Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!eecae!netnews.upenn.edu!eniac.seas.upenn.edu!culmer
From: culmer@eniac.seas.upenn.edu (Charles Culmer)
Newsgroups: comp.sys.apollo
Subject: GPR, turn on one pixel, big pictures
Message-ID: <7892@netnews.upenn.edu>
Date: 12 Feb 89 00:02:59 GMT
Sender: news@netnews.upenn.edu
Reply-To: culmer@eniac.seas.upenn.edu (Charles Culmer)
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Organization: University of Pennsylvania
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I inherited a model 3000 last week and started playing with gpr.
Please excuse me for asking some really novice questions.  (I'm
using version 9.7.)

(1)  Is there any way to turn on a single pixel besides drawing
a line of length 0 with gpr_$line?  Why isn't there gpr_$pixel?

(I wanted to write a program to draw the chaos triangle shown on
a recent episode of Nova.)

(2)  I want to draw pictures larger than the screen and move them
around under my window.  A brief skim of the gpr manual suggested
that frame mode was the way to do it, but the manual recommended
against using frame mode.  What should I do?  Do I build a bitmap
in main memory and then do transfers as I move the window?  Isn't
that what frame mode does?  I hardly expect to do it better than
the professional programmers and basketball gurus at Apollo.

Thanks.

Charles W. Culmer
culmer@eniac.seas.upenn.edu      Truth, justice, and the American way.