QML performance concerns

RickF

I have a lot of experience developing desktop apps for medical and scientific apps using Qt and VTK, OpenGL, and CUDA.

These include "real time" image guided surgery etc.

I now am trying to figure out if Qt quick will be useful fir a tablet ( Android, iOS ) for displyonh brain waves in pseudo real time coming in over WiFi.

A little googling and research says to me NO. QML is great for the UI, but not for drawing thousands of points ( with smoothing, etc).

Am I right?

The ( old school?) way I would do this is have a timer fire 30 FPS to draw each view ( I need to draw 6 or more wave forms) .

I would love to use Qt mobile forthis but I'm wary...can someone give me some advice?

Thanks!

Rick

sierdzio

QtWidgets still work on iOS and Android, so you can go with them - no problem.

As for QML drawing - indeed, drawing thousands of points is not going to be fast in "plain" QML. But there are many ways to address that:

use QQuickPaintedItem - there you can paint anything with QPainter, like in the old days ;-)
use QQuickItem and draw pre-rendered textures with your points
use QQuickItem and draw using OpenGL / Vulkan / whatever - probably the fastest, but also hardest to do

sierdzio

Ah, I forgot. There is also QNanoPainter: https://github.com/QUItCoding/qnanopainter Haven't tried it myself, but I've heard a lot of good opinions about it.

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QML performance concerns