%% This is file 'prerex.sty'
%%
%% Copyright (C) 2006-09 R. D. Tennent, rdt@cs.queensu.ca
%%
%% This work may be distributed and/or modified under the
%% conditions of the LaTeX Project Public License, either version 1.3
%% of this license or (at your option) any later version.
%% The latest version of this license is in
%% http://www.latex-project.org/lppl.txt
%% and version 1.3 or later is part of all distributions of LaTeX
%% version 2003/12/01 or later.
%%
%% This work has the LPPL maintenance status "author-maintained".
%
% Instructions supported inside \begin{chart} ... \end{chart}:
%
% \[req]{half|full}course x,y: {course code}{course title}{timetable code}
%
% \mini x,y: {course code}
%
% solid arrow: \prereq x0,y0,x1,y1: \prereqc x0,y0,x1,y1;curvature:
% dotted arrow: \coreq x0,y0,x1,y1: \coreqc x0,y0,x1,y1;curvature:
% dashed arrow: \recomm x0,y0,x1,y1: \recommc x0,y0,x1,y1;curvature:
%
% \text x,y: {line of text}
%
% \grid coordinate grid background
%
% Stand-alone instructions (for explanatory notes):
%
% \solidarrow in-line solid arrow
% \dottedarrow in-line dotted arrow
% \dashedarrow in-line dashed arrow
%
% \lightbox in-line light course box
% \boldbox in-line bold course box
%
% The following defaults are defined in prerex.sty (but may be re-defined by the user):
%
% \newcommand{\DefaultCurvature}{20}
%
% where the argument should be in the range 0-100; 0 means no curvature.
%
% \newcommand{\CourseURL}[3]{file:#3.html}
%
% where the arguments supplied at the call are the x and y coordinates
% and the course code.
%
% \newcommand{\background}{yellow!15}
%
% \setlength{\unit}{5.7816pt} length of a coordinate unit; gives 10 pixels per unit at 125dpi
% \newcommand{\dpi}{125}
% \newcommand\PixelsPerUnit{10}
% \setcounter{diagheight}{75} but reduced to 65 in landscape mode
% \newcommand{\solidwidth}{0.5pt}
% \newcommand{\dottedwidth}{0.8pt}
% \newcommand{\dashedwidth}{0.5pt}
% \newcommand{\boldwidth}{1.0pt}
% \newcommand{\smallersize}{\relsize{-3}}
%
% The nominal diagram width is 10 + (\textwidth divided by \unit).
%
\NeedsTeXFormat{LaTeX2e}[1995/12/01]
\ProvidesPackage{prerex}[2009/11/12 v5.4 LaTeX style for prerequisite charts, pgf version]
% Changelog:
%
% Version 5.4
%
% code clean-up
%
% Version 5.3
%
% produces an image-generating script in \jobname.sh
%
% Version 5.2
%
% use \grid and \foreach (tikz) instead of \multido
% half-course boxes now have a minimum height (5 units) to improve uniformity
%
% Version 5.1
%
% generates image-map data in \jobname_n.html for nth chart when n>1
%
% Version 5.0
%
% also generates \jobname.html with image-map data for all node URLs
% new configuration commands \dpi and \PixelsPerUnit
% default \unit length adjusted to give 10 pixels per coordinate unit at 125 dpi
%
% Version 4.4
%
% increase ysep parameter to 1.8pt to separate course-code or text and arrow tails for minis
% and text boxes
%
% Version 4.3
%
% introduce \smallersize configuration command
%
% Version 4.2
%
% using tinting with xcolor package to ease background-color changes
%
% Version 4.1
%
% Version 4.0
%
% Implement the \text command to place a line of text (centered at the coordinates) in a chart
%
% Version 3.8.1:
%
% adjust arraystretch factors to work with long-ascender fonts such as Futura
% adjust inner sep parameters to work with oblique/italic fonts
% remove workaround for pgf-1.10 bug described at
% http://sourceforge.net/forum/forum.php?thread_id=1621660&forum_id=477363
% require version 1.18 (or later) of pgf
%
% Version 3.8:
%
% require version 1.10 (or later) of pgf
%
% Version 3.7:
%
% anchor nodes must be non-null for latex/dvips
%
% Version 3.6:
%
% first pgf-based version
%
% Version 3.5:
% Version 3.4:
%
% introduce arrow borders to improve the appearance of crossing arrows
% change default widths to artifacts created when arrow borders
% occlude box boundaries
%
% Version 3.3:
%
% arrows (as well as course boxes and minis) are hyperlinked with coordinate URIs
%
% Version 3.2:
%
% Version 3.1:
%
% Version 3.0:
%
% "anchor" hyperlinks are added to coordinate grid to allow computation of
% chart coordinates at mouse clicks
%
% Version 2.0:
%
% CourseURL now takes 3 arguments
% box/mini coordinates displayed in (some) PDF viewers when grid on
%
% Version 1.0.2:
%
% using \relsize{-3} rather than \scriptsize
% using \textsf in \lightbox and \boldbox
%
% Version 1.0.1:
%
% using \RequirePackage rather than \usepackage (suggested by Herbert Voss)
%
\newlength{\unit}
\setlength{\unit}{5.7816pt} % 10 pixels per unit at 125dpi; 1pt = (1/72.27) in.
