% !TeX root = ./examples/hippo.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-hippos}[2020/04/22 version v0.3 Drawing hippos in TikZ]

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

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

\newif\ifhippo@threeD
\newif\ifhippo@back

\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, 
  back/.code         = \hippo@backtrue,
}

\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))*sqrt(abs((\pgf@xx/1cm)*(\pgf@yy/1cm)-(\pgf@xy/1cm)*(\pgf@yx/1cm)))}%
\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)
% 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% adding hook for users to customise %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\csname hippohookbackground\endcsname
\csname tikzlinghookbackground\endcsname 
%
% Ears %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\hippo@part@draw[\hippo@body] (0.23,2.03) ellipse[x radius=0.09, y radius=0.13, rotate=-30];
\hippo@part@draw[\hippo@body] (-0.23,2.03) ellipse[x radius=0.09, y radius=0.13, rotate=30];
%
% Feet if back %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\ifhippo@back
  \begin{scope}
    \clip (-0.5,0.4) rectangle (0.5,0.13);
    \hippo@part@draw[\hippo@body] (-0.25,0.15) ellipse[x radius=0.16, y radius=0.17];
    \hippo@part@draw[\hippo@body] (0.25,0.15) ellipse[x radius=0.16, y radius=0.17];
  \end{scope}
\fi
%
% Nose if back %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\ifhippo@back
  \hippo@part@draw[\hippo@body!80!white] (0, 1.55) ellipse[x radius=0.42, y radius=0.2];
\fi
%
% 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;
%
% adding hook for users to customise %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\csname hippohookbelly\endcsname
\csname tikzlinghookbelly\endcsname
%    
% Arms %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\ifhippo@back\else
  \hippo@part@draw[\hippo@body] (0.35,1.0) ellipse[x radius=0.24, y radius=0.13, rotate=90];
  \hippo@part@draw[\hippo@body] (-0.35,1.0) ellipse[x radius=0.24, y radius=0.13, rotate=-90];
\fi
%
% Head %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\hippo@part@draw[\hippo@body!55!white] (0, 1.76) circle[radius=0.36];
%
% Show details only from the front %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\ifhippo@back\else
%
% Eyes %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\fill[white] (-0.11, 1.83) ellipse[x radius=0.08, y radius=0.12];
\fill[white] (0.11, 1.83) ellipse[x radius=0.08, y radius=0.12];
\fill[black] (-0.105, 1.78) ellipse[x radius=0.04, y radius=0.07];
\fill[black] (0.105, 1.78) ellipse[x radius=0.04, y radius=0.07];
%
% Nose %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\hippo@part@draw[\hippo@body!80!white] (0, 1.55) ellipse[x radius=0.42, y radius=0.2];
\hippo@part@draw[\hippo@body!70!black]  (-0.07, 1.63) circle[radius=0.035];
\hippo@part@draw[\hippo@body!70!black]  (0.07, 1.63) circle[radius=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[x radius=0.16, y radius=0.17];
  \hippo@part@draw[\hippo@body] (0.25,0.15) ellipse[x radius=0.16, y radius=0.17];
  \hippo@part@draw[\hippo@toes] (0.25,0.13) ellipse[x radius=0.05, y radius=0.1];
  \hippo@part@draw[\hippo@toes] (0.13,0.11) ellipse[x radius=0.05, y radius=0.1];
  \hippo@part@draw[\hippo@toes] (0.37,0.11) ellipse[x radius=0.05, y radius=0.1];
  \hippo@part@draw[\hippo@toes] (-0.25,0.13) ellipse[x radius=0.05, y radius=0.1];
  \hippo@part@draw[\hippo@toes] (-0.13,0.11) ellipse[x radius=0.05, y radius=0.1];
  \hippo@part@draw[\hippo@toes] (-0.37,0.11) ellipse[x radius=0.05, y radius=0.1];  
\end{scope}
%
\fi
%
% adding hook for users to customise %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\csname hippohookbody\endcsname
\csname tikzlinghookbody\endcsname
%
}
