Default font does not support Unicode

[Meakk]

Describe the bug The default font should support Unicode characters.

To Reproduce Steps to reproduce the behavior:

1. Open the file using f3d -n f3d\testing\data\(ノಠ益ಠ )ノ.vtp

Expected behavior

Supports Unicode characters in the file name actor and the title bar.

System Information:

• OS: Windows

F3D Information 2.2 RC2

[mwestphal]

not windows specific

[mwestphal]

duplicate of https://github.com/f3d-app/f3d/issues/42

[mwestphal]

more info here.

[Ni-g-3l]

Hello !

I found on many website that VTK support only ASCII character, and the only way to fix this is to modify default font used, by a font which embed Unicode character.

[mwestphal]

good point, that is probably a possible fix.

[Ni-g-3l]

I you want I can make some tests this week :)

[mwestphal]

Ok!

Watch out, this may not be as simple as it looks like, here is what is neede imo:

• Add a default font (with a free license) that support unicode in the resources
• Change the default font by using the dedicated font option (check the libf3d doc)
• Point to a location that works when building, installing and packaging F3D
• Update all baselines that displays text
• Ideally the font should be the same one we use with added unicode char, but this may not exist

Feel free to reach out on discord for help!

[snoyer]

The window title being garbled on the original screenshot is a likely a separate encoding related issue as the OS (window manager?) should be able to display utf8 regardless of VTK's font choices.

[mwestphal]

You are very probably right @snoyer

[snoyer]

I tried some random greek to start easier (better font support/coverage than the japanese+indian+chinese from the original case) by doing cp ../testing/data/\(ノಠ益ಠ\ \)ノ.vtp "/tmp/Γειά σας.vtp" and used the DejaVu font from Fedora:

• gnome-terminal's and Firefox's titles are ok
• F3D's title is not ok
• F3D's text actor is ok as DejaVu has the greek glyphs

[Ni-g-3l]

Hello,

I tried a bunch of fonts which says that it supports Unicode. However only one is working for this type of CJK char.

Fonts :

• Droid Sans
• Droid Sans Fallback
• Noto
• Free Sans
• Roboto
• Deja Vu Sans
• Liberation Sans
• Arial Unicode MS (Screen bellow)

I added some greek char to test both alphabet. However I cann't find if we can embed Arial Unicode MS to F3D I can't find the license ..

[mwestphal]

Turns out its not that simple: https://stackoverflow.com/questions/3370512/font-equivalent-to-arial-unicode-ms

We have a thread currently about it on discord, wanna chat ? https://discord.com/channels/1046005690809978911/1179418393846231050

[Meakk]

Title bar on Windows fixed here: https://gitlab.kitware.com/vtk/vtk/-/merge_requests/10737

[Meakk]

Yes, Arial font requires a license, unfortunately.
It seems like it's possible to merge several Noto fonts: https://github.com/notofonts/nototools/blob/main/nototools/merge_fonts.py
To start, maybe we should try to merge NotoSans-Regular.ttf, NotoSansPhoenician-Regular.ttf (greek probably?) and all NotoSansCJKXX-Regular.otf and see if it works?

[mwestphal]

The title bar has been fixed by #1090 and will be available in the next release. The text actor will not be fixed because we cannot ship a 50 mb font and VTK cannot fallback on system font. Should we close this @Meakk ?

[mwestphal]

Title bar is still broken on some linux desktop env, so we can consider investigating that too.

[mwestphal]

FYI this is not fixed yet.

[incompetentcoder]

You could potentially use GNU Unifont which is considerably smaller but covers most planes with a single otf font and The GNU Font Embedding Exception and the SIL OFL allow for embedding into anything