%% file: TXSdcol.tex (TeXsis version 2.17)
% $Revision: 17.2 $ : $Date: 1997/07/07 17:07:16 $ : $Author: myers $
%======================================================================*
% Double Column Output Routines:
%
% These macros let you create double column output, with balancing
% of partially filled columns, and with top, bottom, and footnote
% insertions in the columns or across the width of the page.
%
% To set up for double column output on a page of a given <width> and
% <height> and with columns of width <c-width> put the following at the
% beginning of your document:
%
% \hsize=<width> \vsize=<height>
% \SetDoubleColumns{<c-width>}
%
% Note that this re-defines TeX's \output routine. It does not actually
% put you in double column mode. To do that, say \doublecolumns. To
% switch back to single column output say \enddoublecolumns (or the
% synonym \singlecolumn). Partially filled columns will be balanced
% to the best of TeX's abilities.
%
% The usual insertions of TeX and TeXsis (\topinsert, \midinsert,
% \pageinsert, \heavyinsert and \bottominsert) put insertions into the
% current column. To force an insertion into a particular column, say
% \forceleft or \forceright INSIDE the insertion material.
%
% Wide insertions across the width of both columns can be made with
% \widetopinsert, \widepageinsert, or \widebottominsert.
%
% Long equations which need to span both columns should be enclosed
% between \longequation (before the first "$$") and \endlongequation
% (after trailing "$$"). Rules to guide the eye are put at the bottom
% of the left column above the equation and above the right column below
% the equation (as is done in Physical Review). You can change this.
%
% Footnotes created with \footnote or \vfootnote will be placed at the
% bottom of the current column. You can place a footnote across the
% bottom of both columns with \widefootnote or \widevfootnote.
%
% You can always force a skip to the next column with \newcolumn.
% To skip to a completely new page use \vfill\eject, as usual.
%
% In single column mode all of these macros either behave as their
% single-column counterparts or do nothing, as appropriate, so that
% your document comes out looking right in single column mode.
%
% WARNING! Formatting double column documents is inherently more
% difficult than regular typesetting. Here are some helpful hints:
% (1) Since double columns are narrow, the normal TeX spacing produces
% many overfull \hbox's. To avoid this, the interword skip \spaceskip is
% changed to \doublecolskip=.3333em plus .3333em minus .1em
% More uniform spacing can be obtained by changing \doublecolskip.
% (2) The value of \vbadness and \hbadness are doubled in double
% column mode, but you may want to increase them further to avoid
% complaints of overfull boxes. But don't increase these too much.
% (3) To balance columns it is essential to have some stretch in the
% column. Using \parskip=\smallskipamount helps, or try adding a little
% stretch to the \baselineskip with: \advance\baselineskip by 0pt plus 0.5pt
%
% This version of these macros is a complete re-write of the TeXsis
% double column macros previous to version 2.16. Some of the methods
% used here are adapted from The TeXBook, pg 417, and The TUGboat, Vol
% 6, pg 29. See the file TXSdcol.doc for further documentation.
%
% Dependencies: none -- this file can be used as it is with plain.tex,
%
% This file is a part ot TeXsis, a set of TeX macros for Physicists
% (C) copyright 1994 by Eric Myers and Frank Paige.
%======================================================================*
\message{- Double column format.}
\catcode`@=11 % make @ a letter for this file
\newdimen\colwidth % width of column
\newdimen\pagewidth % total width of page
\newdimen\pageheight % total height of page
\newdimen\rulewd \rulewd=.5pt % col. rule height
\newdimen\colmaxdepth \colmaxdepth=4pt % max. split depth
\newdimen\@bigColHeight % height of both columns together
\newdimen\@saveSplitmax % to save \splitmaxdepth
\newdimen\@saveVsize % to save \vsize
\newskip\s@veskip % to save \spaceskip
\newskip\doublecolskip % new \spaceskip
\doublecolskip=.3333em plus .3333em minus .1em % with more stretch
\newdimen\@leftpluscenter % how far to move over for rule
\newbox\partialpage % save single column partial page here
\newif\ifleftc@lumn % insert in left column?
