Qt6 compatibility upgrade

[gzotti]

This branch should be used as we adapt to Qt6.

Milestones:

• CMakeLists.txt should work with Qt5.12 and later. Recommended: Qt5.15.2 and Qt6.2.4 (or later)
• external modules should be removed where possible, upgraded to current where required, or fixed.
• esp. qcustomplot does not compile. Get rid of it (use QCharts; AstroCalc with QCharts #2390, Exoplanet plugin with QtChart #2447).
• Replace QtScript by QJSEngine functions (Switch from QtScript to QJSEngine #2461)
• Upgrade libindi (or better, remove source duplication) so that it compiles with latest gcc (Cannot be built with most recent compilers #2157)
• Compile main app (without plugins) with Qt6
• Restore broken text everywhere
• Compile all plugins with Qt6
• Upgrade StelAudioMgr module (compiles, but may need fixes with API change) --> Completion after reactivating Scripting in Qt6!
• Upgrade StelVideoMgr module (compiles, but may need fixes with API change) --> Completion after reactivating Scripting in Qt6!
• Restore Scenery3D rendering (OBJ loader broken?)

To build with Qt6, disable SCRIPTING. This is dealt with in another branch (#2461).

I think the best strategy for now is working on master with Qt5.15+, trying to get rid of deprecated stuff hinted at by clazy, use feature branches for larger tasks, and occasionally rebase this branch from master to test.

Update 2022-06-08

The program builds! However, text is garbled.

Update 2022-06-29

Finally! Text is visible again.

It should be possible to keep compilation compatible between Qt5 and Qt6, without any extra branch. Qt6 requires 64bit CPUs and fully working OpenGL graphics, so Qt5 will likely have to stay around for a few more years. I have re-extended compatibility back to Qt5.12 (Ubuntu 20LTS, and even 5.9, for Ubuntu 18LTS).

Description

Fixes # (issue)

Screenshots (if appropriate):

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• This change requires a documentation update

How Has This Been Tested?

Test Configuration
Operating system: Windows 10

• Graphics Card: Nvidia Geforce 960M
• Qt5.9.9/MSVC2017 configuration with MSVC2019.
• Qt5.12.8/MSVC2017 configuration with MSVC2019.
• Qt5.15.2/MSVC2019 configuration with MSVC2017 and MSVC2019.
• Qt6.2.4/MSVC2019 configuration with MSVC2019. Qt6 really requires MSVC2019!

Operating system: Ubuntu 22.04

• Graphics Card: (Intel, whatever built into i3-5010U)
• Qt5.15.3
• Qt6.2.4

Checklist:

• My code follows the code style of this project.
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (header file)
• I have updated the respective chapter in the Stellarium User Guide
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[gzotti]

Dear all,

I did not play with the version numbers, but this may be Stellarium 1.0 alpha.

2022-06-08T17:10:26
Operating System: Windows 10 Version 2009
Compiled using MSVC++ 16.10, 16.11 (Visual Studio 2019)
Qt runtime version: 6.2.4
Qt compilation version: 6.2.4
Addressing mode: 64-bit
Total physical memory: 32631 MB
Available physical memory: 10046 MB
Physical memory in use: 69%
Processor speed: 2592 MHz
Processor name: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
Processor speed: 2592 MHz
Processor name: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
Processor speed: 2592 MHz
Processor name: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
Processor speed: 2592 MHz
Processor name: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
Processor speed: 2592 MHz
Processor name: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
Processor speed: 2592 MHz
Processor name: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
Processor speed: 2592 MHz
Processor name: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
Processor speed: 2592 MHz
Processor name: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
D:\StelDev\GIT\build-stellarium-Desktop_Qt_6_2_4_MSVC2019_64bit-Release\src\stellarium.exe -platform windows:altgr 
 ---------------------------------------------------------------------------
[ This is Stellarium 0.22.1-532a784 [towards-Qt6] - https://stellarium.org/ ]
[ Copyright �� 2000-2022 Stellarium Developers                              ]
 ---------------------------------------------------------------------------

I will push this soon. However, all texts are squashed to the left of each window, so there is still work ahead. Also 2 plugins do not yet compile.

[alex-w]

I have seriously no idea what's going on with the failing text rendering. @alex-w @xalioth @Atque Any ideas?

On macOS 12.4 with Qt 6.3.0 (official package from Qt.io) the main scene is not render (just a black screen) :(

P.S. I got reports, that Stellarium have just a black screen with official 5.15.2 on macOS, but I see no problem for rendering with Qt 5.15.3 from homebrew.

[gzotti]

Sad. From what I am reading, Mac is leaving OpenGL, replacing by Metal, and Windows still pushes DirectX. Qt6 lost ANGLE, so only full OpenGL PCs will be able to run the Qt6-based series (or MESA should still be available, but of course less fun), unless some GPU hero does the new Qt6 graphics subsystem glue code. .

I cannot find any reports online about bad font rendering or similar terms. This is maddening.

[github-actions]

Great PR! Please pay attention to the following items before merging:

Files matching guide/**:

• Did you remember to update screenshots to match new updates?
• Did you remember to grammar check in changed part of documentation?

This is an automatically generated QA checklist based on modified files

[gzotti]

The failing unit test around units and intersections of SphericalRegions is really bad, and was not able to fix the methods. However the methods are currently not used, so it need not be solved immediately. I #ifdeffed those functions away, and the program still works. Guillaume confirmed he also does not use them.

One side-development in this branch was the program's OpenGL initialisation. ANGLE is of course no longer available. I am however unsure about the current Mac-related code. Else this can now probably be merged for first tests of 1.0beta.

Speaking about version number, @alex-w do you want to develop the new number scheme still in this branch or after merge?

[alex-w]

Speaking about version number, @alex-w do you want to develop the new number scheme still in this branch or after merge?

Of course after merge

[github-actions]

Hello @gzotti! Please check the fresh version (development snapshot) of Stellarium:
https://github.com/Stellarium/stellarium-data/releases/tag/weekly-snapshot

[github-actions]

Hello @gzotti!

Please check the fresh version (development snapshot) of Stellarium:
https://github.com/Stellarium/stellarium-data/releases/tag/weekly-snapshot

[github-actions]

Hello @gzotti!

Please check the latest stable version of Stellarium:
https://github.com/Stellarium/stellarium/releases/latest