GNOME Bugzilla – Bug 742536
fuzzy timeline text on HiDPI display
Last modified: 2015-10-20 13:20:48 UTC
Created attachment 294048 [details] screenshot The text that indicates the time is fuzzy on my laptop with a HiDPI display (3200x1800 on a 13") Looks normal on my other laptop.
That's quite possible as the ruler portion is pure cairo, I don't think it has a notion of High DPI. I had already noticed this in bug #721614, which was more about "fundamentally broken" things (which Lubosz reports as working under GNOME 3.14 — is that your case too?) than details like fuzziness in the ruler.
Can confirm that the labels on the ruler are not rendered in the correct resolution, but upscaled. When you are using Windows 8.1 with HiDPI, you should be used to upscaled buffers ;) Since we render the ruler ourselves in cairo, the buffer size should be changed accordingly for HiDPI and upscaling should be omitted. It seems that GDK_SCALE upscales cairo buffers and does not render them in a native resolution. This issue was already found by BrionVibber in 2013 https://wiki.gnome.org/BrionVibber/HiDpiNotes This behavior needs likely to be fixed in cairo / GDK, but I didn't investigate further though. I also don't know how the application developer can influence cairo rendering on different GDK_SCALE settings. Pitivi cannot be the only application with this problem.
Created attachment 294173 [details] [review] Patch to fix cairo rendering I was wrong, this was our bug. The cairo render code was weirdly duplicating cairo buffers for no reason. There is also confusion with Gtk widget.get_allocated_width()/height, which does not seem change, but the cairo buffer size changes. The coordinates in cairo need to be determined by the gtk w/h. Also removing some cairo calls does not break the rendering for me. Can someone test this on HiDPI / LoDPI ?
This bug has been migrated to https://phabricator.freedesktop.org/T3270. Please use the Phabricator interface to report further bugs by creating a task and associating it with Project: Pitivi. See http://wiki.pitivi.org/wiki/Bug_reporting for details.