I'd like to accelerate and 'manipulate' my Qgraphics 'world'
Now, I see how an item added to the graphics scene rises a boundingrect event for all the previous items.
That is, when I add the 100th item, 'somebodys' rises a boundingrect for the 99 previous. I dont understand why, theese items are currently showed.

Also, I'm going to need a method to draw a line in 'editing mode' and sincereley I dont know any fast method (I remember the easy xor method of 'basic').

I also feel the lack of usefull documentation related to improving, accelerate your drawings, etc.
It seems as I'd have to discover this 'world'.
You can find some information in the www but....
Some usefull links ? Thanks.