2D plot of position and angle in Qt - c++

Question

I have made a controller for a car and I am currently trying to make a GUI for the controller in Qt.
The only thing I am lacking now is a visualization of the car's position and angle relative to its starting point.
I want to make something like this:
where the circle represents the car and the line in it represents its heading/angle.
An added bonus feature would be to have a fading trace of its path as it moves, but if I got the basics down, I should be able to sort that out myself.
I have tried looking at some plot examples, but couldn't extrapolate what I needed to solve my problem.
How would you recommend going about the implementation of something like this?

Answer 1

You say:
I have all the measurements
So let's assume that you have Euler angles such that you can filter out changes in roll and only consider changes in φ.
To do this you'll be looking to extend a QWidget adding a member φ, we'll name it: m_phi. We'll also need to add your QPixMap as a member, we'll call it m_px. And you'll be overriding the QWidget::paintEvent.
paintEvent(qPaintEvent* /*event*/) {
if(!m_px.isNull()) {
QPainter* p;
p.setRenderHint(QPainter::Antialiasing);
p.translate(width() / 2.0, height() / 2.0);
p.save();
p.rotate(m_phi);
QRect r = m_px.rect();
r.moveCenter(QPoint());
p.drawPixmap(r, m_px);
p.restore();
}
}