[Qgis-developer] Benchmarking / optimization

[Paolo Cavallini]

Il 28/11/2011 19:49, Radim Blazek ha scritto:
> Preparing projects for qgis_bench application, I noticed that qgis
> renders the same project much slower than qgis_bench. I found that
> QgsMapCanvasMap was using by default QPixmap, not QImage, which is 7
> times slower! To be precise, QGIS was using QPixmap by default, but in
> options GUI was set as default QImage. If "Fix problems with
> incorrectly filled polygons" is unchecked (default), QImage is used.
> It means that it was sufficient to open options dialog, apply (not
> changing anything) and QgsMapCanvasMap started to use QImage.
> Obviously, this could not be noticed by developers and advanced users,
> because they had used options dialog at least once. Naive users (like
> me), who rely on default settings, were using QPixmap. It seems, that
> since 2006, all the first-time users (and thus maybe also last-time
> users) were experiencing this problem. Is it possible or am I wrong?
> Hopefully. Having fixed this problem (fixed in master [2]), the true
> optimization may start.
Thanks a lot Radim.
I tried checking and unchecking the option, but the results were not 
noticeable at the desktop level: did I miss something?
All the best.

-- 
Paolo Cavallini
See: http://www.faunalia.it/pc