debian man page for qwtcolormap

QwtColorMap(3)							 Qwt User's Guide						    QwtColorMap(3)

NAME
       QwtColorMap -

       QwtColorMap is used to map values into colors.

SYNOPSIS
       #include <qwt_color_map.h>

       Inherited by QwtAlphaColorMap, and QwtLinearColorMap.

   Public Types
       enum Format { RGB, Indexed }

   Public Member Functions
       QColor color (const QwtDoubleInterval &, double value) const
       virtual unsigned char colorIndex (const QwtDoubleInterval &interval, double value) const =0
       virtual QVector< QRgb > colorTable (const QwtDoubleInterval &) const
       virtual QwtColorMap * copy () const =0
       Format format () const
       QwtColorMap (Format=QwtColorMap::RGB)
       virtual QRgb rgb (const QwtDoubleInterval &interval, double value) const =0
       virtual ~QwtColorMap ()

Detailed Description
       QwtColorMap is used to map values into colors.

       For displaying 3D data on a 2D plane the 3rd dimension is often displayed using colors, like f.e in a spectrogram.

       Each color map is optimized to return colors for only one of the following image formats:

       o QImage::Format_Indexed8

       o QImage::Format_ARGB32

       See also:
	   QwtPlotSpectrogram, QwtScaleWidget

Member Enumeration Documentation
   enum QwtColorMap::Format .IP o 2
       RGB
	The map is intended to map into QRgb values.

       o Indexed
	  The map is intended to map into 8 bit values, that are indices into the color table.

       See also:
	   rgb(), colorIndex(), colorTable()

Constructor &; Destructor Documentation
   QwtColorMap::QwtColorMap (Formatformat = QwtColorMap::RGB)
       Constructor.

   QwtColorMap::~QwtColorMap () [virtual]
       Destructor.

Member Function Documentation
   QColor QwtColorMap::color (const QwtDoubleInterval &interval, doublevalue) const [inline] Map a value into a color
       Parameters:
	   interval Valid interval for values
	   value Value

       Returns:
	   Color corresponding to value

       Warning:
	   This method is slow for Indexed color maps. If it is necessary to map many values, its better to get the color table once and find the
	   color using colorIndex().

   virtual unsigned char QwtColorMap::colorIndex (const QwtDoubleInterval &interval, doublevalue) const [pure virtual] Map a value of a given
       interval into a color index
       Parameters:
	   interval Range for the values
	   value Value

       Returns:
	   color index, corresponding to value

       Implemented in QwtLinearColorMap.

   QwtColorTable QwtColorMap::colorTable (const QwtDoubleInterval &interval) const [virtual] Build and return a color map of 256 colors
       The color table is needed for rendering indexed images in combination with using colorIndex().

       Parameters:
	   interval Range for the values

       Returns:
	   A color table, that can be used for a QImage

   virtual QwtColorMap* QwtColorMap::copy () const [pure virtual]
       Clone the color map.

       Implemented in QwtLinearColorMap, and QwtAlphaColorMap.

   QwtColorMap::Format QwtColorMap::format () const [inline] Returns:
	   Intended format of the color map

       See also:
	   Format

   virtual QRgb QwtColorMap::rgb (const QwtDoubleInterval &interval, doublevalue) const [pure virtual] Map a value of a given interval into a rgb
       value.
       Parameters:
	   interval Range for the values
	   value Value

       Returns:
	   rgb value, corresponding to value

       Implemented in QwtLinearColorMap, and QwtAlphaColorMap.

Author
       Generated automatically by Doxygen for Qwt User's Guide from the source code.

Version 5.2.2							  Mon Aug 1 2011						    QwtColorMap(3)