\newcommand{\PixelsPerUnit}{10}
\newcommand{\dpi}{125}
\RequirePackage{relsize}
\RequirePackage{calc}
\RequirePackage{pgf}[2007/06/12]
\RequirePackage{tikz}\usetikzlibrary{arrows}
\RequirePackage{ifthen}
\RequirePackage{textcomp}
\RequirePackage{zref-savepos}
\PassOptionsToPackage{urlcolor=black,colorlinks}{hyperref}
\RequirePackage{hyperref}
\RequirePackage{xcolor}
\definecolor{light}{gray}{0.5}
\definecolor{somewhatlight}{gray}{0.7}
\definecolor{verylight}{gray}{0.85}
\definecolor{white}{rgb}{1.0,1.0,1.0} % not transparent, hides grid
\newcommand{\DefaultCurvature}{20} % 0 for no curvature
\newcommand{\CourseURL}[3]{file:#3.html}
\newcommand{\background}{yellow!15}
\newcommand{\solidwidth}{0.5pt}
\newcommand{\boldwidth}{1.0pt}
\newcommand{\dottedwidth}{0.8pt}
\newcommand{\dashedwidth}{0.5pt}
\newcommand{\smallersize}{\relsize{-3}}
\newcounter{@myangle}
\newcounter{@inangle}
\newcounter{@dx}
\newcounter{@dy}
\newif\ifgridon
\gridonfalse
\newcounter{@gridwidth}
\newcounter{@gridright}
\newcounter{@gridheight}
\newcounter{@gridtop}
\newcounter{@diagwidth}
\newcounter{diagheight}
\setcounter{diagheight}{75}
\ifdim\paperwidth>\paperheight
\setcounter{diagheight}{65}
\fi
\newcounter{chart} % in case there is more than one chart in the document
\newcounter{xNW}\newcounter{yNW} % coordinates of NW corner of a node
\newcounter{xSE}\newcounter{ySE} % coordinates of SE corner of a node
\def\@unitmult{\unit * 5} % used for the grid and as the minimum height of half-course boxes
\def\@outputImapData#1,#2:#3#4#5{%
% #1,#2 coordinates
% #3 URL
% #4 horizontal delta
% #5 vertical delta
%
\setcounter{xNW}{\dpi * \ratio{\zposx{gridOrigin_\thechart}sp}{1in}}% # of pixels from left edge to origin
\addtocounter{xNW}{(#1-#4)*\PixelsPerUnit}% add # pixels from origin to node (-#4 units)
\setcounter{xSE}{\dpi * \ratio{\zposx{gridOrigin_\thechart}sp}{1in}}%
\addtocounter{xSE}{(#1+#4)*\PixelsPerUnit}% add # pixels from origin to node (+#4 units)
\setcounter{yNW}{ \dpi * \ratio{\paperheight}{1in}} % # of pixels for the whole page
\addtocounter{yNW}{ 0 - \dpi * \ratio{\zposy{gridOrigin_\thechart}sp}{1in}} % subtract # pixels from bottom edge to origin
\addtocounter{yNW}{0 - (#2 - #5) * \PixelsPerUnit } % subtract # of pixels from origin to node (-#5)
\setcounter{ySE}{ \dpi * \ratio{\paperheight}{1in}}
\addtocounter{ySE}{0 - \dpi * \ratio{\zposy{gridOrigin_\thechart}sp}{1in}}
\addtocounter{ySE}{0 - (#2 + #5) * \PixelsPerUnit } % subtract # of pixels from origin to node (+#5)
\immediate\write\@imapfile{<area shape=rect coords="\thexNW,\theyNW,\thexSE,\theySE" href="\CourseURL{#1}{#2}{#3}" target="_new">}%
}
\def\@halfcourse#1,#2:#3#4#5{%
\node[draw,thin,fill=\background,rounded corners=2pt,inner ysep=0.5pt,minimum height=\@unitmult](x#1y#2) at (#1,#2)%
