QwtLinearColorMap Class Reference

QwtLinearColorMap builds a color map from color stops. More...

#include <qwt_colormap.h>

Inheritance diagram for QwtLinearColorMap:

Classes
class	ColorStops
class	PrivateData

Public Types
enum	Mode { FixedColors , ScaledColors }
	Mode of color map. More...
Public Types inherited from QwtColorMap
enum	Format { RGB , Indexed }
	Format for color mapping. More...

Public Member Functions
	QwtLinearColorMap (QwtColorMap::Format=QwtColorMap::RGB)
	Build a color map with two stops at 0.0 and 1.0.
	QwtLinearColorMap (const QColor &from, const QColor &to, QwtColorMap::Format=QwtColorMap::RGB)
void	setMode (Mode)
	Set the mode of the color map.
Mode	mode () const
	Return the mode of the color map.
void	setColorInterval (const QColor &color1, const QColor &color2)
	Set the color range.
void	addColorStop (double value, const QColor &)
	Add a color stop.
QVector< double >	stopPos () const
	Return positions of color stops in increasing order.
QVector< QColor >	stopColors () const
	Return the colors of the color stops.
QColor	color1 () const
	Return the first color of the color range.
QColor	color2 () const
	Return the second color of the color range.
virtual QRgb	rgb (double vMin, double vMax, double value) const override
	Map a value of a given interval into a RGB value.
virtual uint	colorIndex (int numColors, double vMin, double vMax, double value) const override
	Map a value of a given interval into a color index.
Public Member Functions inherited from QwtColorMap
	QwtColorMap (Format=QwtColorMap::RGB)
	Constructor.
virtual	~QwtColorMap ()
	Destructor.
void	setFormat (Format)
	Set the format of the color map.
Format	format () const
QColor	color (double vMin, double vMax, double value) const
virtual QVector< QRgb >	colorTable (int numColors) const
	Build and return a color map of arbitrary number of colors.
virtual QVector< QRgb >	colorTable256 () const
	Build and return a color map of 256 colors.

Detailed Description

QwtLinearColorMap builds a color map from color stops.

A color stop is a color at a specific position. The valid range for the positions is [0.0, 1.0]. When mapping a value into a color it is translated into this interval according to mode().

Member Enumeration Documentation

Mode

enum QwtLinearColorMap::Mode

Mode of color map.

See also

setMode(), mode()

Enumerator
FixedColors	Return the color from the next lower color stop.
ScaledColors	Interpolating the colors of the adjacent stops.

Constructor & Destructor Documentation

QwtLinearColorMap()

QwtLinearColorMap::QwtLinearColorMap ( QwtColorMap::Format  format = QwtColorMap::RGB )

explicit

Build a color map with two stops at 0.0 and 1.0.

The color at 0.0 is Qt::blue, at 1.0 it is Qt::yellow.

Parameters

[in]

format

Preferred format of the color map.

Build a color map with two stops at 0.0 and 1.0.

Parameters

[in]	color1	Color used for the minimum value of the value interval.
[in]	color2	Color used for the maximum value of the value interval.
[in]	format	Preferred format for the color map.

Member Function Documentation

addColorStop()

void QwtLinearColorMap::addColorStop	(	double	value,
		const QColor &	color
	)

Add a color stop.

The value has to be in the range [0.0, 1.0]. F.e. a stop at position 17.0 for a range [10.0,20.0] must be passed as: (17.0 - 10.0) / (20.0 - 10.0).

Parameters

[in]	value	Value between [0.0, 1.0].
[in]	color	Color stop.

color1()

QColor QwtLinearColorMap::color1

(

)

const

Return the first color of the color range.

Returns

First color of the color range.

See also

setColorInterval()

color2()

QColor QwtLinearColorMap::color2

(

)

const

Return the second color of the color range.

Returns

Second color of the color range.

See also

setColorInterval()

colorIndex()

uint QwtLinearColorMap::colorIndex ( int  numColors, double  vMin, double  vMax, double  value  ) const

overridevirtual

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

Parameters

[in]	numColors	Size of the color table.
[in]	vMin	Minimum of the value interval.
[in]	vMax	Maximum of the value interval.
[in]	value	Value to map into a color index.

Returns

Index, between 0 and 255.

Note

NaN or Inf values are mapped to 0.

Reimplemented from QwtColorMap.

mode()

QwtLinearColorMap::Mode QwtLinearColorMap::mode

(

)

const

Return the mode of the color map.

Returns

Mode of the color map.

See also

setMode()

rgb()

QRgb QwtLinearColorMap::rgb ( double  vMin, double  vMax, double  value  ) const

overridevirtual

Map a value of a given interval into a RGB value.

Parameters

[in]	vMin	Minimum of the value interval.
[in]	vMax	Maximum of the value interval.
[in]	value	Value to map into a RGB value.

Returns

RGB value for value.

Implements QwtColorMap.

setColorInterval()

void QwtLinearColorMap::setColorInterval	(	const QColor &	color1,
		const QColor &	color2
	)

Set the color range.

Add stops at 0.0 and 1.0.

Parameters

[in]	color1	Color used for the minimum value of the value interval.
[in]	color2	Color used for the maximum value of the value interval.

See also

color1(), color2()

setMode()

void QwtLinearColorMap::setMode

(

Mode

mode

)

Set the mode of the color map.

FixedColors means the color is calculated from the next lower color stop. ScaledColors means the color is calculated by interpolating the colors of the adjacent stops.

Parameters

[in]

mode

Resampling mode.

See also

mode()

stopColors()

QVector< QColor > QwtLinearColorMap::stopColors

(

)

const

Return the colors of the color stops.

Returns

Colors of color stops.

stopPos()

QVector< double > QwtLinearColorMap::stopPos

(

)

const

Return positions of color stops in increasing order.

Returns

Positions of color stops.

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

• /home/runner/work/QWT/QWT/src/core/qwt_colormap.h
• /home/runner/work/QWT/QWT/src/core/qwt_colormap.cpp