%% S. Lurp --- STRETCHY --- MIT License
\ifcsname pdfextension\endcsname
    \protected\def\pdfliteral{\pdfextension literal}
    \let\pdfxform=\saveboxresource
    \let\pdfrefxform=\useboxresource
    \def\pdflastxform{\lastsavedboxresourceindex}
\fi

\let\@xp=\expandafter
\def\strty@gbl#1{}
\def\strty@strip{\@xp\strty@gbl\string}

\bgroup\lccode`?=`p\lccode`!=`t
\lowercase{\egroup\def\strty@rmpt#1?!{#1}}
\def\strty@nopt#1{\@xp\strty@rmpt\the\dimexpr #1\relax}

\def\strty@mult#1#2{\strty@nopt{#1\dimexpr #2pt\relax}}
\def\strty@add#1#2{\strty@nopt{#1pt+#2pt}}

\def\strty@afterfi#1#2\fi{\fi#1}

\def\strty@repeatit#1#2#3{%
    \ifnum#1>0 %
        #2%
        \strty@afterfi{\@xp\strty@repeatit\@xp{\the\numexpr #1-1\relax}{#2}{#3}}%
    \else%
        #3%
    \fi%
}

\def\strty@@prepeat#1#2#3{%
    \unless\ifnum#1>#2 %
        #3{#1}%
        \strty@afterfi{\@xp\strty@@prepat\@xp{\the\numexpr #1+1\relax}{#2}{#3}}%
    \fi%
}
        

\def\strty@prepeat#1#2{\strty@@prepeat{1}{#1}{#2}}

\def\strty@maxdim#1#2{\ifdim\dimexpr#1\relax>\dimexpr#2\relax \dimexpr#1\relax\else\dimexpr#2\relax\fi}

\def\strty@@ifnextchar{%
    \ifx\strty@reg@D\strty@reg@A %
        \expandafter\strty@reg@B%
    \else%
        \expandafter\strty@reg@C%
    \fi%
}

\long\def\strty@ifnextchar#1#2#3{%
    \let\strty@reg@A=#1\relax\def\strty@reg@B{#2}\def\strty@reg@C{#3}%
    \futurelet\strty@reg@D\strty@@ifnextchar%
}

\def\strty@scalebox#1#2{{%
    \setbox0=\hbox{#2}%
    \hbox to#1\wd0{%
        \vrule width\z@ height#1\ht0 depth#1\dp0%
        \pdfliteral{q #1 0 0 #1 0 0 cm}%
        \rlap{\copy0}%
        \pdfliteral{Q}%
        \hfil%
    }%
}}

\def\strty@pttrans{0.996264 0 0 0.996264 0 0 cm}
\def\strty@ptm{.996264}
\def\strty@setpttrans{%
    \def\strty@trans##1##2{{\strty@mult\strty@ptm{##1}}{\strty@mult\strty@ptm{##2}}}%
}

\def\strty@unpack#1#2{#1 #2}
\def\strty@p#1#2{\@xp\strty@unpack\expanded{\strty@trans{#1}{#2}}\space}
\def\strty@unpack@d#1#2#3#4{%
    \strty@nopt{#1pt+\strty@ptm\dimexpr#3\relax} %
    \strty@nopt{#2pt+\strty@ptm\dimexpr#4\relax}%
}
\def\strty@pd#1#2#3#4{\@xp\strty@unpack@d\expanded{\strty@trans{#1}{#2}}{#3}{#4}\space}