A helper class for translating a series of points. More...

#include <qwt_point_mapper.h>

Classes
class	PrivateData
Public Types
enum	TransformationFlag { RoundPoints = 0x01, WeedOutPoints = 0x02, WeedOutIntermediatePoints = 0x04 }
	Flags affecting the transformation process. More...
typedef QFlags < TransformationFlag >	TransformationFlags
	Flags affecting the transformation process.
Public Member Functions
QRectF	boundingRect () const
TransformationFlags	flags () const
	QwtPointMapper ()
	Constructor.
void	setBoundingRect (const QRectF &)
void	setFlag (TransformationFlag, bool on=true)
void	setFlags (TransformationFlags)
bool	testFlag (TransformationFlag) const
QImage	toImage (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtSeriesData< QPointF > *series, int from, int to, const QPen &, bool antialiased, uint numThreads) const
	Translate a series into a QImage.
QPolygon	toPoints (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtSeriesData< QPointF > *series, int from, int to) const
	Translate a series of points into a QPolygon.
QPolygonF	toPointsF (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtSeriesData< QPointF > *series, int from, int to) const
	Translate a series into a QPolygonF.
QPolygon	toPolygon (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtSeriesData< QPointF > *series, int from, int to) const
	Translate a series of points into a QPolygon.
QPolygonF	toPolygonF (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtSeriesData< QPointF > *series, int from, int to) const
	Translate a series of points into a QPolygonF.
	~QwtPointMapper ()
	Destructor.
Private Attributes
PrivateData *	d_data

Detailed Description

A helper class for translating a series of points.

QwtPointMapper is a collection of methods and optimizations for translating a series of points into paint device coordinates. It is used by QwtPlotCurve but might also be useful for similar plot items displaying a QwtSeriesData<QPointF>.

Definition at line 29 of file qwt_point_mapper.h.

Member Typedef Documentation

typedef QFlags<TransformationFlag> QwtPointMapper::TransformationFlags

Flags affecting the transformation process.

See also:: setFlag(), setFlags()

Definition at line 72 of file qwt_point_mapper.h.

Member Enumeration Documentation

enum QwtPointMapper::TransformationFlag

Flags affecting the transformation process.

See also:: setFlag(), setFlags()

Enumerator:

RoundPoints

Round points to integer values.

WeedOutPoints

Try to remove points, that are translated to the same position.

WeedOutIntermediatePoints

An even more aggressive weeding algorithm, that can be used in toPolygon().

A consecutive chunk of points being mapped to the same x coordinate is reduced to 4 points:

first point
point with the minimum y coordinate
point with the maximum y coordinate
last point

In the worst case ( first and last points are never one of the extremes ) the number of points will be 4 times the width.

As the algorithm is fast it can be used inside of a polyline render cycle.

Definition at line 36 of file qwt_point_mapper.h.

Constructor & Destructor Documentation

QwtPointMapper::QwtPointMapper ( )

Constructor.

Definition at line 541 of file qwt_point_mapper.cpp.

QwtPointMapper::~QwtPointMapper ( )

Destructor.

Definition at line 547 of file qwt_point_mapper.cpp.

Member Function Documentation

QRectF QwtPointMapper::boundingRect ( ) const

Returns:: Bounding rectangle

See also:: setBoundingRect()

Definition at line 615 of file qwt_point_mapper.cpp.

QwtPointMapper::TransformationFlags QwtPointMapper::flags ( ) const

Returns:: Flags affecting the transformation process

See also:: setFlags(), setFlag()

Definition at line 567 of file qwt_point_mapper.cpp.

void QwtPointMapper::setBoundingRect ( const QRectF & rect )

Set a bounding rectangle for the point mapping algorithm

A valid bounding rectangle can be used for optimizations

Parameters:

rect	Bounding rectangle

See also:: boundingRect()

Definition at line 606 of file qwt_point_mapper.cpp.

void QwtPointMapper::setFlag	(	TransformationFlag	flag,
		bool	on = `true`
	)

Modify a flag affecting the transformation process

Parameters:

flag	Flag type
on	Value

See also:: flag(), setFlags()

Definition at line 580 of file qwt_point_mapper.cpp.

void QwtPointMapper::setFlags ( TransformationFlags flags )

Set the flags affecting the transformation process

Parameters:

flags Flags

See also:: flags(), setFlag()

Definition at line 558 of file qwt_point_mapper.cpp.

bool QwtPointMapper::testFlag ( TransformationFlag flag ) const

Returns:: True, when the flag is set

Parameters:

flag Flag type

See also:: setFlag(), setFlags()

Definition at line 593 of file qwt_point_mapper.cpp.

