Voronoi diagrams, Delaunay triangulations

GEOMPACK2 is a FORTRAN90 library which carries out certain geometric computations, including the Voronoi diagram, and the Delaunay triangulation of a set of points in the plane, by Barry Joe.

Note that DTRIS2 or RTRIS2, the fundamental routine for constructing the Delaunay triangulation, alters the input coordinate data by sorting it. This has caused me so many problems that I finally wrote a modified version of DTRIS2/RTRIS2 that undoes the sorting before return. In all other programs that use DTRIS2/RTRIS2, I use the modified version, but I have left the original here in this package.


GEOMPACK2 is available in a FORTRAN90 version.

Related Data and Programs:

DUTCH, a FORTRAN90 library which carries out tasks in computational geometry.

GEOMETRY, a FORTRAN90 library which performs geometric calculations in 2, 3 and N dimensional space.

GEOMPACK, a FORTRAN90 library which is a subset of GEOMPACK2, and which is available in several other computer languages.

GEOMPACK3, a FORTRAN90 library which handles 3D geometric problems.

TRIANGULATION_DISPLAY_OPENGL, a C++ program which reads files defining a triangulation and displays an image using OpenGL.

TRIANGULATION_TRIANGLE_NEIGHBORS, a FORTRAN90 program which reads data defining a triangulation, determines the neighboring triangles of each triangle, and writes that information to a file.


Original FORTRAN77 version by Barry Joe; FORTRAN90 version by John Burkardt.


  1. Franz Aurenhammer,
    Voronoi diagrams - a study of a fundamental geometric data structure,
    ACM Computing Surveys,
    Volume 23, pages 345-405, September 1991.
  2. Barry Joe,
    GEOMPACK - a software package for the generation of meshes using geometric algorithms,
    Advances in Engineering Software,
    Volume 13, pages 325-331, 1991.

Source Code:

Examples and Tests:

List of Routines:

You can go up one level to the FORTRAN90 source codes.

Last revised on 12 November 2006.