qwtcolormap(3)
NAME
QwtColorMap
SYNOPSIS
Inherited by QwtAlphaColorMap, and QwtLinearColorMap.
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:
· QImage::Format_Indexed8
· QImage::Format_ARGB32
- See also:
- QwtPlotSpectrogram, QwtScaleWidget
- Definition at line 44 of file qwt_color_map.h.
- Public Types
- enum Format { RGB, Indexed }
- Public Member Functions
- QwtColorMap (Format=QwtColorMap::RGB)
virtual ~QwtColorMap ()
Format format () const
virtual QwtColorMap * copy () const=0
virtual QRgb rgb (const QwtDoubleInterval &interval, double value)const=0 - virtual unsigned char colorIndex (const QwtDoubleInterval &interval,
double value) const=0
- QColor color (const QwtDoubleInterval &, double value) const virtual QVector< QRgb > colorTable (const QwtDoubleInterval &) const
Member Enumeration Documentation
- enum QwtColorMap::Format
- · RGB
The map is intended to map into QRgb values.
- · Indexed
The map is intended to map into 8 bit values, that are indices into
- the color table.
- See also:
- rgb(), colorIndex(), colorTable()
- Definition at line 57 of file qwt_color_map.h.
Constructor & Destructor Documentation
- QwtColorMap::QwtColorMap (Format = QwtColorMap::RGB)
- Constructor.
- Definition at line 164 of file qwt_color_map.cpp.
- QwtColorMap::~QwtColorMap () [virtual]
- Destructor.
- Definition at line 170 of file qwt_color_map.cpp.
Member Function Documentation
- QwtColorMap::Format QwtColorMap::format () const [inline]
- Returns:
Intended format of the color map
- See also:
Format
- Definition at line 216 of file qwt_color_map.h.
- Referenced by QwtPainter::drawColorBar().
- virtual QwtColorMap* QwtColorMap::copy () const [pure virtual]
- Clone the color map.
- Implemented in QwtLinearColorMap, and QwtAlphaColorMap.
- Referenced by QwtScaleWidget::setColorMap(), and
QwtPlotSpectrogram::setColorMap(). - virtual QRgb QwtColorMap::rgb (const QwtDoubleInterval & interval, double
- value) 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.
- Referenced by color(), colorTable(), and QwtPainter::drawColorBar().
- virtual unsigned char QwtColorMap::colorIndex (const QwtDoubleInterval &
- interval, double value) 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.
- Referenced by color(), and QwtPainter::drawColorBar().
- QColor QwtColorMap::color (const QwtDoubleInterval & interval, double
- value) 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(). - Definition at line 198 of file qwt_color_map.h.
- References colorIndex(), colorTable(), and rgb().
- 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
- Definition at line 183 of file qwt_color_map.cpp.
- References QwtDoubleInterval::isValid(), QwtDoubleInterval::minValue(), rgb(), and QwtDoubleInterval::width().
- Referenced by color(), and QwtPainter::drawColorBar().
Author
- Generated automatically by Doxygen for Qwt User's Guide from the source
code.