{\textsf{%
\renewcommand{\arraystretch}{0.8}%
\href{\CourseURL{#1}{#2}{#3}}{\begin{tabular}{@{\hspace{1pt}}c@{\hspace{1pt}}}%
\mbox{\smallersize#3}\,\hfill\,\mbox{\smallersize#5}\\ #4%
\end{tabular}}}%
};%
\@outputImapData#1,#2:{#3}{4}{2}%
}
\def\@reqhalfcourse#1,#2:#3#4#5{%
\node[draw,line width=\boldwidth,fill=\background,rounded corners=2pt,inner ysep=0.5pt,minimum height=\@unitmult](x#1y#2) at (#1,#2)%
{\textsf{\textbf{%
\renewcommand{\arraystretch}{0.8}%
\href{\CourseURL{#1}{#2}{#3}}{\begin{tabular}{@{\hspace{1pt}}c@{\hspace{1pt}}}%
\mbox{\smallersize#3}\,\hfill\,\mbox{\smallersize#5}\\ #4%
\end{tabular}}}%
}};%
\@outputImapData#1,#2:{#3}{4}{2}%
}
\def\@fullcourse#1,#2:#3#4#5{%
\node[draw,thin,fill=\background,rounded corners=2pt,inner ysep=0.5pt](x#1y#2) at (#1,#2)%
{\textsf{%
\renewcommand{\arraystretch}{1.7}%
\href{\CourseURL{#1}{#2}{#3}}{\begin{tabular}{@{\hspace{1pt}}c@{\hspace{1pt}}}%
\mbox{\smallersize#3}\,\hfill\,\mbox{\smallersize#5}\\ #4%
\end{tabular}}}%
};%
\@outputImapData#1,#2:{#3}{4}{5}%
}
\def\@reqfullcourse#1,#2:#3#4#5{%
\node[draw,line width=\boldwidth,fill=\background,rounded corners=2pt,inner ysep=0.5pt](x#1y#2) at (#1,#2)%
{\textsf{\textbf{%
\renewcommand{\arraystretch}{1.7}%
\href{\CourseURL{#1}{#2}{#3}}{\begin{tabular}{@{\hspace{1pt}}c@{\hspace{1pt}}}%
\mbox{\smallersize#3}\,\hfill\,\mbox{\smallersize#5}\\ #4%
\end{tabular}}}}%
};%
\@outputImapData#1,#2:{#3}{4}{5}%
}
\def\@mini#1,#2:#3{%
\node[fill=white,draw=white,inner ysep=1.8pt](x#1y#2) at (#1,#2)%
{\textsf{%
\href{\CourseURL{#1}{#2}{#3}}{%
\mbox{\smallersize#3}}}};%
\@outputImapData#1,#2:{#3}{2}{1}%
}
\def\@text#1,#2:#3{%
% include coordinates if grid on, but don't hyperlink if grid off
\ifgridon
\node[fill=white,draw=white,inner ysep=1.8pt](x#1y#2) at (#1,#2)%
{\href{coord: #1,#2}{\mbox{#3}}};%
\else
\node[fill=white,draw=white,inner ysep=1.8pt](x#1y#2) at (#1,#2){\mbox{#3}};%
\fi
}
\def\@prereq#1,#2,#3,#4:{%
\setcounter{@dy}{#2-#4}
\ifnum\the@dy<10
\@straight#1,#2,#3,#4:
\else\ifnum#1=#3
\@straight#1,#2,#3,#4:
\else\ifnum#2=#4
\@straight#1,#2,#3,#4:
\else
\@prereqc#1,#2,#3,#4;\DefaultCurvature:
\fi\fi\fi
}
\def\@prereqc#1,#2,#3,#4;#5:{%
\ifnum#5=0
\@straight#1,#2,#3,#4:
\else
\@curved#1,#2,#3,#4;#5:
\fi
}
\def\@recomm#1,#2,#3,#4:{%
\setcounter{@dy}{#2-#4}
\ifnum\the@dy<10
\@straightDashed#1,#2,#3,#4:
\else\ifnum#1=#3
\@straightDashed#1,#2,#3,#4:
\else\ifnum#2=#4
\@straightDashed#1,#2,#3,#4:
\else
\@recommc#1,#2,#3,#4;\DefaultCurvature:
\fi\fi\fi
}
\def\@recommc#1,#2,#3,#4;#5:{%
\ifnum#5=0
\@straightDashed#1,#2,#3,#4:
\else
\@curvedDashed#1,#2,#3,#4;#5:
\fi
}
\def\@coreq#1,#2,#3,#4:{%
\setcounter{@dy}{#2-#4}
\ifnum\the@dy<10
\@straightDotted#1,#2,#3,#4:
\else\ifnum#1=#3