\newif\if@wid % flag: this is a wide insert
\newif\if@bot % flag: this is a bottom insert
\def\@LET{\global\let} % we'll use this a lot
%--------------------------------------------------*
% Until you say \SetDoubleColumns, the instructions \doublecolumns,
% \enddoublecolumns, \leftcolrule and \rightcolrule and so on are
% simply \relax. This is so you can put these in a document which
% uses double columns, but then print it with one of the single
% column formats without them getting in the way, or vice versa.
%
\colwidth=\hsize % default column width is \hsize
\def\doublecolumns{\relax} \def\enddoublecolumns{\relax}
\def\leftcolrule{\relax} \def\rightcolrule{\relax}
\def\longequation{\relax} \def\endlongequation{\relax}
\def\wideequation{\relax} \def\endwideequation{\relax}
\def\newcolumn{\relax} \def\widetopinsert{\topinsert}
\def\widepageinsert{\pageinsert}\def\widebottominsert{\bottominsert}
\let\widefootnote=\footnote \let\widevfootnote=\vfootnote
% Save Plain definitions of inserts so we can restore them later
\let\@plaintopinsert=\topinsert \let\@plainmidinsert=\midinsert
\let\@plainbottominsert=\bottominsert\let\@plainheavyinsert=\heavyinsert
\let\@plainpageinsert=\pageinsert\let\@plainendinsert=\endinsert
\let\@plainvfootnote=\vfootnote \let\@plainfootnote=\footnote
% \SetDoubleColumns<column-width> sets things up for double column mode
% with columns of the given width, using the current settings for \vsize
% and \hsize.
\def\SetDoubleColumns#1{% set up double column mode
\global\colwidth=#1\relax % column width
\pagewidth=\hsize \pageheight=\vsize % page sizes
\@bigColHeight=\vsize % total height = \vsize
\multiply \@bigColHeight by 2 % times 2
\@leftpluscenter=\pagewidth % \@leftpluscenter = size
\advance \@leftpluscenter by -\colwidth % to right column
\dimen\NWins=\pageheight \dimen\NEins=\pageheight % maximum top insert size
\dimen\SWins=\pageheight \dimen\SEins=\pageheight % max bottom insert
\output={\@nepageout{\pagecontents}}% % new \output, single columns
\let\doublecolumns=\@doublecolumns % enable \doublecolumns
\let\rightcolrule=\@rightcolrule % enable rule
\let\leftcolrule=\@leftcolrule %
\let\longequation=\@longequation % enable wide eqns.
\let\wideEquation=\@longequation %
}
% \setdoublecolumns<page-width><page-height><column-width> is included
% for backward compatability with TeXsis 2.15 and earlier.
\def\setdoublecolumns#1#2#3{%
\emsg{> Please use \string\SetDoubleColumns\ instead}%
\global\hsize=#1\global\vsize=#2\relax
\SetDoubleColumns{#3}}
% \@doublecolumns starts double column output. It redefines \endinsert
% to handle double column insertions and \widetopinsert and \widepageinsert
% to do them. The inserts are made global so that they get to \output
% from inside groups.
\def\@doublecolumns{% begin double column formatting
\begingroup % keep changes local
\def\enddoublecolumns{\@enddoublecolumns}% % enable \enddoublecolumns
\def\doublecolumns{\relax}% % in case twice
\def\endmode{\@enddoublecolumns}% % implicit end, if needed
\let\newcolumn=\@newcolumn %
%
\output={\global\setbox\partialpage=\vbox{% % save page so far,
\ifvoid\topins\else\unvbox\topins % including top inserts
\bigskip\fi % with some space between
\unvbox255 % main page
}}\eject % in \partialpage
\output={\@doublecolumnout}% % set to 2 column output
%
\@saveVsize=\vsize % save old \vsize
\hsize=\colwidth \vsize=\@bigColHeight % set width to column width,
\advance\vsize by -2\ht\partialpage % height to 2*page minus
\advance\vsize by -2\dp\partialpage % what's already there
\global\s@veskip=\spaceskip % save old interword glue
\global\spaceskip=\doublecolskip % stretch for small cols.
