On 20 February 2018 at 01:26, Alessandro Pasotti <apaso...@gmail.com> wrote: > It's rather obscure to me too :) > > For Qt 5.10 on Linux I use > > QT_AUTO_SCREEN_SCALE_FACTOR to 0 > QT_DEVICE_PIXEL_RATIO to 1 > > > but on the same machine and display with Qt 5.9.3 I need to use > > QT_AUTO_SCREEN_SCALE_FACTOR to 1 > QT_DEVICE_PIXEL_RATIO to 2 > > > in order to have the same effect, that is the SVG icons are not pixelated > neither are the Qt GUI elements (like checkboxes) which are actually too > small. > > > If I set QT_AUTO_SCREEN_SCALE_FACTOR to 1 QT_DEVICE_PIXEL_RATIO to 2 on 5.10 > I get the correct size for the Qt GUI elements but I get pixelated SVG > icons. > > > I've not yet found the perfect solution.
I think this whole thing is a mess :P I believe the correct solution (on QGIS side) is to use a device pixel ratio of 1, i.e. a pixel is a pixel and don't do any tricks to try to automatically handle this. And then we should avoid all hardcoded pixel sizes and just use sizes relative to font metrics. Which is what we've done a lot of for 3.0, but there's still work to do. I think the OSX builds are auto-setting the pixel ratio to 2 somewhere (it's not in the qgis code -- so maybe it's in the homebrew package or something. I dunno... the mess which is OSX package repos makes even npm look stable and a joy to use by comparison). What I can't work out is why Qt widgets themselves badly handle hidpi screens. E.g. a QDockWidget on hidpi has a TINY close button. I think that needs fixing in Qt itself though, and until they do we just learn to squint... but we DON'T try to hack around it using the pixel ratio settings. I also can't work out how to automatically scale layout padding/margins by font metrics. It seems a huge endeavour to manually set all these... yet without doing so the layouts on hidpi look very cramped because widgets a smooshed up against each other with barely any padding. Bah. I wish my laptop could run natively in a low dpi mode with the correct aspect ratio. I'd just do that until Qt gets its mess sorted out. Nyall* * Feeling very much like a grumpy old "get off my lawn" type guy. Maybe it's because the photos from Madiera are starting to flow in on social media... _______________________________________________ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer