summaryrefslogtreecommitdiff
path: root/macros/latex/contrib/pbalance
diff options
context:
space:
mode:
authorNorbert Preining <norbert@preining.info>2020-12-05 03:00:47 +0000
committerNorbert Preining <norbert@preining.info>2020-12-05 03:00:47 +0000
commit042d4edb85997e17a0b71f0f584e7c6371b2bf39 (patch)
tree5f4c6f9d7566fa96afec11e038da430979c6a4b1 /macros/latex/contrib/pbalance
parentc21dfc1b6264e70868fc851d90a124d5b1d9c341 (diff)
CTAN sync 202012050300
Diffstat (limited to 'macros/latex/contrib/pbalance')
-rw-r--r--macros/latex/contrib/pbalance/LICENSE11
-rw-r--r--macros/latex/contrib/pbalance/README.md14
-rw-r--r--macros/latex/contrib/pbalance/pbalance.dtx1069
-rw-r--r--macros/latex/contrib/pbalance/pbalance.ins49
-rw-r--r--macros/latex/contrib/pbalance/pbalance.pdfbin0 -> 307144 bytes
5 files changed, 1143 insertions, 0 deletions
diff --git a/macros/latex/contrib/pbalance/LICENSE b/macros/latex/contrib/pbalance/LICENSE
new file mode 100644
index 0000000000..dea471c70c
--- /dev/null
+++ b/macros/latex/contrib/pbalance/LICENSE
@@ -0,0 +1,11 @@
+Copyright 2020 Nelson Lago <lago@ime.usp.br>
+
+This work may be distributed and/or modified under the conditions of the
+LaTeX Project Public License, either version 1.3 of this license or (at
+your option) any later version. The latest version of this license can be
+found at http://www.latex-project.org/lppl.txt and version 1.3 or later
+is part of all distributions of LaTeX version 2005/12/01 or later.
+
+This work has the LPPL maintenance status `maintained'.
+
+The Current Maintainer of this work is Nelson Lago <lago@ime.usp.br>.
diff --git a/macros/latex/contrib/pbalance/README.md b/macros/latex/contrib/pbalance/README.md
new file mode 100644
index 0000000000..6ac43ea0c8
--- /dev/null
+++ b/macros/latex/contrib/pbalance/README.md
@@ -0,0 +1,14 @@
+# pbalance - poor man's balance package for LaTeX
+
+This is a LaTeX package that tries to *safely* make the columns on the last
+page of a two-column document have approximately the same height. It should
+"just work" without user intervention, which is particularly useful for
+class authors, but also offers the user a command to control the result.
+There are, however, three caveats:
+
+1. Results are adequate, but often not optimal;
+2. In some cases, the package may give up (the document is
+ generated correctly but the last page is not balanced);
+3. The package demands additional LaTeX passes.
+
+Code etc: <https://gitlab.com/lago/pbalance>
diff --git a/macros/latex/contrib/pbalance/pbalance.dtx b/macros/latex/contrib/pbalance/pbalance.dtx
new file mode 100644
index 0000000000..e63bee62a9
--- /dev/null
+++ b/macros/latex/contrib/pbalance/pbalance.dtx
@@ -0,0 +1,1069 @@
+% \iffalse meta-comment
+% Copyright 2020 Nelson Lago <lago@ime.usp.br>
+%
+% This work may be distributed and/or modified under the conditions of the
+% LaTeX Project Public License, either version 1.3 of this license or (at
+% your option) any later version. The latest version of this license can be
+% found at http://www.latex-project.org/lppl.txt and version 1.3 or later
+% is part of all distributions of LaTeX version 2005/12/01 or later.
+%
+% This work has the LPPL maintenance status `maintained'.
+%
+% The Current Maintainer of this work is Nelson Lago <lago@ime.usp.br>.
+%
+% \fi
+% \iffalse
+%
+%<package>\NeedsTeXFormat{LaTeX2e}[2015/01/01]
+%<package>\ProvidesPackage{pbalance}[2020/12/03 v1.0 Poor man's balance]
+%
+%<*driver>
+
+\documentclass{ltxdoc}
+
+\usepackage[hyperref,svgnames,x11names,table]{xcolor}
+\usepackage{url}
+\urlstyle{sf}
+\usepackage{hyperref}
+\hypersetup{
+ pdfborder={0 0 .6},
+ pdfborderstyle={/S/U/W .6},
+ urlbordercolor=DodgerBlue,
+ citebordercolor=White,
+ linkbordercolor=White,
+ filebordercolor=White,
+}
+
+\usepackage[draft]{pbalance}
+\makeatletter
+\dimgdef\@PBtmpHeight{0pt}
+\dimgdef\@PBtmpLeftHeight{0pt}
+\dimgdef\@PBtmpLeftFloatsHeight{0pt}
+\dimgdef\@PBtmpRightHeight{0pt}
+\dimgdef\@PBtmpRightFloatsHeight{0pt}
+\dimgdef\@PBtmpUsedLeft{0pt}
+\dimgdef\@PBtmpUsedRight{0pt}
+\makeatother
+
+\usepackage{libertinus}
+\usepackage[scale=.85]{sourcecodepro}
+
+%%\EnableCrossrefs
+%%\CodelineIndex
+%%\RecordChanges
+
+%%\OnlyDescription
+
+\begin{document}
+\DocInput{pbalance.dtx}
+\end{document}
+
+%</driver>
+%
+% \fi
+%
+% \CheckSum{0}
+%
+% \changes{v1.0}{2020/09/14}{Initial version}
+%
+% \GetFileInfo{pbalance.sty}
+%
+% \title{The \textsf{pbalance} (poor man's balance) package\thanks{This
+% document corresponds to \textsf{pbalance}~\fileversion, dated~\filedate.}}
+%
+% \author{
+% Nelson Lago\\
+% \texttt{lago@ime.usp.br}\\
+% ~\\
+% \url{https://gitlab.com/lago/pbalance}
+%}
+%
+% \maketitle
+%
+% \begin{abstract}
+%
+% This package tries to \emph{safely} make the columns on the last page
+% of a two-column document have approximately the same height. It should
+% ``just work'' without user intervention, which is particularly useful
+% for class authors, but also offers the user a command to control the
+% result. There are, however, three caveats:
+%
+% \begin{enumerate}
+% \item Results are adequate, but often not optimal;
+% \item In some cases, the package may give up (the document is
+% generated correctly but the last page is not balanced);
+% \item The package demands additional \LaTeX{} passes.
