Hi everyone,

I'm trying to display plots with QwtPlot in this way:
http://www.youtube.com/watch?v=-K9Aj49hHzA
Note how the curve is "eaten up" and not just moved.

My first approach looks like this:
Qt Code: 
  1. void QwtTest::timerEvent(QTimerEvent * event)
  2. {
  3. 	for(int i = 0; i < 5; ++i)
  4. 	{
  5. 		yData_[currXPos_] = sin(2*pi*sinPos_/(0.169*dataSize_));
  6. 		++sinPos_;
  7. 		currXPos_ = (currXPos_ + 1) % dataSize_;	
  8. 	}
  9. 	ui.qwtPlot->replot();
  10.          //everything until here is working, this makes the curve restart at the left hand side when the right hand side is reached
  11.          //now i want to overpaint parts of the plot to get the free space between the 2 parts of the curve
  12. 	QPainter painter(ui.qwtPlot);
  13. 	painter.setPen(Qt::blue);
  14. 	painter.fillRect(ui.qwtPlot->rect(), QColor(0,0,0));
  15.         //this part does not do anything...
  16. }
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Do you have any suggestions?
Thanks in advance!