/* -*- c++ -*- */

/*

 * Copyright 2004,2006 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.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <gr_squelch_base_ff.h>

#include <gr_io_signature.h>

gr_squelch_base_ff::gr_squelch_base_ff(const char *name, int ramp, bool gate) : 

        gr_block(name,

                 gr_make_io_signature(1, 1, sizeof(float)),

                 gr_make_io_signature(1, 1, sizeof(float)))

{

  set_ramp(ramp);

  set_gate(gate);

  d_state = ST_MUTED;

  d_envelope = d_ramp ? 0.0 : 1.0;

  d_ramped = 0;

}

int gr_squelch_base_ff::general_work(int noutput_items,

                                     gr_vector_int &ninput_items,

                                     gr_vector_const_void_star &input_items,

                                     gr_vector_void_star &output_items)

{

  const float *in = (const float *) input_items[0];

  float *out = (float *) output_items[0];

  int j = 0;

  for (int i = 0; i < noutput_items; i++) {

    update_state(in[i]);

    // Adjust envelope based on current state

    switch(d_state) {

      case ST_MUTED:

        if (!mute()) 

          d_state = d_ramp ? ST_ATTACK : ST_UNMUTED; // If not ramping, go straight to unmuted

        break;

      case ST_UNMUTED:

        if (mute())

          d_state = d_ramp ? ST_DECAY : ST_MUTED;    // If not ramping, go straight to muted

        break;

      case ST_ATTACK:

        d_envelope = 0.5-std::cos(M_PI*(++d_ramped)/d_ramp)/2.0; // FIXME: precalculate window for speed

        if (d_ramped >= d_ramp) { // use >= in case d_ramp is set to lower value elsewhere

          d_state = ST_UNMUTED;

          d_envelope = 1.0;

        }

        break;

      case ST_DECAY:

        d_envelope = 0.5-std::cos(M_PI*(--d_ramped)/d_ramp)/2.0; // FIXME: precalculate window for speed

        if (d_ramped == 0.0)

          d_state = ST_MUTED;

        break;

    };

    // If unmuted, copy input times envelope to output

    // Otherwise, if not gating, copy zero to output

    if (d_state != ST_MUTED)

      out[j++] = in[i]*d_envelope;

    else

      if (!d_gate)

          out[j++] = 0.0;

  }

  consume_each(noutput_items);  // Use all the inputs

  return j;                        // But only report outputs copied

}