/* -*- c++ -*- */
/*
 * Copyright 2008 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 <stdexcept>
#include <gr_squash_ff.h>
#include <gr_io_signature.h>

// expect input vector of igrid.size y-values,
// produce output vector of ogrid.size y-values

gr_squash_ff_sptr
gr_make_squash_ff(const std::vector<float> &igrid,
		  const std::vector<float> &ogrid)
{
  return gr_squash_ff_sptr(new gr_squash_ff(igrid, ogrid));
}

gr_squash_ff::gr_squash_ff(const std::vector<float> &igrid,
			   const std::vector<float> &ogrid)
  : gr_sync_block("squash_ff",
		  gr_make_io_signature(1, 1, sizeof(float) * igrid.size()),
		  gr_make_io_signature(1, 1, sizeof(float) * ogrid.size()))
{
  d_inum  = igrid.size();
  d_onum  = ogrid.size();
  d_igrid = (double *) malloc(d_inum * sizeof(double));
  d_iwork = (double *) malloc(d_inum * sizeof(double));
  d_ogrid = (double *) malloc(d_onum * sizeof(double));
  for (unsigned int i = 0; i < d_inum; i++)
    d_igrid[i] = igrid[i];
  for (unsigned int i = 0; i < d_onum; i++)
    d_ogrid[i] = ogrid[i];

  d_accel = gsl_interp_accel_alloc();
  d_spline = gsl_spline_alloc(gsl_interp_cspline, d_inum);	// FIXME check w/ Frank
}

gr_squash_ff::~gr_squash_ff()
{
  free((char *) d_igrid);
  free((char *) d_iwork);
  free((char *) d_ogrid);
  gsl_interp_accel_free(d_accel);
  gsl_spline_free(d_spline);
}

int
gr_squash_ff::work(int noutput_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];

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

    for (unsigned int i = 0; i < d_inum; i++)
      d_iwork[i] = in[i];

    gsl_spline_init(d_spline, d_igrid, d_iwork, d_inum);
    
    for (unsigned int i = 0; i < d_onum; i++)
      out[i] = gsl_spline_eval(d_spline, d_ogrid[i], d_accel);

    in  += d_inum;
    out += d_onum;
  }

  return noutput_items;
}