+% \end{enumerate}
+%
+% \end{abstract}
+%
+% \section{Introduction and usage}
+%
+% First things first: this package is a \textbf{hack}. It is also
+% \textbf{beta} quality. However, I believe it is \emph{safe},
+% i.e., it should not generate incorrect output.
+%
+% In a two-column document, it is desirable for the columns in the last
+% page to have the same height (the columns should be ``balanced''). Two
+% packages (\texttt{balance} and \texttt{flushend}) try to provide this
+% in \LaTeX, but both may generate defective output in some circumstances.
+% This package tries to solve this problem.
+%
+% Balancing is often not possible: imagine a document with an odd number
+% of lines on the last page, or with ten lines of text together with an
+% image that takes the height of fifteen lines of text, or a document where
+% making columns the same height would leave a sectioning comand at the
+% bottom of the first column etc. Since such cases happen often, we consider
+% it enough for the columns to be ``not too unequal'', even when equal
+% heights might be possible (the algorithm cannot deliver better results
+% and, in fact, striving to make columns exactly the same height with it
+% may sometimes yield poor results, so we do not even try).
+%
+% To use the package, add \verb|\usepackage{pbalance}| to the preamble
+% and things should ``just work''. However, the document will take more
+% \LaTeX{} passes to compile, and minute changes to it that would normally
+% need one additional \LaTeX{} pass will likely need three.
+%
+% If the last page does not have floats, footnotes, or marginpars, the
+% package simply uses \verb|\balance|, from the \texttt{balance} package;
+% otherwise it uses its own algorithm. You may instead use
+% \verb|\shrinkLastPage{some-measurement}| to manually define how much
+% shorter the first column of the last page should be. This, however, will
+% not eliminate the need for extra passes (the package needs to find out
+% which page is the last).
+%
+% \section{How does it work}
+%
+% This package works on two fronts:
+%
+% \begin{enumerate}
+%
+% \item It uses a \LaTeX{} pass to gather information: which is the last page?
+% Does it have floats? Footnotes? How much free space in each column?
+%
+% \item It uses this information in a subsequent pass to balance the last
+% page. If there are no floats or footnotes, it uses the balance
+% package; otherwise it uses the measurements collected to shrink
+% the first column (using \verb|\enlargethispage|) by a
+% ``reasonable'' amount.
+%
+% \end{enumerate}
+%
+% If measurements change between passes, this means the document was
+% edited, so we forget the previously gathered data and start over.
+% However, the package cannot detect changes that happen between the
+% ``collect data'' pass and the ``balance for the first time'' pass:
+% it has to assume that any change at this point is caused by the fact
+% that we started balancing (it can, however, detect if the last text
+% page changed; if this happens, we give up balancing). If the change is
+% small, that is acceptable: we are not aiming at balancing perfectly
+% anyway. If it is a big change (for example, the addition of the
+% bibliography block), results will suffer.
+%
+% To prevent this, it would be ideal to only start the process after all
+% passes needed to stabilize the document have run. In practice, however,
+% this would be too hard to detect. What we do instead is simply wait for
+% two consecutive passes to result in columns of the same size in the
+% last page. When this happens, we proceed to balance in the next pass
+% and assume (quite reasonably) that, as long as the document is not
+% modified, the effect of further passes in the last page is small, so
+% ignoring it disturbs the balancing only slightly\footnote{Like I said
+% on the introduction: this package is a hack.}.
+%
+% \section{TODO / wish list}
+%
+% Some useful stuff we should consider implementing:
+%
+% \begin{itemize}
+%
+% \item add \verb|\if@twocolumn| tests to prevent crashes and
+% other problems;
+%
+% \item add options to (1) allow using the balance package on pages with
+% floats and (2) completely disable the balance package;
+%
+% \item make the mechanism able to work with any page, not just the last,
+% and with more than one page at once. This is useful for book
+% chapters, for example;
+%
+% \item on top of that:
+% \begin{enumerate}
+% \item create command to manually indicate the page numbers to balance
+% \item create command similar to \verb|\balance| from the
+% \texttt{balance} package
+% \item allow user to set manual balancing for each page independently
+% \end{enumerate}
+%
+% \end{itemize}
+%
+% \StopEventually{}
+%
+% \section{The implementation}
+%
+% We define \verb|\@PBlastPage| using \texttt{zref-abspage}; It is the page
+% number for the last page of text. This might \emph{not} be the last page
+% of the document: there may be one or more float pages after it. Still,
+% it \emph{is} the page we want to balance. We do not act on it, however;
+% instead, we save its value to the aux file as \verb|\@PBprevLastPage| and
+% proceed to balance on the next \LaTeX{} pass.
+%
+% We also define two toggles:
+%
+% \begin{description}
+% \item[\texttt{@PBstabilized}] There have been a few passes
+% already and the document has apparently stabilized.
+% \item[\texttt{@PBimpossible}] We tried to balance on a
+% previous pass and failed.
+% \end{description}
+%
+% \subsection{Initialization, required packages etc.}
+%
+% Besides some other required packages, here we load the \texttt{balance}
+% package; if there are no floats or footnotes involved, we will simply use
+% it. We need to load it after we modify \verb|\@outputdblcol|, so we use
+% \verb|\AtEndOfPackage|.
+%
+% We also define the \texttt{draft} option, which disables processing.
+%
+% \begin{macrocode}
+
+\RequirePackage{etoolbox}
+\RequirePackage{expl3}
+\RequirePackage{atbegshi} % Manipulate the page output routine
+\RequirePackage{atveryend} % Write to the aux file after processing ends
+\RequirePackage{zref-abspage} % Figure out the current page
+
+\AtEndOfPackage{\RequirePackage{balance}}
+
+% See https://github.com/latex3/latex2e/issues/399#issuecomment-703081793
+\gdef \@reinserts{%
+ \ifvbox\@kludgeins\insert\@kludgeins
+ {\unvbox\@kludgeins}\fi
+ \ifvoid\footins\else\insert\footins{\unvbox\footins}\fi
+}
+
+\providetoggle{@PBstabilized}
+\providetoggle{@PBimpossible}
+
+\newtoggle{@PBdraft}
+\DeclareOption{draft}{\toggletrue{@PBdraft}}
+\ProcessOptions\relax
+
+% \end{macrocode}
+
+% \subsection{The balancing front}
+%
+% The basic balancing process is reasonably simple: right before each
+% new page, check whether it should be balanced. If so, add the adequate
+% code to the top of the page (either call \verb|\balance|, from the
+% \texttt{balance} package, or add \verb|\enlargethispage|).
