Hello, I'd like to be able to rotate some horizontal lines about the midpoint of a QGraphicsScene, but keep the lines themselves horizontal. Is there a simple way to do this? My only idea is to create a QTransform object and call QTransform::rotate, then use QTransform::map to map one of every line's two coordinates, then translate each line individually using QGraphicsItem::translate. But I can't figure out how I'd actually get each line's initial coordinate (for putting into QTransform::map), or if there is a more elegant and efficient way of doing it. Speed is a bit of a concern because there will be about one or two hundred lines, and the rotation will be continuous.

I'd appreciate any advice.