I'd like to be able to use pgfplots to show a skier going down a ski slope. Here is what I have done so far.
\documentclass{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.7}
\makeatletter
\pgfkeyssetvalue{/pgf/shapes/ski/ski length}{1cm}
\pgfkeyssetvalue{/pgf/shapes/ski/ski radius}{.075cm}
\pgfkeyssetvalue{/pgf/shapes/ski/leg length}{.3cm}
\pgfkeyssetvalue{/pgf/shapes/ski/leg angle}{140}
\pgfkeyssetvalue{/pgf/shapes/ski/back length}{.5cm}
\pgfkeyssetvalue{/pgf/shapes/ski/head radius}{.1cm}
\pgfdeclareplotmark{skimark}{%
% ski
\pgfpathmoveto{\pgfpoint{-.5\pgfkeysvalueof{/pgf/shapes/ski/ski
length}}{-\pgfkeysvalueof{/pgf/shapes/ski/leg length}}}
\pgfpathlineto{\pgfpoint{.5\pgfkeysvalueof{/pgf/shapes/ski/ski
length}}{-\pgfkeysvalueof{/pgf/shapes/ski/leg length}}}
\pgfpatharc{-90}{0}{\pgfkeysvalueof{/pgf/shapes/ski/ski radius}}
\pgfsetlinewidth{.5mm}
\pgfusepath{stroke}
% body
\pgfpathmoveto{%
\pgfpoint{+0pt}{-\pgfkeysvalueof{/pgf/shapes/ski/leg length}}}
\pgfpathlineto{\pgfpointorigin}
\pgfpathlineto{%
\pgfpointpolar{\pgfkeysvalueof{/pgf/shapes/ski/leg angle}}{%
\pgfkeysvalueof{/pgf/shapes/ski/leg length}}}
\pgfpathlineto{\pgfpointadd{%
\pgfpointpolar{%
\pgfkeysvalueof{/pgf/shapes/ski/leg angle}}{%
\pgfkeysvalueof{/pgf/shapes/ski/leg length}}}{%
\pgfpoint{%
\pgfkeysvalueof{/pgf/shapes/ski/back length}}{+0pt}}}
\pgfsetroundjoin
\pgfsetlinewidth{1mm}
\pgfusepath{stroke}
%
\pgfpathcircle{%
\pgfpointadd{%
\pgfpointpolar{%
\pgfkeysvalueof{/pgf/shapes/ski/leg angle}}{%
\pgfkeysvalueof{/pgf/shapes/ski/leg length}}}{%
\pgfpoint{%
\pgfkeysvalueof{/pgf/shapes/ski/back length}}{+0pt}}}{%
\pgfkeysvalueof{/pgf/shapes/ski/head radius}}
\pgfusepath{fill}
}
\makeatother
\begin{document}
\begin{tikzpicture}
\begin{axis}[domain = 0:5,
]
\addplot+[mark = skimark,
only marks,
forget plot,
scatter,
scatter src = {-exp(-x)}] gnuplot[samples=5] {exp(-x)};
\addplot+[no markers] gnuplot[samples=30] {exp(-x)};
\end{axis}
\end{tikzpicture}
\end{document}

How can I use the scatter source information to rotate the markers so that the skier's skis are parallel to the slope (a bit of shifting would be good as well since I made a design error not defining the origin on the skis...) ?
Note: I can provide a ski shape as well.
\pgfdeclareshape{ski}{%
\anchor{center}{\pgfpointorigin}
\savedanchor\bottomleg{%
\pgfpoint{+0pt}{-\pgfkeysvalueof{/pgf/shapes/ski/leg length}}}
%
\backgroundpath{%
% ski
\pgfpathmoveto{\pgfpoint{-.5\pgfkeysvalueof{/pgf/shapes/ski/ski
length}}{-\pgfkeysvalueof{/pgf/shapes/ski/leg length}}}
\pgfpathlineto{\pgfpoint{.5\pgfkeysvalueof{/pgf/shapes/ski/ski
length}}{-\pgfkeysvalueof{/pgf/shapes/ski/leg length}}}
\pgfpatharc{-90}{0}{\pgfkeysvalueof{/pgf/shapes/ski/ski radius}}
\pgfsetlinewidth{.5mm}
\pgfusepath{stroke}
% body
\pgfpathmoveto{\pgf@process{\bottomleg}}
\pgfpathlineto{\pgfpointorigin}
\pgfpathlineto{\pgfpointpolar{\pgfkeysvalueof{/pgf/shapes/ski/leg
angle}}{\pgfkeysvalueof{/pgf/shapes/ski/leg length}}}
\pgfpathlineto{\pgfpointadd{%
\pgfpointpolar{%
\pgfkeysvalueof{/pgf/shapes/ski/leg angle}}{%
\pgfkeysvalueof{/pgf/shapes/ski/leg length}}}{%
\pgfpoint{%
\pgfkeysvalueof{/pgf/shapes/ski/back length}}{+0pt}}}
\pgfsetroundjoin
\pgfsetlinewidth{1mm}
\pgfusepath{stroke}
%
\pgfpathcircle{%
\pgfpointadd{%
\pgfpointpolar{%
\pgfkeysvalueof{/pgf/shapes/ski/leg angle}}{%
\pgfkeysvalueof{/pgf/shapes/ski/leg length}}}{%
\pgfpoint{%
\pgfkeysvalueof{/pgf/shapes/ski/back length}}{+0pt}}}{%
\pgfkeysvalueof{/pgf/shapes/ski/head radius}}
\pgfusepath{fill}
%
}
}


