[XeTeX] Proposed new \special{}s

[Jonathan Kew]

I'm getting close to releasing version 0.6, though it may be a few days 
yet as I'm in a conference much of this week. But before I do, I'd like 
to invite comments on a couple of proposed new \special{} commands for 
xdv2pdf, intended to support things like \rotatebox or \reflectbox 
(which could be implemented at the TeX macro level).

I have in mind--well, in working code, actually--the following:

\special{x:gsave}
\special{x:grestore}

Save and restore the graphics state in the driver (PostScript's gsave 
and grestore, in effect). Can be nested.

\special{x:scale X Y}

Apply a scaling (X and Y are decimals) about the current point.

\special{x:rotate D}

Rotate by D degrees about the current point.

Given these, it is straightforward to define

\def\reflect#1{{\setbox0=\hbox{#1}\rlap{\kern0.5\wd0
   	\special{x:gsave}\special{x:scale -1 1}}\box0 \special{x:grestore}}}

which can be used to write \reflect{backwards}, and

\def\rotate#1#2{{\setbox0=\hbox{#1}\rlap{\kern0.5\wd0
   \dimen0=\ht0 \advance\dimen0 by -\dp0
   \raise0.5\dimen0\hbox{\special{x:gsave}\special{x:rotate #2}}}%
   \box0 \special{x:grestore}}}

which lets me \rotate{spin a box}{20} about its center.

Ross, or others, would these be sufficient to support some more of the 
LaTeX stuff? Would some other approach be easier to work with?

Jonathan