% !TeX root = ./examples/panda.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-pandas}[2022/06/17 version v1.0 Drawing pandas in TikZ]

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

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

\newif\ifpanda@threeD
\newif\ifpanda@back
\newif\ifpanda@contour

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

\def\panda@draw{%
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % minimal bounding box size 
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \path (-0.62,0.05) rectangle (0.62, 2.18);
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % 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
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \ifpanda@threeD
    \def\panda@part@draw[##1]{\shade[ball color=##1]}
  \else% 3D
    \ifpanda@contour
      \def\panda@part@draw[##1]{\draw[##1,\panda@contour,fill=white,line width=\scalingfactor*0.4pt]}
    \else% contour
      \def\panda@part@draw[##1]{\fill[##1]}
    \fi% contour
  \fi% 3D
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % Body parts
  % 
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % adding hook for users to customise %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \csname pandahookbackground\endcsname
  \csname tikzlinghookbackground\endcsname
  %
  % Feet if back %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \ifpanda@back
    \panda@part@draw[black] (0.32, 0.27) circle[radius=0.2]; 
    \panda@part@draw[black] (-0.32, 0.27) circle[radius=0.2];
  \fi% back
  %
  % Body %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \panda@part@draw[\panda@body!55!white] (0,0.78) ellipse[x radius=0.57, y radius=0.65];
  %
  % adding hook for users to customise %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \csname pandahookbelly\endcsname
  \csname tikzlinghookbelly\endcsname
  %
  % Arms %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \unless\ifpanda@back
    \begin{scope}[yshift=-0.08cm]
    \panda@part@draw[black] (0.28,0.93) ellipse[x radius=0.24, y radius=0.13, rotate=70];
    \panda@part@draw[black] (-0.28,0.93) ellipse[x radius=0.24, y radius=0.13, rotate=-70];
    \end{scope}
  \fi% back
  %
  % Feet %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \unless\ifpanda@back
    \panda@part@draw[black] (0.32, 0.27) circle[radius=0.2]; 
    \panda@part@draw[black] (-0.32, 0.27) circle[radius=0.2];
  \fi% back
  %
  % Ears %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \panda@part@draw[black] (0.32, 2) circle[radius=0.15];
  \panda@part@draw[black] (-0.32, 2) circle[radius=0.15];
  %
  % Head %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \panda@part@draw[\panda@body!55!white] (0.4897, 1.5886) .. controls (0.4614, 1.8238) and (0.25, 2.1172) .. (0, 2.1134) .. controls (-0.25, 2.1172) and (-0.4614, 1.8238) .. (-0.4897, 1.5886) .. controls (-0.5261, 1.3269) and (-0.2748, 1.2377) .. (0, 1.2377) .. controls (0.2748, 1.2377) and (0.5261, 1.3269) .. (0.4897, 1.5886) -- cycle;
  %
  % Show details only from the front %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \unless\ifpanda@back
    %
    % Eyes %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \panda@part@draw[black] (0.3732, 1.6905) .. controls (0.3498, 1.767) and (0.2032, 1.8059) .. (0.0944, 1.7715) .. controls (-0.0145, 1.7371) and (0.173, 1.5479) .. (0.2508, 1.5443) .. controls (0.3286, 1.5407) and (0.3965, 1.614) .. (0.3732, 1.6905) -- cycle;
    \panda@part@draw[black] (-0.3732, 1.6905) .. controls (-0.3498, 1.767) and (-0.2032, 1.8059) .. (-0.0944, 1.7715) .. controls (0.0145, 1.7371) and (-0.173, 1.5479) .. (-0.2508, 1.5443) .. controls (-0.3286, 1.5407) and (-0.3965, 1.614) .. (-0.3732, 1.6905) -- cycle;
    \panda@part@draw[\panda@eye] (-0.18, 1.7) circle[radius=0.05];
    \panda@part@draw[\panda@eye] (0.18, 1.7) circle[radius=0.05];
    \panda@part@draw[\panda@pupil] (0.17, 1.695) circle[radius=0.02];
    \panda@part@draw[\panda@pupil] (-0.17, 1.695) circle[radius=0.02];
    %
    % Mouth %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \draw[\panda@mouth,line width=\scalingfactor*0.2pt] (-0.16, 1.477) .. controls (-0.16, 1.477) and (-0.062, 1.37) .. (0, 1.506)  .. controls (0.062, 1.37) and (0.16, 1.477) .. (0.16, 1.477);
    %
    % Nose %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \panda@part@draw[black] (0,1.55) ellipse[x radius=0.07, y radius=0.04];
    %
  \fi% back
  %
  % adding hook for users to customise %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \csname pandahookbody\endcsname
  \csname tikzlinghookbody\endcsname
  %
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Documentation
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%\clearpage
%\section[Panda]{Meng Meng, the panda}
%
%\emph{Meng Meng is named after one of the pandas at the zoological garden Berlin}
%
%\subsection{Package name}
%
%\begin{tcolorbox}[lower separated=false, lefthand width=.8\linewidth]
%\vspace*{0.5cm}
%\lstinline|\usepackage{tikzlings-pandas}| 
%\vspace*{0.5cm}
%\end{tcolorbox}
%
%\subsection{Basic Usage}
%
%\begin{tcblisting}{}
%\panda
%\end{tcblisting}
%
%\subsection{Options}
%
%The basic panda can be modified by changing its colour:
%\begin{tcblisting}{}
%\panda[body=blue]
%\end{tcblisting}
%
%In addition to the colour of the body, the colour of various body parts can be adjusted:
%\begin{tcblisting}{}
%\panda[eye=red]
%\end{tcblisting}
%\begin{tcblisting}{}
%\panda[pupil=red]
%\end{tcblisting}
%\begin{tcblisting}{}
%\panda[mouth=red]
%\end{tcblisting}
%
%To view the panda from behind:
%\begin{tcblisting}{}
%\panda[back]
%\end{tcblisting}
%
%The key \lstinline|3D| will make the panda 3-dimensional:
%\begin{tcblisting}{}
%\panda[3D]
%\end{tcblisting}
%
%And finally the \lstinline|contour| key will only draw the outlines:
%\begin{tcblisting}{}
%\panda[contour=black]
%\end{tcblisting}