UI broken on MacOS Mojave using OpenGL

[asaf-wa]

Hello
I'm trying to develop a QT desktop application for MacOS Mojave. As part of the application, there is a QGLWidget for rendering 3D content.
Ever since I've upgraded to MacOS Mojave, the UI is completely broken:
Either I enable support for the Retina display (using the plist file and the AA_EnableHighDpiScaling flag) and the UI completely breaks down, or I disable support for Retina and the UI appears blurred as it's scaled up.

As part of the investigation, I've decided to try and run a sample project from Qt Creator (the 40000 chips project). It looked fine, until I clicked the 'OpenGL' button - and then the UI broke down just like it did in my own application (illustration images below).

Has anyone else experienced issues with Qt UI scaling on MacOS Mojave?
Does anyone have any idea what I should do?
Thanks in advance to everyone!

Exhibit A. Everything is Fine:

Exhibit B. Everything Breaks Down:

[AndyS]

Hi @asaf-wa,

Which version of Qt is this? A lot of fixes have gone into Qt 5.12 and some backported to 5.11 and 5.9 for Mojave, so you might need to upgrade to Qt 5.12 to check this. If it is broken there then can you report a bug at JIRA. Thanks!

[Michael Wilson]

Are you running a Mojave Beta by any chance? There are reports that the latest version of the Mojave Beta broke Sublime Text. It may be related:

https://forum.sublimetext.com/t/sublimetext-3180-turned-into-totally-dark-after-mojave-upgraded-to-10-14-1-beta/39901/12

[kenchan]

@asaf-wa

I tried the same thing as you with Qt 5.9.2 on macOS mojave v12.14, using xCode 10.0 with a Retina 5k 27inch monitor and AMD Radeon R9 M395X 4096 MB graphics . It worked perfectly at all the resolutions I could set it to, including the low res ones. I did not see the artefacts that you are showing.

Now, having seen your results I am concerned it might be broken in some newer version of Qt :-(.

[asaf-wa]

@AndyS I'm using Qt 5.11.2, but I don't see any way to download 5.12
@Michael-Wilson No beta, just the normal Mojave installed from the AppStore
@kenchan Actually, the same application compiled with Qt 5.10.0 on MacOS High Sierra works perfectly fine on Mojave... the plot thickens?

[AndyS]

@asaf-wa Snapshots for Qt 5.12 are available via the online installer, or you can build it yourself too.

[asaf-wa]

@AndyS
Thanks for the suggestion: updating to Qt 5.12 beta did solve the UI problems.

[aha_1980]

@asaf-wa So please close this topic as SOLVED. Thanks.