\@straightDotted#1,#2,#3,#4:
\else\ifnum#2=#4
\@straightDotted#1,#2,#3,#4:
\else
\@coreqc#1,#2,#3,#4;\DefaultCurvature:
\fi\fi\fi
}
\def\@coreqc#1,#2,#3,#4;#5:{%
\ifnum#5=0
\@straightDotted#1,#2,#3,#4:
\else
\@curvedDotted#1,#2,#3,#4;#5:
\fi
}
\def\@straight#1,#2,#3,#4:{%
\ifgridon
\draw[draw=white,line width=1.5pt](x#1y#2) -- (x#3y#4) node[midway] {\href{coord: #1,#2,#3,#4}{\quad}};
\else
\draw[draw=white,line width=1.5pt](x#1y#2) -- (x#3y#4) ;
\fi
\draw[-latex',draw=white,very thin](x#1y#2) -- (x#3y#4) ;
\draw[line width=\solidwidth](x#1y#2) -- (x#3y#4) ;
}
\def\@curved#1,#2,#3,#4;#5:{
\ifnum#3<#1
\setcounter{@dx}{#1-#3}
\setcounter{@myangle}{(-#5) * \the@dx * \the@dy * 2}
\else
\setcounter{@dx}{#3-#1}
\setcounter{@myangle}{#5 * \the@dx * \the@dy * 2}
\fi
\setcounter{@myangle}{\the@myangle / ((\the@dx + \the@dy) * (\the@dx + \the@dy))}
\setcounter{@inangle}{180 - \the@myangle}
\ifgridon
\draw[draw=white,line width=1.5pt](x#1y#2) to[out=\the@myangle,in=\the@inangle,relative] (x#3y#4) node[midway] {\href{coord: #1,#2,#3,#4}{\quad}} ;
\else
\draw[draw=white,line width=1.5pt](x#1y#2) to[out=\the@myangle,in=\the@inangle,relative] (x#3y#4) ;
\fi
\draw[-latex',draw=white,very thin](x#1y#2) to[out=\the@myangle,in=\the@inangle,relative] (x#3y#4) ;
\draw[line width=\solidwidth](x#1y#2) to[out=\the@myangle,in=\the@inangle,relative] (x#3y#4) ;
}
\def\@straightDashed#1,#2,#3,#4:{%
\ifgridon
\draw[draw=white,line width=1.5pt] (x#1y#2) -- (x#3y#4) node[midway] {\href{coord: #1,#2,#3,#4}{\quad}};
\else
\draw[draw=white,line width=1.5pt] (x#1y#2) -- (x#3y#4);
\fi
\draw[-latex',draw=white,very thin] (x#1y#2) -- (x#3y#4);
\draw[dashed,line width=\dashedwidth] (x#1y#2) -- (x#3y#4);
}
\def\@curvedDashed#1,#2,#3,#4;#5:{
\ifnum#3<#1
\setcounter{@dx}{#1-#3}
\setcounter{@myangle}{(-#5) * \the@dx * \the@dy * 2}
\else
\setcounter{@dx}{#3-#1}
\setcounter{@myangle}{#5 * \the@dx * \the@dy * 2}
\fi
\setcounter{@myangle}{\the@myangle / ((\the@dx + \the@dy) * (\the@dx + \the@dy))}
\setcounter{@inangle}{180 - \the@myangle}
\ifgridon
\draw[draw=white,line width=1.5pt](x#1y#2) to[out=\the@myangle,in=\the@inangle,relative] (x#3y#4) node[midway] {\href{coord: #1,#2,#3,#4}{\quad}} ;
\else
\draw[draw=white,line width=1.5pt](x#1y#2) to[out=\the@myangle,in=\the@inangle,relative] (x#3y#4) ;
\fi
\draw[-latex',draw=white,very thin](x#1y#2) to[out=\the@myangle,in=\the@inangle,relative] (x#3y#4) ;
\draw[dashed,line width=\dashedwidth](x#1y#2) to[out=\the@myangle,in=\the@inangle,relative] (x#3y#4) ;
}
\def\@straightDotted#1,#2,#3,#4:{%
\ifgridon
\draw[draw=white,line width=1.5pt] (x#1y#2) -- (x#3y#4) node[midway] {\href{coord: #1,#2,#3,#4}{\quad}};
\else
\draw[draw=white,line width=1.5pt] (x#1y#2) -- (x#3y#4);
\fi
\draw[-latex',draw=white,very thin] (x#1y#2) -- (x#3y#4);
