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# 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 \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/