[Qt-interest] QGraphicItem rotate problem

[Riccardo Roasio]

Hi,

I need to rotate a QGraphicItem and make a union between its QPolygon
and another QGraphicItem QPolygon in this way:

QString Table::attachBrother(Table *b)
{
      int i;

      int my_x=this->x();
      int my_y=this->y();
      int brother_x=b->x();
      int brother_y=b->y();

      int x_diff=brother_x-my_x;
      int y_diff=brother_y-my_y;

      attached_brothers<<b;


      QPolygon polygon=b->getTablePolygon();

      polygon.translate(x_diff,y_diff);


      table_polygon=table_polygon.united(polygon);
               std::cout << "Brother attached" << std::endl;
       update();

....


If both objects have 0 degrees of rotation all is ok, but if i rotate
one or both of them so the union result in strange stuff.
I think is because rotating aa QGraphicItem mantains the original
points,so if one point is at -10,-10 and another is at -10,-20 after
the rotation they are in the same positions so this cause
preoblems....

There is  a way to rotate also these points?

Thanks,
RIccardo