QGraphicsItem clip to scene Rect

[yonnak]

Hi,
I'm trying to clip my items inside the scene rect.
I have customs items whith the paint method redifined and the following line inside it:

painter->setClipRect(mapRectFromScene(QRect(0,0,50000,50000))); 

where the rect is my scene rect. If no rotation is applied to the item or if the rotation is 90, 180 or 270 degrees it works well but when I rotate the item by 45° for example (using qtransform) the rect return by mapRectFromScene is not what I expect.

I have some difficulties understanding transformations and matrix, any help would be appreciated!

Thanks

[yonnak]

I've solved it like this (in custom item paint method):

    QRectF r = QRectF(0,0,50000,50000).translated(-scenePos());
    QPainterPath p;
    p.addRect(r);
    p = transform().inverted().map(p);
    painter->setClipPath(p);