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

/*

 * Copyright 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 <gri_fir_filter_with_buffer_ccf.h>

gri_fir_filter_with_buffer_ccf::gri_fir_filter_with_buffer_ccf(const std::vector<float> &taps)

{

  d_buffer = NULL;

  set_taps(taps);

}

gri_fir_filter_with_buffer_ccf::~gri_fir_filter_with_buffer_ccf()

{

  if(d_buffer != NULL)

    free(d_buffer);

}

void

gri_fir_filter_with_buffer_ccf::set_taps (const std::vector<float> &taps)

{

  d_taps = gr_reverse(taps);

  if(d_buffer != NULL) {

    free(d_buffer);

    d_buffer = NULL;

  }

  // FIXME: memalign this to 16-byte boundaries for SIMD later

  size_t t = sizeof(gr_complex) * 2 * d_taps.size();

  d_buffer = (gr_complex*)malloc(t);

  memset(d_buffer, 0x00, t);

  d_idx = 0;

}

gr_complex

gri_fir_filter_with_buffer_ccf::filter (gr_complex input)

{

  unsigned int i;

  d_buffer[d_idx] = input;

  d_buffer[d_idx+ntaps()] = input;

  // using the later for the case when ntaps=0;

  // profiling shows this doesn't make a difference

  //d_idx = (d_idx + 1) % ntaps();

  d_idx++;

  if(d_idx >= ntaps())

    d_idx = 0;

  gr_complex out = 0;

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

    out +=  d_buffer[d_idx + i] * d_taps[i];

  }

  return out;

}

void

gri_fir_filter_with_buffer_ccf::filterN (gr_complex output[],

                 const gr_complex input[],

                 unsigned long n)

{

  for(unsigned long i = 0; i < n; i++) {

    output[i] = filter(input[i]);

  }

}