Hello!
I want to plot a lot of data on the screen. I draw curves made from a lot of little lines connecting the neighbouring data points and this typically leads to a laggy widget. I'm not using Qwt because I have some custom requirements such as being able to drag and scale the curves with the mouse and I figured it would be easier to implement those using just native Qt.
Anyhow, I could just plot all the curves once on a QPixmap and then show the pixmap in the paintEvent() and draw some additional things on top that are fast to draw. The only problem with this is zooming. If I zoom in by using painter.scale(), the lines on the pixmap get thick and edgy. I can't repaint the whole pixmap with every zoom operation.
Does anyone have an idea how I can solve the zooming problem? What technique does Qwt use to draw the plots?
Thanks,
Cruz
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