QImage QwtPointMapper::toImage	(	const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QwtSeriesData< QPointF > *	series,
		int	from,
		int	to,
		const QPen &	pen,
		bool	antialiased,
		uint	numThreads
	)		const

Translate a series into a QImage.

Parameters:

xMap	x map
yMap	y map
series	Series of points to be mapped
from	Index of the first point to be painted
to	Index of the last point to be painted
pen	Pen used for drawing a point of the image, where a point is mapped to
antialiased	True, when the dots should be displayed antialiased
numThreads	Number of threads to be used for rendering. If numThreads is set to 0, the system specific ideal thread count is used.

Returns:: Image displaying the series

Definition at line 877 of file qwt_point_mapper.cpp.

QPolygon QwtPointMapper::toPoints	(	const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QwtSeriesData< QPointF > *	series,
		int	from,
		int	to
	)		const

Translate a series of points into a QPolygon.

WeedOutPoints & boundingRect().isValid() All points that are mapped to the same position will be one point. Points outside of the bounding rectangle are ignored.

WeedOutPoints & !boundingRect().isValid() All consecutive points that are mapped to the same position will one point

!WeedOutPoints & boundingRect().isValid() Points outside of the bounding rectangle are ignored.

Parameters:

xMap	x map
yMap	y map
series	Series of points to be mapped
from	Index of the first point to be painted
to	Index of the last point to be painted

Returns:: Translated polygon

Definition at line 827 of file qwt_point_mapper.cpp.

QPolygonF QwtPointMapper::toPointsF	(	const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QwtSeriesData< QPointF > *	series,
		int	from,
		int	to
	)		const

Translate a series into a QPolygonF.

WeedOutPoints & RoundPoints & boundingRect().isValid() All points that are mapped to the same position will be one point. Points outside of the bounding rectangle are ignored.

WeedOutPoints & RoundPoints & !boundingRect().isValid() All consecutive points that are mapped to the same position will one point

WeedOutPoints & !RoundPoints All consecutive points that are mapped to the same position will one point

!WeedOutPoints & boundingRect().isValid() Points outside of the bounding rectangle are ignored.

When RoundPoints is set all points are rounded to integers but returned as PolygonF - what only makes sense when the further processing of the values need a QPolygonF.

Parameters:

xMap	x map
yMap	y map
series	Series of points to be mapped
from	Index of the first point to be painted
to	Index of the last point to be painted

Returns:: Translated polygon

Definition at line 753 of file qwt_point_mapper.cpp.

QPolygon QwtPointMapper::toPolygon	(	const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QwtSeriesData< QPointF > *	series,
		int	from,
		int	to
	)		const

Translate a series of points into a QPolygon.

When the WeedOutPoints flag is enabled consecutive points, that are mapped to the same position will be one point.

Parameters:

xMap	x map
yMap	y map
series	Series of points to be mapped
from	Index of the first point to be painted
to	Index of the last point to be painted

Returns:: Translated polygon

Definition at line 696 of file qwt_point_mapper.cpp.

QPolygonF QwtPointMapper::toPolygonF	(	const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QwtSeriesData< QPointF > *	series,
		int	from,
		int	to
	)		const

Translate a series of points into a QPolygonF.

When the WeedOutPoints flag is enabled consecutive points, that are mapped to the same position will be one point.

When RoundPoints is set all points are rounded to integers but returned as PolygonF - what only makes sense when the further processing of the values need a QPolygonF.

When RoundPoints & WeedOutIntermediatePoints is enabled an even more aggressive weeding algorithm is enabled.

Parameters:

xMap	x map
yMap	y map
series	Series of points to be mapped
from	Index of the first point to be painted
to	Index of the last point to be painted

Returns:: Translated polygon

Definition at line 641 of file qwt_point_mapper.cpp.

Member Data Documentation

PrivateData* QwtPointMapper::d_data [private]

Definition at line 105 of file qwt_point_mapper.h.

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

Classes

Public Types

Public Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation