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qtmultimedia/demos/spectrum/3rdparty/fftreal/FFTReal.h
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Branched from the monolithic repo, Qt master branch, at commit
896db169ea224deb96c59ce8af800d019de63f12
2011-04-27 12:05:43 +02:00

143 lines
4.0 KiB
C++

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