License

Table of Contents

• Introduction
  • Copyright and License Notices
• Package License Headers
• Including License Headers in Package Header Files
• Using the License Checking Mechanism

Introduction

CGAL header files are under LGPL-3+ or GPL-3+. Some users only want to use LGPL headers, other will get a commercial license for some packages. In order to make sure that the header used follow what was intended, a license checking mechanism has been implemented in CGAL. This page describes how it is working, and what a new header file in an existing or new package must contain.

Copyright and License Notices

Note that this wiki page does not describe the license and copyright notices that every CGAL source files should include as well. See the section File header in the CGAL developers manual.

Package License Headers

For each package under GPL-3+, a license file is available in Installation/include/CGAL/license/. These files are automatically generated using the template Installation/include/CGAL/license/gpl.h.in. Calling cmake -P generate_files.cmake from Installation/include/CGAL/license/ will read the file Installation/include/CGAL/license/gpl_package_list.txt and will generate a license file for each entry in the file. An entry in gpl_package_list.txt is a line with the short name of the package (the name of the directory of the package) followed by the complete name of the package (the name used in the documentation). For example

Triangulation_2 2D Triangulations

Including License Headers in Package Header Files

All the header files of a package must include the license file of its package. All the include directives have been added using the script Scripts/developer_scripts/add_license_in_pkg_header.py. It takes two arguments. The first one is the short name of the package and the second one (optional if identical) is the name of the directory containing the header files. The script must be called at the root of a CGAL checkout.

Example calls:

# example for Triangulation_2 package
add_license_in_pkg_header.py Triangulation_2
# example for Polyhedron_3_IO that uses Polyhedron_3 license file
add_license_in_pkg_header.py Polyhedron_3  Polyhedron_3_IO

The script will update only headers that do not already contain the include directive. The mechanism is rather simple and expects the include directive to follow the include guards (that must be something like CGAL_.*_H).

Here is an example for the file Delaunay_triangulation_2.h in the Triangulation_2 package.

#ifndef CGAL_DELAUNAY_TRIANGULATION_2_H
#define CGAL_DELAUNAY_TRIANGULATION_2_H

#include <CGAL/license/Triangulation_2.h>

Using the License Checking Mechanism

If you want to test this mechanism yourself, you need to update the file Installation/include/CGAL/license.h. As explained in the file, enable one of the checking mechanisms (error or warning):

// #define CGAL_LICENSE_WARNING  1   // in order to get a warning during compilation
// #define CGAL_LICENSE_ERROR    1   // in order to get an error during compilation

Then define a macro for all packages you think you are using:

#define CGAL_AABB_TREE_COMMERCIAL_LICENSE  20140101

The name of the macro is CGAL_+short name of the package in uppercase+_COMMERCIAL_LICENSE. The number following corresponds to the release date for which you have a commercial license.