Bug 1226400

Summary:	Some applications don't support variable fonts well
Product:	[openSUSE] openSUSE Tumbleweed	Reporter:	JS <obs.coke518>
Component:	Usability	Assignee:	Yunhe Guo <i>
Status:	NEW ---	QA Contact:	E-mail List <qa-bugs>
Severity:	Normal
Priority:	P5 - None	CC:	chcao, pujos.michael
Version:	Current
Target Milestone:	---
Hardware:	Other
OS:	openSUSE Tumbleweed
Whiteboard:
Found By:	---	Services Priority:
Business Priority:		Blocker:	---
Marketing QA Status:	---	IT Deployment:	---

Description JS 2024-06-16 08:12:35 UTC

google-noto-sans-cjk-fonts and google-noto-serif-cjk-fonts switched to variable fonts, but some applications don't support it well.

For the following two examples, assume the font "Noto Sans CJK JP" is installed as a variable font.

JDownloader (installed by flatpak):
1. Open Settings from the menu
2. Select Advanced Settings in the left panel
3. enter "font name" in the textbox to filter the settings
4. enter Noto Sans CJK JP in the value field
5. Restart JDownloader
6. The new characters are too thin. It seems like it's using the smallest weight. And there is no way to select other weights.

Freeplane (from repo http://download.opensuse.org/repositories/Office/openSUSE_Tumbleweed/):
1. Select Noto Sans CJK JP by the pulldown menu in the the toolbar
2. The characters in nodes are very thin

For static fonts, all weights are installed as separate fonts and can be selected in the UI of the applications.

I think giving users the option to install static fonts instead is more feasible than identifying all those applications incompatible with variable fonts and have them support it.

Comment 1 Chenzi Cao 2024-07-16 16:28:03 UTC

Hi Yunhe, would you please help to take a look at this issue? I'm not sure whether it is correct to assign it to you, please feel free to reassign whenever necessary, thanks.

Comment 2 Michael Pujos 2024-07-16 19:09:20 UTC

I had a quick look at it and could reproduce it in Freeplane.

Both these programs are using Java.

The font in question is /usr/share/fonts/truetype/NotoSansCJKjp-VF.otf, which an OTF Variable Font, which means it includes all weights: thin, regular, bold, etc.

It seems Java does not support enumerating all of the different weight variants of this font, thus there is just "Noto Sans CJK JP" listed and it is drawn in "Thin" weight.

The workaround (did not tried it but it should work) would be to manually download that font as a zip including separate TTF files for each weight:

https://fonts.google.com/noto/specimen/Noto+Sans+JP


(click "Get font" and download)

Then:

- place the .ttf files in ~/.local/share/fonts/
- invoke 'fc-cache' command
- pick the correct CJK JP font weight in the program

A proper solution would be make a package of this font as individual .ttf.