% !TeX root = ./examples/bear.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-bears}[2022/06/17 version v1.0 Draw teddy bears in TikZ]

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

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

\newif\ifbear@threeD
\newif\ifbear@back
\newif\ifbear@contour

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

\def\bear@draw{%
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % minimal bounding box size 
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \path (-0.8, 0.0) rectangle (0.8, 2.13);
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % 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
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \ifbear@threeD
    \def\bear@part@draw[##1]{\shade[ball color=##1]}
  \else% 3D
    \ifbear@contour
      \def\bear@part@draw[##1]{\draw[##1,\bear@contour,fill=white,line width=\scalingfactor*0.4pt]}
    \else% contour
      \def\bear@part@draw[##1]{\fill[##1]}
    \fi% contour
  \fi% 3D
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % Body parts
  % 
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % adding hook for users to customise %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \csname bearhookbackground\endcsname
  \csname tikzlinghookbackground\endcsname
  %
  % Arms %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \bear@part@draw[\bear@body!70!black] (0.525,0.9) ellipse[x radius=0.35, y radius=0.15, rotate=-50];
  \bear@part@draw[\bear@body!70!black] (-0.525,0.9) ellipse[x radius=0.35, y radius=0.15, rotate=50];
  %
  % Feet if back %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \ifbear@back
    \bear@part@draw[\bear@body!70!black] (0.425, 0.3) circle[radius=0.28]; 
    \bear@part@draw[\bear@body!70!black] (-0.425, 0.3) circle[radius=0.28];
  \fi% back
  %
  % Body %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \bear@part@draw[\bear@body!70!black] (0,0.75) ellipse[x radius=0.55, y radius=0.65]; 
  \unless\ifbear@back
    \bear@part@draw[\bear@body!50!white] (0,0.7) ellipse[x radius=0.35, y radius=0.4];
  \fi% back
  %
  % adding hook for users to customise %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \csname bearhookbelly\endcsname
  \csname tikzlinghookbelly\endcsname
  %
  % Feet %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \unless\ifbear@back
    \bear@part@draw[\bear@body!70!black] (0.425, 0.3) circle[radius=0.28]; 
    \bear@part@draw[\bear@body!70!black] (-0.425, 0.3) circle[radius=0.28];
    \bear@part@draw[\bear@body!50!white] (0.425, 0.3) circle[radius=0.17]; 
    \bear@part@draw[\bear@body!50!white] (-0.425, 0.3) circle[radius=0.17];
  \fi% back
  %
  % Ears %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \bear@part@draw[\bear@body!70!black] (0.375, 1.95) circle[radius=0.15];
  \bear@part@draw[\bear@body!70!black] (-0.375, 1.95) circle[radius=0.15];
  \unless\ifbear@back
    \bear@part@draw[\bear@body!50!white] (0.375, 1.95) circle[radius=0.1];
    \bear@part@draw[\bear@body!50!white] (-0.375, 1.95) circle[radius=0.1];
  \fi% back
  %
  % Head %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \bear@part@draw[\bear@body!70!black] (0, 1.55) circle[radius=0.5]; 
  %
  % Show details only from the front %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \unless\ifbear@back
    %
    % Muzzle %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \bear@part@draw[\bear@body!50!white] (0, 1.4) ellipse[x radius=0.28, y radius=0.2]; 
    \bear@part@draw[\bear@body!70!white!80!red] (0, 1.5) ellipse[x radius=0.15, y radius=0.08]; 
    %
    % Eyes %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \bear@part@draw[\bear@eye] (-0.155, 1.7) circle[radius=0.05]; 
    \bear@part@draw[\bear@eye] (0.155, 1.7) circle[radius=0.05]; 
    %
    % Mouth %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \draw[\bear@mouth,line width=\scalingfactor*0.4pt] (0.145, 1.38) arc [start angle=-20, end angle=-160, radius=0.16];
  %
  \fi% back
  %
  % adding hook for users to customise %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \csname bearhookbody\endcsname
  \csname tikzlinghookbody\endcsname
  %
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Documentation
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%\clearpage
%\section[Bear]{B\"ar, the teddy bear}
%
%\emph{If you look very closely at the group picture in \href{https://www.tug.org/TUGboat/tb39-2/tb122wright-tug18.pdf}{TUG goes to Rio} you can spot the real B\"ar in it}
%
%\subsection{Package name}
%
%\begin{tcolorbox}[lower separated=false, lefthand width=.8\linewidth]
%\vspace*{0.5cm}
%\lstinline|\usepackage{tikzlings-bears}| 
%\vspace*{0.5cm}
%\end{tcolorbox}
%
%\subsection{Basic Usage}
%
%\begin{tcblisting}{}
%\bear
%\end{tcblisting}
%
%\subsection{Options}
%
%The basic teddy bear can be modified by changing its colour:
%\begin{tcblisting}{}
%\bear[body=blue]
%\end{tcblisting}
%
%In addition to the colour of the body, the colour of various body parts can be adjusted:
%\begin{tcblisting}{}
%\bear[eye=red]
%\end{tcblisting}
%\begin{tcblisting}{}
%\bear[mouth=red]
%\end{tcblisting}
%
%To view the teddy bear from behind:
%\begin{tcblisting}{}
%\bear[back]
%\end{tcblisting}
%
%The key \lstinline|3D| will make the teddy bear 3-dimensional:
%\begin{tcblisting}{}
%\bear[3D]
%\end{tcblisting}
%
%And finally the \lstinline|contour| key will only draw the outlines:
%\begin{tcblisting}{}
%\bear[contour=black]
%\end{tcblisting}
%
%\subsection{Extension}
%
%The B\"ar and Ulrike Fischer wrote the fantastic \lstinline|bearwear| package, that provides many different clothing options for the \lstinline|TikZbears|. All the other \tikzlings admire them for the nice clothing!
%
%A short example:
%
%\begin{tcblisting}{}
%%\usepackage{bearwear}
%\bear
%\bearwear[
%  long sleeves, 
%  shirt=red!80!black
%]
%\end{tcblisting}
%
%Many more options and examples can be found in the package documentation \url{https://ctan.org/pkg/bearwear}.