On Fri, Mar 04, 2011 at 11:29:13PM +0100, Philipp Stephani wrote: > @Andreas: please use only the ZIP archive format since it's the only one > everybody can read. > > Am 04.03.2011 22:50, schrieb Khaled Hosny: > > On Fri, Mar 04, 2011 at 09:53:10PM +0100, Andreas Harder wrote: > >> Hi all, > >> > >> I was asked to post this also on the LuaLaTeX-list, so here it is. > >> > >> I'm tying to draw some attention to the $n\choose k$-issue with OpenType > >> math > >> fonts. > >> > >> I've made some test files: > >> http://dl.dropbox.com/u/151837/OpenType-Math.7z > >> > >> The best output is generated by LuaLaTeX (at least for Asana and Cambria). > > > > So you are getting the best output which, IMHO, is a good thing, what is > > the problem then? :) > > "Best" here unfortunately means "not very good, but not as bad as the > others." > > For the following discussion, I use the notation LN, where X is the > letter A, C, or X, depending on the font, and N is a number representing > the N-th symbol from the left. I'm only looking at the document ending > in lualatex.pdf. > A1, A2, A3, A5, A6, A7, A8, A9, A11, C1, C2, C3, C5, C6, C7, C8, C9, > C10, C11, X5, X9, X10, X11 look good. > A4, C4, X4: upper and lower part are too far away from each other; as > there is no fraction bar, they should be closer to each other than the > numerator/denominator in ACX5. > A10: numerator and denominator are too far away from the fraction bar. > X1, X3, X6, X7, X8: lower part is too far to the bottom. > X2: parentheses are too high. > > The issues that occur with Computer Modern are: 4, 10, i.e. those that > also appear with A and C; these are more-or-less design problems; > someone should check if they also occur in Word. X has more issues; > LuaLaTeX + A/C can be declared okay-ish, but not perfect IMO. > > It would be interesting to know whether there are established > conventions regarding the vertical gaps in fractions vs. binomials. > Personally I'd prefer a smaller gap for the latter since the bar is absent.
Thanks Philipp, that was very helpful. Comparing to CM I think Cambria's is OK, so 10 might be related to actual TeX math algorithms (someone have to check Appendix G rules regarding this). I'd be interested in knowing what MATH parameters are involved here to see what need to be fixed; the fonts or luaotfload. Regards, Khaled -- Khaled Hosny Egyptian Arab
