qgscliptominmaxenhancement.cpp

来自「一个非常好的GIS开源新版本」· C++ 代码 · 共 51 行

/* **************************************************************************
              qgscliptominmaxenhancement.cpp -  description
                       -------------------
begin                : Fri Nov 16 2007
copyright            : (C) 2007 by Peter J. Ersts
email                : [e-mail]

****************************************************************************/

/* **************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/
 
#include "qgscliptominmaxenhancement.h"
 
QgsClipToMinMaxEnhancement::QgsClipToMinMaxEnhancement(QgsContrastEnhancement::QgsRasterDataType theQgsRasterDataType, double theMinimumValue, double theMaximumValue) : QgsContrastEnhancementFunction(theQgsRasterDataType, theMinimumValue, theMaximumValue)
{
}

int QgsClipToMinMaxEnhancement::enhanceValue(double theValue)
{
  if(theValue < mMinimumValue || theValue > mMaximumValue)
  {
    return -1;
  }
      
  if(mQgsRasterDataType == QgsContrastEnhancement::QGS_Byte)
  {
    return static_cast<int>(theValue);
  }
  else
  {
    return static_cast<int>((((theValue - QgsContrastEnhancement::getMinimumPossibleValue(mQgsRasterDataType))/(QgsContrastEnhancement::getMaximumPossibleValue(mQgsRasterDataType) - QgsContrastEnhancement::getMinimumPossibleValue(mQgsRasterDataType)))*255.0));
  }
}

bool QgsClipToMinMaxEnhancement::isValueInDisplayableRange(double theValue)
{
  if(theValue < mMinimumValue || theValue > mMaximumValue)
  {
    return false;
  }
  
  return true;
}