%
% bounddvi.sty
% 2020/09/25 v8.0-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}[2020/09/25 v8.0 bounddvi]

% catcode trick to hide \iftombow ... \else ... \fi
% since \iftombow is defined only in pLaTeX.
\ifx\pfmtname\@undefined
  \catcode`\Q=14\relax
\else
  \catcode`\Q=9\relax
\fi

% 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 by pLaTeX;
% so, we set \stock{width,height} to invoke stock test in those
% files (probably meant for memoir.cls).
Q \iftombow
Q   % if \stockwidth/\stockheight are not available,
Q   % define them now
Q   \ifx\stockwidth\@undefined \newdimen\stockwidth \fi
Q   \ifx\stockheight\@undefined \newdimen\stockheight \fi
Q   % if \stockwidth already has effective value, do nothing;
Q   % otherwise assume pLaTeX-style tombow and set it to
Q   % \paperwidth + 2in (similar for \stockheight)
Q   \ifdim\stockwidth>\z@\else
Q     \stockwidth\paperwidth \advance\stockwidth2in
Q   \fi
Q   \ifdim\stockheight>\z@\else
Q     \stockheight\paperheight \advance\stockheight2in
Q   \fi
Q \fi

% reset catcode trick
\catcode`\Q=11\relax

%% 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.)
\ifx\AddToHook\@undefined\else
  \AtBeginDocument{\AtBeginDvi{%
    \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}}
  \expandafter\endinput
\fi

%% 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 append the specification to the _beginning_ of
% \@begindocumenthook; this ensures proper papersize when
% dvips (TeX Live 2016 or earlier) is used.
\begingroup
\def\@prependto@begindocumenthook{\global\setbox\@begindvibox
  \vbox{\csname yoko\endcsname\unvbox\@begindvibox
    \begingroup
      \ifx\stockwidth\@undefined\else \ifdim\stockwidth>\z@
        \paperwidth\stockwidth
      \fi\fi
      \ifx\stockheight\@undefined\else \ifdim\stockheight>\z@
        \paperheight\stockheight
      \fi\fi
      \divide\paperwidth\@m\multiply\paperwidth\mag
      \divide\paperheight\@m\multiply\paperheight\mag
      \special{papersize=\the\paperwidth,\the\paperheight}%
    \endgroup}}
\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