Apple SF Fonts on Windows

Jim Parrillo
Jim Parrillo Posts: 10
I downloaded the various SF fonts from the Apple developer site (https://developer.apple.com/fonts/) and installed them on my work computer (Win 10) but I noticed that the italics are not showing up in Illustrator or Photoshop. They work fine on my Mac - has anyone else had this problem in Windows?

Comments

  • I'm not sure if you're allowed to use them on Windows, but they probably don't conform to the specs. I suggest you run the fonts through Font Validator to reveal potential issues.
  • If you're not allowed I would do it anyway. And I would freely modify them to work (even if the EULA contains a no-mod clause, something I personally find generally unethical).
  • Thomas Phinney
    Thomas Phinney Posts: 2,898
    My first thought was that, as these are Apple system fonts, a reasonable argument could be made that there is no reason they should be built to meet the usual cross-platform standards so as to work on Windows.

    However, the license has no prohibition against running them on Windows; it just says they are provided solely to do interface mockups for macOS, iOS and watchOS. But it seems to allow doing those mockups on Windows, Linux, or wherever else you like. (It also requires you to be a registered Apple Developer or otherwise authorized by Apple. And has other restrictions and terms.)

    Still, one can understand why Apple wouldn't have worried much about cross-platform concerns in building and testing them.
  • Theunis de Jong
    Theunis de Jong Posts: 112
    edited May 2019
    [..] I suggest you run the fonts through Font Validator to reveal potential issues.
    Rather odd: I checked them with an OTF explorer I wrote myself, and there are no immediate problems that stand out ... except for the minor point where it reports the main table checksum in head as wrong.

    It could be my code (although it does work correctly for all other fonts I have, as far as I know), and it has nothing to do with the Regular vs. Italic problem as reported, since both of these have this "error".

    Also – worth mentioning – when I install the font on my Mac, FontBook's Validator reports no errors whatsoever.

    No obvious differences between these two in encoding, name tables, head, or metric tables. Funny, though, that only a few of name entries appear properly encoded for both Windows and Mac, but the majority only for Windows.

    FreeType has no problem using the font:

    freetypetest -F ./SF-Pro-Text-RegularItalic -f ss01 "1966"
    ..........###.........#######.................###................###...
    .......#####........####...####.............###................###.....
    ....########.......###.......###..........###................###.......
    ...###...###......###.........###........###................###........
    .........##.......###.........###......###................###..........
    ........###.......###.........##......#########..........#########.....
    ........###........###......####....####.....####......####.....####...
    ........##..........###########.....##.........###.....##.........###..
    .......###................###......###.........###....###.........###..
    .......###...............###.......###.........###....###.........###..
    .......##..............###.........###........###.....###........###...
    ......###............###............####....####.......####....####....
    ......###..........####...............########...........########......
    
    ... where feature ss01 is "Straight-sided six and nine".
  • Micha Mirck
    Micha Mirck Posts: 23
    I looked at version 13.0d1e33. The fsSelection is not assigned. Maybe that is causing the problem
  • Erwin Denissen
    Erwin Denissen Posts: 302
    edited May 2019
    I took a closer look at one of the Italic SF fonts:
    • The general rangeShift field is invalid
    • The font checksum is incorrect
    • Incorrect head table checksum
    • Invalid Panose data
    • The fsSelection regular bit is set
    • The macStyle italic bit is clear

    The last two errors cause it to behave like a regular font.

    Here is a tutorial about how to ensure proper style linking for large font families:

    FWIW if this was an OpenType font with TrueType based outlines, Windows would not install it, as it would then consider it a corrupt font, due to the first 3 errors. I think it should be as strict with CFF based outlines as well.
  • Apple’s San Francisco font family is also used for all texts on their website, which is served to Web browsers on every OS, including Windows, without issues.
  • SiDaniels
    SiDaniels Posts: 277
    I don't think modern browsers care too much if a font's style linking isn't set up properly. The CSS tells the browser specifically which web font to use for different text styles including italic.