FFTReal.h Example File

demos/spectrum/3rdparty/fftreal/FFTReal.h
 /*****************************************************************************

         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 \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/