Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!amdahl!pacbell!att!alberta!calgary!allan
From: allan@calgary.UUCP (Jeff Allan)
Newsgroups: comp.graphics
Subject: Re: A question
Summary: Polygon Clipping, Hidden Line Removal
Keywords: Polygon Cliping/Hidden lines
Message-ID: <1676@vaxb.calgary.UUCP>
Date: 15 Jun 88 15:52:54 GMT
References: <1932@pt.cs.cmu.edu>
Organization: U. of Calgary, Calgary, Ab.
Lines: 23

In article <1932@pt.cs.cmu.edu>, ych@maps.cs.cmu.edu (Yuan Hsieh) writes:
> Is there a good algorithm to clip two polygons against each other?

The most general polygon clipping algorithm that I know of is the 
Weiler-Atherton algorithm. It is described in:

"Fundamentals of Computer Graphics", J.D. Foely & A. van Dam,
Addison Wesley, 1983.

It was originally published in:

Hidden Surface Removal using Polygon Area Sorting, Kevin Weiler & 
Peter Atherton, SIGGRAPH '77 Procedings published as 
Computer Graphics 11(2), Summer 1977, pp.214-222.

The algorithm clips a concave polygon (possibly with holes) to another
concave polygon (also, possibly with holes). I am not convinced that the
hidden surface/line removal algorithm described in the paper works for
line drawings, but then I've never tried to implement it.

Hope this helps.
-- 
        Jeff Allan,  University of Calgary
	..!{ubc-vision,ihnp4}!alberta!calgary!allan