tiroj
commented
3 years ago Closing this for now, as the inquiry was not pursued.
Closed tiroj closed 3 years ago
tiroj
commented
3 years ago Closing this for now, as the inquiry was not pursued.
We've been approached by an educational publisher who has expressed interest in using the OpenType Layout fraction feature for display of nut fractions* and very simple linear equations that might have an arithmetic operation above and/or below the line. Some time ago, I figured out a couple of ways to handle nut fractions of limited length (e.g. up to ten characters in numerator or denominator) in OpenType Layout, which I published as Nutso.
At present, the STIX Two Text fonts contain a set of precomposed diagonal fraction glyphs mapped to Unicode characters, and component elements to build arbitrary diagonal fractions using the OTL 'frac' feature. The STIX Two Math font contains the same precomposed Unicode fractions, but no 'frac' feature implementation, since it is presumed that math layout will be used instead of OTL.
Four options present themselves. The set of characters available in numerator and denominator would be the same in all four: 0123456789+−×÷
1) Add nut fraction OTL support to the STIX Two Text fonts using the secondary 'afrc' Alternative Fractions feature. This has the downside of not being exposed in InDesign's user interface (that is the software being used by the educational publisher, which is generally sufficient for their linear layout needs).
2) Add nut fraction OTL support to the STIX Two Text fonts, replacing the diagonal fraction support in the 'frac' feature, and relegating the latter to the 'afrc' feature. This makes the nut fractions easily accessible in InDesign, and perhaps appropriate as the default fraction style in math oriented fonts?
3) Add nut fraction OTL support to the STIX Two Math font only, using the 'frac' feature. This would give publishers the option to get diagonal fractions from the Text fonts and vertical fractions from the Math font. We'd need to confirm that there are no conflicts between the OTL feature and math layout.
4) Fork the STIX Two fonts and make a custom version for this publisher.