Performance comparison: eglfs and linuxfb in QWidget based applications

[jcsistemas]

Hello,

An application is acquiring data (from 12 sensors at 1KHz/sec) and displaying using in a custom graph widget.

The mode this widget show the signals, is bar moving, meaning the signal is fixed and the new data arrived, is painted to the right side of the last data point. Similar to an oscilloscope or patient monitoring device.

Specifically, the data is show in a paintEvent method of the QWidget class, using some methods from QPainter class [setRenderHint, setPen, setWindow, setViewport, drawPolyline].

This application is running in a ARM device with linuxfb platform by default.

My question is, if there is any benefit on using the eglfs platform when all the data is painted as described previously (using widgets)?.

Any other approach to paint this data in real time is welcome.

Thanks for any feedback,

[sierdzio]

@jcsistemas said in Performance comparison: eglfs and linuxfb in QWidget based applications:

My question is, if there is any benefit on using the eglfs platform when all the data is painted as described previously (using widgets)?.

No. QWidgets are painted using raster engine and the platform plugin does not matter here. There is a big difference with QML, which is drawn using OpenGL.

But you can always try - I can be wrong.

What you can also try is to force OpenGL rendering for widgets. Might help even if the actual painting will still be done using CPU.

[jcsistemas]

Thanks for your feedback. Appreciated.