ChartView is too slow

[Atr0p0s]

Hello again :)

I use QML ChartView to display a big number of points, but it renders them too slowly. For example, it takes ~5 sec for 4500 points and app freezes with 21k points.

I tried to append points to LineSeries from c++ code but no change.

I thought it is because ChartView is redrawn every time I add a point, but I set Series.visible to false before adding the points and it didn't work either.

As far as I understand I can't add points to separate Series and then add this series to ChartView (maybe it would help).

I don't use c++ charts (as QChartView) because I also want to deploy the app for an android device.

Can you please suggest a way out of the situation? Or is there only a choice to use custom classes, e.g., based on QSGGeometry?

[Atr0p0s]

Problem was solved with replace(QList<QPointF> points) in cpp file:

if (QLineSeries* lineSeries = qobject_cast<QLineSeries*>(series)) {
    lineSeries->replace(m_pointList);
}

It works really fast even with big numbers of points.

[aka123]

Have yo try to use QSGGeometry?Is it faster?

[Atr0p0s]

@aka123 No, I didn't. ChartView adds points one by one quickly enough, as long as there is no need to add a large number of points at the same time. But in this case, LineSeries's replace() method solves the problem.