Mathematical Tool GCLC (Geometry Constructions -> LaTeX Converter) by Predrag Janičić

I am happy that, almost 30 years after the very first versions of GCLC and with many related tools that appeared in the meanwhile, there is still a steady and wide need for the tool GCLC. With thousands of GCLC users worldwide, with many books, journal articles, and theses illustrated with the help of GCLC, and with many courses on different levels that are taught using GCLC, I am encouraged to keep the project GCLC active.
After turning open-source in 2020, in March 2024 it was time to announce one great novelty - a web-based version of GCLC, a contribution by Nikola Ubavić!
In May 2024, the git project got a new cmake system thanks to Matthew Fernandez!
Please find the links to the source code, to current versions of executables, and to the web-based version in the Downloads section.

Predrag Janičić [home page]

May 2024

What is GCLC?

GCLC (from "Geometry Constructions -> LaTeX Converter") is a tool for visualizing geometry, and for producing mathematical illustrations. Its main purposes are:
  • producing digital mathematical illustrations of high quality;
  • use in teaching geometry;
  • use in studying geometry with the help of automated theorem provers.
The basic idea behind GCLC is that constructions are formal procedures, rather than drawings. Thus, in GCLC, producing mathematical illustrations is based on "describing figures" rather than on "drawing figures". Created figures, of course, can be displayed and can be exported to LaTeX and other formats.
Although GCLC was initially built as a tool for producing LaTeX figures from descriptions of geometric constructions, now it is much more than that. It provides easy-to-use support for many isometric transformations, conics, parametric curves, dealing with expressions, flow control, automated theorem proving, etc.
There versions for Windows and for Linux. There are command line versions and versions with graphical user interfaces (that provide a range of additional functionalities).
The very first version of GCLC was written in Nov 1995. GCLC had its first public release in 1996, and several releases since then. It has thousands of users wordwide and it has been used for producing digital illustrations for a number of books, journal articles, theses, and in a number of high-school and university courses worldwide.

Main Features of GCLC

  • Freely available;
  • Support for a range of elementary and compound constructions, and isometric transformations;
  • Support for symbolic expressions, second order curves, parametric curves, flow control, user-defined functions, etc;
  • User-friendly interface, interactive work, animations, tracing points, "watch window" ("geometry calculator"), and other tools;
  • Support for drawing trees and graphs;
  • Built-in automated theorem provers, capable of proving many complex theorems;
  • Simple, easy to use, small in size;
  • Export of high quality figures into LaTeX (simple LaTeX format, PSTricks format, TikZ format), EPS (Encapsualted PostScript), SVG (Scalable Vector Graphics), bitmap, PNG, JPG format;
  • Command line and version with graphical user interface both for Windows and Linux;
  • Import from JavaView JVX format.

Downloads (Free)

Open source (git repository with source code and pre-built executables for Linux and Windows, available since Dec 5, 2020): Current release (command line version (gclc), GUI version (gclc-gui), manual, sample files, etc. (current version February 19, 2024):

Web-version of GCLC

GCLC Manual

The original address of this page is: www.matf.bg.ac.rs/~predrag.janicic/gclc (mirrored versions are not always up-to-date)

GCLC is available also from EMIS (The European Mathematical Information Service) servers: http://www.emis.de/misc/software/gclc/.


GCLC is being developed by Predrag Janičić (Faculty of Mathematics, University of Belgrade) and, in some parts, by Predrag Janičić and his coauthors:

Feedback Welcome

Copyright Notice

GCLC Examples


Prof. Zoran Lučić (University of Belgrade, Serbia): Euclid's construction of dodecahedron (2005)
Prof. Zoran Lučić (University of Belgrade, Serbia): Archita's construction of cube doubling (2006)
Bojan Radusinović (Serbia): Pythagora's theorem (2007)
Prof. Pierre Larochelle (USA): 3D circles (2008)
Prof. Pierre Larochelle (USA): Spherical quadrilateral (2008)
Robert Hartmann (Germany): Hyperboloid (2009)
Thomas Speziale (USA): Golden Spiral (2007)
Ania Piktas (Poland): The Koch curve (2007)
Milan Mitrović (Slovenia): four figures from his textbook on projective geometry (2007)
Vladimir Baltić (Serbia): several figures from his book textbook on discrete mathematical structures (2010)
Prof. Ebert Brea (Venezuela): Convolution between two functions (2023)
Prof. Ebert Brea (Venezuela): Karush–Kuhn–Tucker Conditions (2023)

Selected References

More on the background of GCLC can be found in:


I am grateful to: