view Lib/fftw-3.2.1/doc/f77_wisdom.f @ 1:e86e9c111b29

Updates stuff that potentially fixes the memory leak and also makes it work on Windows and Linux (Need to test). Still have to fix fftw include for linux in Jucer.

c     Copyright (c) 2003, 2007-8 Matteo Frigo
c     Copyright (c) 2003, 2007-8 Massachusetts Institute of Technology
c     
c     This program is free software; you can redistribute it and/or modify
c     it under the terms of the GNU General Public License as published by
c     the Free Software Foundation; either version 2 of the License, or
c     (at your option) any later version.
c     
c     This program is distributed in the hope that it will be useful,
c     but WITHOUT ANY WARRANTY; without even the implied warranty of
c     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
c     GNU General Public License for more details.
c     
c     You should have received a copy of the GNU General Public License
c     along with this program; if not, write to the Free Software
c     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
c
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c     
c     This is an example implementation of Fortran wisdom export/import
c     to/from a Fortran unit (file), exploiting the generic
c     dfftw_export_wisdom/dfftw_import_wisdom functions.
c     
c     We cannot compile this file into the FFTW library itself, lest all
c     FFTW-calling programs be required to link to the Fortran I/O
c     libraries.
c     
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c     Strictly speaking, the '$' format specifier, which allows us to
c     write a character without a trailing newline, is not standard F77.
c     However, it seems to be a nearly universal extension.
      subroutine write_char(c, iunit)
      character c
      integer iunit
      write(iunit,321) c
 321  format(a,$)
      end      

      subroutine export_wisdom_to_file(iunit)
      integer iunit
      external write_char
      call dfftw_export_wisdom(write_char, iunit)
      end

c     Fortran 77 does not have any portable way to read an arbitrary
c     file one character at a time.  The best alternative seems to be to
c     read a whole line into a buffer, since for fftw-exported wisdom we
c     can bound the line length.  (If the file contains longer lines,
c     then the lines will be truncated and the wisdom import should
c     simply fail.)  Ugh.
      subroutine read_char(ic, iunit)
      integer ic
      integer iunit
      character*256 buf
      save buf
      integer ibuf
      data ibuf/257/
      save ibuf
      if (ibuf .lt. 257) then
         ic = ichar(buf(ibuf:ibuf))
         ibuf = ibuf + 1
         return
      endif
      read(iunit,123,end=666) buf
      ic = ichar(buf(1:1))
      ibuf = 2
      return
 666  ic = -1
      ibuf = 257
 123  format(a256)
      end
      
      subroutine import_wisdom_from_file(isuccess, iunit)
      integer isuccess
      integer iunit
      external read_char
      call dfftw_import_wisdom(isuccess, read_char, iunit)
      end