FFTReal.h Example File

  /*****************************************************************************

          FFTReal.h
          Copyright (c) 2005 Laurent de Soras

  --- Legal stuff ---

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

  *Tab=3***********************************************************************/

  #if ! defined (FFTReal_HEADER_INCLUDED)
  #define FFTReal_HEADER_INCLUDED

  #if defined (_MSC_VER)
          #pragma once
          #pragma warning (4 : 4250) // "Inherits via dominance."
  #endif

  /*\\\ INCLUDE FILES \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/

  #include        "def.h"
  #include        "DynArray.h"
  #include        "OscSinCos.h"

  template <class DT>
  class FFTReal
  {

  /*\\\ PUBLIC \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/

  public:

          enum {                  MAX_BIT_DEPTH   = 30    };      // So length can be represented as long int

          typedef DT      DataType;

          explicit                        FFTReal (long length);
          virtual                 ~FFTReal () {}

          long                            get_length () const;
          void                            do_fft (DataType f [], const DataType x []) const;
          void                            do_ifft (const DataType f [], DataType x []) const;
          void                            rescale (DataType x []) const;
          DataType *              use_buffer () const;

  /*\\\ PROTECTED \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/

  protected:

  /*\\\ PRIVATE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/

  private:

     // Over this bit depth, we use direct calculation for sin/cos
     enum {             TRIGO_BD_LIMIT    = 12  };

          typedef OscSinCos <DataType>    OscType;

          void                            init_br_lut ();
          void                            init_trigo_lut ();
          void                            init_trigo_osc ();

          FORCEINLINE const long *
                                                  get_br_ptr () const;
          FORCEINLINE const DataType      *
                                                  get_trigo_ptr (int level) const;
          FORCEINLINE long
                                                  get_trigo_level_index (int level) const;

          inline void             compute_fft_general (DataType f [], const DataType x []) const;
          inline void             compute_direct_pass_1_2 (DataType df [], const DataType x []) const;
          inline void             compute_direct_pass_3 (DataType df [], const DataType sf []) const;
          inline void             compute_direct_pass_n (DataType df [], const DataType sf [], int pass) const;
          inline void             compute_direct_pass_n_lut (DataType df [], const DataType sf [], int pass) const;
          inline void             compute_direct_pass_n_osc (DataType df [], const DataType sf [], int pass) const;

          inline void             compute_ifft_general (const DataType f [], DataType x []) const;
          inline void             compute_inverse_pass_n (DataType df [], const DataType sf [], int pass) const;
          inline void             compute_inverse_pass_n_osc (DataType df [], const DataType sf [], int pass) const;
          inline void             compute_inverse_pass_n_lut (DataType df [], const DataType sf [], int pass) const;
          inline void             compute_inverse_pass_3 (DataType df [], const DataType sf []) const;
          inline void             compute_inverse_pass_1_2 (DataType x [], const DataType sf []) const;

          const long              _length;
          const int               _nbr_bits;
          DynArray <long>
                                                  _br_lut;
          DynArray <DataType>
                                                  _trigo_lut;
          mutable DynArray <DataType>
                                                  _buffer;
     mutable DynArray <OscType>
                                                  _trigo_osc;

  /*\\\ FORBIDDEN MEMBER FUNCTIONS \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/

  private:

                                                  FFTReal ();
                                                  FFTReal (const FFTReal &other);
          FFTReal &               operator = (const FFTReal &other);
          bool                            operator == (const FFTReal &other);
          bool                            operator != (const FFTReal &other);

  };      // class FFTReal

  #include        "FFTReal.hpp"

  #endif  // FFTReal_HEADER_INCLUDED

  /*\\\ EOF \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/