+%
+% \begin{macrocode}
+
+% Right before the first page
+\AtBeginDocument{
+ \@PBifShouldBalanceNascentPage
+ {\@PBStartBalancing}
+ {}
+}
+
+% Right before all other pages
+\AtBeginShipout{
+ \@PBifShouldBalanceNascentPage
+ {\@PBStartBalancing}
+ {}
+}
+
+\newcommand\@PBifShouldBalanceNascentPage[2]{
+ \ifboolexpr
+ {
+ togl {@PBdraft}
+ or not togl {@PBstabilized}
+ or test {\ifdefvoid{\@PBprevLastPage}}
+ }
+ {#2}
+ {
+ % abspage refers to the finished page, not the nascent page
+ \ifnumcomp{\@PBprevLastPage - 1}{=}{\value{abspage}}
+ {#1}
+ {#2}
+ }
+}
+
+% Let's give the user a chance to manually define what to do
+\newcommand\shrinkLastPage[1]{\dimgdef\@PBslack{#1}}
+
+\newcommand\@PBStartBalancing{
+ \ifdefvoid{\@PBslack}
+ {\@PBautomaticBalance}
+ {\@PBshrinkPage}
+}
+
+\newcommand\@PBautomaticBalance{
+ \@PBifBalancePossible
+ {
+ \@PBifBalancePkgPossible
+ {\balance} % easy peasy, use the balance package
+ {
+ \@PBifPoorBalancePossible
+ {
+ % use the poor man's balance algorithm
+ \@PBcalculateShrinkage
+ \@PBshrinkPage
+ }
+ {}
+ }
+ }
+ {}
+}
+
+% Calculate how much we should shrink the left column of the last
+% page based on the measurements we took on previous LaTeX passes.
+\newcommand\@PBcalculateShrinkage{
+
+ % Let's use some shorter names, please
+ \dimdef\@PBtmpH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}Height}}
+ \dimdef\@PBtmpUL{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}UsedLeft}}
+ \dimdef\@PBtmpUR{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}UsedRight}}
+
+ \dimdef\@PBtmpLH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}LeftHeight}}
+ \dimdef\@PBtmpLFH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}LeftFloatsHeight}}
+ \dimdef\@PBtmpRH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}RightHeight}}
+ \dimdef\@PBtmpRFH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}RightFloatsHeight}}
+
+ % Figure out the amount of unused space on the last page (both
+ % cols); we will reduce the first column height by half that amount
+ \dimgdef\@PBslack{2\dimexpr\@PBtmpH\relax - \@PBtmpUL - \@PBtmpUR}
+ \dimgdef\@PBslack{.5\dimexpr\@PBslack\relax}
+
+ % Actually, I lied. While half, as said above, sometimes yields
+ % perfectly balanced columns, that is often not the case (the page
+ % may have an odd number of lines, or textheight may not be a
+ % multiple of baselineskip, or there may be glues etc.). Sometimes
+ % the difference is very small, less than a line, which does not
+ % look good at all, and sometimes the right column is slightly
+ % higher than the left, which is also not ideal. Here, we force
+ % the left column to always be somewhat taller than the left; the
+ % result is often ``better''.
+ \dimgdef\@PBslack{\@PBslack - 1.5\baselineskip}
+
+ % If necessary, reduce @PBslack to prevent LaTeX from adding a page
+ \@PBsafetyCheck
+}
+
+\def\@PBshrinkPage{
+ % Zero obviously means ``do nothing''. We could
+ % ``enlarge'' by 0, but IDK, maybe that would
+ % trigger another LaTeX pass or something.
+ \ifdimcomp{\@PBslack}{=}{0pt}
+ {}
+ {
+ % Shrink the first column
+ \enlargethispage{-\@PBslack}
+
+ % Modify the behavior of \@outputdblcol
+ % to raise footnotes in the second column.
+ \global\let\@PBbalanceSecondColumn\@PBrealBalanceSecondColumn
+ }
+}
+
+% If there are footnotes on the right column, it is better to
+% ``push'' them up to be aligned with the end of the left column,
+% especially if there are footnotes on the left column too. We
+% do this by manipulating \@textbottom in \@outputdblcol.
+\pretocmd{\@outputdblcol}{\@PBbalanceSecondColumn}{}{}
+
+\let\@PBbalanceSecondColumn\relax
+
+\def\@PBrealBalanceSecondColumn{
+ \if@firstcolumn
+ % Affects the next column
+ \global\let\@PBorigtextbottom\@textbottom
+ \gdef\@textbottom{\vskip \@PBslack plus .0001fil minus 10000fill\relax \@PBorigtextbottom}
+ \else
+ % Back to normal before starting the next page
+ \global\let\@textbottom\@PBorigtextbottom
+ \global\let\@PBbalanceSecondColumn\relax
+ \fi
+}
+
+% \end{macrocode}
+
+% \subsection{The measuring front}
+% For the mechanism above to work, we need to know:
+%
+% \begin{enumerate}
+% \item The page number of the last page;
+% \item Whether the last page has floats, footnotes etc.;
+% \item The available height in the last page;
+% \item The height of the columns in the last page.
+% \end{enumerate}
+%
+% Let's collect this info for every page.
+%
+% \subsubsection{Are there floats, footnotes, or marginpars in the last page?}
+%
+% \begin{macrocode}
+
+% To check whether there are floats etc. in the last page,
+% we will copy the fancyhdr package:
+% https://tex.stackexchange.com/questions/56673/is-there-a-way-to-determine-if-there-is-a-float-on-a-page
+% But we add the tests to a different place.
