[CMake] Include all subfolders and files?

[motes motes]

In a make file I have:

INCLUDE_DIRECTORIES(${MY_PROJECT}/lib)
INCLUDE_DIRECTORIES(${MY_PROJECT}/lib/CImg-1.21)
INCLUDE_DIRECTORIES(${MY_PROJECT}/lib/revised)
INCLUDE_DIRECTORIES(${MY_PROJECT}/lib/revised/io)

Is it possible to just specify that everything inside
${MY_PROJECT}/lib should be included instead of manullay specifying
each subfolder?