\global\displaywidth=\colwidth % equations have \colwidth
\global\hyphenpenalty=0 % hyphens are OK
\multiply\vbadness by 2 \multiply\hbadness by 2 % be more tolerant
\clubpenalty=150 % club line penalty
\widowpenalty=150 % widow line penalty
% Set macros to their double column dopplegangers
\@LET\topinsert=\@doubletopinsert
\@LET\bottominsert=\@doublebottominsert
\@LET\pageinsert=\@doublefullinsert
\@LET\midinsert=\@doublemidinsert
\@LET\heavyinsert=\@doubleheavyinsert
\@LET\endinsert=\@enddoubleinsert
\@LET\widetopinsert=\@widetopinsert
\@LET\widepageinsert=\@widepageinsert
\@LET\widebottominsert=\@widebottominsert
\@LET\vfootnote=\@doubleVfootnote % \footnote uses this one
\@LET\widefootnote=\@widefootnote
\@LET\widevfootnote=\@wideVfootnote
}
% \@enddoublecolumns ends double column output and balances the columns.
% This also allows for double width equations. The grouping insures that
% \endinsert is reset to the Plain version.
\def\@enddoublecolumns{% end double column mode, go back to single column
\global\output={\@balancecolumns}\eject % balance & output so far
\global\output={\@nepageout{\pagecontents}}% % back to single column output
\global\vsize=\@saveVsize % reset vsize
\endgroup % end 2 col. group
\pagegoal=\vsize % reset overall goal size
\spaceskip=\s@veskip % reset interword glue...
\hyphenpenalty=50 \displaywidth=\hsize
\def\endmode{\relax}% % reset \endmode
% Reset macros to single column version:
\@LET\topinsert=\@plaintopinsert
\@LET\midinsert=\@plainmidinsert
\@LET\pageinsert=\@plainpageinsert
\@LET\endinsert=\@plainendinsert
\@LET\bottominsert=\@bottominsert
\@LET\heavyinsert=\@heavyinsert
\@LET\vfootnote=\@plainvfootnote
\@LET\widetopinsert=\@plaintopinsert
\@LET\widepageinsert=\@plainpageinsert
\@LET\widefootnote=\@plainfootnote
\@LET\widebottominsert=\@plainbottominsert
\@LET\widevfootnote=\@plainvfootnote
}% end of \@enddoublecolumns
\def\begindoublecolumns{\doublecolumns} % synonym
\def\singlecolumn{\enddoublecolumns} % synonym
% How to skip to a new column. If we are in the left column, fill it
% up to force a skip to the right. If in the right column, skip to the
% next page.
\def\@newcolumn{% skip to next column, left or right
\vskip\z@ % force vertical mode
\ifdim\pagetotal<\pageheight % left column?
\dimen@=\pageheight \advance\dimen@ by -\pagetotal % room left in left
\vskip\dimen@\goodbreak % fill up to end of left col
\else \vfill\eject \fi} % else skip to next page
%--------------------------------------------------*
% FLOATING INSERTIONS:
% Since there can now be insertions at the top and bottom of both
% the left and right columns, they will be labeled by compass points.
\newinsert\NWins \skip\NWins=0pt \newinsert\SWins \skip\SWins=0pt
\newinsert\NEins \skip\NEins=0pt \newinsert\SEins \skip\SEins=0pt
% There are also insertions for footnotes at the bottom of either column
\newinsert\LFins \count\LFins=1000 \dimen\LFins=5cm \skip\LFins=\bigskipamount
\newinsert\RFins \count\RFins=1000 \dimen\RFins=5cm \skip\RFins=\bigskipamount
% \@enddoubleinsert is a modified version of \endinsert which
% decides whether to put an insertion in the left or the right column.
% \endinsert is let equal this in \doublecolumns mode.
\def\@enddoubleinsert{% end an \insert in double column mode
\egroup % finish the \vbox\z@
%
% Decide whether in left or right column:
%
\ifdim\pagetotal<\pageheight\leftc@lumntrue % left if page total < 1 col
\else \leftc@lumnfalse\fi % right otherwise
\ifx L\LRf@rce \leftc@lumntrue \fi % or forced left
\ifx R\LRf@rce \leftc@lumnfalse \fi % or forced right
%
% If midinsert requested, decide whether there is room...
%
\if@mid % midinsert selected
\dimen@=\ht\z@ \advance\dimen@ by \dp\z@ % dimen0 = height + depth
\advance\dimen@ by \baselineskip % + baselineskip
\advance\dimen@ by \pagetotal % + page total
\ifleftc@lumn % if in left column
\ifdim\dimen@>\pageheight % \pageheight = 1 col height
\@midfalse\p@gefalse\fi % top insert
\else % in right column
\ifdim\dimen@>\@bigColHeight % \@bigColHeight = 2 col height
\@midfalse\p@gefalse\fi\fi % top insert
\fi % end if@mid
%
% If room for midinsert, do it; otherwise make insert in same column.