+\newcommand\@PBifmidfloat[2]{\ifx\@midlist\empty #2\else #1\fi}
+\newcommand\@PBiftopfloat[2]{\ifx\@toplist\empty #2\else #1\fi}
+\newcommand\@PBifbotfloat[2]{\ifx\@botlist\empty #2\else #1\fi}
+\newcommand\@PBiffootnote[2]{\ifvoid\footins #2\else #1\fi}
+\newcommand\@PBiffloatcol[2]{\if@fcolmade #1\else #2\fi}
+% dbltop floats are apparently ok with the balance package
+%%%\newcommand\@PBifdbltopfloat[2]{\ifx\@dbltoplist\empty #2\else #1\fi}
+% dblbotlist only exists with package stfloats
+\newcommand\@PBifdblbotfloat[2]{%
+ \ifdefvoid{\@dblbotlist}
+ {#2}
+ {\ifx\@dblbotlist\empty #2\else #1\fi}%
+}
+
+% If there are footnotes, floats or marginpars in
+% the page, we should not use the balance package
+\newtoggle{@PBtmpHasFootnotes}
+\newtoggle{@PBtmpHasFloats}
+\newtoggle{@PBtmpHasMarginpars}
+
+\def\@PBcollectPageInfo{
+
+ \ifboolexpr
+ {
+ test {\@PBifmidfloat} or test {\@PBiftopfloat} or
+ test {\@PBifbotfloat} or test {\@PBifdblbotfloat}
+ }
+ {\global\toggletrue{@PBtmpHasFloats}}
+ {}
+
+ \@PBiffootnote
+ {\global\toggletrue{@PBtmpHasFootnotes}}
+ {}
+}
+
+\pretocmd{\@makecol}{\@PBcollectPageInfo}{}{}
+
+% This only gets called if there is a marginpar, so that's easy
+\pretocmd{\@addmarginpar}{\global\toggletrue{@PBtmpHasMarginpars}}{}{}
+
+% \end{macrocode}
+%
+% \subsubsection{What are the sizes of the floats in the left column?}
+%
+% \begin{macrocode}
+
+\ExplSyntaxOn
+\seq_gclear_new:N \@PBtmpLeftFloatHeights
+\seq_gclear_new:N \@PBtmpLeftFloatSpacesBelow
+\def\@PBcollectFloatHeights{
+ \if@firstcolumn
+ \dimdef\@PBfloatHeight{\@textfloatsheight - \@PBtmpHeightBefore}
+ \ifdimcomp{\@PBfloatHeight}{>}{0pt}
+ {
+ \global\seq_put_right:NV \@PBtmpLeftFloatHeights \@PBfloatHeight
+
+ \dimdef\@PBspaceBelow{\@colroom - \@pageht - \@PBfloatHeight}
+ % within \@addtocurcol, \@pageht corresponds to all
+ % currently used space in the column, including footnotes
+ % (check \@specialoutput in the LaTeX kernel). Let's
+ % exclude the footnotes, we only want the space below
+ % the float.
+ \ifvoid\footins\else
+ \dimdef\@PBspaceBelow{\@PBspaceBelow + \ht\footins + \skip\footins + \dp\footins}
+ \fi
+
+ % No idea why, but this can happen; maybe because of the page depth?
+ \ifdimcomp{\@PBspaceBelow}{<}{0pt}
+ {\dimdef\@PBspaceBelow{0pt}}
+ {}
+
+ \global\seq_put_right:NV \@PBtmpLeftFloatSpacesBelow \@PBspaceBelow
+ }
+ {}
+ \fi
+}
+\ExplSyntaxOff
+
+\pretocmd{\@addtocurcol}{\dimgdef{\@PBtmpHeightBefore}{\@textfloatsheight}}{}{}
+\apptocmd{\@addtocurcol}{\@PBcollectFloatHeights}{}{}
+
+% \end{macrocode}
+%
+% \subsubsection{What is the size of each column? Is there a float column / floatpage?}
+%
+% \begin{macrocode}
+
+% If there is a float column in the page, it makes no sense to try to
+% balance; if both columns are float columns, this page cannot be the
+% final text page, i.e., we want to balance some other page.
+\newtoggle{@PBtmpHasFloatcol}
+\newtoggle{@PBtmpIsFloatPage}
+
+\newcommand\@PBcollectColumnInfo{
+
+ \if@firstcolumn
+
+ \@PBiffloatcol
+ {\global\toggletrue{@PBtmpHasFloatcol}}
+ {}
+
+ % Available vertical space excluding
+ % dblfloats; the same for both columns
+ \dimgdef\@PBtmpHeight{\@colht}
+
+ % Available vertical space excluding top/bottom floats
+ \dimgdef\@PBtmpLeftHeight{\@colroom}
+
+ % Space used by \texttt{here} floats
+ \dimgdef\@PBtmpLeftFloatsHeight{\@textfloatsheight}
+
+ \else
+
+ \@PBiffloatcol
+ {
+ \iftoggle{@PBtmpHasFloatcol}
+ {\global\toggletrue{@PBtmpIsFloatPage}}
+ {\global\toggletrue{@PBtmpHasFloatcol}}
+ }
+ {}
+
+ \dimgdef\@PBtmpRightHeight{\@colroom}
+ \dimgdef\@PBtmpRightFloatsHeight{\@textfloatsheight}
+
+ \setbox\@tempboxa=\copy\@leftcolumn
+ \setbox\@tempboxa=\vbox{\unvbox\@tempboxa\unskip\unskip}
+ \dimgdef\@PBtmpUsedLeft{\ht\@tempboxa\relax}
+
+ \setbox\@tempboxa=\copy\@outputbox
+ \setbox\@tempboxa=\vbox{\unvbox\@tempboxa\unskip\unskip}
+ \dimgdef\@PBtmpUsedRight{\ht\@tempboxa\relax}
+ \fi
+}
+
+% The default LaTeX macro
+\pretocmd{\@outputdblcol}{\@PBcollectColumnInfo}{}{}
+
+% The version from the balance package
+\AtEndOfPackage{
+ \pretocmd{\@BAdblcol}{\@PBcollectColumnInfo}{}{}
+ % Revert \balance before next page if it exists (it might be a float page)
+ \patchcmd{\@BAdblcol}{\endgroup}{\endgroup\nobalance}{}{}
+}
+
+% \end{macrocode}
+%
+% \subsubsection{Analyze the obtained information}
+%
+% We have inserted the hooks we need to collect data during
+% the processing of each page and column. Now we inspect the
+% collected data after each page is finalized.
