QwtPointMapper - Man Page
A helper class for translating a series of points.
Synopsis
#include <qwt_point_mapper.h>
Public Types
enum TransformationFlag { RoundPoints = 0x01, WeedOutPoints = 0x02 }
Flags affecting the transformation process.
typedef QFlags< TransformationFlag > TransformationFlags
Flags affecting the transformation process.
Public Member Functions
QwtPointMapper ()
Constructor.
~QwtPointMapper ()
Destructor.
void setFlags (TransformationFlags)
TransformationFlags flags () const
void setFlag (TransformationFlag, bool on=true)
bool testFlag (TransformationFlag) const
void setBoundingRect (const QRectF &)
QRectF boundingRect () const
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.
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.
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.
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.
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>.
Member Typedef Documentation
typedef QFlags<TransformationFlag> QwtPointMapper::TransformationFlags
Flags affecting the transformation process.
- See also
setFlag(), setFlags()
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.
Member Function Documentation
QRectF QwtPointMapper::boundingRect () const
- Returns
Bounding rectangle
- See also
setBoundingRect()
QwtPointMapper::TransformationFlags QwtPointMapper::flags () const
- Returns
Flags affecting the transformation process
- See also
setFlags(), setFlag()
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()
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()
void QwtPointMapper::setFlags (TransformationFlags flags)
Set the flags affecting the transformation process
- Parameters
flags Flags
- See also
flags(), setFlag()
bool QwtPointMapper::testFlag (TransformationFlag flag) const
- Returns
True, when the flag is set
- Parameters
flag Flag type
- See also
setFlag(), setFlags()
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
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
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
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
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.
- 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
Author
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