Scaling stars on a HiDPI devices

[alex-w]

Description

This PR introducing configurable option to enabling scaling stars on a HiDPI devices to better visualisation of a faint stars

Fixes #2840 (issue)

Screenshots (if appropriate):

Before:

After:

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

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

[github-actions]

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

Files matching src/**/*.cpp:

• Are possibly unused includes removed?

This is an automatically generated QA checklist based on modified files

[alex-w]

@gzotti @10110111 please review the PR

[10110111]

Why do we even need a flag? Shouldn't it be always-on?

[gzotti]

I cannot test it. Have a 3880x1440 monitor which is not regarded HiDPI. If this is a hardware property which is either 1 or 2, I agree with @10110111 that this should be set automatically.

[10110111]

If this is a hardware property which is either 1 or 2

No, it's rather an OS property which can be anything from 100% to 500% or something like that.

[gzotti]

OK, I was reading about QScreen::devicePixelRatio(). Is this what you set (on Windows) as gui scaling ("100-500, 500 not recommended")? Checking always requires a logout/login for me, so I don't like to even test it.

[10110111]

Is this what you set (on Windows) as gui scaling ("100-500, 500 not recommended")?

Yes, exactly this setting.

Checking always requires a logout/login for me, so I don't like to even test it.

That's strange, at least on Windows 11 it's applied on the fly (Stellarium needs a relaunch).

[gzotti]

I remember it worked on the fly with my previous screen. It may depend on what screen is attached, HDMI or Thunderbolt. Only the latter has the full resolution, though.

[alex-w]

OK, it's always on now

[gzotti]

Fine for me.

[github-actions]

Hello @alex-w!

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

[github-actions]

Hello @alex-w!

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