Path: utzoo!attcan!uunet!lll-winken!ames!mailrus!iuvax!uxc!uxc.cso.uiuc.edu!uxg.cso.uiuc.edu!uxe.cso.uiuc.edu!mcdonald
From: mcdonald@uxe.cso.uiuc.edu
Newsgroups: comp.graphics
Subject: Re: looking for a fast ellipse algorith
Message-ID: <46900031@uxe.cso.uiuc.edu>
Date: 19 Feb 89 15:09:00 GMT
References: <399@peritek.UUCP>
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Nf-ID: #R:peritek.UUCP:399:uxe.cso.uiuc.edu:46900031:000:712
Nf-From: uxe.cso.uiuc.edu!mcdonald    Feb 19 09:09:00 1989



>Assumptions: Your ellipse is aligned vertically (i.e. not rotated), and
>   the center (h, k) is given in rational numbers with denominator d.
>   Also, the eccentricity is small (since you say it's for a raster device,
>   I assume the pixel aspect ratio (length/width) is near one). I also assume
>   that the major and minor radii (a and b) are rational with denominator d.

Wrong, Wrong, and I guess that's OK. 

In other words, I would like the answer for arbitrary orientation
(e.g. major axis at 23 degrees to the horizontal) and eccentricity.
I have found no usefully fast answers for this. Anybody out there
have the answer? I have looked in several textbooks and never found
any help.

Doug McDonald