[luatex] Unicode math issue with LuaLaTeX

[Ulrik Vieth]

On 06/13/2010 02:10 PM, Taco Hoekwater wrote:
>
> The problem with unicode-math is that the lua table for
> the XITS Math font is *not* created with a valid MathConstants
> table. I do not know why that happens, but it is definitely a
> macro package issue.

So, you mean this is something related to luaotfload ?

I actually did some more testing in the meantime and found some weird 
results, which seem to indicate problems parsing the font params:

Instead of loading the OT font into \fam4, I tried loading it into
\fam 0...3 to make sure that all CM-based values are overidden.

\font\1="XITS Math:script=math" at 10pt
\font\2="XITS Math:script=math;+ssty=0" at 7pt
\font\3="XITS Math:script=math;+ssty=1" at 5pt

\textfont0=\1 \scriptfont0=\2 \scriptscriptfont0=\3
\textfont1=\1 \scriptfont1=\2 \scriptscriptfont1=\3
\textfont2=\1 \scriptfont2=\2 \scriptscriptfont2=\3
\textfont3=\1 \scriptfont3=\2 \scriptscriptfont3=\3

What happens is that I now get a much bigger vertical gap and a
much bigger version of the sqrt sign.

...\hbox(39.86499+0.09)x16.74, direction TLT
....\hbox(20.56+4.04)x11.24, shifted -12.685, direction TLT
.....\1 ��
....\vbox(39.86499+0.09)x5.5, direction TLT
.....\kern6.62
.....\rule(20.56+0.0)x*
.....\kern8.275
.....\hbox(4.41+0.09)x5.5, direction TLT
......\1 ��
...\mathoff

So I end up with the following values:

RadicalExtraAscender 	6.62pt instead of 0.5pt
RadicalRuleThickness	height of radical glyph instead of 0.66 pt
RadicalVerticalGap	8.275 pt instead of 0.5 pt

 From the \tracingall output, I see the following assignments of values:

{assigning \Umathradicalvgap\displaystyle=99941}
{assigning \Umathradicalvgap\crampeddisplaystyle=99941}
{assigning \textfont2=\1}

{assigning \Umathradicalvgap\textstyle=542310}
{assigning \Umathradicalvgap\crampedtextstyle=542310}
{assigning \Umathradicalvgap\displaystyle=507576}
{assigning \Umathradicalvgap\crampeddisplaystyle=507576}
{assigning \textfont3=\1}

There are no values of \Umathradicalrule, so the TFM height is used,
and the value of \Umathradicalvgap is very strange:
542310 sp / 65536 = 8.285 pt

If I look into the font cache for xits-math.lua, I can clearly see
the following values:

RadicalExtraAscender=50,
RadicalRuleThickness=66,
RadicalVerticalGap=50,

Somehow the parsing of these values seems to be very wrong.
If I understand correctly, that's a matter of luaotfload. Right?!

Regards, Ulrik