[Insight-developers] FFT Image Filter Classes Committed: Question about configuration

[Kent Williams]

With some trepidation, I just checked in the classes that implement FFT=20
processing wrapped as ITK Image Filters.  Trepidation because I always se=
em=20
to break something when I do checkins. I've spent some time trying to ver=
ify=20
that the code is going to be Kosher on the platforms I have access to.

The baseline implementation uses the VNL library FFT routines. I also inc=
lude=20
a class that uses the FFTW library, but does not include any FFTW code at=
=20
all.  The FFTW code only gets used in Testing/Code/Algorithms if the CMak=
e=20
boolean USE_FFTW is defined.=20

What I'd like to have happen is for USE_FTTW to be a top-level advanced C=
Make=20
variable. I'd also need FFTW_INCLUDE and FFT_LIBRARY to tell CMake where =
the=20
header and library is.  Could someone point me at an example of defining =
and=20
setting advanced variables in the CMakelist files?

Thanks!