[Qt-interest] QGraphicsView matrix and computer performance

[Nadia Pio]

Hello,

in my application I draw (insert) rectangles and lines on a
graphicsScene, resizing this items while the mouse moves.
Now I set the graphicView matrix in order to change the direction of
the y-axis, and after this, when I draw a new item onto the scene, the
graphicsView isn't so fast to show the scene update as the mouse is.

Is there any relation between the overhead of the graphicsView that
has to map scene coordinates and this "delay" ?
How can I solve this problem?

Thank you.

Nadia