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使用 OPmac 宏时分页符处的多列问题

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使用 OPmac 宏时分页符处的多列问题

我正在使用 OPmac 宏来处理 tcolorbox 中的多列，如下所建议： tcolorbox 可破坏框内的多列

到目前为止，它运行得很好，但我遇到了一个问题。每当我想从普通文本切换到两列文本（不适合一页）时，页面上的剩余空间就不会被使用。相反，两列文本从下一页开始。如果文本对于此页面来说也太大，它会形成正常的分页符。这个问题也发生在 tcolorbox 之外。有没有办法让列在普通文本之后立即开始并在页面末尾中断？

\documentclass[11pt, oneside, a4paper]{report}

\usepackage{lipsum}


\newdimen\colsep \colsep=2em

\newcount\mullines
\newcount\tmpnum
\def\corrsize #1{%% #1 := #1 + \splittopskip - \topskip
   \advance #1 by \splittopskip \advance #1 by-\topskip
}
\def\begmulti #1 {\par\bgroup\penalty0 \def\Ncols{#1}
   \setbox6=\vbox\bgroup\penalty0
   %% \hsize := Sirka sloupce = (\hsize+\colsep) / n - \colsep
   \advance\hsize by\colsep
   \divide\hsize by\Ncols  \advance\hsize by-\colsep
   \mullines=0
   \def\par{\ifhmode\endgraf\global\advance\mullines by\prevgraf\fi}%
}
\def\endmulti{\vskip-\prevdepth\vfil
   \expandafter\egroup\expandafter\baselineskip\the\baselineskip\relax 
   \dimen0=.8\maxdimen \tmpnum=\dimen0 \divide\tmpnum by\baselineskip 
   \splittopskip=\baselineskip
   \setbox1=\vsplit6 to0pt
   %% \dimen1 := the free space on the page
   \vsize=.95\vsize
   \ifdim\pagegoal=\maxdimen \dimen1=\vsize \corrsize{\dimen1}
   \else \dimen1=\pagegoal \advance\dimen1 by-\pagetotal \fi
   \ifdim \dimen1<2\baselineskip
     \vfil\break \dimen1=\vsize \corrsize{\dimen1} \fi
   \ifnum\mullines<\tmpnum \dimen0=\ht6 \else \dimen0=.8\maxdimen \fi
   \divide\dimen0 by\Ncols \relax
   %% split the material to more pages?
   \ifdim \dimen0>\dimen1 \splitpart
   \else \balancecolumns \fi  % only balancing
   \egroup
}
\def\makecolumns{\bgroup % full page, destination height: \dimen1
   \vbadness=20000 \setbox1=\hbox{}\tmpnum=0
   \loop \ifnum\Ncols>\tmpnum
      \advance\tmpnum by1
      \setbox1=\hbox{\unhbox1 \vsplit6 to\dimen1 \hss}
   \repeat
   \hbox{}\nobreak\vskip-\splittopskip \nointerlineskip
   \null\nobreak\medskip\hbox to\hsize{\unhbox1\unskip}
   \dimen0=\dimen1 \divide\dimen0 by\baselineskip \multiply\dimen0 by\Ncols
   \global\advance\mullines by-\dimen0
   \egroup
}
\def\splitpart{%
   \makecolumns % full page
   \vskip 0pt plus 1fil minus\baselineskip \break
   \ifnum\mullines<\tmpnum \dimen0=\ht6 \else \dimen0=.8\maxdimen \fi
   \divide\dimen0 by\Ncols \relax
   \ifx\balancecolumns\flushcolumns \advance\dimen0 by-.5\vsize \fi
   \dimen1=\vsize \corrsize{\dimen1}\dimen2=\dimen1
   \advance\dimen2 by-\Ncols\baselineskip
   %% split the material to more pages?
   \ifvoid6 \else
      \ifdim \dimen0>\dimen2 \expandafter\expandafter\expandafter \splitpart
      \else \balancecolumns % last balancing
   \fi \fi
}
\def\balancecolumns{\bgroup \setbox7=\copy6 % destination height: \dimen0
   \ifdim\dimen0>\baselineskip \else \dimen0=\baselineskip \fi
   \vbadness=20000
   \def\tmp{%
      \setbox1=\hbox{}\tmpnum=0
      \loop \ifnum\Ncols>\tmpnum
         \advance\tmpnum by1
         \setbox1=\hbox{\unhbox1
              \ifvoid6 \hbox to\wd6{\hss}\else \vsplit6 to\dimen0 \fi\hss}
      \repeat
   \ifvoid6 \else
      \advance \dimen0 by.2\baselineskip
      \setbox6=\copy7
      \expandafter \tmp \fi}\tmp
   \hbox{}\nobreak\vskip-\splittopskip \nointerlineskip
   \null\nobreak\medskip\hbox to\hsize{\unhbox1\unskip}%
   \egroup
}

\begin{document}

\chapter{Example}

\lipsum[1-9]

\begmulti 2
\lipsum[1-4]
\endmulti

\end{document}

在此处输入图片描述

答案1

请注意，和\begmulti在\endmulti纯 TeX 中没有问题。我不知道为什么 LaTeX 在这种情况下不起作用，但我不会深入研究它，因为 LaTeX 不是我的首要任务。可以有一个补丁（也许它会在更多情况下起作用：）：

\advance\dimen1 by-\baselineskip尝试在代码第 29 行后添加，即：

   \ifdim\pagegoal=\maxdimen \dimen1=\vsize \corrsize{\dimen1}
   \else \dimen1=\pagegoal \advance\dimen1 by-\pagetotal \fi
   \advance\dimen1 by-\baselineskip % <<< this line is added
   \ifdim \dimen1<2\baselineskip
   ...

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