//   fft.h - declaration of class
//   of fast Fourier transform - FFT
//

#ifndef _FFT_H_
#define _FFT_H_

//   Include Complex numbers header
#include "config.h"
#include "complex.h"

class IFFT {
  static constexpr unsigned int M = FFTORDER, N = 1u << FFTORDER;
  public:
    explicit IFFT  () noexcept;
    bool Forward     (complex * const Data) const;
    bool Inverse     (complex * const Data) const;
    void Precompute  ();
  protected:
    void Rearrange   (complex * const Data) const;
    void Perform     (complex * const Data, const bool Inverse = false) const;
    void PrecomputeOrder    ();
    void PrecomputeOnes     ();
  private:
    const unsigned short * const reverse;
    const complex        * const ones;
};
extern void CopyToComplex (complex * dst, const unsigned short * src, const unsigned len);
#endif