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

/*

 * Copyright 2007,2010 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_glfsr_source_f.h>

#include <gri_glfsr.h>

#include <gr_io_signature.h>

#include <stdexcept>

gr_glfsr_source_f_sptr 

gr_make_glfsr_source_f(int degree, bool repeat, int mask, int seed)

{

  return gnuradio::get_initial_sptr(new gr_glfsr_source_f(degree, repeat, mask, seed));

}

gr_glfsr_source_f::gr_glfsr_source_f(int degree, bool repeat, int mask, int seed)

  : gr_sync_block ("glfsr_source_f",

                   gr_make_io_signature (0, 0, 0),

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

    d_repeat(repeat),

    d_index(0)

{

  if (degree < 1 || degree > 32)

    throw std::runtime_error("gr_glfsr_source_f: degree must be between 1 and 32 inclusive");

  d_length = (unsigned int)((1ULL << degree)-1);

  if (mask == 0)

    mask = gri_glfsr::glfsr_mask(degree);

  d_glfsr = new gri_glfsr(mask, seed);

}

gr_glfsr_source_f::~gr_glfsr_source_f()

{

  delete d_glfsr;

}

int

gr_glfsr_source_f::work(int noutput_items,

                        gr_vector_const_void_star &input_items,

                        gr_vector_void_star &output_items)

{

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

  if ((d_index > d_length) && d_repeat == false)

    return -1; /* once through the sequence */

  int i;

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

    out[i] = (float)d_glfsr->next_bit()*2.0-1.0;

    d_index++;

    if (d_index > d_length && d_repeat == false)

      break;

  }

  return i;

}

int

gr_glfsr_source_f::mask() const

{

  return d_glfsr->mask();

}