Re: A performance question...

[Uwe R. <Uwe...@ti...>]

> I will try replacing QImage with QPixmap then...

I would implement a small dummy application, where you paint a text string 
1000 times to a widget and another one, where you draw a pixmap 1000 times ( 
it doesn't matter what is in it ).

Simply overload paintEvent, set up a QPainter and run the loops.

> I'll give a look at backingstore, don't know what it is.. has it to do
> with the PaintCached and PaintPacked attributes of QwtPlotCanvas?

Yes, QwtPlotCanvas::PaintCached is the backing store ( in Qwt 6 this attribute 
is renamed to BackingStore ). Note, that Qt has another backing store.

Uwe