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    Qwt move marker with mouse between interpolated points

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    • E
      Eligijus last edited by

      Hello,

      Let's say i have curve with coordinates (x, y)(1, 1) (2, 1) (3, 1) and a marker. I want to get more x points for my marker to snap on when i move it with mouse. In other words i want my marker to snap to 1.1 , 1.2 , 1.3 x coordinates( now it only snaps to 1, 2 ,3).

      Code snippet of how i move my marker:

          marker->setLineStyle(QwtPlotMarker::VLine);
          marker->attach(tracePlot);
      
          picker = new QwtPlotPicker(tracePlot->xBottom, tracePlot->yLeft, QwtPicker::NoRubberBand,
      QwtPicker::AlwaysOff, tracePlot->canvas());
          pickerMachine = new QwtPickerDragPointMachine();
          picker->setStateMachine(pickerMachine);
      
      connect(picker, &QwtPicker::moved, this, &Widget::moveMarker);
      
      void Widget::moveMarker(QPoint actualMousePosition)
      {
          if(!flagZoom)
          {
              QwtText label;
              QString temp;
              int x = curve->closestPoint(actualMousePosition, NULL);
              QPointF position = curve->sample(x);
              marker->setValue(position);
              temp = QString::number(marker->xValue());
              label.setText(temp);
              marker->setLabel(label);
          }
          tracePlot->replot();
      }
      

      I figured i get limited by

      closestPoint(actualMousePosition, NULL);
      sample(x);
      

      returning ints but can't find any other solution.

      1 Reply Last reply Reply Quote 0
      • SGaist
        SGaist Lifetime Qt Champion last edited by

        Hi,

        That's a question you should bring to the Qwt mailing list. Qwt's author is very active there.

        Interested in AI ? www.idiap.ch
        Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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