+%
+% \begin{macrocode}
+
+\ExplSyntaxOn
+\AtBeginShipout{
+ \ifboolexpr
+ {
+ % A float page is not the last text page, ignore
+ togl {@PBtmpIsFloatPage}
+ or
+ % A page with a float column on the left and an empty
+ % column on the right is not the last text page, ignore
+ (
+ togl {@PBtmpHasFloatcol}
+ and
+ test {\ifdimcomp{\@PBtmpUsedRight}{=}{\topskip}}
+ )
+ }
+ {}
+ {
+ % This page is a candidate to be the last page
+ \xdef\@PBlastPage{\the\value{abspage}}
+ \@PBcopyPageData{tmp}{candidate}
+ }
+
+ % Reset before processing next page
+ \global\togglefalse{@PBtmpHasFloats}
+ \global\togglefalse{@PBtmpHasFloatcol}
+ \global\togglefalse{@PBtmpHasFootnotes}
+ \global\togglefalse{@PBtmpHasMarginpars}
+ \global\togglefalse{@PBtmpIsFloatPage}
+
+ \seq_gclear_new:N \@PBtmpLeftFloatHeights
+ \seq_gclear_new:N \@PBtmpLeftFloatSpacesBelow
+}
+\ExplSyntaxOff
+
+% \end{macrocode}
+%
+% All pages processed, the last candidate page is actually the last page.
+% Instead of continuing to use the \texttt{@PBcandidate*} macros we already
+% have, we will keep the information we just gathered associated with the
+% page number. We do this because, in the future, we may want to add suport
+% for balancing multiple pages (such as the last page of each chapter) and
+% not only the last one. This also makes it easier to handle the situation
+% where the document was modified and the last page has changed.
+%
+% \begin{macrocode}
+
+\AfterLastShipout{\@PBcopyPageData{candidate}{pg\@Roman{\@PBlastPage}}}
+
+% \end{macrocode}
+%
+% \subsubsection{Saving measurements}
+% The whole document has already been processed and data about the last
+% page has been collected in macros with names \texttt{@PBpgNUM*}. We now
+% process this collected data and save whatever is relevant in the aux
+% file for the next \LaTeX{} pass.
+%
+% In the first \LaTeX{} pass, we will save data to the aux file in macros
+% with names \texttt{@PBunbalpgNUM*}. That is all we need for balancing.
+% However, to detect whether the document has changed and, therefore,
+% whether we should re-balance, we will also record the same data after
+% balancing (during the second pass) in macros with names
+% \texttt{@PBbalpgNUM*}. If, in the third or later \LaTeX{} passes,
+% \texttt{@PBbalpgNUM*} differ from \texttt{@PBpgNUM*}, the document
+% has been changed and we need to re-balance.
+%
+% So, we have:
+%
+% \begin{description}
+% \item[\texttt{@PBpgNUM*}] data collected during the current pass;
+% \item[\texttt{@PBunbalpgNUM*}] data collected in the first pass;
+% \item[\texttt{@PBbalpgNUM*}] data collected in the second pass (after
+% balancing); in subsequent passes, these should always be equal
+% to \texttt{@PBpgNUM*}.
+% \end{description}
+%
+% The last two are saved to / read from the aux file.
+%
+% \begin{macrocode}
+
+% Make sure the document has stabilized before using \@PBmanageBalancingPasses
+\AfterLastShipout{
+ % Reset \@PBimpossible if we are in draft mode,
+ % so the user can start over if they want to.
+ \iftoggle{@PBdraft}{\togglefalse{@PBimpossible}}{}
+
+ \ifboolexpr{togl {@PBdraft} or togl {@PBimpossible}}
+ {}
+ {
+ \ifdefvoid{\@PBprevLastPage}
+ {\@PBsaveUnbalancedInfo\@PBnotifyRerun} % First pass
+ {
+ \iftoggle{@PBstabilized}
+ {\@PBmanageBalancingPasses}
+ {
+ \@PBifSomethingChanged[unbal]
+ % Document still changing; discard data from previous pass
+ {\@PBsaveUnbalancedInfo[update]\@PBnotifyRerun}
+ % No changes, so let's balance from now on (once @PBstabilized
+ % becomes true, it never reverts back to false, unless the aux
+ % file is deleted).
+ {\toggletrue{@PBstabilized}\@PBsaveUnbalancedInfo\@PBnotifyRerun}
+ }
+ }
+ \@PBsaveToggle{@PBstabilized}
+ }
+
+ \@PBsaveToggle{@PBimpossible}
+ \immediate\write\@mainaux{\gdef\string\@PBprevLastPhysPage{\the\value{abspage}}}
+}
+
+\newcommand\@PBmanageBalancingPasses{
+ % This is the second pass or later after we started balancing
+
+ \providetoggle{@PBpg\@Roman{\@PBlastPage}alreadyBalanced}
+
+ \iftoggle{@PBpg\@Roman{\@PBlastPage}alreadyBalanced}
+ {
+ % Third pass or later; document was already
+ % balanced, so there should be no more changes
+ \@PBifSomethingChanged
+ % The document has changed, so we need to measure
+ % stuff again; clear aux file and start over.
+ {\@PBnotifyRerun}
+ % Nothing changed, just write the same info down
+ {\@PBsaveUnbalancedInfo\@PBsaveBalancedInfo}
+ }
+ % Second pass, which means something did change: we have just
+ % balanced the columns for the first time.
+ {
+ \xdef\@tempa{\the\value{abspage}}
+ \ifboolexpr
+ {
+ test {\ifdefstrequal{\@PBprevLastPage}{\@PBlastPage}}
+ and
+ test {\ifdefstrequal{\@PBprevLastPhysPage}{\@tempa}}
+ }
+ % All is well; save the new info
+ {\@PBsaveUnbalancedInfo\@PBsaveBalancedInfo}
+ % Oh, no! As we attempted to balance, we actually changed
+ % the number of pages (maybe we added a float page, maybe
+ % we turned the last float page into a text page etc.). If
+ % we continue, the document might never converge (endless
+ % ``please rerun LaTeX'' messages). Let's give up balancing.
+ {\toggletrue{@PBimpossible}}
+ }
+}
+
+% \end{macrocode}
+%
+% \subsection{Auxiliary macros}
+%
+% \begin{macrocode}
+
+\newcommand\@PBifBalancePossible[2]{
+ \iftoggle{@PBunbalpg\@Roman{\@PBprevLastPage}HasFloatcol}
+ {#2}
+ {#1}
+}
+
+% The balance package may fail badly in the presence of footnotes:
+% they may end up in the middle of the text. Marginpars may end up
+% on the wrong side of the page. Floats are usually ok, but in some
+% cases the columns may become very badly balanced. For ordinary
+% text, it works perfectly.
