/* -*- c++ -*- */
/*
 * Copyright 2004,2007,2008,2010,2012 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 "fft_vfc_fftw.h"
#include <gr_io_signature.h>
#include <math.h>
#include <string.h>

namespace gr {
  namespace fft {
    
    fft_vfc::sptr fft_vfc::make(int fft_size, bool forward,
				const std::vector<float> &window,
				int nthreads)
    {
      return gnuradio::get_initial_sptr(new fft_vfc_fftw
					(fft_size, forward, window,
					 nthreads));
    }
    
    fft_vfc_fftw::fft_vfc_fftw(int fft_size, bool forward,
			       const std::vector<float> &window,
			       int nthreads)
      : gr_sync_block("fft_vfc_fftw",
		      gr_make_io_signature(1, 1, fft_size * sizeof(float)),
		      gr_make_io_signature(1, 1, fft_size * sizeof(gr_complex))),
	d_fft_size(fft_size), d_forward(forward)
    {
      d_fft = new fft_complex(d_fft_size, forward, nthreads);
    }

    fft_vfc_fftw::~fft_vfc_fftw()
    {
      delete d_fft;
    }

    void
    fft_vfc_fftw::set_nthreads(int n)
    {
      d_fft->set_nthreads(n);
    }

    int
    fft_vfc_fftw::nthreads() const
    {
      return d_fft->nthreads();
    }
    
    bool
    fft_vfc_fftw::set_window(const std::vector<float> &window)
    {
      if(window.size()==0 || window.size()==d_fft_size) {
	d_window=window;
	return true;
      }
      else
	return false;
    }
    
    int
    fft_vfc_fftw::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];
      gr_complex *out = (gr_complex *)output_items[0];
      
      unsigned int output_data_size = output_signature()->sizeof_stream_item (0);
      
      int count = 0;
      
      while(count++ < noutput_items) {
	
	// copy input into optimally aligned buffer
	if(d_window.size()) {
	  gr_complex *dst = d_fft->get_inbuf();
	  for(unsigned int i = 0; i < d_fft_size; i++)    // apply window
	    dst[i] = in[i] * d_window[i];
	}
	else {
	  gr_complex *dst = d_fft->get_inbuf();
	  for(unsigned int i = 0; i < d_fft_size; i++)    // float to complex conversion
	    dst[i] = in[i];
	}
	
	// compute the fft
	d_fft->execute();
	
	// copy result to output stream
	memcpy(out, d_fft->get_outbuf(), output_data_size);
	
	in  += d_fft_size;
	out += d_fft_size;
      }
      
      return noutput_items;
    }

  } /* namespace fft */
} /* namespace gr */