\draw[loosely dotted,line width=\dottedwidth] (x#1y#2) -- (x#3y#4);
}
\def\@curvedDotted#1,#2,#3,#4;#5:{
\ifnum#3<#1
\setcounter{@dx}{#1-#3}
\setcounter{@myangle}{(-#5) * \the@dx * \the@dy * 2}
\else
\setcounter{@dx}{#3-#1}
\setcounter{@myangle}{#5 * \the@dx * \the@dy * 2}
\fi
\setcounter{@myangle}{\the@myangle / ((\the@dx + \the@dy) * (\the@dx + \the@dy))}
\setcounter{@inangle}{180 - \the@myangle}
\ifgridon
\draw[draw=white,line width=1.5pt](x#1y#2) to[out=\the@myangle,in=\the@inangle,relative] (x#3y#4) node[midway] {\href{coord: #1,#2,#3,#4}{\quad}} ;
\else
\draw[draw=white,line width=1.5pt](x#1y#2) to[out=\the@myangle,in=\the@inangle,relative] (x#3y#4) ;
\fi
\draw[-latex',draw=white,very thin](x#1y#2) to[out=\the@myangle,in=\the@inangle,relative] (x#3y#4) ;
\draw[loosely dotted,line width=\dottedwidth](x#1y#2) to[out=\the@myangle,in=\the@inangle,relative] (x#3y#4) ;
}
\def\solidarrow{%
\tikz[x=\unit,y=\unit,baseline=-0.5ex]
\draw[-latex',line width =\solidwidth] (0,0) -- (4,0);
}
\def\dottedarrow{%
\tikz[x=\unit,y=\unit,baseline=-0.5ex]
\draw[loosely dotted,line width=\dottedwidth,-latex'] (0,0) -- (4,0);
}
\def\dashedarrow{%
\tikz[x=\unit,y=\unit,baseline=-0.5ex]
\draw[dashed,line width=\dashedwidth,-latex'] (0,0) -- (4,0);
}
\def\lightbox{%
\tikz[thin,baseline=-0.5ex]\node[draw,fill=\background,rounded corners=2pt,inner sep=1.5pt]
{\textsf{light}};}
\def\boldbox{%
\tikz[baseline=-0.65ex]\node[draw,line width=\boldwidth,fill=\background,rounded corners=2pt,inner sep=1.8pt]
{\textsf{\textbf{bold}}};}
\def\@grid{
\gridontrue
\renewcommand{\CourseURL}[3]{coord: ##1,##2} % "coord:" makes it look like a URI
\setcounter{@gridwidth}{(\the@diagwidth-5) / 10}
\setcounter{@gridright}{10 * \value{@gridwidth}}
\setcounter{@gridheight}{\thediagheight / 10}
\setcounter{@gridtop}{10 * \value{@gridheight} }
\draw[line width=0.3pt,draw=verylight] (0,0) grid [step=1] (\value{@gridright},\value{@gridtop});
\draw[line width=0.4pt,draw=somewhatlight] (0,0) grid [step=5] (\value{@gridright},\value{@gridtop});
\foreach \i in {0,10,...,\value{@gridright}}
\node at (\i,-4){\mbox{\textsf{\small \i}}};
\foreach \i in {0,10,...,\value{@gridtop}}
\node at (-5,\i){\mbox{\textsf{\small \i}}};
\foreach \i in {0,10,...,\value{@gridright}}
\node at (\i,\value{@gridtop}+4){\mbox{\textsf{\small \i}}};
\foreach \i in {0,10,...,\value{@gridtop}}
\node at (\value{@gridright}+5,\i){\mbox{\textsf{\small \i}}};
% anchors are to allow computation of coordinates from mouse clicks in kpdf/okular:
% latex/dvips requires non-null href box
\node at (-5,-4) {\href{anchor: -5,-4}{\kern1sp}};
\setcounter{@gridtop}{\value{@gridtop} + 4}
\setcounter{@gridright}{\value{@gridright} + 5}
