Am Tue, 13 Feb 2018 16:26:10 +0100 schrieb Hans Hagen:
basically it boils down to fonts being bad: traditional tex fonts cheat about the width for italics and have lots or corrections that get always added as a starter and removed in some cases (heuristics); opentype on the other hand has proper widths and only applies italics in some cases
But xits is in this case not lying about the italic. The cal-P has a large overhang and one would like to take this somehow into account. Actually the italic is taken into account *inside* math. This here inserts \kern1.52 after the "F0151 and \kern2.45 after the "1D4AB (the math.italic values of these glyphs): \tracingoutput1 \showboxbreadth\maxdimen \showboxdepth\maxdimen \input luaotfload.sty \font\xits={file:xits-math.otf} at 10pt \textfont0=\xits $\Umathchar"7"0"F0151 \Umathchar"7"0"1D4AB \Umathchar"7"0"78 $ \bye The problem is the boundary between math and text. There seem to be no way to insert automatically or manually the kern if the \cal P (\Umathchar"7"0"1D4AB) is the last char in the math. Btw: I found in the luatex manuel the options \mathoption nocharitalic 1 but it seems to do nothing (the example in the manual show imho identical output). -- Ulrike Fischer http://www.troubleshooting-tex.de/