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

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