%%
%% *SpHEAR Project
%% sphear_fir_render_directions: render impulse responses throught the FIR filter A2B matrix
%%
%% usage:
%%   [] = sphear_fir_render_directions(FIR, fmin, fmax, N, Npre, Nfft, plot_on, smooth)
%%
%% FIR: A2B matrix of FIR filters
%% fmin, fmax: range of frequencies to use
%% N: number of samples to filter
%% Npre: number of samples before the main impulse peak
%% Nfft: size of FFT
%%
%% optional parameters:
%%
%% plot_on: plot frequency response of components, default is "epsc"
%%          can be one of 0, "eps", "epsc" (color), "png", "pngc" (color)
%% smooth: number of samples to average, default is 0
%%
%% Copyright 2016, Fernando Lopez-Lezcano, All Rights Reserved
%% nando@ccrma.stanford.edu
%%
%%  This program 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 of the License, or
%%  (at your option) any later version.
%%
%%  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

function [BFF] = sphear_fir_render_directions(FIR, fmin, fmax, N, Npre, Nfft, plot_on, smooth)

  %% no smoothing or plotting by default
  if (!exist("smooth"))
    smooth = 0;
  end
  if (!exist("plot_on"))
    plot_on = "epsc";
  else
    if (plot_on == 1)
      plot_on = "epsc"
    end
  end

  [ref, Fs] = wavread('../cal/2016.04.20/export/reference-001-1.wav');
  %% find highest peak location and define sample range
  [index, value] = findmaxpeak(ref);
  r_start = index - Npre;
  r_end = r_start + N -1;
  range = r_start:r_end;
  ref_fft = fft(tukeywin(size(range)(2), 0.02) .* ref(range), N);
  printf("reference: peak %f at %d, sample range [%d %d]\n", value, index, r_start, r_end);
  
  %% plot if requested
  if (plot_on != 0)
    if (strcmp(plot_on, "epsc") || strcmp(plot_on, "pngc"))
      %% color plot
      wopts = 'k;W;';
      popts = 'r;X;';
      dopts = 'b;Y;';
      copt = '-color';
      cext = "_color";
    else
      %% mono plot
      wopts = '-;W;';
      popts = '--;X;';
      dopts = '-.;Y;';
      copt = '-mono';
      cext = "_mono";
    end
    f = figure;
    hold on;
    grid on;
    axis([fmin, fmax, -30, 0]);
    tics('y', [6, 0, -3, -6, -9, -12, -15, -20, -25, -30]);
    tics('x', [300, 500, 1000, 2000, 3000, 5000, 7000, 10000, 15000, 20000]);

    idx = 1;
    for m = [1, 5, 9, 13, 3, 7, 11, 15]
      %% render b format components
      bf(idx,:,:) = sphear_a_to_b(m, FIR, range, N);

      %% calculate B format frequency responses
      for b = 1:4
	if (smooth > 0)
	  bfft(idx,b,:) = fastsmooth(20*log10(abs(fft(bf(idx,b,:), Nfft))), smooth, 2, 1);
	else
	  bfft(idx,b,:) = 20*log10(abs(fft(bf(idx,b,:), Nfft)));
	end
      end
      fr = (1:Nfft/2) * Fs/Nfft;
      %% W
      semilogx(fr, bfft(idx,1,1:end/2) * 10^(6/20), wopts);
      %% print principal and diagonal directions with different colors
      if (idx > 4)
	col = popts;
      else
	col = dopts;
      end
      if (rem(idx, 2) == 1)
	semilogx(fr, bfft(idx,2,1:end/2), col);
      else
	semilogx(fr, bfft(idx,3,1:end/2), col);
      end

      idx = idx + 1;
    end

    l = legend('W (+6dB)', 'XY principal', 'XY diagonal');
    legend(l, 'location', 'west');
    if (strcmp(plot_on, 'eps') || strcmp(plot_on, 'epsc') || plot_on == 1)
      print(f, '-deps', '-tight', copt,["figures/sphear_directions.eps"]);
    else
      print(f, '-deps', copt, ["figures/sphear_directions.eps"]);
    end

  end
end