Quantum GIS API Documentation  1.8
src/analysis/raster/qgsaspectfilter.cpp
Go to the documentation of this file.
00001 /***************************************************************************
00002                           qgsaspectfilter.cpp  -  description
00003                           -----------------------------------
00004     begin                : August 7th, 2009
00005     copyright            : (C) 2009 by Marco Hugentobler
00006     email                : marco dot hugentobler at karto dot baug dot ethz dot ch
00007  ***************************************************************************/
00008 
00009 /***************************************************************************
00010  *                                                                         *
00011  *   This program is free software; you can redistribute it and/or modify  *
00012  *   it under the terms of the GNU General Public License as published by  *
00013  *   the Free Software Foundation; either version 2 of the License, or     *
00014  *   (at your option) any later version.                                   *
00015  *                                                                         *
00016  ***************************************************************************/
00017 
00018 #include "qgsaspectfilter.h"
00019 
00020 QgsAspectFilter::QgsAspectFilter( const QString& inputFile, const QString& outputFile, const QString& outputFormat ) :
00021     QgsDerivativeFilter( inputFile, outputFile, outputFormat )
00022 {
00023 
00024 }
00025 
00026 QgsAspectFilter::~QgsAspectFilter()
00027 {
00028 
00029 }
00030 
00031 float QgsAspectFilter::processNineCellWindow(
00032   float* x11, float* x21, float* x31,
00033   float* x12, float* x22, float* x32,
00034   float* x13, float* x23, float* x33 )
00035 {
00036   float derX = calcFirstDerX( x11, x21, x31, x12, x22, x32, x13, x23, x33 );
00037   float derY = calcFirstDerY( x11, x21, x31, x12, x22, x32, x13, x23, x33 );
00038 
00039   if ( derX == mOutputNodataValue ||
00040        derY == mOutputNodataValue ||
00041        ( derX == 0.0 && derY == 0.0 ) )
00042   {
00043     return mOutputNodataValue;
00044   }
00045   else
00046   {
00047     return 180.0 + atan2( derX, derY ) * 180.0 / M_PI;
00048   }
00049 }
00050 
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Defines