Follow-up Comment #5, bug #60587 (project groff): As comment #4 affirms, generating data to use the mechanism requested in this ticket is out of scope for this ticket. But there seems little point in opening a new ticket for that, when we are a long way from needing any such data: as comment #2 alludes, providing a user-level mechanism such as Heirloom's .kernpair is the best first step, and even that (bug #44244) is unlikely to happen soon. (And there isn't even universal buy-in that this ticket's ask is a good idea.)
But lacking an appropriate venue to brainstorm ideas for generating such data, I'm using this as the least inappropriate one. A recent email from Deri James (http://lists.gnu.org/r/groff/2022-07/msg00219.html) provides a possible starting point for this: "Italic fonts have extra metrics which determine how much space to add for italic correction." So some tool could read the font metrics and spit out a list of italic glyphs that are candidates for the first glyph of each such pair. The immediate trouble with any system to autogenerate the second glyph comes up in a point Tadziu once made (http://lists.gnu.org/r/groff/2013-11/msg00031.html): "'italic correction' is the space needed between the italic character and a _tall_ upright character." He cites an italic _f_ followed by a comma as a sequence that won't need extra space. Do font metrics include height information that could be used to pare the list? And even this is less than sufficient. To assuage Branden's comment #3 concern about data proliferation, I submit that an automated system should not try to handle all cases, only common ones. For example, it's not unheard of for a font change to happen in the middle of a word, and such a font change might even benefit from some correction, such as, "I said _off_load." But here we veer into the realm of copious data for little benefit. The cases I think should be automated are the more common ones of adjacent letters and punctuation from different fonts. And while font metrics (probably) don't classify a font's glyphs by type like that, happily, Unicode does. So that gives an automated way to substantially whittle down the list of candidate pairs. _______________________________________________________ Reply to this item at: <https://savannah.gnu.org/bugs/?60587> _______________________________________________ Message sent via Savannah https://savannah.gnu.org/
