Split `official` and `unofficial` icons into separate fonts

[lgarron]

Now that we have some more powerful build tools, we can start implementing some optimizations.

One option might be to load fonts only when needed. One natural split for this is official vs. unofficial. Pages that only use official icons could get a reduction in page loading bandwidth without losing the ability to use unofficial icons (at the cost of an extra round-trip when they do use unofficial icons). We'd have to check that the per-font overhead is not too high, though.

Once incremental font transfer is available in enough browsers, that will also be a great option (assuming it can be bundled): https://w3c.github.io/IFT/Overview.html

(I haven't thought about where the penalty icons would fit into this yet.)

[jfly]

This is arguably a breaking change (depending on if you think of the font as part of our "stable API" or an implementation detail hidden by our CSS). That said, I'm OK with this change if it's justified. Our font is currently only 7,612 bytes:

$ curl -s https://icons.cubing.net/@cubing/icons/cubing-icons.woff2 | wc -c
7612

Does that feel large enough to you that it's worth doing anything?

One natural split for this is official vs. unofficial [...] (I haven't thought about where the penalty icons would fit into this yet.)

I think the natural split would be "official" and "everything else".

[lgarron]

This is arguably a breaking change (depending on if you think of the font as part of our "stable API" or an implementation detail hidden by our CSS).

The font itself is not listed in the package "exports". I am strongly against considering it part of any stable API.

$ curl -s https://icons.cubing.net/@cubing/icons/cubing-icons.woff2 | wc -c
7612

Does that feel large enough to you that it's worth doing anything?

Yeah, that's definitely snazzy. But:

• Some sites are small, and that might still make a difference.
• I don't want font file size to be an argument against adding unofficial icons in the future.

I think the natural split would be "official" and "everything else".

Yeah, that does make sense to me!

[jfly]

I don't want font file size to be an argument against adding unofficial icons in the future.

I've never heard anyone make this argument before, and I am strongly opposed to anyone making it in the future.

[lgarron]

$ curl -s https://icons.cubing.net/@cubing/icons/cubing-icons.woff2 | wc -c 7612

Does that feel large enough to you that it's worth doing anything?

Also, just checked. Including only the official icons right now is 2360 bytes, and everything else is 6204 bytes. So that's a 69% reduction if you're just using the official events (ignoring the CSS and compression — our CSS file minified and gzipped right now is 702 bytes, although we could decrease that).