QwtColorMap - QwtColorMap is used to map values into colors.

NAME  SYNOPSIS  Public Types  Public Member Functions  Public Attributes  Detailed Description  Member Enumeration Documentation  enum QwtColorMap::Format  Constructor & Destructor Documentation  QwtColorMap::QwtColorMap (Format format = QwtColorMap::RGB) [explicit]  QwtColorMap::˜QwtColorMap () [virtual]  Member Function Documentation  QColor QwtColorMap::color (const QwtInterval & interval, double value)const [inline]  uint QwtColorMap::colorIndex (int numColors, const QwtInterval & interval,double value) const [virtual]  QVector< QRgb > QwtColorMap::colorTable (int numColors) const [virtual]  QVector< QRgb > QwtColorMap::colorTable256 () const [virtual]  virtual QRgb QwtColorMap::rgb (const QwtInterval & interval, double value)const [pure virtual]  void QwtColorMap::setFormat (Format format)  Member Data Documentation  QwtColorMap::Format QwtColorMap::const [inline]  Author 

---

NAME

QwtColorMap − QwtColorMap is used to map values into colors.

SYNOPSIS

#include <qwt_color_map.h>

Inherited by QwtAlphaColorMap, QwtHueColorMap, QwtLinearColorMap, and QwtSaturationValueColorMap.

Public Types

enum Format { RGB, Indexed }

Public Member Functions

QwtColorMap (Format=QwtColorMap::RGB)
virtual ˜QwtColorMap ()
Destructor.
void setFormat (Format)
virtual QRgb rgb (const QwtInterval &interval, double value) const =0
virtual uint colorIndex (int numColors, const QwtInterval &interval, double value) const
Map a value of a given interval into a color index.
QColor color (const QwtInterval &, double value) const
virtual QVector< QRgb > colorTable (int numColors) const
virtual QVector< QRgb > colorTable256 () const

Public Attributes

Format const

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 37 of file qwt_color_map.h.

Member Enumeration Documentation

enum QwtColorMap::Format

Format for color mapping

See also

rgb(), colorIndex(), colorTable()

Enumerator

RGB

The map is intended to map into RGB values.

Indexed

Map values into 8 bit values, that are used as indexes into the color table.

Indexed color maps are used to generate QImage::Format_Indexed8 images. The calculation of the color index is usually faster and the resulting image has a lower memory footprint.

See also

colorIndex(), colorTable()

Definition at line 45 of file qwt_color_map.h.

Constructor & Destructor Documentation

QwtColorMap::QwtColorMap (Format format = QwtColorMap::RGB) [explicit]

Constructor

Parameters

format Format of the color map

Definition at line 249 of file qwt_color_map.cpp.

QwtColorMap::˜QwtColorMap () [virtual]

Destructor.

Definition at line 255 of file qwt_color_map.cpp.

Member Function Documentation

QColor QwtColorMap::color (const QwtInterval & interval, double value)const [inline]

Map a value into a color

Parameters

interval Valid interval for values
value Value

Returns

Color corresponding to value

Definition at line 248 of file qwt_color_map.h.

uint QwtColorMap::colorIndex (int numColors, const QwtInterval & interval,double value) const [virtual]

Map a value of a given interval into a color index.

Parameters

numColors Number of colors
interval Range for all values
value Value to map into a color index

Returns

Index, between 0 and numColors - 1, or -1 for an invalid value

Reimplemented in QwtLinearColorMap.

Definition at line 278 of file qwt_color_map.cpp.

QVector< QRgb > QwtColorMap::colorTable (int numColors) const [virtual]

Build and return a color map of arbitrary number of colors

The color table is needed for rendering indexed images in combination with using colorIndex().

Parameters

numColors Number of colors

Returns

A color table

Definition at line 325 of file qwt_color_map.cpp.

QVector< QRgb > QwtColorMap::colorTable256 () 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().

Returns

A color table, that can be used for a QImage

Definition at line 304 of file qwt_color_map.cpp.

virtual QRgb QwtColorMap::rgb (const QwtInterval & 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 QwtAlphaColorMap, QwtHueColorMap, QwtLinearColorMap, and QwtSaturationValueColorMap.

void QwtColorMap::setFormat (Format format)

Set the format of the color map

Parameters

format Format of the color map

Definition at line 264 of file qwt_color_map.cpp.

Member Data Documentation

QwtColorMap::Format QwtColorMap::const [inline]

Initial value:
{
return m_format

Returns

Intended format of the color map

See also

Format

Definition at line 67 of file qwt_color_map.h.

Author

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

---