Partial canvas redraw

[qgib]

Author Name: Per Gammerath (Per Gammerath)
Original Redmine Issue: 9737

Redmine category:map_canvas

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When panning a map, Qgis blanks and redraws the entire canvas. I think this is a big issue, as the user looses all sense of track with the map. MapInfo only redraws the new canvas area while retaining the panned area. That is a much better transition, and probably faster.
I hope that this issue is not reduced to low priority, because zooming and panning in Qgis is really a weak spot that would compel some to give up on Qgis. At my work, I replaced MapInfo with Qgis on my colleagues computers, and the most significant feedback I got was the low speed canvas handling, thus loss of track.

[qgib]

Author Name: Jürgen Fischer (@jef-n)

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• category_id was configured as Map Canvas

[qgib]

Author Name: Per Gammerath (Per Gammerath)

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So glad to see that QGIS Pisa has embraced this solution. Thumbs up :)

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• easy_fix was configured as 0

[jdugge]

I believe QGIS no longer blanks and redraws the entire screen, so this can probably be closed (which is also supported by the issue reporters comment from 10 Sep 2015). I can't point to the QGIS version or commit where this behaviour changed, but I assume that it was handled with the overhaul as part of the multi-threaded rendering