#ifndef KISS_FFT_H

#define KISS_FFT_H

#include <stdlib.h>

#include <math.h>

#include "arch.h"

#ifdef __cplusplus

extern "C" {

#endif

/*

 ATTENTION!

 If you would like a :

 -- a utility that will handle the caching of fft objects

 -- real-only (no imaginary time component ) FFT

 -- a multi-dimensional FFT

 -- a command-line utility to perform ffts

 -- a command-line utility to perform fast-convolution filtering

 Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c

  in the tools/ directory.

*/

#ifdef USE_SIMD

# include <xmmintrin.h>

# define kiss_fft_scalar __m128

#define KISS_FFT_MALLOC(nbytes) memalign(16,nbytes)

#else	

#define KISS_FFT_MALLOC celt_alloc

#endif	

#ifdef FIXED_POINT

#include "arch.h"	

#ifdef DOUBLE_PRECISION

#  define kiss_fft_scalar celt_int32_t

#  define kiss_twiddle_scalar celt_int32_t

#  define KF_SUFFIX _celt_double

#else

#  define kiss_fft_scalar celt_int16_t

#  define kiss_twiddle_scalar celt_int16_t

#  define KF_SUFFIX _celt_single

#endif

#else

# ifndef kiss_fft_scalar

/*  default is float */

#   define kiss_fft_scalar float

#   define kiss_twiddle_scalar float

#   define KF_SUFFIX _celt_single

# endif

#endif

/* This adds a suffix to all the kiss_fft functions so we

   can easily link with more than one copy of the fft */

#define CAT_SUFFIX(a,b) a ## b

#define SUF(a,b) CAT_SUFFIX(a, b)

#define kiss_fft_alloc SUF(kiss_fft_alloc,KF_SUFFIX)

#define kf_work SUF(kf_work,KF_SUFFIX)

#define ki_work SUF(ki_work,KF_SUFFIX)

#define kiss_fft SUF(kiss_fft,KF_SUFFIX)

#define kiss_ifft SUF(kiss_ifft,KF_SUFFIX)

#define kiss_fft_stride SUF(kiss_fft_stride,KF_SUFFIX)

#define kiss_ifft_stride SUF(kiss_ifft_stride,KF_SUFFIX)

typedef struct {

    kiss_fft_scalar r;

    kiss_fft_scalar i;

}kiss_fft_cpx;

typedef struct {

   kiss_twiddle_scalar r;

   kiss_twiddle_scalar i;

}kiss_twiddle_cpx;

typedef struct kiss_fft_state* kiss_fft_cfg;

/** 

 *  kiss_fft_alloc

 *  

 *  Initialize a FFT (or IFFT) algorithm's cfg/state buffer.

 *

 *  typical usage:      kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL);

 *

 *  The return value from fft_alloc is a cfg buffer used internally

 *  by the fft routine or NULL.

 *

 *  If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc.

 *  The returned value should be free()d when done to avoid memory leaks.

 *  

 *  The state can be placed in a user supplied buffer 'mem':

 *  If lenmem is not NULL and mem is not NULL and *lenmem is large enough,

 *      then the function places the cfg in mem and the size used in *lenmem

 *      and returns mem.

 *  

 *  If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough),

 *      then the function returns NULL and places the minimum cfg 

 *      buffer size in *lenmem.

 * */

kiss_fft_cfg kiss_fft_alloc(int nfft,void * mem,size_t * lenmem); 

void kf_work(kiss_fft_cpx * Fout,const kiss_fft_cpx * f,const size_t fstride,

             int in_stride,int * factors,const kiss_fft_cfg st,int N,int s2,int m2);

/** Internal function. Can be useful when you want to do the bit-reversing yourself */

void ki_work(kiss_fft_cpx * Fout, const kiss_fft_cpx * f, const size_t fstride,

             int in_stride,int * factors,const kiss_fft_cfg st,int N,int s2,int m2);

/**

 * kiss_fft(cfg,in_out_buf)

 *

 * Perform an FFT on a complex input buffer.

 * for a forward FFT,

 * fin should be  f[0] , f[1] , ... ,f[nfft-1]

 * fout will be   F[0] , F[1] , ... ,F[nfft-1]

 * Note that each element is complex and can be accessed like

    f[k].r and f[k].i

 * */

void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);

void kiss_ifft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);

/**

 A more generic version of the above function. It reads its input from every Nth sample.

 * */

void kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride);

void kiss_ifft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride);

/** If kiss_fft_alloc allocated a buffer, it is one contiguous 

   buffer and can be simply free()d when no longer needed*/

#define kiss_fft_free celt_free

#ifdef __cplusplus

} 

#endif

#endif