[CMake] Include subdirectories

[Christian Werner]

Hello!

I am sure this has been asked before, but somehow I don't find a place 
where I can easily browse the mailing list postings (I just found that 
link where you can browse isolated months). I am writing plugins for 
ParaView and I want to know how I can make cmake recursively search all 
subdirectories for included .h files. For example I have:

INCLUDE_DIRECTORIES(
    ${PV_PLUGIN_DIR}/Filter
    ${PV_PLUGIN_DIR}/Segmentation
    ${PV_PLUGIN_DIR}/Transformation
    ${PV_PLUGIN_DIR}/vtk2itk2vtk
)

But all these directories contain no .h file. Instead they consist of 
subdirectories, each containing their own .h files. For every Paraview 
Plugin I write there will be a new subdirectory, e.g.

    ${PV_PLUGIN_DIR}/Segmentation/DisDyn

It would be nice if I wasn't forced to enter every new directory into 
some CMakelist.


Best regards,
Christian