Arabic Al-Sufi lunar mansions' names are shifted with respect to their sections

[10110111]

Expected Behaviour

The labels of the lunar mansions should be centered in the mansions' sections. Ideally, the number should be fixed to the name.

Actual Behaviour

In Arabic Al-Sufi, when Native and Translated names are on, the Arabic name is centered, while the translated one is attached to its left and, depending on the zoom level, overlaps with the mansion number.

Steps to reproduce

1. Switch to Arabic (Al-Sufi) sky culture
2. Make sure lunar mansions are enabled
3. Enable Native and Translated names (I did so in both rows)
4. Zoom out to see several mansions at the same time
5. Zoom in gradually, notice how the names are shifting with respect to mansion numbers, and how decentered they are.

System

• Stellarium version: v25.2-189-g7093812068
• Operating system: Ubuntu 20.04
• Graphics Card: Intel UHD Graphics 620
• Screen type (if applicable): 1920×1080, no scaling

Logfile

log.txt

[gzotti]

Yes, with the Arab names now completed, I also have seen the issue around RTL languages.

• The canonical layout of labels should have been to have the native (original glyph) part always on the left side.
• As mentioned in Bab. SCs: add cuneiform in "Native" tags #4339, apparently there are font metrics issues which cut off strings under some unknown circumstances (is that the string->texture conversion with too small texture?) Maybe the cuneiform fonts don't provide bounding box values? Or whatever font mixing happens behind the screens, maybe this fails?
• Probably we need another particle setting for the Zodiac/LunarStation strings to avoid them to become too long. Presumably users would here only use one part for brevity, so a simple 5-value combo could be enough. And separate font sizes.

Not sure how to solve this. Should the string->texture conversion work with the name parts, and assemble larger textures from the name part textures?

[10110111]

A wild guess is that maybe the bounding box is computed correctly, but has large negative offsets (because the Arabic text does look well centered). I haven't checked the code though, maybe this is already taken into account.

[gzotti]

I just see the ConstellationMgr and AsterismMgr have their own fonts, modify sizes, but never set the actual font. This looks more than weird to me.

[alex-w]

The fonts in these classes should be inherited from core

[gzotti]

Should or are already? I am just investigating...
Nope, StelCore has no font. StelApp has, and a font change should be propagated to the Mgr classes by Qt messaging.