Introduction - If you have any usage issues, please Google them yourself
This code is described in "Computational Geometry in C" (Second Edition),
Chapter 4. It is not written to be comprehensible without the
explanation in that book.
Input: 3n integer coordinates for the points.
Output: the 3D convex hull, in postscript with embedded comments
showing the vertices and faces.
Compile: gcc-o chull chull.c (or simply: make)