+\newcommand\@PBifBalancePkgPossible[2]{
+ \ifboolexpr
+ {
+ togl {@PBunbalpg\@Roman{\@PBprevLastPage}HasFloats}
+ or
+ togl {@PBunbalpg\@Roman{\@PBprevLastPage}HasFootnotes}
+ or
+ togl {@PBunbalpg\@Roman{\@PBprevLastPage}HasMarginpars}
+ }
+ {#2}
+ {#1}
+}
+
+% \end{macrocode}
+%
+% We only want to balance if:
+%
+% \begin{enumerate}
+%
+% \item The left column is higher than the right one. If that is not the
+% case, either things are already balanced or the right column is
+% higher, which means \LaTeX{} was forced into a bad solution already.
+%
+% \item This difference is ``large enough'' (6 lines), which means two things:
+% \begin{enumerate}
+%
+% \item There will be an actual improvement in the result.
+%
+% \item There is plenty of free space on the right column, so even if
+% our changes happen to take more space than before, \LaTeX{} will
+% hopefully not add a new page (but it might make the right
+% column higher than the left, which is not so great).
+% \end{enumerate}
+%
+% \end{enumerate}
+%
+% If there is material only on the left column, we want to balance even
+% if the difference in height is not ``large enough'', as long as there
+% are more than 4 lines to split among columns. This is actually quite
+% unlikely: if there is so little material, the page probably has only
+% normal text and we will use the balance package.
+%
+% \begin{macrocode}
+
+\newcommand\@PBifPoorBalancePossible[2]{
+
+ % Let's use some shorter names, please
+ \dimdef\@PBtmpH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}Height}}
+ \dimdef\@PBtmpUL{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}UsedLeft}}
+ \dimdef\@PBtmpUR{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}UsedRight}}
+
+ \dimdef\@PBtmpLH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}LeftHeight}}
+ \dimdef\@PBtmpLFH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}LeftFloatsHeight}}
+ \dimdef\@PBtmpRH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}RightHeight}}
+ \dimdef\@PBtmpRFH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}RightFloatsHeight}}
+
+ \ifboolexpr{
+ % Plenty of space on right column, difference is worth it
+ test {\ifdimcomp{\@PBtmpUL}{>}{\@PBtmpUR + 6\baselineskip}}
+ or
+ (
+ test {\ifdimcomp{\@PBtmpUL}{>}{4\baselineskip}}
+ and
+ test {\ifdimcomp{\@PBtmpUR}{=}{\topskip}} % column is empty
+ )
+ }{#1}{#2}
+}
+
+% \end{macrocode}
+%
+% If there are floats, things can get messy: imagine that we want to
+% shrink by 50pt, but there is a 250pt float near the end of the left
+% column that won't fit after we shrink, so it will move to the right.
+% What if there is no room for such a large float there? Here, we try
+% to prevent this situation and shrink by a smaller amount if there
+% is a float that won't fit. Note that, if the float goes to the
+% right column, there will be more room for text in the left column.
+% Therefore, a float will not fit only if the floats on the right
+% column take too much space. So, what we do here is, starting from
+% the bottom, check whether the accumulated height of the floats
+% from the left column fit in the right. If we find a float that
+% will not fit, we know that we should limit shrinking to the space
+% below that float.
+%
+% In the same vein, we do not want top/bottom floats from the left
+% column that were deferred from a previous page to be pushed to
+% the right column. To that end, we limit the shrinking amount to
+% the space on the left column not taken by top/bottom floats.
+
+% \textbf{TODO:} Top and bottom floats may appear in two cases: (1) they
+% were generated on a previous page and deferred or (2) the user
+% chose placement options \texttt{t} or \texttt{b}, without
+% \texttt{h}. Deferred floats are not a problem: we do not reduce
+% the space available for top/bottom floats, so they should
+% continue to fit. Floats on the left column with placement
+% options \texttt{t} and \texttt{b} without \texttt{h} can be
+% a problem: \LaTeX{} only considers putting a float on the
+% top/bottom of the current column if, at the point of its
+% definition, there is enough space for it. Since we are shrinking
+% the column, it may not fit and be deferred - something the
+% algorithm does not take into consideration. However, not all is
+% lost: most likely, the user will only use such placement
+% options when trying to manually adjust the page, which
+% means they will be able to detect and work around eventual
+% problems.
+%
+% \begin{macrocode}
+
+\ExplSyntaxOn
+\def\@PBsafetyCheck{
+
+ % Let's use some shorter names, please
+ \dimdef\@PBtmpH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}Height}}
+ \dimdef\@PBtmpUL{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}UsedLeft}}
+ \dimdef\@PBtmpUR{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}UsedRight}}
+
+ \dimdef\@PBtmpLH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}LeftHeight}}
+ \dimdef\@PBtmpLFH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}LeftFloatsHeight}}
+ \dimdef\@PBtmpRH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}RightHeight}}
+ \dimdef\@PBtmpRFH{\csuse{@PBunbalpg\@Roman{\@PBprevLastPage}RightFloatsHeight}}
+
+
+ % Make sure we do not push top/bottom floats out of the left col
+ \dimdef\@PBmaxSlack{\@PBtmpLH}
+
+ \dimdef\@PBtmpdim{0pt}
+
+ % Start from the bottom
+ \numdef{\@PBtmpcnt}{\seq_count:c {@PBunbalpg\@Roman{\@PBprevLastPage}LeftFloatHeights}}
+ \int_while_do:nNnn {\@PBtmpcnt} > {0}
+ {
+
+ \dimdef\@PBcurrentFloatHeight
+ {\seq_item:cn {@PBunbalpg\@Roman{\@PBprevLastPage}LeftFloatHeights} {\@PBtmpcnt}}
+
+ \dimdef\@PBcurrentFloatSpaceBelow
+ {\seq_item:cn {@PBunbalpg\@Roman{\@PBprevLastPage}LeftFloatSpacesBelow} {\@PBtmpcnt}}
+
+ \dimdef{\@PBtmpdim}{\@PBtmpdim + \@PBcurrentFloatHeight}
+
+ \ifboolexpr
+ {
+ % Does the float fit in the second column?
