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From: pmoran@m.cs.uiuc.edu
Newsgroups: comp.graphics
Subject: Re: Graphics Texts etc.
Message-ID: <4400074@m.cs.uiuc.edu>
Date: 17 Sep 90 18:14:00 GMT
References: <101880023@hpcvlx.cv.hp.com>
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Nf-ID: #R:hpcvlx.cv.hp.com:101880023:m.cs.uiuc.edu:4400074:000:966
Nf-From: m.cs.uiuc.edu!pmoran    Sep 17 13:14:00 1990


/* Written 11:53 am  Sep 14, 1990 by gordon@cs.tamu.edu ... */

> Maybe you can clear up something that has been a mystery to me: why
> does Hearn & Baker use a most inefficient polygon scan conversion 
> algorithm? Is it to avoid using linked lists? If you look up polygon
> scan-conversion in Foley & van Dam (old and new versions) and in many
> other books, you will see that a simple linked list is used to maintain
> the active edge table (or list). 

Being neither Hearn nor Baker, I cannot give the final answer to this
question, but my guess would be that they felt that the algorithm
would be fairly easy to understand.  I didn't see anything in the text
asserting "... this is the fastest polygon scan conversion algorithm ...".
If one is serious about doing a fast scan conversion algorithm
he or she should expect to do more than take an algorithm
directly out of an introductory graphics book.

Patrick Moran
University of Illinois at Urbana Champaign