if(PROJECT_ENABLE_SFML)
  if(PROJECT_BUILD)
    find_package(OpenGL REQUIRED)
    find_package(X11 REQUIRED)

    find_package(SFML ${SFML_VERSION}
      COMPONENTS 
        audio
        graphics
        network
        system
        window
      REQUIRED
    )

    add_definitions(-DPROJECT_ENABLE_SFML)

    if(PROJECT_BUILD_SHARED_LIBS)
      link_libraries(
        ${X11_LIBRARIES}
        sfml-audio
        sfml-graphics
        sfml-network
        sfml-system
        sfml-window
      )
    else()
      link_libraries(
        ${X11_LIBRARIES}
        sfml-audio-s
        sfml-graphics-s
        sfml-network-s
        sfml-system-s
        sfml-window-s
      )
    endif()

    include_directories(BEFORE SYSTEM
      ${X11_INCLUDE_DIR}
      ${SFML_INCLUDE_DIR}
    )
  elseif(NOT PROJECT_IS_MINGW OR CMAKE_HOST_WIN32)
    ExternalProject_Add(sfml_project
      PREFIX external
      URL ${PROJECT_3RD_PARTY_DIR}/SFML-${SFML_VERSION}.tar.gz
      URL_HASH SHA256=82535db9e57105d4f3a8aedabd138631defaedc593cab589c924b7d7a11ffb9d
      PATCH_COMMAND ${PROJECT_3RD_PARTY_DIR}/SFML_patch.sh
      LIST_SEPARATOR |
      CMAKE_ARGS ${PROJECT_EXTERNAL_CMAKE_FLAGS}
        -DBUILD_SHARED_LIBS=${PROJECT_BUILD_SHARED_LIBS}
        -DBUILD_STATIC_LIBS=ON
    )

    set(PROJECT_DEPENDENCIES 
      ${PROJECT_DEPENDENCIES}
      sfml_project
    )

    add_dependencies(sfml_project 
      flac_project
      fontconfig_project
      freetype2_project
      openal_project
    )
  endif()
endif()