Summary of CGAL's Configuration Variables

Most configuration variables are not environment variables but CMake variables. They are given in the command line to CMake via the -D option, or passed from the interactive interface of cmake-gui. Unless indicated differently, all the variables summarized below are CMake variables.

Component Selection

The following boolean variables indicate which CGAL components to configure and/or build. Their values can be ON or OFF.

Variable	Default Value
WITH_examples	OFF
WITH_demos	OFF
WITH_CGAL_Core	ON
WITH_CGAL_Qt5	ON
WITH_CGAL_ImageIO	ON

Compiler and Linker Flags

The following variables specify compiler and linker flags. Each variable holds a space-separated list of command-line switches for the compiler and linker and their default values are automatically defined by CMake based on the target platform.

Have in mind that these variables specify a list of flags, not just one single flag. If you provide your own definition for a variable, you will entirely override the list of flags chosen by CMake for that particular variable.

The variables that correspond to both debug and release builds are always used in conjunction with those for the specific build type.

Program	Both Debug and Release	Release Only	Debug Only
C++ Compiler	CMAKE_CXX_FLAGS	CMAKE_CXX_FLAGS_RELEASE	CMAKE_CXX_FLAGS_DEBUG
Linker (shared libs)	CMAKE_SHARED_LINKER_FLAGS	CMAKE_SHARED_LINKER_FLAGS_RELEASE	CMAKE_SHARED_LINKER_FLAGS_DEBUG
Linker (static libs)	CMAKE_MODULE_LINKER_FLAGS	CMAKE_MODULE_LINKER_FLAGS_RELEASE	CMAKE_MODULE_LINKER_FLAGS_DEBUG
Linker (programs)	CMAKE_EXE_LINKER_FLAGS	CMAKE_EXE_LINKER_FLAGS_RELEASE	CMAKE_EXE_LINKER_FLAGS_DEBUG

Additional Compiler and Linker Flags

The following variables can be used to add flags without overriding the ones defined by cmake.

Program	Both Debug and Release	Release Only	Debug Only
C++ Compiler	CGAL_CXX_FLAGS	CGAL_CXX_FLAGS_RELEASE	CGAL_CXX_FLAGS_DEBUG
Linker (shared libs)	CGAL_SHARED_LINKER_FLAGS	CGAL_SHARED_LINKER_FLAGS_RELEASE	CGAL_SHARED_LINKER_FLAGS_DEBUG
Linker (static libs)	CGAL_MODULE_LINKER_FLAGS	CGAL_MODULE_LINKER_FLAGS_RELEASE	CGAL_MODULE_LINKER_FLAGS_DEBUG
Linker (programs)	CGAL_EXE_LINKER_FLAGS	CGAL_EXE_LINKER_FLAGS_RELEASE	CGAL_EXE_LINKER_FLAGS_DEBUG

Miscellaneous Variables

Note that the default build type is Debug, which should only be used to debug and will serverly limit performances.

Variable	Description	Type	Default Value
CMAKE_BUILD_TYPE	Indicates type of build. Possible values are 'Debug' or 'Release'	CMake	none
CMAKE_INSTALL_PREFIX	Installation directory path	CMake	platform-dependent
CMAKE_C_COMPILER	Full-path to the executable corresponding to the C compiler to use.	CMake	platform-dependent
CMAKE_CXX_COMPILER	Full-path to the executable corresponding to the C++ compiler to use.	CMake	platform-dependent
CXX	Idem	Environment	Idem
BUILD_SHARED_LIBS	Whether to build shared or static libraries.	CMake	ON

Variables Used Only When Building Programs (Such as Demos or Examples)

Variable	Description	Type	Default Value
CGAL_DIR	Full-path to the binary directory where CGAL was configured	Either CMake or Environment	none
Qt5_DIR	Full-path to the Qt cmake directory	CMake	platform-dependent

Variables Providing Information About 3rd-Party Libraries

The following variables provide information about the availability and location of the 3rd party libraries used by CGAL. CMake automatically searches for dependencies so you need to specify these variables if CMake was unable to locate something. This is indicated by a value ending in NOTFOUND.

Since 3rd-party libraries are system wide, many of the CMake variables listed below can alternatively be given as similarly-named environment variables instead. Keep in mind that you must provide one or the other but never both.

