# [luatex] Italic correction for normal text with LuaLaTex

Reinhard Kotucha reinhard.kotucha at web.de
Mon Mar 12 01:54:59 CET 2012

On 2012-03-12 at 01:19:12 +0100, Heiko Oberdiek wrote:

> On Sun, Mar 11, 2012 at 09:47:06PM +0100, Reinhard Kotucha wrote:
>
> > On 2012-03-11 at 20:54:32 +0100, Bernhard Tempel wrote:
> >
> >  > Am 11.03.2012 18:48, schrieb Khaled Hosny:
>
> >  > >  Try \setmainfont[RawFeature={+itlc}]{Latin Modern Roman}, it
> >  > >  seems to make a noticeable improvement.
> >  >
> >  > Thanks a lot for this. It really makes an improvement. In some
> >  > cases the guessed glue is to big, but better results would be very
> >  > difficult to reach when using heuristics. To calculate the extreme
> >  > "\emph{f}!" combination works fine; with the less extreme
> >  > combination "\emph{f}:" the kerning could be more tight, but I can
> >  > see that the guessed value must be the the same as for "\emph{f}!".
> >
> > But if you try
> >
> >   \parindent0pt
> >   \emph{f}! \par
> >   \emph{f}: \par
> >   \emph{f}; \par
> >   \emph{f}. \par
> >
> > you'll see that the period is treated differently.  Is this a result
> > of the heuristics or does it come from somewhere else?
>
> >From LaTeX. It manages a list \nocorrlist with the entries ,'
> and .' as default. \emph suppresses the italic correction
> before a character in \nocorrlist.

Thanks for the hint.  It explains a lot.  Maybe for : and ; LaTeX
should provide a \halfcorrlist as well. :)

However, things are more difficult, of course, especially if you are
going to emphasize a part of a composed word.  You can't guess the
amount of italic correction needed from the bounding box.  Imagine the
characters d and b, which have the same height.  On the other hand it
seems that Khaled's heuristics are sufficient here:

\emph{b}d \par
\emph{d}b \par
\emph{b}b \par
\emph{d}d \par

The output is at least reasonable and going much further doesn't make
much sense if the information isn't provided by the fonts themselves.

Regards,
Reinhard

--
----------------------------------------------------------------------------
Reinhard Kotucha                                      Phone: +49-511-3373112
Marschnerstr. 25
D-30167 Hannover                              mailto:reinhard.kotucha at web.de
----------------------------------------------------------------------------
Microsoft isn't the answer. Microsoft is the question, and the answer is NO.
----------------------------------------------------------------------------