Am 05.03.2011 09:23, schrieb Taco Hoekwater: > On 03/05/2011 03:04 AM, Philipp Stephani wrote: >> >> No, the parameters are fine and I think the only difference is the size >> of the delimiters, which is caused by LuaOTFLoad setting the >> FractionDelimiterSize parameters which don't really exist in the fonts >> (they are LuaTeX-only additions); changing line 116 of luaotfload.lua to >> mc.FractionDelimiterDisplayStyleSize = 1.7 * size >> yields much better results. However, that is a font-specific design >> issue, and I wonder whether LuaTeX should really use those parameters if >> the font doesn't have them. > > The problem is that nothing in the existing MATH parameters seems to > apply. But perhaps the results could be better if the FractionDelimiter > parameters were initialized based on some MATH parameter that does > exist.
There surely exists a reason why Microsoft chose to leave out the three parameters delim1, delim2, and sub2. Perhaps they thought that distinguishing between \left(1 \atop 2\right) and 1 \atopwithdelims() 2 would be too surprising and seldom relevant. (On the LaTeX side, I have encountered very few instances of \genfrac which wraps all the stacking primitives.) I think better than guessing correct parameter values would be to do the equivalent of \left(1 \atop 2\right) if the user requested 1 \atopwithdelims() 2 and the parameters are undefined.
