[CMake] qt module

[Marie-Christine Vallet]

why do I have to  include and link qt_dir and qt_libs when I set this  
variable ?

SET ( QT_USE_OPENGL TRUE )


INCLUDE_DIRECTORIES (
                       ${CMAKE_CURRENT_BINARY_DIR}
                      ${QT_INCLUDE_DIR}
                      ${QT_QTOPENGL_INCLUDE_DIR}

                    )

TARGET_LINK_LIBRARIES ( mdi
                        ${QT_LIBRARIES}
                        ${QT_QTOPENGL_LIBRARIES}
                        ${QGLVIEWER_LIBRARY}
                      )