% !TeX root = ./examples/owl.tex
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% This package is part of the TikZlings package
%% A package to bring cute little animals and other beings into tikz
%% Maintained by samcarter
%%
%% Project repository and bug tracker:
%% https://github.com/samcarter/tikzlings
%%
%% Released under the LaTeX Project Public License v1.3c or later
%% See http://www.latex-project.org/lppl.txt
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\ProvidesPackage{tikzlings-owls}[2022/06/17 version v1.0 Draw owls in TikZ]

\RequirePackage{tikz}
\RequirePackage{tikzlings-addons}

\newcommand*{\owl}[1][]{%
  \begin{scope}%
    \tikzset{/owl/.cd,#1}%
    \owl@draw%
  \end{scope}%
  \thing[#1]%
  % adding hook for users to customise %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \csname owlhookforeground\endcsname
  \csname tikzlinghookforeground\endcsname
  %  
}

\newif\ifowl@threeD
\newif\ifowl@back
\newif\ifowl@contour

\tikzset{
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % Pass unknown keys on to tikz
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  /owl/.search also={/tikz,/pgf,/thing},
  /owl/.cd,
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % body
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  body/.store in     = \owl@body,
  body               = brown!70!black,
  eye/.store in      = \owl@eye,
  eye                = white!90!gray,
  pupil/.store in    = \owl@pupil,
  pupil              = brown!30!black,
  bill/.store in     = \owl@bill,
  bill               = orange,
  feet/.store in     = \owl@feet,
  feet               = orange,  
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % options
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  3D/.code           = \owl@threeDtrue,
  back/.code         = \owl@backtrue,  
  contour/.code      = \owl@contourtrue
                       \def\owl@contour{#1},
  contour/.default   = black,  
  outline/.forward to = /owl/contour,   
}

