QML Chart does not respect width when using OpenGL 3.3 in macOS

[Ronis_BR]

Hi guys!

I am building a simulator in which the GUI needs to update some charts (6) very fast (60 Hz). I am using QML Charts and it is painfully slow. After reading a lot, doing the data handling in C++, etc. I saw that I can improve the performance by using OpenGL.

However, if I use this code:

ChartView {
    title: "Line"
    anchors.fill: parent
    antialiasing: true

    LineSeries {
        name: "LineSeries"
        XYPoint { x: 0; y: 0 }
        XYPoint { x: 1.1; y: 2.1 }
        XYPoint { x: 1.9; y: 3.3 }
        XYPoint { x: 2.1; y: 2.1 }
        XYPoint { x: 2.9; y: 4.9 }
        XYPoint { x: 3.4; y: 3.0 }
        XYPoint { x: 4.1; y: 3.3 }
    }
}

with vanilla settings w.r.t. OpenGL, I get this as expected:

However, if I change the OpenGL version to 3.3 (which I need to draw a 3D view) using this code:

    QSurfaceFormat glFormat;

    glFormat.setVersion(3,3);
    glFormat.setProfile(QSurfaceFormat::CoreProfile);
    QSurfaceFormat::setDefaultFormat(glFormat);

then I get this output:

Notice that the line width is not respected anymore. Is there anything I can do to avoid this?