COLRv1 Support

[jlarmstrongiv]

The COLRv1 is on the horizon, with gradients, compositing, blending, and more. Currently, fontkit supports COLRv0

• the spec
  • https://docs.microsoft.com/en-us/typography/opentype/spec/colr#colr-formats
  • https://github.com/googlefonts/colr-gradients-spec/
• chrome
  • https://chromestatus.com/feature/5638148514119680
  • https://developer.chrome.com/blog/colrv1-fonts/
  • https://blog.chromium.org/2022/01/chrome-98-beta-color-gradient-vector.html
• caniuse https://github.com/Fyrd/caniuse/issues/6097
• examples
  • https://github.com/googlefonts/color-fonts
  • https://github.com/rsheeter/Bungee/blob/main/README.md#build-your-own-copy
• related
  • the example on https://github.com/foliojs/fontkit/issues/260#issuecomment-894583312
  • this issue https://github.com/foliojs/fontkit/issues/211#issuecomment-948603970

[Pomax]

Note that the real spec is https://docs.microsoft.com/en-us/typography/opentype/spec/colr#colr-formats, though. The github repo is just the working location, inclusion in the OpenType spec is when things become official.

[jlarmstrongiv]

Great find @Pomax!

I haven’t worked much with parsers, but I think your svg example and restructure is interesting.

I can extract and post my existing COLRv0 code and then explore how to add support for the new features.

[Pomax]

In terms of the parser: we can probably hack something into existence, similar to what we did with the SVG parser, as COLRv1 isn't terribly complex, just "a lot more (linked) simple structures". The tricky bit will be in turning them into something you can actually see.

[jlarmstrongiv]

@Pomax it certainly sounds possible. If you’re able to hack together the parser, then I will be able to format and massage the data into a usable svg. I think it’d be useful to other people in the future too 😄

[Pomax]

stubbing something out over on https://github.com/Pomax/fontkit-colrv1, but it's a lot of small bits of code, so no promises on when I might finish (if ever, because "yet another repo" is exactly what my overloaded schedule needed ;)

Unless someone wants to commission this work, of course, then things become radically different =D

[jlarmstrongiv]

Thank you @Pomax ! That’s a great start. What’s the best way to contact you?

[Pomax]

Email's best, although I may be slow to respond (I think you already emailed me) because things have gotten a bit crazy and I'm currently balancing "having to use a keyboard" with "not actually being able to use a keyboard due to an injury" >_>

[jlarmstrongiv]

Ouch! Hope you make a full recovery @Pomax. I remember a few tips for hands-free coding from https://www.joshwcomeau.com/blog/hands-free-coding/ Feel free to followup in a few weeks or a few months, whenever you feel better with schedule permitting.

[Lorp]

This is @simoncozens’ PR for COLRv1 support: #298

[jlarmstrongiv]

Closing in favor of #298