/***************************************************************************
                          qgstotalcurvaturefilter.h  -  description
                             -------------------
    begin                : August 21th, 2009
    copyright            : (C) 2009 by Marco Hugentobler
    email                : marco dot hugentobler at karto dot baug dot ethz dot ch
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef QGSTOTALCURVATUREFILTER_H
#define QGSTOTALCURVATUREFILTER_H

#include "qgsninecellfilter.h"

/**Calculates total curvature as described by Wilson, Gallant (2000): terrain analysis*/
class ANALYSIS_EXPORT QgsTotalCurvatureFilter: public QgsNineCellFilter
{
  public:
    QgsTotalCurvatureFilter( const QString& inputFile, const QString& outputFile, const QString& outputFormat );
    ~QgsTotalCurvatureFilter();

  protected:
    /**Calculates total curvature from nine input values. The input values and the output value can be equal to the \
      nodata value if not present or outside of the border. Must be implemented by subclasses*/
    float processNineCellWindow( float* x11, float* x21, float* x31, \
                                 float* x12, float* x22, float* x32, float* x13, float* x23, float* x33 );
};

#endif // QGSTOTALCURVATUREFILTER_H
