I am trying to create a multitouch gametable application. I have been trying to use a QGraphicsScene with a QGraphicsView for the gametable. I will be allowing users to add maps and create maps. What is the best way to add QGraphicsPixmapItems and allow users to scale and rotate the image without affecting performance. I have noticed that if I just apply a transformation matrix to the QGraphicsPixmapItem the rendering of the image takes a really long time. I have tried adjusting the cache mode but it doesn't allow me to adjust the transformation matrix.

Does anyone have a better idea for transforming pixmaps?