Behdad Esfahbod

> I'm not sure which way is best. @khaledhosny @jfkthame Your insight is appreciated. Should we leave as is, or match other shapers?

I tried to add a test for this, but `hb-subset` is modifying the font in a way that the subset font behaves differently. Because of assumptions... Reopening to fix `hb-subset`...

Just ' 19' to activate feature code 19 sounds fine with me.

Let's work on this. I think both the mapping API, and the number API, and possibly a `_{to/from}_feature_tag` would be interesting.

It seems like [TrueType dropout control](https://learn.microsoft.com/en-us/typography/opentype/spec/ttch01#what-is-a-dropout) is not implemented? Fontations doesn't have a rasterizer itself. Dropout control is a technique implemented in a scanline mono rasterizer. A relic of the...

That sounds like something we decided can be done with existing BASE table, and HB exposes it in https://harfbuzz.github.io/harfbuzz-hb-ot-layout.html#hb-ot-layout-get-font-extents2

This is duplicate of https://github.com/harfbuzz/boring-expansion-spec/issues/88 We should make a proposal to MPEG for next round. Other than that, I think the best case scenario would be a major platform implementation....

cc @nedley for CoreText. That part of the code is so complicated, I need to see what to do to match DWrite without breaking other things...

So walk me through this a bit. You expect the mark to try to attach to the first glyph in a multiple-subst, yeah? That's something we do for mark-to-base already,...

> So walk me through this a bit. You expect the mark to try to attach to the first glyph in a multiple-subst, yeah? That's something we do for mark-to-base...