+ test {\ifdimcomp{\@PBtmpdim}{<}{\@PBtmpRH - \@PBtmpRFH}}
+ and
+ % Is there something above this float, i.e., if we move
+ % this float to the next column, will anything remain?
+ test
+ {
+ \ifdimcomp
+ {\@PBcurrentFloatSpaceBelow + \@PBcurrentFloatHeight}
+ {<}
+ {\@PBtmpLH - 6\baselineskip}
+ }
+ }
+ {\numdef{\@PBtmpcnt}{\@PBtmpcnt - 1}} % this one is ok; check next
+ {
+ % this one should not be moved, we found the limit
+ \ifdimcomp{\@PBmaxSlack}{>}{\@PBcurrentFloatSpaceBelow}
+ {\dimdef{\@PBmaxSlack}{\@PBcurrentFloatSpaceBelow}}
+ {}
+ \numdef{\@PBtmpcnt}{0} % exit the loop
+ }
+ }
+
+ \ifdimcomp{\@PBmaxSlack}{<}{\@PBslack}
+ {\dimgdef{\@PBslack}{\@PBmaxSlack}}
+ {}
+}
+\ExplSyntaxOff
+
+% Compare current measurements with previous ``bal'' or ``unbal'' measurements
+\newcommand\@PBifSomethingChanged[3][bal]{
+ \ifdefstrequal{\@PBprevLastPage}{\@PBlastPage}
+ {
+ \@PBifPageDataMatches
+ {pg\@Roman{\@PBlastPage}}
+ {#1pg\@Roman{\@PBlastPage}}
+ {#3}
+ {#2}
+ }
+ {#2}
+}
+
+\newcommand\@PBifPageDataMatches[4]{
+ \ifboolexpr{
+ test {\@PBifTogglesMatch{@PB#1HasFloats}{@PB#2HasFloats}}
+ and test {\@PBifTogglesMatch{@PB#1HasFloatcol}{@PB#2HasFloatcol}}
+ and test {\@PBifTogglesMatch{@PB#1HasFootnotes}{@PB#2HasFootnotes}}
+ and test {\@PBifTogglesMatch{@PB#1HasMarginpars}{@PB#2HasMarginpars}}
+ and test {\@PBifDimensionsMatch{@PB#1Height}{@PB#2Height}}
+ and test {\@PBifDimensionsMatch{@PB#1LeftHeight}{@PB#2LeftHeight}}
+ and test {\@PBifDimensionsMatch{@PB#1RightHeight}{@PB#2RightHeight}}
+ and test {\@PBifDimensionsMatch{@PB#1UsedLeft}{@PB#2UsedLeft}}
+ and test {\@PBifDimensionsMatch{@PB#1UsedRight}{@PB#2UsedRight}}
+ }
+ {#3}
+ {#4}
+}
+
+% https://en.wikipedia.org/wiki/XNOR_gate
+\newcommand\@PBifTogglesMatch[4]{
+ \ifboolexpr{(togl{#1} or not togl{#2}) and (togl{#2} or not togl{#1})}
+ {#3}
+ {#4}
+}
+
+\newcommand\@PBifDimensionsMatch[4]{
+ \ifdimcomp{\csuse{#1}}{=}{\csuse{#2}}
+ {#3}
+ {#4}
+}
+
+\newcommand\@PBsaveUnbalancedInfo[1][]{
+
+ \immediate\write\@mainaux{\gdef\string\@PBprevLastPage{\@PBlastPage}}
+
+ \ifboolexpr{test {\ifdefvoid{\@PBprevLastPage}} or test {\ifstrequal{#1}{update}}}
+ % Columns are currently unbalanced, either because this is
+ % the first pass (we do not have any previous information)
+ % or because the document has not stabilized yet, so any
+ % previous information is unreliable. Save the information
+ % we just collected as ``unbalanced''.
+ {\@PBsavePageDataAs{pg\@Roman{\@PBlastPage}}{unbalpg\@Roman{\@PBlastPage}}}
+ % Not the first pass, so columns are possibly balanced;
+ % to save the unbalanced information, repeat what was
+ % gathered during the first pass.
+ {\@PBsavePageData{unbalpg\@Roman{\@PBprevLastPage}}}
+}
+
+\def\@PBsaveBalancedInfo{
+ \global\toggletrue{@PBpg\@Roman{\@PBlastPage}alreadyBalanced}
+ \@PBsaveToggle{@PBpg\@Roman{\@PBlastPage}alreadyBalanced}
+
+ \@PBsavePageDataAs{pg\@Roman{\@PBlastPage}}{balpg\@Roman{\@PBlastPage}}
+}
+
+\def\@PBnotifyRerun{
+ \AtVeryEndDocument{
+ \PackageWarningNoLine{pbalance}
+ {Last page columns not balanced. Rerun LaTeX}
+ }
+}
+
+\ExplSyntaxOn
+\newcommand\@PBcopyPageData[2]{
+
+ \global\providetoggle{@PB#2HasFloats}
+ \global\providetoggle{@PB#2HasFloatcol}
+ \global\providetoggle{@PB#2HasFootnotes}
+ \global\providetoggle{@PB#2HasMarginpars}
+
+ \iftoggle{@PB#1HasFloats}
+ {\global\toggletrue{@PB#2HasFloats}}
+ {\global\togglefalse{@PB#2HasFloats}}
+
+ \iftoggle{@PB#1HasFloatcol}
+ {\global\toggletrue{@PB#2HasFloatcol}}
+ {\global\togglefalse{@PB#2HasFloatcol}}
+
+ \iftoggle{@PB#1HasFootnotes}
+ {\global\toggletrue{@PB#2HasFootnotes}}
+ {\global\togglefalse{@PB#2HasFootnotes}}
+
+ \iftoggle{@PB#1HasMarginpars}
+ {\global\toggletrue{@PB#2HasMarginpars}}
+ {\global\togglefalse{@PB#2HasMarginpars}}
+
+ \csdimgdef{@PB#2Height}{\csuse{@PB#1Height}}
+ \csdimgdef{@PB#2LeftHeight}{\csuse{@PB#1LeftHeight}}
+ \csdimgdef{@PB#2LeftFloatsHeight}{\csuse{@PB#1LeftFloatsHeight}}
+ \csdimgdef{@PB#2RightHeight}{\csuse{@PB#1RightHeight}}
+ \csdimgdef{@PB#2RightFloatsHeight}{\csuse{@PB#1RightFloatsHeight}}
+ \csdimgdef{@PB#2UsedLeft}{\csuse{@PB#1UsedLeft}}
+ \csdimgdef{@PB#2UsedRight}{\csuse{@PB#1UsedRight}}
