%% This is part of the OpTeX project, see http://petr.olsak.net/optex \_codedecl \begmulti {Balanced columns <2022-11-26>} % preloaded in format \_doc ----------------------------- \`\_betweencolumns` or \`\_leftofcolumns` or \`\_rightofcolumns` include a material printed between columns or left of all columns or right of all columns respectivelly. The \^`\_betweencolumns` must include a stretchability or a material with exactly \^`\colsep` width. You can redefine these macros. For example the rule between colums can be reached by `\_def\_betweencolumns{\hss\vrule\hss}`.\nl \`\_multiskip` puts its material at the start and at the end of \^`\begmulti`...\^`\endmulti`. \_cod ----------------------------- \_def\_betweencolumns{\_hss} \_def\_leftofcolumns{} \_def\_rightofcolumns{} \_def\_multiskip{\_medskip} % space above and below \begmulti...\endmulti \_doc ----------------------------- The code used here is documented in detail in the \"\TeX/book naruby", pages 244--246, free available, \url{http://petr.olsak.net/tbn.html}, but in Czech. Roughly speaking, macros complete all material between \`\begmulti``` and \`\endmulti` into one `\vbox 6`. Then the macro measures the amount of free space at the current page using `\pagegoal` and `\pagtotal` and does `\vsplit` of `\vbox 6` to columns with a height of such free space. This is done only if we have enough amount of material in `\vbox 6` to fill the full page by columns. This is repeated in a loop until we have less amount of material in `\vbox 6`. Then we run \`\_balancecolumns` which balances the last part of the columns. Each part of printed material is distributed to the main vertical list as `\hbox{}` and we need not do any change in the output routine. If you have paragraphs in \^`\begmulti`... \^`\endmulti` environment then you may say `\raggedright` inside this environment and you can re-assign `\widowpenalty` and `\clubppenalty` (they are set to 10000 in \OpTeX/). \_cod ----------------------------- \_newcount\_mullines \_def\_begmulti #1 {\_par\_bgroup\_wipeepar \_ifnum\_lastpenalty>10000 \_vskip4.5\_baselineskip\_penalty9999 \_vskip-4.5\_baselineskip \_fi \_multiskip \_def\_Ncols{#1} \_setbox6=\_vbox\_bgroup\_bgroup \_let\_setxhsize=\_relax \_penalty-99 %% \hsize := column width = (\hsize+\colsep) / n - \colsep \_setbox0=\_hbox{\_leftofcolumns\_rightofcolumns}% \_advance\_hsize by-\_wd0 \_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 \_ea\_egroup\_ea\_egroup\_ea\_baselineskip\_the\_baselineskip\_relax \_dimen0=.8\_maxdimen \_tmpnum=\_dimen0 \_divide\_tmpnum by\_baselineskip \_splittopskip=\_baselineskip \_setbox1=\_vsplit6 to0pt % initialize first \splittopskip in \box6 %% \dimen1 := the free space on the page \_penalty0 % initialize \_pageoal \_ifdim\_pagegoal=\_maxdimen \_setcolsize\_vsize \_else \_setcolsize{\_dimexpr\_pagegoal-\_pagetotal}\_fi \_ifdim \_dimen1<2\_baselineskip \_vfil\_break \_setcolsize\_vsize \_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 \_multiskip \_egroup } \_doc ----------------------------- Splitting columns... \_cod ----------------------------- \_def\_makecolumns{\_bgroup % full page, destination height: \dimen1 \_vbadness=20000 \_dimen6=\_wd6 \_createcolumns \_printcolumns \_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 \_setcolsize\_vsize \_dimen2=\_dimen1 \_advance\_dimen2 by-\_baselineskip %% split the material to more pages? \_ifvoid6 \_else \_ifdim \_dimen0>\_dimen2 \_ea\_ea\_ea \_splitpart \_else \_balancecolumns % last balancing \_fi \_fi } \_doc ----------------------------- Final balancing of the columns. \_cod ----------------------------- \_def\_balancecolumns{\_bgroup \_setbox7=\_copy6 % destination height: \dimen0 \_ifdim\_dimen0>\_baselineskip \_else \_dimen0=\_baselineskip \_fi \_vbadness=20000 \_dimen6=\_wd6 \_dimen1=\_dimen0 \_def\_tmp{\_createcolumns \_ifvoid6 \_else \_advance \_dimen1 by.2\_baselineskip \_setbox6=\_copy7 \_ea \_tmp \_fi}\_tmp \_printcolumns \_egroup } \_doc ----------------------------- \`\_setcolsize``` sets initial value `\dimen1=` which is used as height of columns at given page. The correction `\splittopskip`$-$`\topskip` is done if the columns start at the top of the page.\nl \`\_createcolumns` prepares columns with given height `\dimen1` side by side to the `\box1`.\nl \`\_printcolumns` prints the columns prepared in `\box1`. The first `\hbox{}` moves typesetting point to the next baseline. Next negative skip ensures that the first line from splitted columns is at this position. \_cod ----------------------------- \_def\_setcolsize #1{\_dimen1=#1\_relax \_ifdim\_dimen1=\_vsize \_advance \_dimen1 by \_splittopskip \_advance \_dimen1 by-\_topskip \_fi } \_def\_createcolumns{% \_setbox1=\_hbox{\_leftofcolumns}\_tmpnum=0 \_loop \_ifnum\_Ncols>\_tmpnum \_advance\_tmpnum by1 \_setbox1=\_hbox{\_unhbox1 \_ifvoid6 \_hbox to\_dimen6{\_hss}\_else \_vsplit6 to\_dimen1 \_fi \_ifnum\_Ncols=\_tmpnum \_rightofcolumns \_else \_betweencolumns \_fi}% \_repeat } \_def\_printcolumns{% \_hbox{}\_nobreak\_vskip-\_splittopskip \_nointerlineskip \_hbox to\_hsize{\_unhbox1}% } \_public \begmulti \endmulti ; \_endcode % ------------------------------------- 2022-11-26 \at least three lines in the beginning of \begmulti at the page 2022-05-05 `\_betweencolumns` etc. introduced. 2021-05-20 Colors inside \begmulti...\endmuti, bug fixed 2020-03-26 Introduced