QML Canvas plotting continuous sinus wave

[KeineAhnung]

Okay sounds good.
Is it a good idea to do the sinus wave with canvas and plot it pixel by pixel or is there a better way to do that in QML?

[wysota]

Well... it depends on your skills. You can use the canvas, you can subclass QQuickPaintedItem and paint using QPainter or you can subclass QQuickItem and implement it using scene graph primitives.

[KeineAhnung]

My skills? Very little. But looking at the options I think I have to go with canvas because these are all the libraries I am allowed to use:

• libQt5Core.so.5
• libQt5Quick.so.5
• libQt5Qml.so.5
• libQt5Network.so.5
• libQt5Gui.so.5

[wysota]

The libraries don't matter. All of the approaches I mentioned make use of the same set of libraries. If you have little skills then stay away from approach 3.

[KeineAhnung]

Thanks for the advise.

[KeineAhnung]

I think I found exactly what I need to get a nice visualisation: G Force Sensor

If you take out the shadow effect and the simulation values, it is like ten lines of code to do that. How is this possible? I have been reeding though the code a couple of times know but I just do not understand how this is done. Why are the bars moving from right to left? How are new bars added?

[wysota]

It's using a recursive shader, as far as I remember. Contents of the previous frame is kept, shifted and redrawn the next frame together with the latest data.

[KeineAhnung]

Yes, your are right. So it says in the blog post where I found it. But I do not understand the code. Where is this shift done?

If I understand this right, I can use the two files as they are, put the QUItMeterComponent in my QML file and update the meter.value with each increment?

[wysota]

Where is this shift done?

In the shader, I guess.

If I understand this right, I can use the two files as they are, put the QUItMeterComponent in my QML file and update the meter.value with each increment?

Could be. Or you could continue using Canvas