[csswg-drafts] @font-face overrides for superscript/subscript metrics (#5518)

fantasai has just created a new issue for https://github.com/w3c/csswg-drafts:

== @font-face overrides for superscript/subscript metrics ==
In https://github.com/w3c/csswg-drafts/issues/4792 we resolved to accept @font-face descriptors for overriding the ascent/descent metrics. In https://github.com/w3c/csswg-drafts/issues/5225 @litherum suggested also adding metrics for superscripts and subscripts.

The proposal then would be to add:
- `superscript-shift-override`, affecting `vertical-align: super` and `font-variant-position` synthesis
- `subscript-shift-override, affecting `vertical-align: super` and `font-variant-position` synthesis
- `superscript-size-override`, affecting `font-variant-position` synthesis (and maybe some future `super` keyword for `font-size`, if we end up going there)
- `subscript-size-override, affecting  `font-variant-position` synthesis (and maybe some future `sub` keyword for `font-size`, if we end up going there)

See https://www.w3.org/TR/css-fonts-4/#font-variant-position-prop for an illustration of how these metrics are used for superscript and subscript glyph synthesis.

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/5518 using your GitHub account


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Received on Wednesday, 16 September 2020 18:24:45 UTC