On 10 February 2016 at 21:36, David J. Perry <hospes.pri...@verizon.net> wrote: > I know nothing whatsoever about math, so perhaps I shouldn't even join this > discussion, but I am curious. I do have considerable experience in font > development and supporting things like the use of combining marks and > variation selectors outside of math contexts. > > I looked in a font editor at the font (XITS) that was used to produce the > sample PDF. As far as I can see, it has no support for combining marks or > variation selectors of the sort that I would expect, based on my non-math > experience. (For instance, fonts that support combining marks usually have > a Mark to Base lookup.) Is there an expectation that in TeX the math > typesetting can properly position combining characters and handle variation > selectors without support from the font? > > David >
Note I was using Khaled's xits-math variant not the original stix version, xits-math has many improvements to the opentype internals. The VS1 combinations in xits-math work for example in firefox. David > > On 2/9/2016 8:54 AM, David Carlisle wrote: > > Sending this separately to xetex luatex lists... > > The current Unicode math alphabets in U+1D400 ...include a "script" > alphabet this was intended to cover both "caligraphic/chancery" and > "script/roundhand" as font variants, in the hope that no document > would need both. > > Unicode is considering adding separate markup for the two forms, see > Murray's blog here > > http://blogs.msdn.com/b/murrays/archive/2016/02/05/unicode-math-calligraphic-alphabet.aspx > > As explained in the article at least two possible suggestions are > being considered: adding the new alphabet in a new code block range, > or defining "variant selector" characters that would force one or > other interpretation. > > Unicode combining characters following the base have always been a bit > tricky in TeX so I wondered whether the engine (or font) developers > (as opposed to macro level hacker like myself) have a view on what is > a reasonable input form here. > > You could either reply here or as a comment on the above Blog. > > I attach a (latex) text file that produces more or less the same > output in xetex and luatex showing that by default neither a simple > combining character like e-acute nor VS1 work but the combining acute > at least can perhaps be made to work but VS1 seems tricky as the base > is a \mathop atom so it's not really amenable to being combined with > the following variant selector character. > > Since current combining character use seems tricky I'm worried about > the suggestion to use that method for selecting the entire script > alphabet. > > (The combining acute could be normalised away by running filter to NFC > form but don't do that as it's just standing in for a possible new > character to switch script forms:-) > > Tests 0 and A show that both combining forms work fine in text, but > math is the issue here.... > > David > > > > > -------------------------------------------------- > Subscriptions, Archive, and List information, etc.: > http://tug.org/mailman/listinfo/xetex > > > > > > -------------------------------------------------- > Subscriptions, Archive, and List information, etc.: > http://tug.org/mailman/listinfo/xetex > -- http://dpcarlisle.blogspot.com/ -------------------------------------------------- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex