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From: bhyde@inmet.UUCP
Newsgroups: net.micro.mac
Subject: Re: Deficiencies in QuickDraw support fo
Message-ID: <26700020@inmet.UUCP>
Date: Mon, 24-Jun-85 13:28:00 EDT
Article-I.D.: inmet.26700020
Posted: Mon Jun 24 13:28:00 1985
Date-Received: Thu, 27-Jun-85 08:23:16 EDT
References: <202@harvard.UUCP>
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Nf-ID: #R:harvard:-20200:inmet:26700020:000:764
Nf-From: inmet!bhyde    Jun 24 13:28:00 1985



  What a sad note about quickdraw and the laser writer.

  This is no comfort but it turns out that regions aren't
really very useful beyond the screen maintainance problem.  A
region is encoded in bands.   Each band is a contigous set of rows all
identical.  Thus a rectangle can be encoded in a single band,
but a diamond or circle will require a band for each row of pixels.
Regions are as grainy as the Mac screen.

You can slip around the problem by drawing to a virtual screen with the
resolution of the your device but then the application must support device
dependent modes.

  So there are good reasons to use polygons and not regions.
No comfort if you've designed the entire system to use regions for
the hidden line elimination problem.
			ben hyde.