QwtPointMapper(3) Qwt User's Guide QwtPointMapper(3) NAME QwtPointMapper - A helper class for translating a series of points. SYNOPSIS #include Public Types enum TransformationFlag { RoundPoints = 0x01, WeedOutPoints = 0x02, WeedOutIntermediatePoints = 0x04 } Flags affecting the transformation process. typedef QFlags< TransformationFlag > TransformationFlags 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. Definition at line 32 of file qwt_point_mapper.h. Member Typedef Documentation typedef QFlags QwtPointMapper::TransformationFlags An ORed combination of TransformationFlag values. Definition at line 71 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: o first point o point with the minimum y coordinate o point with the maximum y coordinate o 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 39 of file qwt_point_mapper.h. Member Function Documentation QRectF QwtPointMapper::boundingRect () const Returns Bounding rectangle See also setBoundingRect() Definition at line 621 of file qwt_point_mapper.cpp. QwtPointMapper::TransformationFlags QwtPointMapper::flags () const Returns Flags affecting the transformation process See also setFlags(), setFlag() Definition at line 573 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 612 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 586 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 564 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 599 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 883 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. o WeedOutPoints & boundingRect().isValid() All points that are mapped to the same position will be one point. Points outside of the bounding rectangle are ignored. o WeedOutPoints & !boundingRect().isValid() All consecutive points that are mapped to the same position will one point o !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 833 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. o 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. o WeedOutPoints & RoundPoints & !boundingRect().isValid() All consecutive points that are mapped to the same position will one point o WeedOutPoints & !RoundPoints All consecutive points that are mapped to the same position will one point o !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 759 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 702 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 647 of file qwt_point_mapper.cpp. Author Generated automatically by Doxygen for Qwt User's Guide from the source code. Version 6.2.0 Sun Jul 18 2021 QwtPointMapper(3)