%%% Usage:

%%% \input cropmarks
%%% \topcropmark = <dimen> [plus <dimen>] [minus <dimen>]
%%% \bottomcropmark = <dimen> [plus <dimen>] [minus <dimen>]
%%% \leftcropmark = <dimen> [plus <dimen>] [minus <dimen>]
%%% \rightcropmark = <dimen> [plus <dimen>] [minus <dimen>]
%%% \lrcropmarkstrue ;;; iff you want alternating left and right cropmarks only
%%% \rvcropmarkstrue ;;; iff you want recto and verso specified independently
%%%                     (in which case the first four variables are two-valued
%%%                      as \recto<var> and \verso<var>).

%%% Square brackets indicate optional items, and the <dimen>s are
%%% respectively (and all measured w.r.t. the origin, which is the
%%% top left corner of the notional, rather than physical page; the
%%% exact origin will need to be determined by inspection)

%%% 	The distance to the centre of the cross;
%%% 	The distance which the cross extends beyond the page limits;
%%% 	The distance which the cross extends within the page limits.

%%% Any or all can be zero <unit>s.  For conventional (exo-) cropmarks, the
%%% `plus' component indicates the length of the mark, and the `minus' component
%%% should be omitted or zero.  For inverted (endo-) cropmarks, the `plus'
%%% component should be omitted or zero, and the `minus' component indicates the
%%% length of the mark.  If `plus' or `minus' components are negative, this
%%% has the effect of a `white cropmark' extending in the reverse direction
%%% for the specified distance; this may be used to achieve non-touching marks.
%%% The first and only mandatory component may be also negative, to cope with
%%% pathological origins. 

%
%%% A test which will allow us to be read regardless of the \catcode of `@'
%

\newif \ifatletter
\ifcat @A\atlettertrue \else \catcode `\@ = 11 \atletterfalse \fi

\ifx \c@tcodeminus \undefined 
\else \message {Warning: previous meaning of \string \c@tcodeminus \space lost}
\fi
\edef \c@tcodeminus {\the \catcode `\-}
\catcode `\- = 12

%
\message {CROPMARKS.TEX V1.5 Copyright (C) 14-JUL-1994 14:52:34 Philip Taylor}
%

