E:/dev/eLynx/include/elx/math/ResampleHelper.h

//============================================================================
//  ResampleHelper.h                                    Math.Component package
//============================================================================
//  Usage : define resample helper using filters
//----------------------------------------------------------------------------
//  Copyright (C) 2006 by eLynx project
//
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Library General Public
//  License as published by the Free Software Foundation; either
//  version 2 of the License, or (at your option) any later version.
//
//  This library 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 Library General Public License for more details.
//----------------------------------------------------------------------------
#ifndef __ResampleHelper_h__
#define __ResampleHelper_h__

#include "ResampleFilterImpls.h"
#include <boost/scoped_array.hpp>

namespace eLynx {
namespace Math {

class ExportedByMath ResampleHelper
{
public:

  ResampleHelper(uint32 iOldSize, uint32 iNewSize, EResampleFilter iFilter);
 
  uint32 GetContributorCount(uint32 iNewIndex) const;

  uint32 GetOldIndex(uint32 iNewIndex, uint32 iContributor) const;

  double GetWeight(uint32 iNewIndex, uint32 iContributor) const;

private:
  struct SampleWeight
  {
    SampleWeight() : _sample(0), _weight(0.0) {}
    int32 _sample;
    double _weight;
  };

  struct Contributor
  {
    int32 _n;
    SampleWeight * _plSampleList;
    double _weightSum;
    Contributor() : _plSampleList(0) {}
    ~Contributor() { delete [] _plSampleList; }
  };

  uint32 _newSize;
  boost::scoped_array<Contributor> _spContributors;
};

} // namespace Image
} // namespace eLynx

#endif // __ResampleHelper_h__