% MULTIBOX.STY - a style option to provide multiple boxes in pictures
% ============
% Author: Brian HAMILTON KELLY, Royal Military College of Science,
%                               Shrivenham, SWINDON, SN6 8LA, United Kingdom
% Date:   13 October 1988
%
% This style file option provides two new commands for use in the picture
% environment:
%
% \multimake(x,y)(dx,dy){n}(w,h)[<pos>]{Text_1}{Text_2}...{Text_n}
% \multiframe(x,y)(dx,dy){n}(w,h)[<pos>]{Text_1}{Text_2}...{Text_n}
%
% These commands set the n texts Text_1..Text_n inside a \makebox or
% \framebox respectively.  The first box has its lower-left corner at (x,y),
% and successive boxes are located at (x+dx,y+dy),..,(x+(n-1)dx,y+(n-1)dy).
% Each box has width and height determined by (w,h), and the optional
% box placement parameter <pos> is applied to all the generated texts
%

\newtoks\multi@rg

\def\multiframe{\let\@putitem=\@iframepicbox \multib@x}
\def\multimake{\let\@putitem=\@imakepicbox \multib@x}

\def\multib@x(#1,#2)(#3,#4)#5(#6,#7){\@xdim=#1\unitlength \@ydim=#2\unitlength
  \def\@dxdim{#3} \def\@dydim{#4}
  \@multicnt=#5 \def\@Xsize{#6} \def\@Ysize{#7}
  \@ifnextchar [{\imultib@x}{\imultib@x[]}
  }

% The liberal use of % at the ends of lines is to prevent the ingestion of
% superfluous spaces which would otherwise upset the horizontal positioning
% of the boxes.

\def\imultib@x[#1]{\@killglue\relax
  \def\p@sarg{#1}%
  \d@multi
  }

% We need the expanded definition of \i@putitem because \@imakepicbox DOESN'T
% expand its #3 argument (the optional text placement bit).  However, it can
% only recognize the letters b, t, l and r in this position, so \p@sarg is no
% use.  Therefore we expand the arguments, producing an appropriate call.

\def\d@multi{%
  \ifnum\@multicnt > 0
    \def\next@rg##1{%
      \multi@rg={{##1}}% Assign the next argument of original text to \multi@rg
      \edef\@iputitem{%
	\noexpand\@putitem(\@Xsize,\@Ysize)[\p@sarg]{\the\multi@rg}%
      }%
      \raise\@ydim\hbox to \z@{\kern \@xdim \@iputitem\hss}%
      \advance\@xdim by \@dxdim\unitlength \advance\@ydim by \@dydim\unitlength
      \advance\@multicnt by \m@ne
      \d@multi}% End of (re-)definition of \next@rg
  \else
    \let\next@rg=\ignorespaces
  \fi      % Now execute \next@rg;
  \next@rg % This will read the text, set it and then call \d@multi recursively
  }