Message-Id: <9210011617.AA23498@sc.zib-berlin.dbp.de>
Reply-To: Mailing list for the LaTeX3 project <LATEX-L@vm.urz.Uni-Heidelberg.de>
Date:         Thu, 1 Oct 92 17:17:30 CET
From: Don Hosek <DHOSEK@HMCVAX.CLAREMONT.EDU>
Sender: Mailing list for the LaTeX3 project <LATEX-L@vm.urz.Uni-Heidelberg.de>
To: Multiple recipients of <LATEX-L@vm.urz.Uni-Heidelberg.de>
Subject:      Re: picture mode in LaTeX3/additional fonts in distribution
Status: R


-In the discussion of whether to tie LaTeX3 to Postscript, I haven't
-seen a discussion of how one might handle one of the most desirable
-(to me) Postscript features---the ability to rotate boxes, so tables
-can be printed sideways---outside of Postscript. This cannot be
-accomplished with the \special s of any other drivers that I am aware
-of. Perhaps the LaTeX3 folks, along with the DVI standards committee
-could take up the idea of standardizing a rotation \special.

Little known fact: The DVI driver standards committee has
proposed a rotation  special which has been "on the books" for
several years now. The syntax is \special{rotate N} where N is
the angle in 1/65536 degrees. Rotations are cumulative and are
scoped by DVI push/pop pairs. The only driver which I know of
which currently implements this special is TeXrox which rounds
the angle to the nearest 90 degree. A macro which would use this
special would be:

% Short form which doesn't adjust box dimensions because I'm
% coding off the top of my head. #1 is the angle in  degrees,
% #2 is the text to rotate.
\def\rotate#1#2{%
  \dimen0=#1pt
  \rlap{\special{rotate \number\dimen0}#2}%
}

Some code could be written to position this in an appropriately
sized box for space reservation purposes. As anyone who has ever
looked in rotate.sty/tex knows, this is a far simpler approach.

Incidentally, as an implementation note, rotation by 90's can be
effected on any printer which allows downloadable fonts, not just
those which allow one to have multiple orientations on a single
page. The solution to handling this rotation with non-rotatable
PDLs (e.g., PCL (I don't know if PCL5 changed this)) is to have
the driver rotate fonts before downloading. Just because we read
a font sideways doesn't mean a printer has to be able to print
sideways.

-On a related topic, why not have LaTeX3 accomplish fancy graphics as
-Tom Leathrum's mfpic package does: by writing a .mf file, which
-metafont then processes. This saves wear and tear on the
-wheel-reinventing shop and avoids reliance on \special s, since
-metafont is already part of the standard TeX distribution.

Not everyone has MF. MF can't handle some graphics features
conveniently (e.g., gray shades). etc.

Direct PostScript calls should be avoided at all costs.

-dh