Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wasatch!cs.utah.edu!banks
From: banks%cs.utah.edu@wasatch.UUCP (Michael J. Banks)
Newsgroups: comp.graphics
Subject: Re: looking for a fast ellipse algorithm
Keywords: ellipse, graphics, circle
Message-ID: <1121@wasatch.UUCP>
Date: 15 Feb 89 01:22:36 GMT
References: <399@peritek.UUCP> <1311@ndmath.UUCP>
Sender: news@wasatch.UUCP
Reply-To: banks%cs.utah.edu.UUCP@wasatch.UUCP (Michael J. Banks)
Organization: University of Utah, Computer Science Dept.
Lines: 24

In article <1311@ndmath.UUCP> krueger@ndmath.UUCP (Andreas Krueger) writes:
>In article <399@peritek.UUCP>, dig@peritek.UUCP (David Gotwisner) writes:
>> 
>> 	I am looking for an algorithm (or code) which will allow circle
>> generation onto a graphics device which drives a monitor with non-square
>> pixels.
>
>Drawing a circle on a device with non-square pixels is
>equivalent to drawing an ellipse on a monitor with square pixels.
>
>From any third-semester calculus book ("calculus with analytic
>geometry") you can find the formula of an ellipse:
>

A very fast integer algorithm was presented several years ago
by Jerry Van Aken and Mark Novak of Texas Instruments:

Curve-Drawing Algorithms for Raster Displays
Jerry Van Aken and Mark Novak
ACM Transactions on Graphics
Vol. 4, No.2, April 1985

mike.
(banks@cs.utah.edu)