% !TeX root = ./examples/hippo.tex
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% The tikzlings-hippos package (part of the tikzlings collection)
% A package to bring little hippos 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
%
% Version 0.2
% April 7, 2019   
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\ProvidesPackage{tikzlings-hippos}
 [2019/04/07 v0.2 Drawing hippos in TikZ]

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

\newcommand*{\hippo}[1][]{%
  \begin{scope}%
    \tikzset{/hippo/.cd,#1}%
    \hippo@draw%
  \end{scope}%
  \thing[#1]%
}

\newif\ifhippo@threeD

\tikzset{
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % Pass unknown keys on to tikz
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  /hippo/.search also={/tikz,/pgf,/thing},
  /hippo/.cd,
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % body
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  body/.code         = \def\hippo@body{#1},
  body               = gray,
  toes/.code         = \def\hippo@toes{#1},
  toes               = \hippo@body!55!white,
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %
  % options
  %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  3D/.code           = \hippo@threeDtrue, 
}

\def\hippo@draw{%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% minimal bounding box size 
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\path (-0.625,0.1) rectangle (0.625, 2.17);
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% 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))}%
\pgfmathsetmacro{\xscalefactor}{\tmpscaleA}
\pgfmathsetmacro{\yscalefactor}{\tmpscaleD}
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 
% switch between 2D and 3D, from
% https://chat.stackexchange.com/transcript/message/45991801#45991801
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\ifhippo@threeD
  \def\hippo@part@draw[##1]{\shade[ball color=##1]}
\else
  \def\hippo@part@draw[##1]{\fill[##1]}
\fi
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Body parts (center: x=0)
% 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Ears %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\hippo@part@draw[\hippo@body,rotate around={-30:(0.23,2.03)}] (0.23,2.03) ellipse (0.09 and 0.13);
\hippo@part@draw[\hippo@body,rotate around={30:(-0.23,2.03)}] (-0.23,2.03) ellipse (0.09 and 0.13);
%
% Body %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\hippo@part@draw[\hippo@body!55!white] ( 0.6,  0.8 ) .. controls ( 0.6 , 0.4) and ( 0.35, 0.19) .. ( 0.0,  0.19) .. controls (-0.35, 0.19) and (-0.6 , 0.4) .. (-0.6,  0.8 ) .. controls (-0.6 , 1.3) and (-0.35, 1.65) .. ( 0.0,  1.65) .. controls ( 0.35, 1.65) and ( 0.6 , 1.3) .. ( 0.6,  0.8) -- cycle;
%
% Arms %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\hippo@part@draw[\hippo@body,rotate around={90:(0.35,1.0)}] (0.35,1.0) ellipse (0.24 and 0.13);
\hippo@part@draw[\hippo@body,rotate around={-90:(-0.35,1.0)}] (-0.35,1.0) ellipse (0.24 and 0.13);
%
% Head %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\hippo@part@draw[\hippo@body!55!white] (0, 1.76) circle (0.36);
%
% Eyes %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\fill[white] (-0.11, 1.83) ellipse (0.08 and 0.12);
\fill[white] (0.11, 1.83) ellipse (0.08 and 0.12);
\fill[black] (-0.105, 1.78) ellipse (0.04 and 0.07);
\fill[black] (0.105, 1.78) ellipse (0.04 and 0.07);
%
% Nose %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\hippo@part@draw[\hippo@body!80!white] (0, 1.55) ellipse (0.42 and 0.2);
\hippo@part@draw[\hippo@body!70!black]  (-0.07, 1.63) circle (0.035);
\hippo@part@draw[\hippo@body!70!black]  (0.07, 1.63) circle (0.035);
%
% Mouth %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\ifhippo@threeD
	\draw[black,line width=\scalingfactor*0.4pt] (0.125, 1.5) arc [start angle=-50, end angle=-130, radius=0.2] ;
	\else
		\draw[\hippo@body!70!black,line width=\scalingfactor*0.4pt] (0.125, 1.5) arc [start angle=-50, end angle=-130, radius=0.2] ;
		\fi
		%
% Feet %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{scope}
	\clip (-0.5,0.4) rectangle (0.5,0.13);
	\hippo@part@draw[\hippo@body] (-0.25,0.15) ellipse (0.16 and 0.17);
	\hippo@part@draw[\hippo@body] (0.25,0.15) ellipse (0.16 and 0.17);
	\hippo@part@draw[\hippo@toes] (0.25,0.13) ellipse (0.05 and 0.1);
	\hippo@part@draw[\hippo@toes] (0.13,0.11) ellipse (0.05 and 0.1);
	\hippo@part@draw[\hippo@toes] (0.37,0.11) ellipse (0.05 and 0.1);
	\hippo@part@draw[\hippo@toes] (-0.25,0.13) ellipse (0.05 and 0.1);
	\hippo@part@draw[\hippo@toes] (-0.13,0.11) ellipse (0.05 and 0.1);
	\hippo@part@draw[\hippo@toes] (-0.37,0.11) ellipse (0.05 and 0.1);	
\end{scope}
%
}