QGIS not running in HiDPI by default on Retina display

[nextstopsun]

A good reason to try out qgis3-dev is to get HiDPI support on OS X. I guess that wasn't possible for QT4-based versions, but ok for Qt5.
Could be great to have QGIS built with HiDPI enabled by default on retina displays.
Or maybe this should it be a configuration checkbox.

Meanwhile, how do I enable it manually?

[dakcarto]

Hi @nextstopsun, thanks for bringing this up. You can try the following:

1. Edit /usr/local/opt/qgis3-dev/QGIS.app/Contents/Info.plist
2. Change NSHighResolutionCapable key to True, then save Info.plist
3. Run touch /usr/local/opt/qgis3-dev/QGIS.app to ensure launch services is notified of plist change

Looks like the qgis3-dev formula needs updated here, since it sets that key to False.

Note: I don't see any major changes here when I do that (this is a good thing). Also, the low resolution icon is due to a missing high-res one for Mac, not due to incompatible NSHighResolutionCapable settings.

[dakcarto]

If you change NSHighResolutionCapable as noted above, the Finder's Info dialog for the QGIS.app will now display the "Open in Low Resolution" checkbox, which should be unchecked by default.

[nextstopsun]

@dakcarto Thanks. I'll try that. I'm mostly interested in getting map canvas display in HiDPI.
BTW, are missing menu icons related to this one, or it's a separate issue?

[dakcarto]

BTW, are missing menu icons related to this one, or it's a separate issue?

Separate issue, I think, possibly related to packaging and whether they are SVG or PNG. Haven't looked into it yet. Also here for me, the Options menu is replaced by the one from Processing. I'll work on fixing that upstream ASAP.

[nextstopsun]

According to window elements, qgis started in HiDPI mode, however map canvas seems to be in low res still. @dakcarto Are you getting this also?

[dakcarto]

According to window elements, qgis started in HiDPI mode, however map canvas seems to be in low res still. @dakcarto Are you getting this also?

Sorry, don't have any more time right now to test. It may be that something in code has to be changed to fully enable HiDPI.

[m-kuhn]

Can you try to insert the following code in src/gui/qgsmapcanvas.cpp at line 585 (after mSettings.setExpressionContext( expressionContext );

mSettings.setOutputDpi( logicalDpiX() );

[dakcarto]

If looking to edit QGIS source during a build of qgis3-dev, one will need to:

1. Edit the formula and put a raise statement just prior to the run of cmake ...
2. Build with brew install qgis3-dev -dv (or at least -d)
3. When raise is thrown, drop into a debug shell, edit the file, then exit debug shell
4. Choose to 'ignore' thrown raise, which will continue building

This is because any changes to ~/Library/Caches/Homebrew/qgis3-dev--git/* will probably be reset prior to building QGIS inside the formula.

...
==> Checking out branch master
git checkout -f master --
Already on 'master'
Your branch is behind 'origin/master' by 119 commits, and can be fast-forwarded.
  (use "git pull" to update your local branch)
git reset --hard origin/master <-- !!!
...

Alternatively, @nextstopsun, you could use the dependencies to do your own build.

[nextstopsun]

@dakcarto I have all the deps installed, I think I'm going to setup QT Creator build. On a second thought, what if I just clone master and edit the formula to build from a local repo?

[dakcarto]

On a second thought, what if I just clone master and edit the formula to build from a local repo?

@nextstopsun that should work, though I recommend adding a revision 1 just under version "2.99" and then use brew upgrade -dv qgis3-dev, so you do not loose your current build. Later, you can just brew uninstall qgis3-dev to clear the most recent, edited build.

Qt Creator setup is better and will be added soon to the tutorial.

[m-kuhn]

If anyone can test this patch, that would be much appreciated.

qgis/QGIS#3847

[brncsk]

@m-kuhn No changes for me: UI chrome shows up in high res when NSHighResolutionCapable is set, but the map canvas is still rendering pixelated.

[m-kuhn]

@brncsk any chance you could find the value reported by logicalDpiX() - either with a debugger or temporarily add

qWarning() << "Logical DPI X " << logicalDpiX();

[brncsk]

will try later today

…

On Dec 8, 2016 10:22, "Matthias Kuhn" ***@***.***> wrote: @brncsk <https://github.com/brncsk> any chance you could find the value reported by logicalDpiX() - either with a debugger or temporarily add qWarning() << "Logical DPI X " << logicalDpiX(); — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#5 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABJjvFJllXWteaymMjmIwDMllNesJCurks5rF8xygaJpZM4LGuva> .

[brncsk]

@m-kuhn:

logicalDpiX() reports 72.
physicalDpiX() reports 111, though, which yields a somewhat better, albeit still suboptimal result.

I also tried multiplying that by devicePixelRatio() == 2 but it still feels a bit rough.

[brncsk]

In fact, increasing the argument of setOutputDpi() only seems to increase outline width (given in millimeters) and label font size (given in pts) but does not help with the rendering problem itself.

Screenshots at different setOutputDpi() resolutions:

72 (logicalDpiX()):

111 (physicalDpiX()):

222 (physicalDpiX() * devicePixelRatio()):

444 (physicalDpiX() * devicePixelRatio() * 2):

[m-kuhn]

In fact, increasing the argument of setOutputDpi() only seems to increase outline width

Correct, that's exactly what needs to be done in the rendering engine - but each pixel of the screen should be used (I guess now there are 4 equal pixels sitting next to each other on your map).

There's an issue in Qt with QGraphicsView and HiDpi: https://bugreports.qt.io/browse/QTBUG-26795 but it looks like caching is not explicitly enabled and defaults to disabled and I don't think we use the GL version, so this shouldn't affect us.

[dakcarto]

Hi. Can someone retest the rendering issue with latest qgis3-dev, which now fully builds against Qt 5.8.0? See known issues in #22.

Fixed with Qt 5.8.0: SVG menu icons now show properly (sweet!).

Also, I have updated the dock and app switcher icon to 1024x1024.

[brncsk]

It does not seem to fix the rendering issue, output is still pixellated. The 1024x1024 icon is a nice touch, though!

[Malauch]

I just want to report, that problem with pixelated output on canvas is still here. In addition plugin description (in plugin manager window) is oversized.

[dakcarto]

Hi. I am closing this as it is an issue to be discussed on the main QGIS issue tracker:
https://issues.qgis.org

I believe I have done what can be via the Homebrew formula and something more needs addressed in the core codebase.

[dakcarto]

This is the only current issue of similar topic I could find:
https://issues.qgis.org/issues/15357

[dakcarto]

I also created a saved query on the tracker for "Subjects with dpi":
https://issues.qgis.org/projects/qgis/issues?query_id=145