%
%%% Miscellaneous variables
%

\newif    \iflrcropmarks			\lrcropmarksfalse
\newif    \ifrvcropmarks         		\rvcropmarksfalse
\newdimen \cropmarkwidth			\cropmarkwidth = 0.4 pt
\newdimen \t@pshift
\newdimen \b@ttomshift
\newdimen \l@ftshift
\newskip  \topcropmark
\newskip  \leftcropmark
\newskip  \rightcropmark
\newskip  \bottomcropmark
\newskip  \rectotopcropmark
\newskip  \rectoleftcropmark
\newskip  \rectorightcropmark
\newskip  \rectobottomcropmark
\newskip  \versotopcropmark
\newskip  \versoleftcropmark
\newskip  \versorightcropmark
\newskip  \versobottomcropmark
\newskip  \m@rkskip
\newskip  \m@rkplus
\newskip  \m@rkminus
\newbox   \p@gebox
\newbox   \cr@pmarkbox
\newbox   \topcr@pmarkbox
\newbox   \bottomcr@pmarkbox
%
%%% Extraordinary arcanery, to parse <skip>s into <dimen>s; any better ways ?
%
\begingroup
\catcode `\P = 12 \catcode `\L = 12 \catcode `\U = 12 \catcode `\S = 12 
\catcode `\M = 12 \catcode `\I = 12 \catcode `\N = 12 \catcode `\T = 12 
\globaldefs = 1
\lowercase
{%
\def \p@rseskip #1%
	{\expandafter \p@rs@skip \the #1 PLUS 0.0PT MINUS 0.0PT \@ndparse #1 }
\def \p@rs@skip #1 PLUS #2 MINUS #3\@ndparse #4
	{%
	 \m@rkskip  = #1%
	 \m@rkplus  = #2%
	 \m@rkminus = #3%
	 \ifdim \m@rkminus = 0.0 pt
		\expandafter \p@rs@sk@p \the \m@rkskip MINUS 0.0PT \@ndparse
	 \fi
	}%
\def \p@rs@sk@p #1MINUS #2\@ndparse {\m@rkskip = #1 \m@rkminus = #2 }
}
\endgroup
%
%%% Take control of \shipout, to force it to add cropmarks
%
\let \ship@ut = \shipout
\def \shipout {\futurelet \b@x \whichb@x}
\def \whichb@x
 	{%
 	 \ifx 	\b@x \vbox
	 	\def \n@xt {\setbox \p@gebox = }%
 	      	\afterassignment \Shipout
 	 \else 	\ifx 	\b@x \hbox
 			\def \n@xt {\setbox \p@gebox = }%
 	 	     	\afterassignment \Shipout
	 	\else 	\ifx 	\b@x \box
	 			\def \n@xt {\setbox \p@gebox = }%
 	 		   	\afterassignment \Ship@ut
	 		\else	\ifx 	\b@x \copy
	 				\def \n@xt {\setbox \p@gebox = }%
 	 	 			\afterassignment \Ship@ut
	 			\else
	 				\def \n@xt {\ship@ut}%
	 	 			\message {Sorry, can't understand 
	 						what follows \shipout}%
	 			\fi
	 		\fi
	 	\fi
	 \fi
 	 \n@xt
	}
\def \Shipout {\aftergroup \Ship@ut}
\def \Ship@ut 
	{%
         \ifrvcropmarks
                \ifodd \pageno
                        \topcropmark = \rectotopcropmark
                        \bottomcropmark = \rectobottomcropmark
                        \leftcropmark = \rectoleftcropmark
                        \rightcropmark = \rectorightcropmark
                \else
                        \topcropmark = \versotopcropmark
                        \bottomcropmark = \versobottomcropmark
                        \leftcropmark = \versoleftcropmark
                        \rightcropmark = \versorightcropmark
                \fi
         \fi
         \hoffset = \leftcropmark
	 \setbox \topcr@pmarkbox = 
	 \hbox	 \bgroup
		 \p@rseskip \leftcropmark
 		 \iflrcropmarks
 		    \ifodd \count 0 
 			\let \next = \phantom 
 		    \else 
 			\let \next = \relax
 		    \fi 			 			
 		 \else 
 		    \let \next = \relax		    
  		 \fi
 		 \next {\ifdim  \m@rkminus < 0 pt
                                \begingroup
                                \advance \m@rkplus by \m@rkminus
 			        \vrule height \cropmarkwidth 
                                       depth 0 pt width \m@rkplus
                                \kern -\m@rkminus
                                \endgroup
                        \else
 			        \vrule height \cropmarkwidth 
                                        depth 0 pt width \m@rkplus
                        \fi
 			        \begingroup
 			        \p@rseskip \topcropmark
 			        \vrule	height \m@rkplus 
 				        depth \m@rkminus 
 				        width \cropmarkwidth
 			        \endgroup
                        \ifdim  \m@rkplus < 0 pt
                                \begingroup
                                \advance \m@rkminus by \m@rkplus
 			        \rlap {\kern -\m@rkplus
                                       \vrule height \cropmarkwidth 
 					      depth 0 pt width \m@rkminus}%
                                \endgroup
                        \else                                        
 			        \rlap {\vrule height \cropmarkwidth 
 					      depth 0 pt width \m@rkminus}%
                        \fi
 		       }%
		 \hskip \m@rkskip
		 \p@rseskip \rightcropmark
		 \hskip \m@rkskip
 		 \iflrcropmarks
 		    \ifodd \count 0 
 			\let \next = \relax
 		    \else 
 			\let \next = \phantom 
 		    \fi 			 			
 		 \else 
 		    \let \next = \relax		    
  		 \fi
 		 \next {\ifdim  \m@rkplus < 0 pt
                                \begingroup
                                \advance \m@rkminus by \m@rkplus
			        \llap {\vrule	height \cropmarkwidth 
 					depth 0 pt width \m@rkminus
                                        \kern -\m@rkplus
                                      }%
                                \endgroup
                        \else
			        \llap {\vrule	height \cropmarkwidth 
