On Sat Nov 10 00:03:47 GMT 2007, Vadim Gutnik wrote: > I'm new to GUIs, but thinking about writing a GUI that is a little bit > like a simple vector drawing program. So I've been looking at various > toolkit and language options. > > So far, it looks like my first choice would be PyQt... but it seems > slow. I wrote the attached code. If you select more than a couple dozen > shapes and move them, there's substantial lag, and I see python pegging > the CPU.
I tried your code and can confirm that it's slow. :-( However, there is a solution to your problem - see below. :-) > The question: > > 1) Is there something I'm doing that is seriously inefficient and could > be rewritten for speed? Not at all. It would appear that you've written an example that leaves pretty much all the processing to the underlying framework. > 2) What sort of speedup might I expect from this same program if it were > rewritten in C++ with qt? First, I rewrote it in C++, built it against Qt 4.2, and saw the same performance issues. Then, I searched the Task Tracker for similar reports to yours and found this one: http://trolltech.com/developer/task-tracker/index_html?method=entry&id=144901 So, I built it against Qt 4.3 - still the same problem. I followed the advice given in the task description. The resulting performance is _much_ better - you have to see it to believe it. :-) If you can, you should use PyQt 4.3.1 with Qt 4.3 so that you can take advantage of the improved performance and configurability of QGraphicsView. Have fun! David _______________________________________________ PyQt mailing list PyQt@riverbankcomputing.com http://www.riverbankcomputing.com/mailman/listinfo/pyqt