%
\if@mid \bigskip\box\z@\bigbreak % fits: just do it
\else % otherwise: where to put it?
\if@wid % wide insert
\if@bot\let\@whichins=\botins % bottom?
\else\let\@whichins=\topins\fi % or top?
\else % not wide, so...
\if@bot % bottom?
\ifleftc@lumn\let\@whichins=\SWins % bottom left is SW
\else \let\@whichins=\SEins\fi % bottom right is SE
\else % top?
\ifleftc@lumn\let\@whichins=\NWins % top left is NW
\else \let\@whichins=\NEins\fi % top right is NE
\fi %
\fi % end of \if@wid
\C@lumnInsert\@whichins % do the insertion
\fi % end \if@mid
\endgroup % end the insertion group
\global\let\LRf@rce=X % reset forcing flag
}
% \C@lumnInsert{<insert#>} makes an appropriate insertion of the
% material into the named insert. It also inserts a \bigskip after or
% before the inserted box, just like the Plain \endinsert. Note that
% all the skips for these inserts are 0pt.
\def\C@lumnInsert#1{% make an insertion into insertion #1
\if@wid\count#1=2000\relax % wide inserts count x 2
\else\count#1=1000\fi % otherwise x 1
\insert#1{% % make the insertion
\penalty100 \splitmaxdepth=\maxdimen %
%% \topskip=\z@skip \splittopskip=\z@skip %
\floatingpenalty=\z@ % no penalty for floating
\if@wid\hsize=\pagewidth\fi % full width
\ifp@ge \dimen@=\dp\z@ % dimen0 = depth
\vbox to\pageheight{\unvbox\z@ \kern-\dimen@}% full page = \pageheight
\else % not full page
\ifx#1\botins\bigskip\fi % skip before bottom insert
\ifx#1\SWins\bigskip\fi % skip before bottom insert
\ifx#1\SEins\bigskip\fi % skip before bottom insert
\box\z@\nobreak % now add box0
\ifx#1\topins\bigskip\fi % space below top insert
\ifx#1\NWins\bigskip\fi % space below top insert
\ifx#1\NEins\bigskip\fi % space below top insert
\fi % end of \ifp@ge
}% % end of insert
}
% \wideXXXinsert make floating insertions across both columns. They
% use the same insert as the normal (single column) insert of the same
% name because it goes in the same place.
\def\@widetopinsert{% make a full width (wide) insertion at top of page
\@midfalse\p@gefalse\@widtrue\@botfalse
\@ins \hsize=\pagewidth}
\def\@widepageinsert{% full width, full length (i.e. full page) insertion
\@midfalse\p@getrue\@widtrue\@botfalse % wide page insert
\@ins \hsize=\pagewidth}
\def\@widebottominsert{% full width insertion at bottom of page
\@midfalse\p@gefalse\@widtrue\@bottrue % wide page insert
\@ins \hsize=\pagewidth}
% \@doubleXXXinsert is like \XXXinsert in Plain but also sets
% \@widfalse to prevent wide inserts.
\def\@doubletopinsert{\@midfalse\p@gefalse\@botfalse\@widfalse\@ins}
\def\@doublemidinsert{\@midtrue\@botfalse\@widfalse\@ins}
\def\@doublefullinsert{\@midfalse\p@getrue\@botfalse\@widfalse\@ins}
\def\@doublebottominsert{\@midfalse\p@gefalse\@bottrue\@widfalse\@ins}
\def\@doubleheavyinsert{\@midtrue\p@gefalse\@bottrue\@widfalse\@ins}
% \forceleft and \forceright force left and right insertions independent
% of the current column position.
\def\forceleft{\global\let\LRf@rce=L} % force left insert
\def\forceright{\global\let\LRf@rce=R} % force right insert
\let\LRf@rce=X % default is no force
%--------------------------------------------------*
% FOOTNOTES: wide footnotes go across the bottom of both columns,
% while the others just go in the left or right column. The names
% begin with @ because these are only enabled in double column mode.
