[math-font-discuss] Ugly drawn rules in Adobe Reader

[Taco Hoekwater]

Karl Berry wrote:

> How will this "something" be specified?  Will there be a new primitive
> (ugh) or will it be invisibly changed in the implementation of \atop et
> al.?  And if the latter, is there a circumstance where a rule would be
> preferable?  From what font will this character come?

There has to be a new primitive, no way around that. TFM is not flexible
enough to come up with a transparent solution.
Specification would be like \mathchardef, say:

    \rulechar="0130

Defining both the family and the character.

> In general, do we really have to work around acrobat problems by
> changing the TeX core?  It seems pretty invasive.  Has Adobe refused to
> fix it?  How do the rules look in ghostscript and xpdf?  Can you post a
> pdf with the problem?

See   http://tex.aanhet.net/temp/mathtest.pdf

Especially look at the  top left of the sqrt signs. Adobe will not
listen to bug reports if you are not a multi-million client, but xpdf
and ghostscript are even worse. The basic problem is that rendering
graphics and rendering text are not the same thing in PostScript/PDF,
and that makes it hard to align the two objects correctly.

>     On the other hand, there is also the possibility to change the
>     TFM  format
> 
> That sounds even more frightening than the other proposal!

Agree.

Taco