Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!rutgers!mcnc!thorin!unc!bolter
From: bolter@unc.cs.unc.edu (Jay D. Bolter)
Newsgroups: comp.sys.mac.programmer
Subject: Dissolve effect
Message-ID: <16209@thorin.cs.unc.edu>
Date: 23 Sep 90 01:45:49 GMT
Sender: news@thorin.cs.unc.edu
Lines: 9


  I would like to be able duplicate in my own programs the visual dissolve 
effect in Hypercard. That is, I would like to make the pixels of a window 
change quickly and randomly from one image to a new image. This trick was 
discussed a few months ago on the net. I believe the suggestion was to draw 
the new image offscreen and then call copybits repeatedly with a suitable 
mask that changes with each call. Can anyone provide me with the details (in 
particular how do you create and update the mask?), or with a pointer to an 
article on this subject?