QwtColorMap is used to map values into colors. More...

#include <qwt_color_map.h>

Inheritance diagram for QwtColorMap:

[legend]

Public Types
enum	Format { RGB, Indexed }

Public Member Functions
QColor	color (const QwtInterval &, double value) const

virtual uint	colorIndex (int numColors, const QwtInterval &interval, double value) const
	Map a value of a given interval into a color index. More...

virtual QVector< QRgb >	colorTable (int numColors) const

virtual QVector< QRgb >	colorTable256 () const

Format	format () const

	QwtColorMap (Format=QwtColorMap::RGB)

virtual QRgb	rgb (const QwtInterval &interval, double value) const =0

void	setFormat (Format)

virtual	~QwtColorMap ()
	Destructor. More...

Private Attributes
Format	m_format

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

◆ Format

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::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::~QwtColorMap ( )

virtual

Destructor.

Definition at line 255 of file qwt_color_map.cpp.

Member Function Documentation

◆ color()

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.

◆ colorIndex()

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.

◆ colorTable()

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.

◆ colorTable256()

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.

◆ format()

QwtColorMap::Format QwtColorMap::format ( ) const

inline

Returns: Intended format of the color map

See also: Format

Definition at line 257 of file qwt_color_map.h.

◆ rgb()

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 QwtSaturationValueColorMap, QwtHueColorMap, QwtAlphaColorMap, and QwtLinearColorMap.

◆ setFormat()

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

◆ m_format

Format QwtColorMap::m_format

private

Definition at line 88 of file qwt_color_map.h.

The documentation for this class was generated from the following files:

Public Types

Public Member Functions

Private Attributes

Detailed Description

Member Enumeration Documentation

◆ Format

Constructor & Destructor Documentation

◆ QwtColorMap()

◆ ~QwtColorMap()

Member Function Documentation

◆ color()

◆ colorIndex()

◆ colorTable()

◆ colorTable256()

◆ format()

◆ rgb()

◆ setFormat()

Member Data Documentation

◆ m_format