QPainter performance for zooming and draw...

[Programm3r]

Hi All !!

I have attached a small example where I drawing a line with mouse movement and zooming the image, but the drawing of the line under the mouse is slow....

Any idea ?

Another question....the zoom in this way is correct ?
"I mean using the transformation matrix"

Thanks alot ! ...I am sorry for my poor english .

[wysota]

You are doing it all wrong. Graphics View is object (item) based whereas you are using it as if it was a regular QWidget. This is where the overhead comes from.