Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!visix!nsx!ed
From: ed@nsx.Berkeley.EDU (Ed Devinney)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Optimizing animation processing speed
Message-ID: <1991May20.202641.5094@visix.com>
Date: 20 May 91 20:26:41 GMT
References: <1776@babcock.cerc.wvu.wvnet.edu> <8996@ucdavis.ucdavis.edu> <1991May18.231302.16630@nntp-server.caltech.edu>
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Reply-To: ed@visix.com
Organization: Institute for Advanced Latency
Lines: 24

In article <1991May18.231302.16630@nntp-server.caltech.edu>, palmer@nntp-server.caltech.edu (David Palmer) writes:
|> Do an 'InvalRect()' on the place where you remove the icons, and on the
|> new location of the icon.  Then when you respond to an 'update' event,
|> just write the background and the icons.  This does what you suggested--
|> only writing to the invalidated regions.
|> 
|> The Macintosh Way is to not write anything to the screen except during
|> update events.

Which is all very nice, but not for animation.  Like the commercial says, sometimes you
gotta break the rules, and smooth, consistent animation requires taking control of the
drawing.  (Kind of hard to guarantee a frame rate in a purely user-event-driven 
environment).

|> 		David Palmer
|> 		palmer@gap.cco.caltech.edu

-- 
ed devinney						ed@visix.com
Visix Software Inc., Reston, VA				...!uunet!visix!ed
	
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