IF(WITH_DRIVER_OPENGL) ADD_SUBDIRECTORY(opengl) ENDIF(WITH_DRIVER_OPENGL) IF(WITH_DRIVER_OPENGLES) ADD_SUBDIRECTORY(opengles) ENDIF(WITH_DRIVER_OPENGLES) IF(WIN32) IF(WITH_DRIVER_DIRECT3D) ADD_SUBDIRECTORY(direct3d) ENDIF(WITH_DRIVER_DIRECT3D) ENDIF(WIN32)