Boost Libraries

Version 1.70 and Later

Starting from Boost 1.70, the cmake config mode can be used for configuring the Boost version to use by setting the environment variable Boost_DIR to the path containing the file BoostConfig.cmake. For example if you manually installed Boost 1.77 with --prefix=<path>, then you should set Boost_DIR=<path>/lib/cmake/Boost-1.77.0.

Version 1.69 and Earlier

Warning

If you have a version of Boost greater than 1.69 already installed on your system, and you want to configure and compile with an earlier version of Boost, then you will need to set the CMake variable Boost_NO_BOOST_CMAKE to ON (otherwise the FindBoost.cmake module of CMake will start searching for BoostConfig.cmake, and ignore the BOOST_ROOT variable).

In most cases, if Boost is not automatically found, setting the BOOST_ROOT variable is enough. If it is not, you can specify the header and library directories individually. You can also provide the full pathname to a specific compiled library if it cannot be found in the library directory or its name is non-standard.

By default, when Boost binary libraries are needed, the shared versions are used if present. You can set the variable CGAL_Boost_USE_STATIC_LIBS to ON if you want to link with static versions explicitly.

On Windows, if you link with Boost shared libraries, you must ensure that the .dll files are found by the dynamic linker, at run time. For example, you can add the path to the Boost .dll to the PATH environment variable.

Variable	Description	Type
BOOST_ROOTThe environment variable can be spelled either BOOST_ROOT or BOOSTROOT	Root directory of your Boost installation	Either CMake or Environment
Boost_INCLUDE_DIR	Directory containing the boost/version.hpp file	CMake
BOOST_INCLUDEDIR	Idem	Environment
Boost_LIBRARY_DIRS	Directory containing the compiled Boost libraries	CMake
BOOST_LIBRARYDIR	Idem	Environment
Boost_(xyz)_LIBRARY_RELEASE	Full pathname to a release build of the compiled 'xyz' Boost library	CMake
Boost_(xyz)_LIBRARY_DEBUG	Full pathname to a debug build of the compiled 'xyz' Boost library	CMake

GMP and MPFR Libraries

Under Windows, auto-linking is used, so only the directory containing the libraries is needed and you would specify GMP|MPFR_LIBRARY_DIR rather than GMP|MPFR_LIBRARIES. On the other hand, under Linux the actual library filename is needed. Thus you would specify GMP|MPFR_LIBRARIES. In no case you need to specify both.

CGAL uses both GMP and MPFR so both need to be supported. If either of them is unavailable the usage of GMP and of MPFR will be disabled.

Variable	Description	Type
CGAL_DISABLE_GMP	Indicates whether to search and use GMP/MPFR or not	CMake
GMP_DIR	Directory of GMP default installation	Environment
GMP_INCLUDE_DIR	Directory containing the gmp.h file	CMake
GMP_INC_DIR	Idem	Environment
GMP_LIBRARIES_DIR	Directory containing the compiled GMP library	CMake
GMP_LIB_DIR	Idem	Environment
GMP_LIBRARIES	Full pathname of the compiled GMP library	CMake
MPFR_INCLUDE_DIR	Directory containing the mpfr.h file	CMake
MPFR_INC_DIR	Idem	Environment
MPFR_LIBRARIES_DIR	Directory containing the compiled MPFR library	CMake
MPFR_LIB_DIR	Idem	Environment
MPFR_LIBRARIES	Full pathname of the compiled MPFR library	CMake

Under Linux, the GMPXX is also searched for, and you may specify the following variables:

Variable	Description	Type
GMPXX_DIR	Directory of GMPXX default installation	Environment
GMPXX_INCLUDE_DIR	Directory containing the gmpxx.h file	CMake
GMPXX_LIBRARIES	Full pathname of the compiled GMPXX library	CMake

Qt5 Library

You must set the cmake or environment variable Qt5_DIR to point to the path to the directory containing the file Qt5Config.cmake created by your Qt5 installation. If you are using the open source edition it should be <path>/qt-everywhere-opensource-src-<version>/qtbase/lib/cmake/Qt5.

LEDA Library

When the LEDA libraries are not automatically found, yet they are installed on the system with base names 'leda' and 'ledaD' (for the release and debug versions resp.), it might be sufficient to just indicate the library directory via the LEDA_LIBRARY_DIRS variable. If that doesn't work because, for example, the names are different, you can provide the full pathnames of each variant via LEDA_LIBRARY_RELEASE and LEDA_LIBRARY_DEBUG.

The variables specifying definitions and flags can be left undefined if they are not needed by LEDA.

