/* -*- c++ -*- */
/*
 * Copyright 2002,2013 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * GNU Radio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3, or (at your option)
 * any later version.
 *
 * GNU Radio 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#ifndef _GR_NCO_H_
#define _GR_NCO_H_

#include <vector>
#include <gr_sincos.h>
#include <cmath>
#include <gr_complex.h>

namespace gr {
  namespace blocks {

    /*!
     * \brief base class template for Numerically Controlled Oscillator (NCO)
     * \ingroup misc
     *
     * Calculate sine and cosine based on the current phase. This
     * class has multiple ways to calculate sin/cos and when
     * requensting a range will increment the phase based on a
     * frequency, which can be set using set_freq. Similar interfaces
     * to the fxpt_vco can also be used to set or adjust the current
     * phase.
     *
     * \sa fxpt_nco.h for fixed-point implementation.
     */
    template<class o_type, class i_type>
    class nco
    {
    public:
      nco() : phase(0), phase_inc(0) {}

      virtual ~nco() {}

      //! Set the current phase \p angle in radians 
      void set_phase(double angle) {
        phase = angle;
      }

      //! Update the current phase in radians by \p delta_phase
      void adjust_phase(double delta_phase) {
        phase += delta_phase;
      }

      //! angle_rate is in radians / step
      void set_freq(double angle_rate) {
        phase_inc = angle_rate;
      }

      //! angle_rate is a delta in radians / step
      void adjust_freq(double delta_angle_rate) {
        phase_inc += delta_angle_rate;
      }

      //! increment current phase angle
      void step()
      {
        phase += phase_inc;
        if(fabs (phase) > M_PI) {

          while(phase > M_PI)
            phase -= 2*M_PI;

          while(phase < -M_PI)
            phase += 2*M_PI;
        }
      }

      //! increment current phase angle n times
      void step(int n)
      {
        phase += phase_inc * n;
        if(fabs (phase) > M_PI) {

          while(phase > M_PI)
            phase -= 2*M_PI;

          while(phase < -M_PI)
            phase += 2*M_PI;
        }
      }

      //! units are radians / step
      double get_phase() const { return phase; }
      double get_freq() const { return phase_inc; }

      //! compute sin and cos for current phase angle
      void sincos(float *sinx, float *cosx) const;

      //! compute cos or sin for current phase angle
      float cos() const { return std::cos (phase); }
      float sin() const { return std::sin (phase); }

      //! compute a block at a time
      void sin(float *output, int noutput_items, double ampl = 1.0);
      void cos(float *output, int noutput_items, double ampl = 1.0);
      void sincos(gr_complex *output, int noutput_items, double ampl = 1.0);
      void sin(short *output, int noutput_items, double ampl = 1.0);
      void cos(short *output, int noutput_items, double ampl = 1.0);
      void sin(int *output, int noutput_items, double ampl = 1.0);
      void cos(int *output, int noutput_items, double ampl = 1.0);

    protected:
      double phase;
      double phase_inc;
    };

    template<class o_type, class i_type>
    void
    nco<o_type,i_type>::sincos(float *sinx, float *cosx) const
    {
      gr_sincosf(phase, sinx, cosx);
    }

    template<class o_type, class i_type>
    void
    nco<o_type,i_type>::sin(float *output, int noutput_items, double ampl)
    {
      for(int i = 0; i < noutput_items; i++) {
        output[i] = (float)(sin() * ampl);
        step();
      }
    }

    template<class o_type, class i_type>
    void
    nco<o_type,i_type>::cos(float *output, int noutput_items, double ampl)
    {
      for(int i = 0; i < noutput_items; i++){
        output[i] = (float)(cos() * ampl);
        step();
      }
    }

    template<class o_type, class i_type>
    void
    nco<o_type,i_type>::sin(short *output, int noutput_items, double ampl)
    {
      for(int i = 0; i < noutput_items; i++) {
        output[i] = (short)(sin() * ampl);
        step();
      }
    }

    template<class o_type, class i_type>
    void
    nco<o_type,i_type>::cos(short *output, int noutput_items, double ampl)
    {
      for(int i = 0; i < noutput_items; i++) {
        output[i] = (short)(cos() * ampl);
        step();
      }
    }

    template<class o_type, class i_type>
    void
    nco<o_type,i_type>::sin(int *output, int noutput_items, double ampl)
    {
      for(int i = 0; i < noutput_items; i++) {
        output[i] = (int)(sin() * ampl);
        step();
      }
    }

    template<class o_type, class i_type>
    void
    nco<o_type,i_type>::cos(int *output, int noutput_items, double ampl)
    {
      for(int i = 0; i < noutput_items; i++) {
        output[i] = (int)(cos() * ampl);
        step();
      }
    }

    template<class o_type, class i_type>
    void
    nco<o_type,i_type>::sincos(gr_complex *output, int noutput_items, double ampl)
    {
      for(int i = 0; i < noutput_items; i++) {
        float cosx, sinx;
        sincos(&sinx, &cosx);
        output[i] = gr_complex(cosx * ampl, sinx * ampl);
        step();
      }
    }

  } /* namespace blocks */
} /* namespace gr */

#endif /* _NCO_H_ */