\documentclass[a4paper, 11pt, BCOR = 0 pt, oneside, english]{scrartcl}
\usepackage{tikz}
\usepackage{fancyvrb}
\usetikzlibrary{arrows, shapes}
\usepackage[light, largesmallcaps]{kpfonts}
\usepackage{coffeestains}
\usepackage[useregional]{datetime2}
\usepackage{gitinfo2}
\usepackage{scrlayer-scrpage}
\usepackage{tcolorbox}
\usepackage{varioref}
\usepackage[english]{babel}
\author{Patrick Bideault}
\usepackage{hyperref}
\hypersetup{
	  pdftitle = LaTeX Coffee Stains,
          colorlinks,
	  linkcolor={brown!60!black},
          citecolor={brown!60!black},
          urlcolor={brown!60!black}
        }
\ifoot{\textsf{\textcolor{lightgray}{version \gitRel{} -- \DTMtoday}
  }}
\cfoot{}
\ofoot{\textsf{\thepage}}

\begin{document}

\title{LaTeX Coffee Stains}
\author{a package by Hanno Rein\\
  maintained by Patrick Bideault\\
  \texttt{pb-latex@gmx.fr}\\
  ~\\
  \url{https://framagit.org/Pathe/coffeestains}}
\renewcommand{\today}{version \gitRel{} -- \DTMtoday{}}
\maketitle

\coffeestainA{0.9}{0.85}{-25}{5cm}{1.3cm}
\label{stainA}
\section{Introduction}
This package provides an essential feature to \LaTeX~that has been missing for
too long. It adds a coffee stain to your documents. A lot of time can be saved
by printing stains directly on the page rather than adding them manually. You can
choose from four different stain types:
\begin{itemize}
\item[A.] $270^\circ$ circle stain with two tiny splashes, like \vpageref{stainA}
  \item[B.] $60^\circ$ circle stain, as \vpageref{stainB}
  \item[C.] two splashes with light colours, as \vpageref{stainC}
  \item[D.] and a colourful twin splash, as \vpageref{stainD}
\end{itemize}

\section{Usage}
To use the package, simply place the \texttt{coffeestains.sty} file in the directory with all of your 
other \texttt{.tex} files \textit{or} install it properly (consult your distribution's manual). 
Then include the following line in the header of your document:
\begin{verbatim}
\usepackage{coffeestains}
\end{verbatim}

\vfill{}

\begin{tcolorbox}
  The command used for the above coffee stain is

  \verb|\coffeestainA{0.9}{0.85}{-25}{5cm}{1.3cm}|
\end{tcolorbox}
\newpage{}
\coffeestainB{0.7}{1}{-30}{18 pt}{-135 pt}
\label{stainB}

To place a coffee stain on a page, put one of the following commands in the source code of the relevant page: 
\begin{verbatim}
\coffeestainA{alpha}{scale}{angle}{xoff}{yoff}
\coffeestainB{alpha}{scale}{angle}{xoff}{yoff}
\coffeestainC{alpha}{scale}{angle}{xoff}{yoff}
\coffeestainD{alpha}{scale}{angle}{xoff}{yoff}
\end{verbatim}

\begin{itemize}
\item \texttt{alpha} is the transparency factor $\in [0,1]$;
\item \texttt{scale} is the scale factor, and the standard is \texttt{scale}=1;
\item \texttt{angle} is the angle of the stain, relative to its center. It is in
  degrees $\in [0,360]$;
\item the position relative to the centre of the page is given by x and
  y offsets \texttt{xoff} and \texttt{yoff}. It is advisable to specify
  a measurement unit.
\end{itemize}


\section{Copyright}
You can freely distribute this package as we do not believe in imaginary
property. All stains were self-made, photographed by Hanno Rein, processed with gimp
and traced with Inkscape. Donations should be made in coffee only to
\begin{quote}
Hanno Rein\\
University of Toronto at Scarborough\\
DPES Physics and Astrophysics\\
1265 Military Trail\\
Toronto, Ontario M1C 1A4\\
Canada
\end{quote}

\section{Desired improvements}
This package obviously helps, but many stains are still manually added to
documents: latte stains, tea stains, gazpacho stains\dots{} they all should be
printed in the future.

And our efforts shall go beyond the liquid stains: how many documents get their
grease stains manually printed in repair shops? The \LaTeX{} community shall
address this issue and create the adequate tools.

\vfill{}

\begin{tcolorbox}
  The command used for the above coffee stain is

  \verb|\coffeestainB{0.7}{1}{-30}{18 pt}{-135 pt}|
\end{tcolorbox}
\newpage{}
\section{Change Log}
\begin{itemize}
\item April 3, 2009: initial coffee stain by Hanno Rein. This version is still
  available at \url{http://legacy.hanno-rein.de/hanno-rein.de/archives/349}. In the actual git repository, this version is now tagged 0.1.
\item November 23, 2010: \texttt{coffee2.sty}, an improved version that works
  with pdflatex. Thanks to \href{http://www.sultanik.com/}{Evan Sultanik}! This
  version is now tagged 0.2.
\item March 24, 2011: \texttt{coffee3}, another improved version that works with
  pdflatex and allows you to scale, rotate and change the transparency of any
  coffee stain. Thanks to \href{http://pcmap.unizar.es/~pilar/}{Professor Luis
    Randez}! This version is now tagged 0.3.
\item May 25, 2012: \texttt{coffee4}, an improved version by
  \href{http://nepsweb.co.uk/homeapr/}{Adrian Robson}, who writes: “I find
  I rarely manage to put my coffee mug down exacly in the middle of my papers.
  So I have amended coffee3.sty to support off centre coffee stains.” This
  version is now tagged 0.4.
\item May 1, 2021: the \texttt{coffeestains} package on a git repository. The
  rotation of the stains is now relative to the centre of the stain itself, not
  anymore to the centre of the page. Version 0.5 by Patrick Bideault.
\end{itemize}
\coffeestainC{1}{1}{180}{0}{-5 mm}
\label{stainC}

\section{Eternal mottos}

Coffee is great.

\vspace{5mm}

\noindent
Coffee will save the world.

\vfill{}

\begin{tcolorbox}
  The command used for the above coffee stain is

  \verb|\coffeestainC{1}{1}{180}{0}{-5 mm}|
\end{tcolorbox}

\begin{tcolorbox}
  The command used for the coffee stain on the next page is

  \verb|\coffeestainD{0.4}{0.5}{90}{3 cm}{4 cm}|
\end{tcolorbox}

\newpage{}
\pagestyle{empty}
~\\

\coffeestainD{0.4}{0.5}{90}{3 cm}{4 cm}
\label{stainD}

\vfill{}
\begin{center}
\textsc{This page was intentionally left blank}

but we had to ruin it by letting you know.
\end{center}

\vfill{}
\end{document}