qgscolorrampshader.h

Go to the documentation of this file.

/* **************************************************************************
                qgscolorrampshader.h -  description
                       -------------------
begin                : Fri Dec 28 2007
copyright            : (C) 2007 by Peter J. Ersts
email                : [email protected]

This class is based off of code that was originally written by Marco Hugentobler and
originally part of the larger QgsRasterLayer class
****************************************************************************/

/* **************************************************************************
 *                                                                         *
 *   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 QGSCOLORRAMPSHADER_H
#define QGSCOLORRAMPSHADER_H

#include <QColor>
#include <QMap>

#include "qgsrastershaderfunction.h"

class CORE_EXPORT QgsColorRampShader : public QgsRasterShaderFunction
{

  public:
    QgsColorRampShader( double theMinimumValue = 0.0, double theMaximumValue = 255.0 );

    //An entry for classification based upon value.
    //Such a classification is typically used for
    //single band layers where a pixel value represents
    //not a color but a quantity, e.g. temperature or elevation
    struct ColorRampItem
    {
      ColorRampItem() : value( 0 ) {}
      ColorRampItem( double val, QColor col, QString lbl = QString() ) : label( lbl ), value( val ), color( col ) {}

      QString label;
      double value;
      QColor color;

      // compare operator for sorting
      bool operator<( const ColorRampItem& other ) const { return value < other.value; }
    };

    enum ColorRamp_TYPE
    {
      INTERPOLATED,
      DISCRETE,
      EXACT
    };

    QList<QgsColorRampShader::ColorRampItem> colorRampItemList() const {return mColorRampItemList;}

    QgsColorRampShader::ColorRamp_TYPE colorRampType() const {return mColorRampType;}

    QString colorRampTypeAsQString();

    int maximumColorCacheSize() { return mMaximumColorCacheSize; }

    void setColorRampItemList( const QList<QgsColorRampShader::ColorRampItem>& theList ); //TODO: sort on set

    void setColorRampType( QgsColorRampShader::ColorRamp_TYPE theColorRampType );

    void setColorRampType( QString );

    void setMaximumColorCacheSize( int theSize ) { mMaximumColorCacheSize = theSize; }

    bool shade( double, int*, int*, int*, int* ) override;

    bool shade( double, double, double, double, int*, int*, int*, int* ) override;

    void legendSymbologyItems( QList< QPair< QString, QColor > >& symbolItems ) const override;

    void setClip( bool clip ) { mClip = clip; }
    bool clip() const { return mClip; }

  private:
    int mCurrentColorRampItemIndex;

    //TODO: Consider pulling this out as a separate class and internally storing as a QMap rather than a QList
    QList<QgsColorRampShader::ColorRampItem> mColorRampItemList;

    QgsColorRampShader::ColorRamp_TYPE mColorRampType;

    QMap<double, QColor> mColorCache;

    int mMaximumColorCacheSize;

    bool discreteColor( double, int*, int*, int*, int* );

    bool exactColor( double, int*, int*, int*, int* );

    bool interpolatedColor( double, int*, int*, int*, int* );

    bool mClip;
};

#endif