+
+ \seq_gclear_new:c {@PB#2LeftFloatHeights}
+ \seq_gclear_new:c {@PB#2LeftFloatSpacesBelow}
+ \seq_gset_eq:cc {@PB#2LeftFloatHeights} {@PB#1LeftFloatHeights}
+ \seq_gset_eq:cc {@PB#2LeftFloatSpacesBelow} {@PB#1LeftFloatSpacesBelow}
+}
+\ExplSyntaxOff
+
+\newcommand\@PBsavePageDataAs[2]{
+ \@PBsaveDimAs{@PB#1Height}{@PB#2Height}
+ \@PBsaveDimAs{@PB#1LeftHeight}{@PB#2LeftHeight}
+ \@PBsaveDimAs{@PB#1LeftFloatsHeight}{@PB#2LeftFloatsHeight}
+ \@PBsaveDimAs{@PB#1RightHeight}{@PB#2RightHeight}
+ \@PBsaveDimAs{@PB#1RightFloatsHeight}{@PB#2RightFloatsHeight}
+ \@PBsaveDimAs{@PB#1UsedLeft}{@PB#2UsedLeft}
+ \@PBsaveDimAs{@PB#1UsedRight}{@PB#2UsedRight}
+
+ \@PBsaveToggleAs{@PB#1HasFloats}{@PB#2HasFloats}
+ \@PBsaveToggleAs{@PB#1HasFloatcol}{@PB#2HasFloatcol}
+ \@PBsaveToggleAs{@PB#1HasFootnotes}{@PB#2HasFootnotes}
+ \@PBsaveToggleAs{@PB#1HasMarginpars}{@PB#2HasMarginpars}
+
+ \@PBsaveSeqAs{@PB#1LeftFloatHeights}{@PB#2LeftFloatHeights}
+ \@PBsaveSeqAs{@PB#1LeftFloatSpacesBelow}{@PB#2LeftFloatSpacesBelow}
+}
+
+\newcommand\@PBsavePageData[1]{
+ \@PBsavePageDataAs{#1}{#1}
+}
+
+\newcommand\@PBsaveToggleAs[2]{
+ \immediate\write\@mainaux{\providetoggle{#2}}
+ \iftoggle{#1}
+ {\immediate\write\@mainaux{\global\toggletrue{#2}}}
+ {\immediate\write\@mainaux{\global\togglefalse{#2}}}
+}
+
+\newcommand\@PBsaveToggle[1]{
+ \@PBsaveToggleAs{#1}{#1}
+}
+
+\newcommand\@PBsaveDimAs[2]{
+ \immediate\write\@mainaux{\csdimgdef{#2}{\csuse{#1}}}
+}
+
+\newcommand\@PBsaveDim[1]{
+ \@PBsaveDimAs{#1}{#1}
+}
+
+\ExplSyntaxOn
+\newcommand\@PBsaveSeqAs[2]{
+ \immediate\write\@mainaux{\string\ExplSyntaxOn}
+ \immediate\write\@mainaux{\string\seq_gclear_new:c {#2}}
+ \seq_map_inline:cn {#1}
+ {\immediate\write\@mainaux{\string\global\string\seq_put_right:cn {#2}{##1}}}
+ \immediate\write\@mainaux{\string\ExplSyntaxOff}
+}
+\ExplSyntaxOff
+
+\newcommand\@PBsaveSeq[1]{
+ \@PBsaveSeqAs{#1}{#1}
+}
+
+% \end{macrocode}
+% \Finale
diff --git a/macros/latex/contrib/pbalance/pbalance.ins b/macros/latex/contrib/pbalance/pbalance.ins
new file mode 100644
index 0000000000..2e7d2a2db8
--- /dev/null
+++ b/macros/latex/contrib/pbalance/pbalance.ins
@@ -0,0 +1,49 @@
+%% Copyright 2020 Nelson Lago <lago@ime.usp.br>
+%%
+%% This work may be distributed and/or modified under the conditions of the
+%% LaTeX Project Public License, either version 1.3 of this license or (at
+%% your option) any later version. The latest version of this license can be
+%% found at http://www.latex-project.org/lppl.txt and version 1.3 or later
+%% is part of all distributions of LaTeX version 2005/12/01 or later.
+%%
+%% This work has the LPPL maintenance status `maintained'.
+%%
+%% The Current Maintainer of this work is Nelson Lago <lago@ime.usp.br>.
+
+\input docstrip.tex
+\keepsilent
+\usedir{tex/latex/pbalance}
+
+\preamble
+Copyright 2020 Nelson Lago <lago@ime.usp.br>
+
+This work may be distributed and/or modified under the conditions of the
+LaTeX Project Public License, either version 1.3 of this license or (at
+your option) any later version. The latest version of this license can be
+found at http://www.latex-project.org/lppl.txt and version 1.3 or later
+is part of all distributions of LaTeX version 2005/12/01 or later.
+
+This work has the LPPL maintenance status `maintained'.
+
+The Current Maintainer of this work is Nelson Lago <lago@ime.usp.br>.
+
+\endpreamble
+
+\generate{\file{pbalance.sty}{\from{pbalance.dtx}{package}}}
+
+\obeyspaces
+\Msg{****************************************************}
+\Msg{* *}
+\Msg{* To finish the installation you have to move the *}
+\Msg{* following file into a directory searched by TeX: *}
+\Msg{* *}
+\Msg{* pbalance.sty *}
+\Msg{* *}
+\Msg{* To produce the documentation run the file *}
+\Msg{* pbalance.dtx through LaTeX. *}
+\Msg{* *}
+\Msg{* Happy TeXing! *}
+\Msg{* *}
+\Msg{****************************************************}
+
+\endbatchfile
diff --git a/macros/latex/contrib/pbalance/pbalance.pdf b/macros/latex/contrib/pbalance/pbalance.pdf
new file mode 100644
index 0000000000..319570a8dd
--- /dev/null
+++ b/macros/latex/contrib/pbalance/pbalance.pdf
Binary files differ