Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!uakari.primate.wisc.edu!ginosko!uunet!csinc!shal
From: shal@csinc.UUCP (Shal Jain x848)
Newsgroups: comp.graphics
Subject: clipping polygons to a viewport
Keywords: polygons,clipping
Message-ID: <120@csinc.UUCP>
Date: 2 Oct 89 21:37:26 GMT
Organization: Control Systems, Inc., St. Paul MN
Lines: 25

Am looking for a very robust algorithm/code for clipping polygons to a 
rectangular viewport. The polygons can be concave,convex or bow-tied.
The only reference I have is Newman-Sproull "Principals of Interactive
Computer Graphics". Any pointers,references etc. will be appreciated
EMAIL   address  uunet!csinc!shal
Phone   612 - 631 - 7848.
A special case I am interested is as such:  
+ denotes viewport boundary. * is outline of target polygon. 
@ is where the polygon crosses the viewport.
           ------------------
           +                +
           +            ****@*****
           +             *  +    *
           +              * +    *
           +               *+    *
           +                @    *
           +                +*   *
           +                + *  *
           +                +*   *
           +                @    *
           +               *+    *
           +              * +    *
           --------------@---    *
                        *        *
                       ***********