%% FILE:   setspace.sty in SYS2.TEX.PUB.ISULATEX.STYLES
%% AUTHOR: Erica M. S. Harris
%% DATE:   April 1990
%% DESCR:  LaTeX Document style option "setspace"
%%         Usage:  \documentstyle[...,setspace,...]{...}
%%         Based on the doublespace option created by Stephen Page.
%%
%%         This style option provides commands and environments for doing
%%         double and  one-and-a-half spacing based on pt size.
%%
%%         Single spacing is the default.
%%
%%         Three commands, \doublespacing, \onehalfspacing, and
%%         \singlespacing, are for use in the preamble to set the overall
%%         spacing for the document.  If a different spacing is required then
%%         the \setstretch{baselinestretch} command can be used in the
%%         preamble to set the baselinestretch appropriately.  The default
%%         spacing with this style option is single spacing.
%%
%%         Three environments, singlespace, onehalfspace, and doublespace,
%%         allow the spacing to be changed within the document.  Both the
%%         onehalfspace and doublespace environments are intended to increase
%%         the spacing, so the onehalfspace environment should not be used in
%%         a double spaced document.  If an increased spacing different from
%%         one-and-a-half or double spacing is required then the spacing
%%         environment can be used.  The spacing environment takes one
%%         argument which is the larger baselinestretch to use,
%%         e.g., \begin{spacing}{2.5}.
%%
%%         \footins is adjusted the same as \parskip - appears to work. Lose
%%         stretch parts but don't consider that to be crucial
%%
%%         Removed code for altering spacing before and after displayed
%%         equations - just looked too much.
%%
%% MODS:
%%
%% PLEASE REPORT ANY BUGS
%%
%%   Old Documentation follows:
%%         1. A new environment "singlespace" is provided, within which single
%%            spacing will apply.
%%            JFL - changed so that it works in regular text and so that
%%            vertical space before and after is correctly computed
%%         2. Double spacing is turned off within footnotes and floats (figures
%%            and tables).
%%         3. Proper double spacing happens below tabular environments and in
%%            other places where LaTeX uses a strut.
%%         4. Slightly more space is inserted before footnotes.
%%         5. JFL - fixes spacing before and after displayed math
%%
%%
%%    mods:   Jean-Francois Lamy
%%            lamy@ai.toronto.edu
%%            lamy@utai.uucp
%%
%% POSSIBLE BUGS:
%%    . Increasing struts may possibly cause some other obscure part of
%%      formatting to fall over.
%%    . \begin{singlespace}\begin{quote} produces the wrong spacing before
%%      the quote (extra glue is inserted).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%---Set up double spacing

\def\doublespacing{\ifcase \@ptsize \relax % 10pt
    \def\baselinestretch{1.667}
  \or % 11pt
    \def\baselinestretch{1.618}
  \or % 12pt
    \def\baselinestretch{1.655}
  \fi}
%\doublespacing % the default

\def\onehalfspacing{\ifcase \@ptsize \relax % 10pt
    \def\baselinestretch{1.25}
  \or % 11pt
    \def\baselinestretch{1.213}
  \or % 12pt
    \def\baselinestretch{1.241}
  \fi}

\def\singlespacing{\def\baselinestretch{1}}

\def\setstretch#1{\renewcommand{\baselinestretch}{#1}}

%---Stretch the baseline BEFORE calculating the strut size. This improves
%   spacing below tabular environments etc., probably...
%   Comments are welcomed.
\ifx\selectfont\undefined\gdef\@setsize#1#2#3#4{\@nomath#1\let\@currsize#1 %
   \baselineskip #2\baselineskip\baselinestretch\baselineskip%
   \parskip\baselinestretch\parskip%
    \setbox\strutbox\hbox{\vrule height.7\baselineskip
       depth.3\baselineskip width\z@}%
   \skip\footins\baselinestretch\skip\footins%
   \normalbaselineskip\baselineskip#3#4}\else
\gdef\@setsize#1#2#3#4{\@nomath#1\size{#4}{#2}\selectfont%
  \let\@currsize#1\baselineskip\baselinestretch\baselineskip%
   \parskip\baselinestretch\parskip%
   \skip\footins\baselinestretch\skip\footins}\fi

%---Increase the space between last line of text and footnote rule.
%\skip\footins 20pt plus4pt minus4pt

%---Reset baselinestretch within footnotes and floats.

\def\@xfloat#1[#2]{\ifhmode \@bsphack\@floatpenalty -\@Mii\else
   \@floatpenalty-\@Miii\fi\def\@captype{#1}\ifinner
      \@parmoderr\@floatpenalty\z@
    \else\@next\@currbox\@freelist{\@tempcnta\csname ftype@#1\endcsname
       \multiply\@tempcnta\@xxxii\advance\@tempcnta\sixt@@n
       \@tfor \@tempa :=#2\do
                        {\if\@tempa h\advance\@tempcnta \@ne\fi
                         \if\@tempa t\advance\@tempcnta \tw@\fi
                         \if\@tempa b\advance\@tempcnta 4\relax\fi
                         \if\@tempa p\advance\@tempcnta 8\relax\fi
         }\global\count\@currbox\@tempcnta}\@fltovf\fi
    \global\setbox\@currbox\vbox\bgroup
    \def\baselinestretch{1}\@normalsize
    \boxmaxdepth\z@
    \hsize\columnwidth \@parboxrestore}

\long\def\@footnotetext#1{\insert\footins{\def\baselinestretch{1}\footnotesize
    \interlinepenalty\interfootnotelinepenalty
    \splittopskip\footnotesep
    \splitmaxdepth \dp\strutbox \floatingpenalty \@MM
    \hsize\columnwidth \@parboxrestore
   \edef\@currentlabel{\csname p@footnote\endcsname\@thefnmark}\@makefntext
    {\rule{\z@}{\footnotesep}\ignorespaces
      #1\strut}}}

% A single spaced quote (say) is done by surrounding singlespace with quote.
%
\def\singlespace{%
\vskip\parskip%
\vskip\baselineskip%
\def\baselinestretch{1}%
\ifx\@currsize\normalsize\@normalsize\else\@currsize\fi%
\vskip-\parskip%
\vskip-\baselineskip}

\def\endsinglespace{\par}

%  spacing, doublespace and onehalfspace all are meant to INCREASE the
%  spacing (i.e. calling onehalfspace from within doublespace will not
%  produce a graceful transition between spacings)
%
\def\spacing#1{\par%
 \def\baselinestretch{#1}%
 \ifx\@currsize\normalsize\@normalsize\else\@currsize\fi}

\def\endspacing{\par%
 \vskip \parskip%
 \vskip \baselineskip%
}% \endgroup%
% \vskip -\parskip%
% \vskip -\baselineskip%
% \begingroup}

% one and a half spacing is 1.5 x pt size
\def\onehalfspace{\ifcase \@ptsize \relax  % 10pt
     \spacing{1.25}
   \or % 11pt
     \spacing{1.213}
   \or % 12pt
     \spacing{1.241}
   \fi}
\let\endonehalfspace=\endspacing

% double spacing is 2 x pt size
\def\doublespace{\ifcase \@ptsize \relax % 10pt
    \spacing{1.667}
  \or % 11pt
    \spacing{1.618}
  \or % 12pt
    \spacing{1.655}
  \fi}
\let\enddoublespace=\endspacing