 					depth 0 pt width \m@rkminus
                                      }%
                        \fi
                                \begingroup
 				\p@rseskip \topcropmark
 				\vrule  height \m@rkplus 
 				        depth \m@rkminus 
 					width \cropmarkwidth
 				\endgroup
                        \ifdim  \m@rkminus < 0 pt
                                \begingroup
                                \advance \m@rkplus by \m@rkminus
                                \kern -\m@rkminus
 			        \vrule height \cropmarkwidth 
                                depth 0 pt width \m@rkplus
                                \endgroup
                        \else
 			        \vrule height \cropmarkwidth 
                                       depth 0 pt width \m@rkplus
                        \fi
 		       }%%%%%%%% end of parameter to \next
		 \egroup%%%%%%%% end of \bgroup ... \egroup to \setbox ...
	 \ht \topcr@pmarkbox = 0 pt
	 \dp \topcr@pmarkbox = 0 pt
	 \wd \topcr@pmarkbox = \wd \p@gebox
	 \setbox \bottomcr@pmarkbox = 
	 \hbox	 \bgroup
		 \p@rseskip \leftcropmark
 		 \iflrcropmarks
 		    \ifodd \count 0 
 			\let \next = \phantom 
 		    \else 
 			\let \next = \relax
 		    \fi 			 			
 		 \else 
 		    \let \next = \relax		    
  		 \fi
 		 \next {\ifdim  \m@rkminus < 0 pt
                                \begingroup
                                \advance \m@rkplus by \m@rkminus
 			        \vrule height \cropmarkwidth 
                                       depth 0 pt width \m@rkplus
                                \kern -\m@rkminus
                                \endgroup
                        \else
 			        \vrule height \cropmarkwidth 
                                        depth 0 pt width \m@rkplus
                        \fi
 			        \begingroup
 			        \p@rseskip \bottomcropmark
 			        \vrule	height \m@rkminus
 				        depth \m@rkplus
 				        width \cropmarkwidth
 			        \endgroup
                        \ifdim  \m@rkplus < 0 pt
                                \begingroup
                                \advance \m@rkminus by \m@rkplus
 			        \rlap {\kern -\m@rkplus
                                       \vrule height \cropmarkwidth 
 					      depth 0 pt width \m@rkminus}%
                                \endgroup
                        \else                                        
 			        \rlap {\vrule height \cropmarkwidth 
 					      depth 0 pt width \m@rkminus}%
                        \fi
 		       }%
		 \hskip \m@rkskip
		 \p@rseskip \rightcropmark
		 \hskip \m@rkskip
 		 \iflrcropmarks
 		    \ifodd \count 0 
 			\let \next = \relax
 		    \else 
 			\let \next = \phantom 
 		    \fi 			 			
 		 \else 
 		    \let \next = \relax		    
  		 \fi
 		 \next {\ifdim  \m@rkplus < 0 pt
                                \begingroup
                                \advance \m@rkminus by \m@rkplus
			        \llap {\vrule	height \cropmarkwidth 
 					depth 0 pt width \m@rkminus
                                        \kern -\m@rkplus
                                      }%
                                \endgroup
                        \else
			        \llap {\vrule	height \cropmarkwidth 
 					depth 0 pt width \m@rkminus
                                      }%
                        \fi
                                \begingroup
 				\p@rseskip \bottomcropmark
 				\vrule  height \m@rkminus
 				        depth \m@rkplus
 					width \cropmarkwidth
 				\endgroup
                        \ifdim  \m@rkminus < 0 pt
                                \begingroup
                                \advance \m@rkplus by \m@rkminus
                                \kern -\m@rkminus
 			        \vrule height \cropmarkwidth 
                                depth 0 pt width \m@rkplus
                                \endgroup
                        \else
 			        \vrule height \cropmarkwidth 
                                       depth 0 pt width \m@rkplus
                        \fi
 		       }%%%%%%%% end of parameter to \next
		 \egroup%%%%%%%% end of \bgroup ... \egroup to \setbox ...
	 \ht \bottomcr@pmarkbox = 0 pt
	 \dp \bottomcr@pmarkbox = 0 pt
	 \wd \bottomcr@pmarkbox = \wd \p@gebox
	 \setbox \cr@pmarkbox = \vbox
	 	\bgroup
		\offinterlineskip
	 	\p@rseskip \leftcropmark	\l@ftshift = \m@rkskip
		\advance \l@ftshift by \m@rkplus
		\advance \l@ftshift by \cropmarkwidth
	 	\p@rseskip \topcropmark		\t@pshift = \m@rkskip
	 	\p@rseskip \bottomcropmark	\b@ttomshift = \m@rkskip
 		\vskip -\t@pshift 
 			\moveleft \l@ftshift \box \topcr@pmarkbox
		\vskip +\t@pshift
 		\vskip +\b@ttomshift
 			\moveleft \l@ftshift \box \bottomcr@pmarkbox
 		\vskip -\b@ttomshift
	 	\egroup
	 \setbox \p@gebox = \vbox 
		{\offinterlineskip 
		 \box \cr@pmarkbox
		 \box \p@gebox}%
	 \ship@ut \box \p@gebox
	}
%
%%% Restore \catcode of `-' & `@'
%

\catcode `\- = \c@tcodeminus
\let \c@tcodeminus = \undefined
\ifatletter \else \catcode `\@ = 12 \fi

%%% All done