Variable	Description	Type
WITH_LEDA	Indicates whether to search and use LEDA or not	CMake
LEDA_DIR	Directory of LEDA default installation	Environment
LEDA_INCLUDE_DIR	Directory containing the file LEDA/system/basic.h	CMake
LEDA_LIBRARIES	Directory containing the compiled LEDA libraries	CMake
LEDA_INC_DIR	Directory containing the file LEDA/system/basic.h	Environment
LEDA_LIB_DIR	Directory containing the compiled LEDA libraries	Environment
LEDA_LIBRARY_RELEASE	Full pathname to a release build of the LEDA library	CMake
LEDA_LIBRARY_DEBUG	Full pathname to a debug build of the LEDA library	CMake
LEDA_DEFINITIONS	Preprocessor definitions	CMake
LEDA_CXX_FLAGS	Compiler flags	CMake
LEDA_LINKER_FLAGS	Linker flags	CMake

MPFI Library

CGAL provides a number type based on this library, but the CGAL library itself does not depend on MPFI. This means that this library must be configured when compiling an application that uses the above number type.

When MPFI files are not on the standard path, the locations of the headers and library files must be specified by using environment variables.

Variable	Description	Type
MPFI_DIR	Directory of MPFI default installation	Environment
MPFI_INCLUDE_DIR	Directory containing the mpfi.h file	CMake
MPFI_INC_DIR	Idem	Environment
MPFI_LIBRARIES_DIR	Directory containing the compiled MPFI library	CMake
MPFI_LIB_DIR	Idem	Environment
MPFI_LIBRARIES	Full pathname of the compiled MPFI library	CMake

RS and RS3 Library

As said before, only the CGAL univariate algebraic kernel depends on the library Rs. As the algebraic kernel is not compiled as a part of the CGAL library, this library is not detected nor configured at installation time.

CMake will try to find Rs in the standard header and library directories. When it is not automatically detected, the locations of the headers and library files must be specified using environment variables.

Rs needs GMP 4.2 or later and MPFI 1.3.4 or later. The variables related to the latter library may also need to be defined.

Variable	Description	Type
RS_DIR	Directory of RS default installation	Environment
RS_INCLUDE_DIR	Directory containing the rs_exports.h file	CMake
RS_INC_DIR	Idem	Environment
RS_LIBRARIES_DIR	Directory containing the compiled RS library	CMake
RS_LIB_DIR	Idem	Environment
RS_LIBRARIES	Full pathname of the compiled RS library	CMake

Similar variables exist for RS3.

Variable	Description	Type
RS3_DIR	Directory of RS3 default installation	Environment
RS3_INCLUDE_DIR	Directory containing the file rs3_fncts.h file	CMake
RS3_INC_DIR	Idem	Environment
RS3_LIBRARIES_DIR	Directory containing the compiled RS3 library	CMake
RS3_LIB_DIR	Idem	Environment
RS3_LIBRARIES	Full pathname of the compiled RS3 library	CMake

NTL Library

Some polynomial computations in CGAL's algebraic kernel are speed up when NTL is available. As the algebraic kernel is not compiled as a part of the CGAL library, this library is not detected nor configured at installation time.

CMake will try to find NTL in the standard header and library directories. When it is not automatically detected, the locations of the headers and library files must be specified using environment variables.

Variable	Description	Type
NTL_DIR	Directory of NTL default installation	Environment
NTL_INCLUDE_DIR	Directory containing the NTL/ZZX.h file	CMake
NTL_INC_DIR	Idem	Environment
NTL_LIBRARIES_DIR	Directory containing the compiled NTL library	CMake
NTL_LIB_DIR	Idem	Environment
NTL_LIBRARIES	Full pathname of the compiled NTL library	CMake

Eigen Library

Eigen is a header-only template library. Only the directory containing the header files of Eigen 3.1 (or greater) is needed.

Variable	Description	Type
EIGEN3_INCLUDE_DIR	Directory containing the file signature_of_eigen3_matrix_library	CMake
EIGEN3_INC_DIR	Idem	Environment

ESBTL Library

One skin surface example requires the ESBTL library in order to read PDB files.

If ESBTL is not automatically found, setting the ESBTL_INC_DIR environment variable is sufficient.

Variable	Description	Type
ESBTL_DIR	Directory of ESBTL default installation	Environment
ESBTL_INC_DIR	Directory containing the ESBTL/default.h file	Environment
ESBTL_INCLUDE_DIR	Directory containing the ESBTL/default.h file	CMake

METIS Library

Some BGL examples require the METIS library in order to partition METIS meshes.

