File /u/gls/postscript.tex

[Guy Steele <gls@Think.COM>]

% PostScript hackery for TeX

\makeatletter

\newcount\@PostScriptCount
    \@PostScriptCount=0
\newwrite\@PostScriptFile
\newdimen\@PostScriptUnit
\newdimen\@PostScriptUnitCent
    \@PostScriptUnit=1in\relax
    \divide\@PostScriptUnit by 72\relax

% Define a PostScript drawing; takes two args but is curried.
% #1	name for drawing
% #2	PostScript commands

\def\defPostScript#1{\global\advance\@PostScriptCount by 1\relax
  \xdef#1{\special{psfile=\@PostScriptDir/\jobname
				PS\the\@PostScriptCount.ps}}\relax
  \begingroup\catcode`\^^A=11\endlinechar=`\^^A\@defPostScript}

\long\def\@defPostScript#1{\newlinechar=`\^^A\relax
  \immediate\openout\@PostScriptFile=\@PostScriptDir/\jobname
				PS\the\@PostScriptCount.ps \relax
  \immediate\write\@PostScriptFile{#1}\relax
  \immediate\closeout\@PostScriptFile
  \endgroup}

\def\PostScriptDirectory#1{\global\def\@PostScriptDir{#1}}



% #1   width dimen
% #2   height dimen
% #3   PostScript gray level

{\catcode`p=12 \catcode`t=12
 \global\def\@DEPOINTDEF#1#2pt{\def#1{#2 }}}

\def\ShadedRectangle#1#2#3{{\dimen0=#1\relax
	\dimen1=#2\relax
	\dimen2=#3pt\relax
	\divide\dimen0 by 803 \multiply\dimen0 by 800
	\divide\dimen1 by 803 \multiply\dimen1 by 800
%	\typeout{dimen0 = \the\dimen0, dimen1 = \the\dimen1,
%			dimen2 = \the\dimen2}\relax 
	\expandafter\def\expandafter\@baz
	    \expandafter{\csname Rect\the\dimen0 \the\dimen1
			 \the\dimen2\endcsname}\relax
	\expandafter\@DEPOINTDEF\expandafter\@width\the\dimen0
	\expandafter\@DEPOINTDEF\expandafter\@height\the\dimen1
	\expandafter\@DEPOINTDEF\expandafter\@gray\the\dimen2
        \def\@twiddlescreen{}\relax
        \ifdim \@gray pt < 1.0 pt \relax
	  \ifdim \@gray pt > .97 pt \relax
	    \def\@twiddlescreen{currentscreen 3 -1 roll
				2 div 3 1 roll setscreen }\fi\fi
	\expandafter\ifx\@baz\relax
	    \edef\@foo
		{ \@twiddlescreen
		  \@gray setgray
		  0 0 moveto
		  0 \@height lineto
		  \@width \@height lineto
		  \@width 0 lineto
		  closepath
		  fill
		}\relax
	    \expandafter\expandafter\expandafter\defPostScript\expandafter\@baz
		\expandafter{\@foo}\relax
	\fi
	\@baz
}}

\def\shadebox(#1,#2)#3{\ShadedRectangle{#1\unitlength}{#2\unitlength}{#3}}


\makeatother