[XeTeX] Patch: Add an entry for stemv

[Yue Wang]

Hi,

> Sure, in theory they can do that (provided the font license permits
> it!). However, many users will not feel competent to undertake
> something like this, even if they become aware that it would be
> possible. On the other hand, a driver-level workaround such as I
> described would allow the XeTeX system as a whole to transparently and
> automatically improve the results (for whichever "common" fonts people
> provide the settings for). Seems like that would be a worthwhile
> benefit for the user community as a whole.
>

driver configuration files make tex code not portable.
One should also copy the configure file in order to obtain similar result.

> So I do think it's worth doing something about this, I just think
> patching xetex to add another option to the \font primitive is not the
> most helpful approach.

Well. maybe we can do this:
- patch xetex, allow something like \font\a="simsun:special={stemv=0,
blablabla...}"
then we ship the special code into xxx1, xxx2, xxx3 or xxx4 related
field just as the \special does. (ship them after t[2], before
post_post, in the <font definitions>)
this might be useful for further development: if user want to set a
parameter (like weight), no xetex change is needed.
on the driver side developers can support whatever extension they want.

Yue Wang