\node at (\the@gridright,\the@gridtop) {\href{anchor: \the@gridright,\the@gridtop}{\kern1sp}};
}
%
%
% \begin{chart} ... \end{chart}
%
%
\newenvironment{chart}
{ \setcounter{@diagwidth}{10 + 1 * \ratio{\textwidth}{\unit}}
\newwrite\@imapfile % image-map data
\newwrite\@scriptfile % shell script to generate image file
\ifthenelse{\value{chart} = 0}
{ \immediate\openout\@imapfile=\jobname.map
\immediate\write\@imapfile{<map name="\jobname">}
}
{ \immediate\openout\@imapfile=\jobname_\thechart.map
\immediate\write\@imapfile{<map name="\jobname_\thechart">}
}
\let\halfcourse=\@halfcourse
\let\reqhalfcourse=\@reqhalfcourse
\let\fullcourse=\@fullcourse
\let\reqfullcourse=\@reqfullcourse
\let\mini=\@mini
\let\text=\@text
\let\prereq=\@prereq
\let\prereqc=\@prereqc
\let\coreq=\@coreq
\let\coreqc=\@coreqc
\let\recomm=\@recomm
\let\recommc=\@recommc
\let\grid=\@grid
\begin{tikzpicture}[x=\unit,y=\unit]
\tikzstyle{every rectangle node}=[inner xsep=1.8pt]
\setcounter{@gridwidth}{(\the@diagwidth-5) / 10}
\setcounter{@gridright}{10 * \value{@gridwidth}}
\setcounter{@gridheight}{\thediagheight / 10}
\setcounter{@gridtop}{10 * \value{@gridheight} }
\useasboundingbox (0,-2) rectangle (\value{@gridright},\value{@gridtop});
node at (0,0) {\kern1sp\zsavepos{gridOrigin_\thechart}};
% access absolute page coordinates of the origin using \zposx and \zposy
}
{
\end{tikzpicture}
\write\@imapfile{</map>}
\closeout\@imapfile
\zsavepos{EndOfChart_\thechart} % determine cropping coordinates
\ifdim\paperwidth<\paperheight
% portrait mode
\setcounter{xSE}{\dpi * \ratio{\zposx{EndOfChart_\thechart}sp}{1in}}%
\setcounter{ySE}{ \dpi * \ratio{\paperheight}{1in}}
\addtocounter{ySE}{0 - \dpi * \ratio{\zposy{EndOfChart_\thechart}sp}{1in}}
\addtocounter{ySE}{0 + 2 * \PixelsPerUnit } % bottom margin
\else
% landscape mode
\setcounter{xSE}{ \dpi * \ratio{\paperwidth}{1in}}
\addtocounter{xSE}{0 - \dpi * \ratio{\zposx{EndOfChart_\thechart}sp}{1in}}%
\addtocounter{xSE}{0 + 2 * \PixelsPerUnit } % bottom margin
\setcounter{ySE}{ \dpi * \ratio{\paperheight}{1in}}
\addtocounter{ySE}{ 0 - \dpi * \ratio{\zposy{EndOfChart_\thechart}sp}{1in}}
\fi
\edef\HasH{\expandafter\@gobble\string\#}
\ifthenelse{\value{chart} = 0}
{ % generate a script to generate, crop, and compress a chart image
\immediate\openout\@scriptfile=\jobname.sh
\immediate\write\@scriptfile{\HasH!/bin/sh}
\immediate\write\@scriptfile{convert -density 125 \jobname.pdf \jobname.png}
% defer remaining output till cropping coordinates are available
\write\@scriptfile{mogrify -crop \thexSE x\theySE +0+0 \jobname.png}
\write\@scriptfile{optipng -q \jobname.png} % maximal loss-less compression
\write\@scriptfile{exit 0}
\closeout\@scriptfile
}
{ % more than one chart; unlikely a script would be usable
}
\stepcounter{chart}
}