SF Mono Font Rendering Problem

[truncuportakal]

Hi,

While I was choosing between fonts, I realized SF Mono’s font name is not rendered correctly on the font list. When I clicked it to inspect it further, I realized SF Mono is being rendered completely gibberish. Below are the examples:

As can be seen in the screenshot, the upper lines are set in SF Mono and contain exactly the same text as the lines below. It seems that LibreOffice renders the lowercase letters incorrectly, while the uppercase letters appear normal.

I checked the other font-rendering issues mentioned on the FAQ page, but they seem to concern more specific cases rather than a problem this general.

I also asked ChatGPT about it and tried changing several settings under View, including anti-aliasing and Skia-related options, but none of them made any difference.

I tested SF Mono in several other applications, including Microsoft Word, Pages, and Obsidian, and it renders correctly in all of them. Because of that, I suspect this may be something specific to LibreOffice’s font rendering on macOS.

I also updated LibreOffice to the latest version available to me, but the problem remains.

Version: 26.8.0.3 (AARCH64)
Build ID: bce0998afefdbc355585ca324285661a2170ba77
CPU threads: 8; OS: macOS 27.0; UI render: Skia/Metal; VCL: osx
Locale: tr-TR (en_US.UTF-8); UI: en-US
Calc: threaded

Has anyone encountered something similar, particularly with SF Mono or other variable/system fonts on macOS?

[ajlittoz]

Are you sure you have no “combining diacritic marks” in the first line? Please attach the corresponding sample file.
Where can the SF Mono font be downloaded? How old is it? If it is really old, it could have been “converted” to Unicode in some compatibility mode, e.g. transferring its glyphs into the Private Use Area (PUA) of the Basic Multilingual Plane without caring for “modern” encoding rules.

[truncuportakal]

sample.odt (12.6 KB)

I’ve attached a small sample ODT file that reproduces the issue.

No, there are no combining diacritic marks involved. I have also experimented with many other fonts, and so far the problem appears to be peculiar to SF Mono.

As for the font itself, I obtained it from Apple’s official font page:

Fonts - Apple Developer

SF Mono is distributed directly by Apple and is widely used across Apple’s own development tools and interfaces, so I would be surprised if this were simply an old or incorrectly converted font file.

Also, the same installed copy of SF Mono renders the same text correctly in Microsoft Word, Pages, Obsidian, and other applications on the same Mac. That makes me suspect there may be some LibreOffice-specific interaction with SF Mono rather than a general problem with the font file itself.

[ajlittoz]

I wanted to check the tables inside the font file but I didn’t succeed in mounting the ad hoc partition of the disk image (I am under Linux). Do you know of another download source only for the font file?

Otherwise, I confirm there are no diacritics in the sample.

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EDIT
I found an alternate download source offering a ZIP. However not sure if it is an official font. It is copyrighted © 2017 Apple Computer; is is the same as yours?

I found nothing “suspicious” in the mapping table. Glyphs appearing in your screeshot are found in the Latin Extended Additional block starting at U+1E00 but this is not consistent: your string is strictly ASCII.

I installed the font and opened your sample. It displays as it should (no fancy diacritics or glyphs).

IMHO, you have a damaged configuration. Have you tried to launch Writer in safe mode?

[EarnestAl]

In Windows 11, I downloaded the file from the location given and unzipped the contents until I found the .otf files. After installing them I found no problem with the fonts.

@truncuportakal I wonder if your font cache needs refreshing?