Greetings All,
Ligatures are found in Ge'ez (Ethiopic) manuscripts but not consistently, whereby within a paragraph the ligature may appear on one line, but not the next. The ግዚ ligature is by far the best-known and most frequently found example. This is different from Latin script where a ligature substitution is desirable 100% of the time. In the Ge'ez case, the user would want to have selective control over the substitution.
Since the CMAP subtable 14 spec supports only a single "base" character in the mapping, I thought to use a liga feature, but add a variation selector as a kind of semaphore, like:
sub uni130D uni12DA uniFE00 by gzi_liga ;
which should work (outside of DirectWrite) so long as subtable 14 does not also have a <uni12DA, uniFE00> mapping.
This abuses the spirit of the variation selector a bit, is there another approach available for selective ligation?
thanks,
-Daniel
0
Comments
rlig: required ligatures. On by default, do not necessarily have any interface method to turn them off.
clig: contextual ligatures. Also on by default, do not necessarily have any interface method to turn them off.
liga: on by default but allowed to be turned off
dlig: discretionary ligatures. Off by default but should have interface method to turn on.
I went back and replaced U+200C with U+FE00, which hadn't worked last year (in Word) when I was experimenting then. It still doesn't work, but then I found by accident that it would work if 2 U+FE00 are present, that is: <130D, 12DA, FE00, FE00> . Weird, but repeatable. Apple Pages was fine with just a single FE00.
I'll stick with U+200C, or maybe U+200D makes more sense for "joining". Reading a little about ZWJ, it seems to get used in two conventions: end of sequence, or between letters. Is the current thought that <130D, 200D, 12DA> is preferable over <130D, 12DA, 200D> ?
No luck with dlig, but I'll research later if Word provides an interface feature for it that I need to enable.
However, making the official OpenType defaults the actual default may have taken years longer. I think it is there now, but for a while I think the default was to keep your files formatted compatibly with earlier versions of Word, so standard ligatures were not on (and maybe not even available IIIRC?) unless you changed your doc defaults to not worry about maintaining formatting compatibility with old versions.
Interestingly, the interface lumps historical and discretionary ligatures together, but assumes you might want them without default ligatures; you need “All” to get both:
Regarding use of ZWJ or ZWNJ, as Denis stated ZWJ can be used to indicate a ligature is requested, and ZWNJ can be used to prevent a ligature. These characters are placed between the characters to be ligated. See the discussion of Cursive Connection and Ligatures in section 23.2 of the Unicode Standard.
Oh look, it’s 2024... anyone know if the latest Word can get to the smcp and c2sc features yet?
@Thomas Phinney thanks for pointing out the menu, I had tried with dlig and the "All" option selected but with no luck for some reason. I thought there might be one more setting to configure.