El mar, 13-05-2014 a las 03:15 +0200, Krzysztof Kosiński escribió:
Is this still a problem in recent revisions? Some time ago I turned off an unfinished feature where the cache would be scaled on zoom - this turned out to be very expensive.
Regards, Krzysztof
Hi Krzysztof: I was affected by the bug you mention, which is fixed. I think I know what Paul is talking about. It's not exactly a performance issue, but the visual feedback of the canvas redrawing when a large object exceeds the view area. It's probably only a perceived performance issue, because the time it takes to have the whole viewing area re-painted and usable is about the same with and without cache, but the screen tearing present *during panning* when cache is on can be perceived as a performance problem.
I used to think it was a performance issue, but some time ago su_v helped me to understant the problem, and in the process I created a screencast and a minimum file to show the differences.
https://dl.dropboxusercontent.com/u/255376/nocache-vs-cache.webm
https://dl.dropboxusercontent.com/u/255376/cache-tearing-sample.svg
Apparently it's caused by the object larger than the view area. If you remove it, panning the star only doesn't produce the tearing shown in the screencast.
Turning off cache *seems to* improve the situation, but that's not a good solution, since you also lose the good things cache offers (like snappier layer view toggles).
These files show the effect of cache on and off with a more complex file. https://dl.dropboxusercontent.com/u/255376/inkscape-panning-cache-disabled.w... https://dl.dropboxusercontent.com/u/255376/Inkscape-panning-cache-enabled.we...
Kind regards,
Gez.