voronoi - compute Voronoi diagram or Delaunay triangulation
SYNOPSIS
	voronoi [-s -t] <pointfile >outputfile

Voronoi reads the standard input for a set of points in the plane and writes either
the Voronoi diagram or the Delaunay triangulation to the standard output.
Each input line should consist of two real numbers, separated by white space.

If option
	-t 
is present, the Delaunay triangulation is produced. 
Each output line is a triple
	i j k
which are the indices of the three points in a Delaunay triangle. Points are
numbered starting at 0. If this option is not present, the
Voronoi diagram is produced.  There are four output record types.
	s a b
indicates that an input point at coordinates 
	l a b c
indicates a line with equation ax + by = c.
	v a b
indicates a vertex at  a b.
	e l v1 v2
indicates a Voronoi segment which is a subsegment of line number l;
with endpoints numbered v1 and v2.  If v1 or v2 is -1, the line
extends to infinity.

AUTHOR
Steve J. Fortune (1987) A Sweepline Algorithm for Voronoi Diagrams,
Algorithmica 2, 153-174.