[Draft] Add font objects

[bluebear94]

See #3488 and #3331.

• Add font type (implicitly convertible from string)
• Add per-font OpenType features – will be a lot more complicated because text::features assumes that text will use the same OpenType features regardless of which font is selected.
• Add per-font Unicode ranges

Unresolved questions:

• Should we deprecate OpenType feature-related options on text?

[Enivex]

Should we deprecate OpenType feature-related options on text?

In my opinion yes. These features are fundamentally tied to each specific font.

[bluebear94]

In my opinion yes. These features are fundamentally tied to each specific font.

Would that only apply to alternates, stylistic_set, and features, or others like kerning, ligatures, and number_type?

[Enivex]

In my opinion yes. These features are fundamentally tied to each specific font.

Would that only apply to alternates, stylistic_set, and features, or others like kerning, ligatures, and number_type?

All of them. But Laurenz may have a different opinion.

[PgBiel]

I have a feeling that it'd still be nice to be able to configure those independently of the font (while also offering the possibility of having per-font configuration).

[Myriad-Dreamin]

I have a feeling that it'd still be nice to be able to configure those independently of the font (while also offering the possibility of having per-font configuration).

"But Laurenz may have a different opinion."
That is: The font-specific features should be move from field of text element to that of font object, but not necessary for those are not font-specific. For example, it is possible not meaningful to share stylistic_set, but can be meaningful to share ligatures.

[PgBiel]

"But Laurenz may have a different opinion."

Yeah! Just wanted to share mine too :)

That is: The font-specific features should be move from field of text element to that of font object, but not necessary for those are not font-specific. For example, it is possible not meaningful to share stylistic_set, but can be meaningful to share ligatures.

Sure, but how could we implement those shared properties other than through the current design?
I guess we could make font() foldable in order to have some default-font property usable within set rules, or something. Not sure though - I feel a bit uneasy about the proposed design (I wonder if this is sufficiently appealing to new users).

[bluebear94]

Right now, I have font-specific features always take precedence over features set in text. I think it would be better to have whatever setting is innermost take precedence, but I’m not sure how this would be done.

[laurmaedje]

I left a few comments in the Fonts forge on Discord.