From:	ovek AT arcticnet DOT no (Ove Kaaven)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Drawing circle arc-segments with spline() in Allegro
Date:	Wed, 01 Apr 1998 19:51:54 GMT
Organization:	Arctic Net AS
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Message-ID:	<352299fc.177101982@isflak.arcticnet.no>
References:	<351b7818 DOT 862586 AT news DOT manawatu DOT gen DOT nz>
NNTP-Posting-Host:	villager.arcticnet.no
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

langtons AT NOTTHISBIT DOT manawatu DOT gen DOT nz (Michael Langton) wrote:

>Hello,
>I need to find a good way to draw segments of a circle (for the
>purpose of drawing lenses).  The spline method seems to be a good way
>to do it, but I can't figure out where the two middle points should
>be.  One must be on each tangent (to the circle at the curve
>end-points), but how far along?

Experimenting with CorelDRAW is instructive. For the best
approximation of a 90-degree circular arc, the two control points
should coincide. Perhaps they should with other angles as well.

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