libigl/CMakeLists.txt

# Detects whether this is a top-level project
get_directory_property(LIBIGL_PARENT_DIR PARENT_DIRECTORY)
if(NOT LIBIGL_PARENT_DIR)
    set(LIBIGL_TOPLEVEL_PROJECT ON)
else()
    set(LIBIGL_TOPLEVEL_PROJECT OFF)
endif()

# Check required CMake version
set(REQUIRED_CMAKE_VERSION "3.16.0")
if(LIBIGL_TOPLEVEL_PROJECT)
    cmake_minimum_required(VERSION ${REQUIRED_CMAKE_VERSION})
else()
    # Don't use cmake_minimum_required here to avoid implicitly overriding parent policies
    if(${CMAKE_VERSION} VERSION_LESS ${REQUIRED_CMAKE_VERSION})
        message(FATAL_ERROR "CMake required version to build Libigl is ${REQUIRED_CMAKE_VERSION}")
    endif()
endif()

# Include user-provided default options if available. We do that before the main
# `project()` so that we can define the C/C++ compilers from the option file.
if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/LibiglOptions.cmake)
    message(STATUS "Using local options file: ${CMAKE_CURRENT_SOURCE_DIR}/LibiglOptions.cmake")
    include(${CMAKE_CURRENT_SOURCE_DIR}/LibiglOptions.cmake)
endif()

# If this option is enabled, this will setup the Hunter package manager.
option(HUNTER_ENABLED "Enable Hunter package manager support" OFF)
if(HUNTER_ENABLED)
    include("cmake/misc/HunterGate.cmake")
    HunterGate(
        URL "https://github.com/cpp-pm/hunter/archive/v0.24.8.tar.gz"
        SHA1 "ca7838dded9a1811b04ffd56175f629e0af82d3d"
    )
endif()

################################################################################
project(libigl VERSION 2.4.0)

# CMake module path
list(PREPEND CMAKE_MODULE_PATH
    ${CMAKE_CURRENT_LIST_DIR}/cmake/
    ${CMAKE_CURRENT_LIST_DIR}/cmake/igl
    ${CMAKE_CURRENT_LIST_DIR}/cmake/find
    ${CMAKE_CURRENT_LIST_DIR}/cmake/recipes/external
)

if(HUNTER_ENABLED)
    list(PREPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR}/cmake/recipes/hunter)
else()
    list(PREPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR}/cmake/recipes/external)
endif()

set_property(GLOBAL PROPERTY __igl_module_path ${CMAKE_MODULE_PATH})

set(LIBIGL_DEFAULT_CGAL ${LIBIGL_TOPLEVEL_PROJECT})
set(MATLAB_ADDITIONAL_VERSIONS
    "R2022b=10.3"
    "R2022a=10.2"
    "R2021b=10.1"
    "R2021a=10.0"
)
set(LIBIGL_DEFAULT_MATLAB ${LIBIGL_TOPLEVEL_PROJECT})
set(LIBIGL_DEFAULT_MOSEK ${LIBIGL_TOPLEVEL_PROJECT})
if(LIBIGL_TOPLEVEL_PROJECT)
    find_package(Matlab QUIET)
    if(NOT Matlab_FOUND)
        set(LIBIGL_DEFAULT_MATLAB OFF)
        message(WARNING "Matlab not found, disabling igl_restricted::matlab module.")
    endif()
    find_package(MOSEK QUIET)
    if(NOT MOSEK_FOUND)
        set(LIBIGL_DEFAULT_MOSEK OFF)
        message(WARNING "Mosek not found, disabling igl_restricted::mosek module.")
    endif()
endif()

# Build tests and tutorials
option(LIBIGL_BUILD_TESTS      "Build libigl unit test"                ${LIBIGL_TOPLEVEL_PROJECT})
option(LIBIGL_BUILD_TUTORIALS  "Build libigl tutorial"                 ${LIBIGL_TOPLEVEL_PROJECT})
option(LIBIGL_INSTALL          "Enable installation of libigl targets" ${LIBIGL_TOPLEVEL_PROJECT})

# USE_STATIC_LIBRARY speeds up the generation of multiple binaries,
# at the cost of a longer initial compilation time
# (by default, static build is off since libigl is a header-only library)
option(LIBIGL_USE_STATIC_LIBRARY "Use libigl as static library" ${LIBIGL_TOPLEVEL_PROJECT})

