Path: utzoo!attcan!uunet!mcvax!hp4nl!ruuinf!markov From: markov@ruuinf.cs.ruu.nl (dr.m.h. overmars) Newsgroups: comp.graphics Subject: Re: Concave polygon problem Summary: This is all wellknown in computational geometry Some references to literature. Message-ID: <1388@ruuinf.cs.ruu.nl> Date: 17 Jun 89 13:07:23 GMT References: <3378@cps3xx.UUCP> <3964@eos.UUCP> <14611@pasteur.Berkeley.EDU> Organization: Univ of Utrecht, Dept of CS Lines: 16 The problem of triangulating a polygon is well-known in computational geometry. See e.g. Preparata and Shamos: Computational Geometry, an introduction, published by Springer-Verlag for some algorithms. Given a n-vertex polygon the theoretically most efficient algorithm runs in time O(n loglog n) but I would not encourage you to implement it. A simple method partitions the polygon into monotone polygons (each horizontal line intersects it only once) and next triangulate these. It does not require you to add vertices in the interior and runs in time O(n log n). See the above book for a clear description. -- -------------------------------------------------------------------------------- Mark Overmars |\/| Dept. of Comp. Science, University of Utrecht, | |ark P.O. Box 80.089, 3508 TB Utrecht, the Netherlands E-mail: hp4nl!ruuinf!markov