--- name: "QwtPointMapper" section: "3" platform: "linux" package: "libqwt-doc" version: "6.1.4-2" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/QwtPointMapper" --- # QwtPointMapper(3) A helper class for translating a series of points. ## NAME QwtPointMapper - A helper class for translating a series of points. ## SYNOPSIS `#include ` ### 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\**. ## Member Typedef Documentation ### typedef QFlags\ 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 *Generated automatically by Doxygen for Qwt User's Guide from the source code.*