get currently visible items in QGraphicsScene

[ChrisW67]

You can ask the view which items fall inside its viewport rectangle:

QList<QGraphicsItem *> items = view->items(view->viewport->rect());

QList<QGraphicsItem *> items = view->items(view->viewport->rect());

To copy to clipboard, switch view to plain text mode 

I am not familiar enough with the API to answer the amount of intersection aspect of this question.