On 18/02/2017 15:23, David Carlisle wrote: > On 18 February 2017 at 15:12, Hans Hagen <[email protected]> wrote: >> On 2/18/2017 3:13 PM, David Carlisle wrote: >>> >>> there is a full (plain TeX) example and screenshots in a (non)answer >>> on stackexchange >>> >>> http://tex.stackexchange.com/a/354485 >>> >>> but in brief: >>> >>> \left| T \right| >>> >>> has a kern between the T and the right hand | matching the kern in |T| >>> >>> if tfm fonts are used in luatex or xetex or pdftex >>> >>> but if Opentype Latin modern is used >>> >>> xetex shows the kern but luatex has no kern once \right or \Uright are >>> used, but does still show the kern with |T|. >>> >>> I'm not sure if this is a luatex or luaotfload issue? >> >> >> It's a font issue ... try pagella or so ... latin modern has old math font >> like properties so it has char boundingboxes / widths that assume that >> italic correction is added. >> >> For opentype fonts luatex doesn't use the traditional 8 bit font code path. >> Early versions had a kind of hybrid but that failed miserably when more >> opentype mathfonts came around and messy heuristics were dropped in favour >> of separate code paths (not even lua magic could beat that so i dropped most >> of that kind of hackery from context). Kerns have similar issues as opentype >> has staircase kerns. >> >> I can of course add a pseudo feature to the font loader that adds italic to >> the width for fonts that need that. I might also cook up some magic related >> to fences but again it's a macro package issue then. >> >> The best solution is proper fonts. >> >> Hans >> > > Hmm not unreasonable from an engine point of view but that still > leaves the users coming to us and us (me at least) not knowing what to > do.. > > If you add something to the font loader could you ping us so we know > to use it in latex, or ... > > I suppose what you are really saying is that best would be a > latin-modern-math-without-legacy-metric-weirdness.otf.
Surely given the developing nature of OpenType math a simple change to the current font file would be best: this is far from stable as-yet. Joseph