\def\@widefootnote#1{% footnote across a double column page
\let\@sf=\empty % parameter #2 (the text) is read later
\ifhmode\edef\@sf{\spacefactor\the\spacefactor}\/\fi
#1\@sf\@wideVfootnote{#1}}
\def\@wideVfootnote#1{\insert\footins\bgroup
\hsize=\pagewidth % as wide as a page
\interlinepenalty=\interfootnotelinepenalty
\splittopskip=\ht\strutbox % top baseline for broken footnotes
\splitmaxdepth=\dp\strutbox \floatingpenalty=\@MM
\leftskip=\z@skip \rightskip=\z@skip \spaceskip=\z@skip \xspaceskip=\z@skip
\textindent{#1}\footstrut\futurelet\next\fo@t}
\def\@doubleVfootnote#1{% double column footnote in left or right column
\ifdim\pagetotal<\pageheight\relax %
\def\next{\@dblVfootnote\LFins{#1}}%
\else\def\next{\@dblVfootnote\RFins{#1}}%
\fi\next}
\def\@dblVfootnote#1#2{% footnote insert in whichever column named by #1
\insert#1\bgroup % begin insert
\interlinepenalty\interfootnotelinepenalty %
\splittopskip=\ht\strutbox % top baseline for broken footnotes
\splitmaxdepth=\dp\strutbox \floatingpenalty\@MM %
\leftskip=\z@skip \rightskip=\z@skip %
\spaceskip=\z@skip \xspaceskip=\z@skip %
\textindent{#2}\footstrut\futurelet\next\fo@t}
%
%--------------------------------------------------*
% OUTPUT ROUTINES for double columns:
% \@nepageout ships out a single page with running headlines
% and footlines added. Can be used with single or double columns,
% depending on what you put as the argument.
\def\@nepageout#1{% % output one page
\shipout\vbox{% % output a box
\offinterlineskip % no interline spacing!
\wideheadline % make wide headline
\vbox to \pageheight{\boxmaxdepth=\maxdepth %
#1\relax}% % box containing #1
\widefootline}% % make wide footline
\advancepageno}% % increment page number
% The following are like \makeheadline and \makefootline in Plain
% except that they use \hbox to\pagewidth instead of \line.
\def\wideheadline{% \makeheadline for double column mode
\vbox to\z@{\vskip-22.5\p@ % skip up some
\ifx\undefined\headlineoffset\else\vskip-\headlineoffset\fi
\hbox to \pagewidth{\vbox to 8.5\p@{}\the\headline}% content in \headline
\vss}%
\nointerlineskip}%
\def\widefootline{% \makefootline for double column mode
\baselineskip=24\p@ % space down
\ifx\undefined\footlineoffset\else\vskip\footlineoffset\fi
\hbox to \pagewidth{\the\footline}}% % content in \footline
% \@doublecolumnout splits the page into two columns, including any
% insertions which have accumulated.
\def\@doublecolumnout{% output routine for double column mode
%
% get height of columns in \dimen@
%
\dimen@=\pageheight % start with total space
\advance\dimen@ by -\ht\partialpage % subtract used height
\advance\dimen@ by -\dp\partialpage % ... and deptn
\ifvoid\topins\else % subtract top inserts
\advance\dimen@ by -\ht\topins %
\advance\dimen@ by -\dp\topins %
\advance\dimen@ by -\bigskipamount % including skip
\advance\dimen@ by -\splittopskip\fi % and extra at top of cols.
\ifvoid\botins\else % subtract any bottom inserts
\advance\dimen@ by -\ht\botins %
\advance\dimen@ by -\dp\botins %
\advance\dimen@ by -\bigskipamount\fi % including skip
\ifvoid\footins\else % subtract full width footnotes
\advance\dimen@ by -\ht\footins %
\advance\dimen@ by -\dp\footins %
\advance\dimen@ by -\skip\footins\fi % including skip
\@saveSplitmax=\splitmaxdepth \splitmaxdepth=\colmaxdepth
\splittopskip=\topskip
%
% construct left and right columns, with inserts inserted, and force
% them to the desired size \dimen@
%
\ifdim\dimen@>\baselineskip % if room for at least 1 line
\MakeColumn{1}{255}{\dimen@}{\NWins}{\LFins}{\SWins}%
\MakeColumn{2}{255}{\dimen@}{\NEins}{\RFins}{\SEins}%
\setbox1=\vbox to \dimen@{\unvbox1}% % reset to same size
\setbox2=\vbox to \dimen@{\unvbox2}% % reset to same size
\else % ... else no room
\setbox1=\vbox{}\setbox2=\vbox{}% % so just empty columns
\fi % end if room for columns
%
\@nepageout{\@pagesofar\@pagebottom}% % ship out double column page
\global\vsize=\@bigColHeight %
\unvbox255 \penalty\outputpenalty % put remaining text back
\splitmaxdepth=\@saveSplitmax} % reset \splitmaxdepth
% \MakeColumn{outbox}{inbox}{size}{topinsert}{footinsert}{bottominsert}
% creates a column of text of the given length, with the topinsert added
% at the top, and the footnote and bottominsert added at the bottom
% of the column (in that order). The result is put in outbox, while
% what is left over remains in inbox.