# Permissive modules. These modules are available under MPL2 license, and their dependencies are available
# under a permissive or public domain license.
option(LIBIGL_EMBREE           "Build target igl::embree"           ${LIBIGL_TOPLEVEL_PROJECT})
option(LIBIGL_GLFW             "Build target igl::glfw"             ${LIBIGL_TOPLEVEL_PROJECT})
option(LIBIGL_IMGUI            "Build target igl::imgui"            ${LIBIGL_TOPLEVEL_PROJECT})
option(LIBIGL_OPENGL           "Build target igl::opengl"           ${LIBIGL_TOPLEVEL_PROJECT})
option(LIBIGL_PNG              "Build target igl::png"              ${LIBIGL_TOPLEVEL_PROJECT})
option(LIBIGL_PREDICATES       "Build target igl::predicates"       ${LIBIGL_TOPLEVEL_PROJECT})
option(LIBIGL_SPECTRA          "Build target igl::spectra"          ${LIBIGL_TOPLEVEL_PROJECT})
option(LIBIGL_XML              "Build target igl::xml"              ${LIBIGL_TOPLEVEL_PROJECT})

# Copyleft modules. These modules are available under GPL license, and their dependencies are
# available under a copyleft license.
option(LIBIGL_COPYLEFT_CORE    "Build target igl_copyleft::core"    ${LIBIGL_TOPLEVEL_PROJECT})
option(LIBIGL_COPYLEFT_CGAL    "Build target igl_copyleft::cgal"    ${LIBIGL_DEFAULT_CGAL})
option(LIBIGL_COPYLEFT_COMISO  "Build target igl_copyleft::comiso"  ${LIBIGL_TOPLEVEL_PROJECT})
option(LIBIGL_COPYLEFT_TETGEN  "Build target igl_copyleft::tetgen"  ${LIBIGL_TOPLEVEL_PROJECT})

# Restricted modules. These modules are available under MPL2 license, but their dependencies are
# only available under a non-commercial or proprietary license.
option(LIBIGL_RESTRICTED_MATLAB   "Build target igl_restricted::matlab"   ${LIBIGL_DEFAULT_MATLAB})
option(LIBIGL_RESTRICTED_MOSEK    "Build target igl_restricted::mosek"    ${LIBIGL_DEFAULT_MOSEK})
option(LIBIGL_RESTRICTED_TRIANGLE "Build target igl_restricted::triangle" ${LIBIGL_TOPLEVEL_PROJECT})


# Option to immediately delete tutorials as their built (an attempt to make the
# Windows build on github actions run out of memory less often/quickly).
option(LIBIGL_DELETE_TUTORIALS_IMMEDIATELY "Delete tutorials as they are built" OFF)

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin")
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib")
set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib")


# Include CMake helper functions
include(igl_add_library)
include(igl_add_test)
include(igl_add_tutorial)
include(igl_copy_dll)
include(igl_include)
include(igl_install)
include(igl_target_sources)

# Enable unit testing at the root level
if(LIBIGL_BUILD_TESTS)
    include(CTest)
endif()

# Defines CMake targets for selected libigl modules
include(libigl)

if(LIBIGL_BUILD_TUTORIALS)
    add_subdirectory(tutorial)
endif()

################################################################################
# Install CMake config files
################################################################################

if(LIBIGL_INSTALL)
    include(GNUInstallDirs)
    set(project_config_in "${PROJECT_SOURCE_DIR}/cmake/igl/libigl-config.cmake.in")
    set(project_config_out "${CMAKE_CURRENT_BINARY_DIR}/libigl-config.cmake")
    set(config_targets_base "LibiglConfigTargets")
    set(version_config_file "${CMAKE_CURRENT_BINARY_DIR}/LibiglConfigVersion.cmake")
    set(export_dest_dir "${CMAKE_INSTALL_LIBDIR}/cmake/igl")

    foreach(suffix IN ITEMS "") #"_restricted" "_copyleft")
        install(EXPORT LibiglTargets${suffix}
            DESTINATION ${export_dest_dir}
            NAMESPACE igl${suffix}::
            FILE ${config_targets_base}${suffix}.cmake
            COMPONENT LibiglDevelopment
        )
    endforeach()

    include(CMakePackageConfigHelpers)
    configure_package_config_file(
            "${project_config_in}"
            "${project_config_out}"
        INSTALL_DESTINATION
            ${CMAKE_INSTALL_DATAROOTDIR}/libigl/cmake
    )

    write_basic_package_version_file("${version_config_file}" COMPATIBILITY SameMajorVersion)
    install(FILES "${project_config_out}" "${version_config_file}" DESTINATION "${export_dest_dir}")
endif()