// -----------------------------------------------------------------------
// filter.hh: Defining a filter function for wavelet reconstruction.
// -----------------------------------------------------------------------
// Copyright (C) 2006, Matthew Whiting, ATNF
//
// 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 2 of the License, or (at your
// option) any later version.
//
// Duchamp 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 Duchamp; if not, write to the Free Software Foundation,
// Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
//
// Correspondence concerning Duchamp may be directed to:
//    Internet email: Matthew.Whiting [at] atnf.csiro.au
//    Postal address: Dr. Matthew Whiting
//                    Australia Telescope National Facility, CSIRO
//                    PO Box 76
//                    Epping NSW 1710
//                    AUSTRALIA
// -----------------------------------------------------------------------
#ifndef FILTER_H
#define FILTER_H

#include <vector>
#include <string>

namespace duchamp
{

  /**
   * A class to store details of the wavelet's filter.
   * This stores all details of and functions related to the filter used to
   *  generate the wavelets used in the reconstruction (and baseline
   *  subtraction) functions.
   * 
   * It stores the coefficients of the filter, as well as the number of scales
   * associated with it, and the sigma factors, that relate the value of the rms
   * at a given scale with the measured value.
   */

  class Filter
  {
  public:
    // these are all in atrous.cc
    Filter();                         ///< Constructor
    Filter(const Filter& f);
    Filter& operator=(const Filter& f);
    virtual ~Filter();                ///< Destructor

    /** Define the parameters for a given filter. */
    void   define(int code);

    /** Calculate the number of scales possible with a given filter and
	data size. */
    int    getNumScales(long length);

    /** Calculate the maximum number of pixels able to be analysed with
	a filter at a given scale. */
    int    getMaxSize(int scale);

    /** Return the width of the filter */
    int    width(){return filter1D.size();};

    // these are inline functions.
    /** Return the text name of the filter */
    std::string getName(){return name;};

    /** Return the i-th value of the coefficient array. */
    double coeff(int i){return filter1D[i];};

    /** Set the i-th value of the coefficient array. */
    void   setCoeff(int i, double val){filter1D[i] = val;};

    /** Return the maximum number of scales in the sigmaFactor array for
	the given dimension */
    int    maxFactor(int dim){return maxNumScales[dim-1];};

    /** Set the maximum number of scales in the sigmaFactor array for
	the given dimension */
    void   setMaxFactor(int dim, int val){maxNumScales[dim-1] = val;};

    /** Return the sigma scaling factor for the given dimension and
	scale of the wavelet transform. */
    double sigmaFactor(int dim, int scale){return (*sigmaFactors[dim-1])[scale];};
    /** Set the sigma scaling factor for the given dimension and
	scale of the wavelet transform. */
    void   setSigmaFactor(int dim, int scale, double val){(*sigmaFactors[dim])[scale] = val;};

  private:
    std::string name;                ///< what is the filter called?
    std::vector <double> filter1D;   ///< filter coefficients.
    std::vector <int> maxNumScales;  ///< max number of scales for the sigmaFactor arrays, for each dim.
    std::vector < std::vector <double>* > sigmaFactors; ///< arrays of sigmaFactors, one for each dim.

    // these are all in atrous.cc
    void   loadSpline();        ///< set up parameters for using the
    ///   B3-Spline filter.
    void   loadTriangle();      ///< set up parameters for using the
    ///   Triangle function.
    void   loadHaar();          ///< set up parameters for using the
    ///   Haar wavelet.

  };

}

#endif