\def\MakeColumn#1#2#3#4#5#6{% make a column with top and bottom inserts
%
% start the column with the topinsert (#4) and the main text (#2)
%
\setbox3=\vbox{\ifvoid#4\else\unvbox#4\vskip\skip#4\fi \unvbox#2}%
%
% also collect column footnotes (#5) and bottom inserts (#6)
%
\setbox4=\vbox{\ifvoid#5\else\vskip\skip#5\footnoterule\unvbox#5\fi%
\ifvoid#6\else\vskip\skip#6\unvbox#6\fi}%
%
% split off just right amount from top stuff to make output column
%
\dimen@ii=#3\relax
\advance\dimen@ii by -\ht4 \advance\dimen@ii by -\dp4\relax
\setbox#1=\vsplit3 to \dimen@ii
%
% put the top and bottom together; put remainder from split back in input
%
\setbox#1=\vbox{\unvbox#1\unvbox4}%
\setbox#2=\vbox{\unvbox3}%
}
% \@pagesofar adds double column material to the page. The left column
% is in box 1, and the right column is in box 2
\def\@pagesofar{% add stuff to top of page collected so far
\ifvoid\topins\else\unvbox\topins % wide top inserts, if any?
\vskip\skip\topins\fi % some space below them
\unvbox\partialpage % partial page from past?
\wd1=\hsize \wd2=\hsize % set column sizes
\hbox to \pagewidth{\box1\hfill\box2}}% % combine 2 column boxes
% \@pagebottom puts the (wide) bottom and footnote inserts in place,
% if there are any.
\def\@pagebottom{% add inserts to bottom of a page
\ifvoid\botins\else\bigskip\unvbox\botins\fi % wide bottom inserts, if any
\ifvoid\footins\else % wide footnotes, if any
\vskip\skip\footins\footnoterule % skip and rule above them
\unvbox\footins\fi} % then the footnotes
% \@balancecolumns is the output routine for balancing 2 columns.
% (Based loosely on \balancecolumns from The TeXbook, pg 417)
\def\@balancecolumns{% balance partial double columns page
%
% get target column height from sum of text and all inserts
%
\setbox255=\vbox{\unvbox255}% reset glue
\dimen@=\ht255 \advance\dimen@ by \dp255 % main text
\@addsize\dimen@\NWins \@addsize\dimen@\NEins % top inserts
\@addsize\dimen@\LFins \@addsize\dimen@\RFins % column footnotes
\@addsize\dimen@\SWins \@addsize\dimen@\SEins % bottom inserts
\divide \dimen@ by 2 % and divide by 2
\@saveSplitmax=\splitmaxdepth %
\splitmaxdepth=\colmaxdepth %
\splittopskip=\topskip % top skip for splits
%
% Loop over possible splits of text into left and right columns.
% Always use copies of boxes to avoid destroying contents.
%
\advance\dimen@ by -.5\baselineskip % and a smidgeon LESS
{\vbadness=20000 \loop % suppress errors
\setbox0=\copy255 %
\setbox5=\copy\NWins \setbox6=\copy\LFins\setbox7=\copy\SWins
\setbox8=\copy\NEins \setbox9=\copy\RFins \setbox10=\copy\SEins
\MakeColumn{1}{0}{\dimen@}{5}{6}{7}% % first column fixed height
\MakeColumn{2}{0}{\pageheight}{8}{9}{10}% % second big enuf for all
\ifdim\ht2>\ht1
\global\advance\dimen@ by 1pt
\repeat}% % increment and try again
%
% End loop over possible splits.
