## FFTW can be compiled and subsequently linked against
## various data types.
## There is a single set of include files, and then muttiple libraries,
## One for each type.  I.e. libfftw.a-->double, libfftwf.a-->float

## The following logic belongs in the individual package
## mark_as_advanced(ITK_USE_FFTWD)
## option(ITK_USE_FFTWD "Use double precision FFTW if found" ON)
## mark_as_advanced(ITK_USE_FFTWF)
## option(ITK_USE_FFTWF "Use single precision FFTW if found" ON)

if(ITK_USE_FFTWD OR ITK_USE_FFTWF)

  set(FFTW_INC_SEARCHPATH
    /sw/include
    /usr/include
    /usr/local/include
    /usr/include/fftw
    /usr/local/include/fftw
  )

  find_path(FFTW_INCLUDE_PATH fftw3.h ${FFTW_INC_SEARCHPATH})

  if(FFTW_INCLUDE_PATH)
    file(TO_CMAKE_PATH "${FFTW_INCLUDE_PATH}" FFTW_INCLUDE_PATH)
    set(FFTW_INCLUDE ${FFTW_INCLUDE_PATH})
  endif()

  if(FFTW_INCLUDE)
    include_directories(${FFTW_INCLUDE})
  endif()

  get_filename_component(FFTW_INSTALL_BASE_PATH ${FFTW_INCLUDE_PATH} PATH)

  set(FFTW_LIB_SEARCHPATH
    ${FFTW_INSTALL_BASE_PATH}/lib
    ${FFTW_INSTALL_BASE_PATH}/lib64
    /usr/lib/fftw
    /usr/local/lib/fftw
  )

  if(ITK_USE_FFTWD)
    mark_as_advanced(FFTWD_LIB)
    find_library(FFTWD_LIB fftw3 ${FFTW_LIB_SEARCHPATH}) #Double Precision Lib
    find_library(FFTWD_THREADS_LIB fftw3_threads ${FFTW_LIB_SEARCHPATH}) #Double Precision Lib only if compiled with threads support

    if(FFTWD_LIB)
      set(FFTWD_FOUND 1)
      get_filename_component(FFTW_LIBDIR ${FFTWD_LIB} PATH)
      if(FFTWD_THREADS_LIB)
        set(FFTWD_LIB ${FFTWD_LIB} ${FFTWD_THREADS_LIB} )
      endif()
    endif()
  endif()

  if(ITK_USE_FFTWF)
    mark_as_advanced(FFTWF_LIB)
    find_library(FFTWF_LIB fftw3f ${FFTW_LIB_SEARCHPATH}) #Single Precision Lib
    find_library(FFTWF_THREADS_LIB fftw3f_threads ${FFTW_LIB_SEARCHPATH}) #Single Precision Lib only if compiled with threads support

    if(FFTWF_LIB)
      set(FFTWF_FOUND 1)
      get_filename_component(FFTW_LIBDIR ${FFTWF_LIB} PATH)
      if(FFTWF_THREADS_LIB)
        set(FFTWF_LIB ${FFTWF_LIB} ${FFTWF_THREADS_LIB} )
      endif()
    endif()
  endif()

endif()