[CMake] Doxygen in out of source build refuses to work

[Jorg CMake]

Hi guys,

I have added an option to create doxygen documentation or not. But when
I choose out of source build as my build env, I cannot execute the
following command:

"C:\Program Files\doxygen\bin\doxygen.exe"
"D:/Projects/Work/treemultictrl/docs/Doxyfile"

My guess is that the Doxyfile itself cannot find some of the files,
although I expected it to be smart enough to switch to that dir first
(pointed out by where the doxyfile is) and generate the documentation
there.

However, it seems that is not possible. How do I go about and make my
documentation in the out of source document tree? Do I need to copy the
files manually, and if zso, does someone have an example of how to do
that ?

This is my CMakeLists.txt input, which does generate the above command.

IF(MAKE_DOXYGEN)

    INCLUDE( ${CMAKE_ROOT}/Modules/FindDoxygen.cmake)
    ADD_CUSTOM_TARGET(api-docs ALL ${DOXYGEN}
\"${TREEMULTICTRL_SOURCE_DIR}/docs/Doxyfile\" )

ENDIF(MAKE_DOXYGEN)


Thanks in advance,
- Jorgen