If METIS is not automatically found, setting the METIS_INCLUDE_DIR and METIS_LIBRARY cmake variables is necessary.

Variable	Description	Type
METIS_INCLUDE_DIR	Directory of METIS default installation	CMAKE
METIS_LIBRARY	Directory containing the libmetis.so or .lib file	CMAKE

TBB Library

If TBB is not automatically found, the user must set some variables, depending on the used version of TBB.

TBB 2020 or before

The TBB_ROOT and TBB_ARCH_PLATFORM=<arch>/<compiler> environment variables must be set. <arch> is ia32 or intel64. <compiler> describes the Linux kernel, gcc version or Visual Studio version used. It should be set to what is used in $TBB_ROOT/lib/<arch>.

For windows users, the folder TBB_ROOT/bin/<arch>/<compiler> should be added to the PATH variable.

Note that the variables in the table below are being used.

Variable	Description	Type
TBB_ROOT	Directory of TBB default installation	Environment
TBB_INCLUDE_DIRS	Directory containing the tbb/tbb.h file	CMake
TBB_LIBRARY_DIRS	Directory(ies) containing the compiled TBB libraries	CMake
TBB_LIBRARIES	Full pathnames of the compiled TBB libraries (both release and debug versions, using "optimized" and "debug" CMake keywords). Note that if the debug versions are not found, the release versions will be used instead for the debug mode.	CMake
TBB_RELEASE_LIBRARY	Full pathname of the compiled TBB release library	CMake
TBB_MALLOC_RELEASE_LIBRARY	Full pathname of the compiled TBB release malloc library	CMake
TBB_DEBUG_LIBRARY	Full pathname of the compiled TBB debug library	CMake
TBB_MALLOC_DEBUG_LIBRARY	Full pathname of the compiled TBB debug malloc library	CMake
TBB_MALLOCPROXY_DEBUG_LIBRARY	Full pathname of the compiled TBB debug malloc_proxy library (optional)	CMake
TBB_MALLOCPROXY_RELEASE_LIBRARY	Full pathname of the compiled TBB release malloc_proxy library (optional)	CMake

OneTBB

Since OneAPI TBB version 2021, Intel provides CMake scripts of their own, and the user only have to set the TBB_DIR CMake variable at configuration time. A typical value for TBB_DIR is /opt/intel/oneapi/tbb/latest/lib/cmake/tbb on Unix systems, and C:/dev/OneAPI/tbb/latest/lib/cmake/tbb on Windows. Alternatively, the user can instead source the setvars script that can be found at /opt/intel/oneapi/setvars.sh on Unix and C:/dev/OneAPI/setvars.bat on Windows. It will setup the PATH and all Intel internal variables to be able to easily use any library of the OneAPI.

LASlib library

If LASLIB is not automatically found, the following variables must be set:

Variable	Description	Type
LASLIB_INCLUDE_DIR	Directory containing the file lasreader.hpp	CMake
LASZIP_INCLUDE_DIR	Directory containing the file mydefs.hpp	CMake
LASLIB_LIBRARIES	Full pathname of the compiled LASLIB library	CMake

OpenCV library

The environment variable OPENCV_DIR should be set to the directory containing the file OpenCVConfig.cmake provided by OpenCV.

SCIP library

The environment variable SCIP_DIR should be set to the directory containing the file scip-config.cmake provided by SCIP.

GLPK library

If GLPK is not automatically found, the following variables must be set:

Variable	Description	Type
GLPK_INCLUDE_DIR	Directory containing the file glpk.h	CMake
GLPK_LIBRARIES	Full pathname of the compiled GLPK library	CMake

Compiler Workarounds

A number of boolean flags are used to workaround compiler bugs and limitations. They all start with the prefix CGAL_CFG. These flags are used to work around compiler bugs and limitations.

For each installation a file <CGAL/compiler_config.h> is defined, with the correct settings of all flags. This file is generated automatically by CMake, and it is located in the include directory of where you run CMake. For an in-source configuration this means CGAL-5.6.1/include.

The test programs used to generate the compiler_config.h file can be found in config/testfiles. Both compiler_config.h and the test programs contain a short description of the problem. In case of trouble with one of the CGAL_CFG flags, it is a good idea to take a look at it.

The file CGAL/compiler_config.h is included from <CGAL/config.h>. which is included by all CGAL header files.