msdfgen generates broken atlases for some fonts

[axeljaeger]

brew config AND brew doctor output OR brew gist-logs <formula> link

brew config             
HOMEBREW_VERSION: 6.0.9
ORIGIN: https://github.com/Homebrew/brew
HEAD: 655769712a9a9499563d9685a8488f349354492d
Last commit: 9 days ago
Branch: stable
Core tap JSON: 13 Jul 09:03 UTC
Core cask tap JSON: 13 Jul 09:03 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_DOWNLOAD_CONCURRENCY: 20
HOMEBREW_FORBID_PACKAGES_FROM_PATHS: set
HOMEBREW_MAKE_JOBS: 10
HOMEBREW_REQUIRE_TAP_TRUST: set
Homebrew Ruby: 4.0.5 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/4.0.5_1/bin/ruby
CPU: deca-core 64-bit arm_firestorm_icestorm
Clang: 21.0.0 build 2100
Git: 2.50.1 => /Library/Developer/CommandLineTools/usr/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 26.5.2-arm64
CLT: 26.6.0.0.1781586589
Xcode: 26.6
Metal Toolchain: N/A
Rosetta 2: false

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Verification

• My brew doctor output says Your system is ready to brew. and am still able to reproduce my issue.
• I ran brew update and am still able to reproduce my issue.
• I have resolved all warnings from brew doctor and that did not fix my problem.
• I searched for recent similar issues at https://github.com/Homebrew/homebrew-core/issues?q=is%3Aissue and found no duplicates.
• My issue is not about a failure to build a formula from source.

What were you trying to do (and why)?

I tried creating a Multi-Channel-Signed-Distance-Field (MSDF) Font from Google Fonts (inter and roboto). I wanted to use this font for a 3D application where SDF and MSDF fonts are a common technique.

What I found out already: The version of msdfgen that was recently added by @lczyk (thank you) is not compiled with skia support. This seems on purpose, I mostly want to point some problem with it and start a discussion how to move on from here.

What happened (include all command output)?

The generated font includes some artifacts. Note the t-junction.

What did you expect to happen?

A font atlas without the artifacts: (Generated using another piece of software).

Step-by-step reproduction instructions (by running brew commands)

brew install msdfgen
msdf-atlas-gen \
  -font "inter.ttf" -chars "'e'" \
  -type sdf -size 256 -pxrange 16 -dimensions 320 320 -yorigin top \
  -imageout assets/homebrew-sdf-atlas-gen-e.png

[daeho-ro]

I think I lost the point, are you asking to add skia support?

[lczyk]

are you asking to add skia support?

that's my read, and yeah, i didn't link with skia on purpose. not really due to technical limitation, just an organisational one. skia is not in home-core and i didn't wanna bundle it (effort).

there is no skia formula afaict there is nothing which bundles skia directly.

$ grep -Firl skia /opt/homebrew/Library/Taps/homebrew/homebrew-core/Formula | grep -v msdf
/opt/homebrew/Library/Taps/homebrew/homebrew-core/Formula/n/neovide.rb
/opt/homebrew/Library/Taps/homebrew/homebrew-core/Formula/s/slint-cpp.rb
/opt/homebrew/Library/Taps/homebrew/homebrew-core/Formula/m/manim.rb

all of the above build skia although indirectly through rust/puthon. we could do smth like that?

[axeljaeger]

are you asking to add skia support?

If this is an easy add, yes, if not, what else can we do.

all of the above build skia although indirectly through rust/puthon. we could do smth like that?

How does this approach work? Isn't it about the same effort + the binding generation?