanks in advance for any help,
(please answer by e-mail)

Bernd Fritzke

Bernd Fritzke ------>  e-mail: fritzke@immd2.informatik.uni-erlangen.de
University of Erlangen, CS IMMD II, Martensstr. 3,  8520 Erlangen (FRG)