%
\MakeColumn{1}{255}{\dimen@}{\NWins}{\LFins}{\SWins}%
\MakeColumn{2}{255}{\pageheight}{\NEins}{\RFins}{\SEins}%
\dimen@=\ht1 \ifdim\ht2>\ht1 \dimen@=\ht2 \fi % larger of two
\setbox1=\vbox to \dimen@{\unvbox1}% % reset to same size
\setbox2=\vbox to \dimen@{\unvbox2}% % reset to same size
\splitmaxdepth=\@saveSplitmax % restore \splitmaxdepth
\output={\@balancingerror}% % prepare for error
\@pagesofar} % put columns on page
\def\@addsize#1#2{% add size of box/insert #2 to counter #1
\ifvoid#2\else\advance#1 by \skip#2\relax % unless void, add skip,
\advance#1 by \ht#2 \advance#1 by \dp#2\relax % and height and depth
\fi}
% If the balanced columns fill the page then \output will be called
% again, and this error message will be displayed.
\newhelp\@balncErrormsg{%
@balancecolumns: I couldn't figure out how to balance the^^M
two columns. Maybe you can re-arange some text to make ^^M
the job easier. Try typing i\string\vfill to see the page anyway.}
\def\@balancingerror{% error, columns not balanced before page finished
\newlinechar=`\^^M % ^^M is line break
\errhelp=\@balncErrormsg % longer help message
\errmessage{Page cannot be balanced}% % error message
\@nepageout{\unvbox255}}% % do something anyway
%--------------------------------------------------*
% \@leftcolrule and \@rightcolrule put rules across left and right
% columns for spanned equations
\def\@leftcolrule{% Rule across bottom of left column
\vskip 2pt\nointerlineskip % some whitespace first
\hbox to \pagewidth{% % left column
\vbox to 6pt{\vfil \hrule width\colwidth height\rulewd}%
\hbox{\vrule height 6pt width\rulewd}\hfill}%
\smallskip\nobreak}
\def\@rightcolrule{% rule across top of a right column after balancing
\vskip\baselineskip\nointerlineskip
\hbox to \pagewidth{\hfill % stretch across to right column
\hbox{\vrule height 6pt width\rulewd}%
\vbox to 6pt{\hrule width\colwidth height\rulewd \vfil}}%
\vskip 2pt}
\def\@longequation{%
\enddoublecolumns % balance what we have
\@leftcolrule % rule below to separage
\def\endlongequation{\@endlongequation}} % enable
\def\@endlongequation{%
\@rightcolrule % with the rule at top of right column
\doublecolumns} % then back to double column mode
\def\longequation{\relax} % default for single column
\def\endlongequation{\relax} % does nothing
%------------------------*
% Plain.tex compatibility:
% If these macros are called from plain TeX \botins won't be defined, so
% just fake it.
\ifx\undefined\botins \let\botins=\topins \fi
% These definitions are copied from TXSinit.tex so that TXSdcol.tex
% can be used with Plain and bottom inserts in columns will work. The
% \if@bot is just ignored by the Plain \endinsert.
\def\topinsert{\@midfalse\p@gefalse\@botfalse\@ins}
\def\midinsert{\@midtrue\p@gefalse\@botfalse\@ins}
\def\pageinsert{\@midfalse\p@getrue\@botfalse\@ins}
\def\bottominsert{\@midfalse\p@gefalse\@bottrue\@ins}
\def\heavyinsert{\@midtrue\p@gefalse\@bottrue\@ins}
\def\pagecontents{% constructs page contents, including bottom inserts
\ifvoid\topins\else\unvbox\topins % top inserts, if any
\vskip\skip\topins\fi % and some space below
\dimen@=\dp\@cclv \unvbox\@cclv % main page contents from \box255
\ifvoid\botins\else\bigskip % bottom inserts? space above
\unvbox\botins\fi % and then insert the text
\ifvoid\footins\else % footnote inserts, if present
\vskip\skip\footins % skip above
\footnoterule % put the rule above footnotes
\unvbox\footins\fi % then the footnotes
\ifr@ggedbottom \kern-\dimen@ \vfil \fi}
\catcode`@=12 % @ back to a letter
% >>> EOF TXSdcol.tex <<<