\def\owl@draw{%
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % minimal bounding box size 
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \path (-0.73, 0.08) rectangle (0.73, 2.24);
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % store the current scale factor
  % from https://github.com/samcarter/tikzlings/issues/3#issuecomment-461373494
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \pgfgettransformentries{\tmpscaleA}{\tmpscaleB}{\tmpscaleC}{\tmpscaleD}{\tmp}{\tmp}%
  \pgfmathsetmacro{\scalingfactor}{sqrt(abs(\tmpscaleA*\tmpscaleD-\tmpscaleB*\tmpscaleC))*sqrt(abs((\pgf@xx/1cm)*(\pgf@yy/1cm)-(\pgf@xy/1cm)*(\pgf@yx/1cm)))}%
  \pgfmathsetmacro{\xscalefactor}{\tmpscaleA}
  \pgfmathsetmacro{\yscalefactor}{\tmpscaleD}
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  % 
  % switch between 2D, 3D and contours, from
  % https://chat.stackexchange.com/transcript/message/45991801#45991801
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \ifowl@threeD
    \def\owl@part@draw[##1]{\shade[ball color=##1]}
  \else% 3D
    \ifowl@contour
      \def\owl@part@draw[##1]{\draw[##1,\owl@contour,fill=white,line width=\scalingfactor*0.4pt]}
    \else% contour
      \def\owl@part@draw[##1]{\fill[##1]}
    \fi% contour
  \fi% 3D
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % Body parts
  % 
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % adding hook for users to customise %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \csname owlhookbackground\endcsname
  \csname tikzlinghookbackground\endcsname
  %
  % Arms %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \owl@part@draw[\owl@body] (0.575,0.8) ellipse[x radius=0.38, y radius=0.1, rotate=-80];
  \owl@part@draw[\owl@body] (-0.575,0.8) ellipse[x radius=0.38, y radius=0.1, rotate=80]; 
  %
  % Feet if back %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \ifowl@back
    \owl@part@draw[\owl@feet] (0.175,0.2) ellipse[x radius=0.03, y radius=0.1];
    \owl@part@draw[\owl@feet] (0.225,0.21) ellipse[x radius=0.03, y radius=0.1, rotate=20];
    \owl@part@draw[\owl@feet] (0.275,0.23) ellipse[x radius=0.03, y radius=0.1, rotate=40];
    \owl@part@draw[\owl@feet] (-0.175,0.2) ellipse[x radius=0.03, y radius=0.1];
    \owl@part@draw[\owl@feet] (-0.225,0.21) ellipse[x radius=0.03, y radius=0.1, rotate=-20];
    \owl@part@draw[\owl@feet] (-0.275,0.23) ellipse[x radius=0.03, y radius=0.1, rotate=-40];
  \fi% back
  %
  % Body %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \owl@part@draw[\owl@body] (0.595, 0.92) .. controls (0.595, 0.26) and (0.355, 0.18) .. (0, 0.18) .. controls (-0.355, 0.18) and (-0.595, 0.26) .. (-0.595, 0.92) .. controls (-0.605, 1.58) and (-0.335, 2.11) .. (0, 2.11) .. controls (0.335, 2.11) and (0.605, 1.58) .. (0.595, 0.92) -- cycle;
  %
  % Ears %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \owl@part@draw[\owl@body] (-0.6361, 1.777) .. controls   (-0.6361, 1.777) and   (-0.7586, 1.9603) ..   (-0.6759, 2.2145) .. controls   (-0.3248, 1.912) and   (0.3248, 1.912) ..   (0.6759, 2.2145) .. controls   (0.7586, 1.9603) and   (0.6361, 1.777) ..   (0.6361, 1.777);
  %
  % Belly %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \unless\ifowl@back
    \owl@part@draw[\owl@body!50!white] (0.425,0.5) .. controls (0.425,0.31) and (0.245,0.27) .. (0,0.27) .. controls (-0.245,0.27) and (-0.425,0.31) .. (-0.425,0.5) .. controls (-0.425,0.81) and (-0.225,0.98) .. (0,0.98) .. controls (0.225,0.98) and (0.425,0.81) .. (0.425,0.5) -- cycle;
  \fi% back
  %
  % adding hook for users to customise %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \csname owlhookbelly\endcsname
  \csname tikzlinghookbelly\endcsname
  %
  % head %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \owl@part@draw[\owl@body] (0,1.55) ellipse[x radius=0.7, y radius=0.55];
  %
  % Eyes %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \unless\ifowl@back
    \ifowl@contour
      \owl@part@draw[\owl@eye] (-0.28, 1.6) circle[radius=0.22];
      \owl@part@draw[\owl@eye] (0.28, 1.6) circle[radius=0.22];
    \else% contour
      \fill[\owl@eye] (-0.28, 1.6) circle[radius=0.22];
      \fill[\owl@eye] (0.28, 1.6) circle[radius=0.22];
    \fi% contour
    \owl@part@draw[\owl@pupil]   (-0.28, 1.6) circle[radius=0.15];
    \owl@part@draw[\owl@pupil]   (0.28, 1.6) circle[radius=0.15];
    \owl@part@draw[white] (0.25, 1.64) circle[radius=0.03];
    \owl@part@draw[white] (-0.31, 1.64) circle[radius=0.03];
  \fi% back
  %
  % Bill %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \unless\ifowl@back
    \owl@part@draw[\owl@bill] (0, 1.4) -- (-0.1, 1.3) -- (0, 1.15) -- (0.1, 1.3) -- cycle;
  \fi% back
  %
  % Feet %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \unless\ifowl@back
    \owl@part@draw[\owl@feet] (0.175,0.2) ellipse[x radius=0.03, y radius=0.1];
    \owl@part@draw[\owl@feet] (0.225,0.21) ellipse[x radius=0.03, y radius=0.1, rotate=20];
    \owl@part@draw[\owl@feet] (0.275,0.23) ellipse[x radius=0.03, y radius=0.1, rotate=40];
    \owl@part@draw[\owl@feet] (-0.175,0.2) ellipse[x radius=0.03, y radius=0.1];
    \owl@part@draw[\owl@feet] (-0.225,0.21) ellipse[x radius=0.03, y radius=0.1, rotate=-20];
    \owl@part@draw[\owl@feet] (-0.275,0.23) ellipse[x radius=0.03, y radius=0.1, rotate=-40];
  \fi% back
  %
  % adding hook for users to customise %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \csname owlhookbody\endcsname
  \csname tikzlinghookbody\endcsname
  %
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Documentation
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%\clearpage
%\section[Owl]{Jake, the owl}
%
%\emph{The owl Jake was inspired by the avatar of one of the world's top TikZperts}
%
%\subsection{Package name}
%
%\begin{tcolorbox}[lower separated=false, lefthand width=.8\linewidth]
%\vspace*{0.5cm}
%\lstinline|\usepackage{tikzlings-owls}| 
%\vspace*{0.5cm}
%\end{tcolorbox}
%
%\subsection{Basic Usage}
%
%\begin{tcblisting}{}
%\owl
%\end{tcblisting}
%
%\subsection{Options}
%
%The basic owl can be modified by changing its colour:
%\begin{tcblisting}{}
%\owl[body=blue]
%\end{tcblisting}
%
%In addition to the colour of the body, the colour of various body parts can be adjusted:
%\begin{tcblisting}{}
%\owl[eye=red]
%\end{tcblisting}
%\begin{tcblisting}{}
%\owl[pupil=red]
%\end{tcblisting}
%\begin{tcblisting}{}
%\owl[bill=red]
%\end{tcblisting}
%\begin{tcblisting}{}
%\owl[feet=red]
%\end{tcblisting}
%
%To view the owl from behind:
%\begin{tcblisting}{}
%\owl[back]
%\end{tcblisting}
%
%The key \lstinline|3D| will make the owl 3-dimensional:
%\begin{tcblisting}{}
%\owl[3D]
%\end{tcblisting}
%
%And finally the \lstinline|contour| key will only draw the outlines:
%\begin{tcblisting}{}
%\owl[contour=black]
%\end{tcblisting}