QwtScaleMap Class Reference

A scale map. More...

#include <qwt_scale_map.h>

Public Member Functions
	QwtScaleMap ()
	Constructor. More...
	QwtScaleMap (const QwtScaleMap &)
	Copy constructor.
	~QwtScaleMap ()
QwtScaleMap &	operator= (const QwtScaleMap &)
	Assignment operator.
void	setTransformation (QwtScaleTransformation *)
const QwtScaleTransformation *	transformation () const
	Get the transformation.
void	setPaintInterval (double p1, double p2)
	Specify the borders of the paint device interval. More...
void	setScaleInterval (double s1, double s2)
	Specify the borders of the scale interval. More...
double	transform (double s) const
double	invTransform (double p) const
double	p1 () const
double	p2 () const
double	s1 () const
double	s2 () const
double	pDist () const
double	sDist () const
bool	isInverting () const

Static Public Member Functions
static QRectF	transform (const QwtScaleMap &, const QwtScaleMap &, const QRectF &)
static QRectF	invTransform (const QwtScaleMap &, const QwtScaleMap &, const QRectF &)
static QPointF	transform (const QwtScaleMap &, const QwtScaleMap &, const QPointF &)
static QPointF	invTransform (const QwtScaleMap &, const QwtScaleMap &, const QPointF &)

Static Public Attributes
static const double	LogMin = 1.0e-150
	Smallest allowed value for logarithmic scales: 1.0e-150.
static const double	LogMax = 1.0e150
	Largest allowed value for logarithmic scales: 1.0e150.

Detailed Description

A scale map.

QwtScaleMap offers transformations from the coordinate system of a scale into the linear coordinate system of a paint device and vice versa.

Constructor & Destructor Documentation

QwtScaleMap::QwtScaleMap

(

)

Constructor.

The scale and paint device intervals are both set to [0,1].

QwtScaleMap::~QwtScaleMap

(

)

Destructor

Member Function Documentation

double QwtScaleMap::invTransform ( double  p ) const

inline

Transform an paint device value into a value in the interval of the scale.

Parameters

p	Value relative to the coordinates of the paint device

See also

transform()

QRectF QwtScaleMap::invTransform ( const QwtScaleMap &  xMap, const QwtScaleMap &  yMap, const QRectF &  rect  )

static

Transform a rectangle from paint to scale coordinates

Parameters

xMap	X map
yMap	Y map
rect	Rectangle in paint coordinates

Returns

Rectangle in scale coordinates

See also

transform()

QPointF QwtScaleMap::invTransform ( const QwtScaleMap &  xMap, const QwtScaleMap &  yMap, const QPointF &  pos  )

static

Transform a rectangle from paint to scale coordinates

Parameters

xMap	X map
yMap	Y map
pos	Position in paint coordinates

Returns

Position in scale coordinates

See also

transform()

bool QwtScaleMap::isInverting ( ) const

inline

Returns

True, when ( p1() < p2() ) != ( s1() < s2() )

double QwtScaleMap::p1 ( ) const

inline

Returns

First border of the paint interval

double QwtScaleMap::p2 ( ) const

inline

Returns

Second border of the paint interval

double QwtScaleMap::pDist ( ) const

inline

Returns

qwtAbs(p2() - p1())

double QwtScaleMap::s1 ( ) const

inline

Returns

First border of the scale interval

double QwtScaleMap::s2 ( ) const

inline

Returns

Second border of the scale interval

double QwtScaleMap::sDist ( ) const

inline

Returns

qwtAbs(s2() - s1())

void QwtScaleMap::setPaintInterval	(	double	p1,
		double	p2
	)

Specify the borders of the paint device interval.

Parameters

p1	first border
p2	second border

void QwtScaleMap::setScaleInterval	(	double	s1,
		double	s2
	)

Specify the borders of the scale interval.

Parameters

s1	first border
s2	second border

Warning

logarithmic scales might be aligned to [LogMin, LogMax]

void QwtScaleMap::setTransformation

(

QwtScaleTransformation *

transformation

)

Initialize the map with a transformation

double QwtScaleMap::transform ( double  s ) const

inline

Transform a point related to the scale interval into an point related to the interval of the paint device

Parameters

s	Value relative to the coordinates of the scale

QRectF QwtScaleMap::transform ( const QwtScaleMap &  xMap, const QwtScaleMap &  yMap, const QRectF &  rect  )

static

Transform a rectangle from scale to paint coordinates

Parameters

xMap	X map
yMap	Y map
rect	Rectangle in scale coordinates

Returns

Rectangle in paint coordinates

See also

invTransform()

QPointF QwtScaleMap::transform ( const QwtScaleMap &  xMap, const QwtScaleMap &  yMap, const QPointF &  pos  )

static

Transform a point from scale to paint coordinates

Parameters

xMap	X map
yMap	Y map
pos	Position in scale coordinates

Returns

Position in paint coordinates

See also

invTransform()

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

• QWT/qwt_scale_map.h
• QWT/qwt_scale_map.cpp