bounddvi.sty

%
% bounddvi.sty
% 2020/10/08 v8.2-v7.0 h.y.acetaminophen [at] gmail.com
% 2004/12/15 v6.0-v1.0 inoue [at] ma.ns.tcu.ac.jp
%
% This package, originally written by Koichi Inoue
% and modified by Hironobu Yamashita, is distributed
% as part of the gentombow bundle.
% https://github.com/aminophen/gentombow
%

\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{bounddvi}[2020/10/08 v8.2 bounddvi]

% Note: graphics/color drivers
%  - dvips.def 2016/07/10 v3.1a or later
%  - dvipdfmx.def 2016/07/10 v4.12 or later
% emit papersize special _only_ when \Gin@setpagesizetrue
% and \mag = 1000. When graphicx(s) or color is used with
% setpagesize option (= default since 2016) and \mag equals
% to 1000, we can exploit its routine.
% (they are using \AtBeginDocument{\AtBeginDvi{...}})
% However, these .def files do _not_ care about tombow; so,
% we set \stock{width,height} to invoke stock test in those
% files (probably meant for memoir.cls).

% detection of \iftombow status is delayed until \AtBeginDocument,
% to support both (u)pLaTeX kernel and ``gentombow.sty''
\def\bddv@maybe@ensure@stock{%
  \ifx\tombowtrue\@undefined
    \let\bddv@ensure@stock\relax % skip if-tokens
  \fi
  \bddv@ensure@stock}

% when \iftombow == \iftrue, we also need \stock{width,height}
\def\bddv@ensure@stock{%
  \iftombow
    % if \stockwidth/\stockheight are not available,
    % define them now
    \ifx\stockwidth\@undefined \newdimen\stockwidth \fi
    \ifx\stockheight\@undefined \newdimen\stockheight \fi
    % if \stockwidth already has effective value, do nothing;
    % otherwise assume pLaTeX-style tombow and set it to
    % \paperwidth + 2in (similar for \stockheight)
    \ifdim\stockwidth>\z@\else
      \stockwidth\paperwidth \advance\stockwidth2in
    \fi
    \ifdim\stockheight>\z@\else
      \stockheight\paperheight \advance\stockheight2in
    \fi
  \fi
}

% prepare actual papersize special
\def\bddv@emit@papersize{%
  \begingroup
    % if \stockwidth/\stockheight are defined & have effective
    % values, copy them to \paperwidth/\paperheight
    % for current group
    \ifx\stockwidth\@undefined\else \ifdim\stockwidth>\z@
      \paperwidth\stockwidth
    \fi\fi
    \ifx\stockheight\@undefined\else \ifdim\stockheight>\z@
      \paperheight\stockheight
    \fi\fi
    % adjust for \mag and emit papersize special
    \divide\paperwidth\@m\multiply\paperwidth\mag
    \divide\paperheight\@m\multiply\paperheight\mag
    \special{papersize=\the\paperwidth,\the\paperheight}%
  \endgroup
}

%% Since LaTeX2e 2020-10-01, \@begindocumenthook is deprecated
%% and \UseHook{begindocument} etc. are used.
%% This code appends papersize special to the _end_ of the hook.
%% (Note: support for old dvips is removed.)
\providecommand\IfFormatAtLeastTF{\@ifl@t@r\fmtversion}
\IfFormatAtLeastTF{2020-10-01}{%
  \AtBeginDocument{%
    \bddv@maybe@ensure@stock
    \AtBeginDvi{\bddv@emit@papersize}}%
  \endinput
}{}

%% The rest of this package is meant for
%% LaTeX2e 2020-02-02 PL5 or older.

% following code is almost equivalent to
%   \AtBeginDocument{\AtBeginDvi{...}}
% however, we put into the _beginning_ of \@begindocumenthook;
% this ensures proper papersize when old dvips
% (TeX Live 2016 or earlier) is used.
% also, note that old pLaTeX (before 2016/07/01) needs \yoko
% at the beginning of \AtBeginDvi.
\begingroup
\def\@prependto@begindocumenthook{%
  \bddv@maybe@ensure@stock
  \global\setbox\@begindvibox\vbox{%
    \csname yoko\endcsname\unvbox\@begindvibox
    \bddv@emit@papersize}}
\toks@\expandafter\expandafter\expandafter
  {\expandafter\@prependto@begindocumenthook\@begindocumenthook}
\xdef\@begindocumenthook{\the\toks@}
% append papersize special again to the _end_ of the
% current \@begindocumenthook; this will be meaningful e.g. when
% geometry is loaded before bounddvi.
% (geometry adds \AtBeginDocument{\AtBeginDvi{...}} specification)
\expandafter\g@addto@macro\expandafter\@begindocumenthook
  \expandafter{\@prependto@begindocumenthook}
\endgroup

\endinput