How to use QGLPixelBuffer or QGLFramebufferObject in QGraphicsItem paint

As we know in QGraphicsScene and QGraphicsView, there are many QGraphicsItems. in the MyQGraphicsItem::paint(QPainter *pxPainter, const QStyleOptionGraphicsItem *pxOption, QWidget *pxWidget) implement, we use the pxPainter to draw image(QImage) or PixelMap(QPixMap). when we set the graphicsView->setViewport(new QGLWidget), we use the OpenGL paintEngine, but we can not use the QGLPixelBuffer or QGLFramebufferObject being the paintDevice. Is there any solution to support? for the QGLFramebufferObject is more efficient as described.