% Entnommen aus:
% Rotated polygons
% Author: Dr. rer. nat. Ismael Gutierrez Garcia
% http://texample.net/tikz/examples/rotated-polygons/
%
% Angepasst von André Hilbig
% mail@andrehilbig.de
%
\setcounter{density}{20}
%\tikzstyle{background grid}=[draw, black!50,step=2.5cm]
\begin{tikzpicture}%[show background grid]
    \def\couleur{OrangeRed}
    \path[coordinate] (-6cm,-6cm)  coordinate(A)
                ++( 90:12cm) coordinate(B)
                ++(0:12cm) coordinate(C)
                ++(-90:12cm) coordinate(D);
    \draw[fill=\couleur!\thedensity] (A) -- (B) -- (C) --(D) -- cycle;
    \foreach \x in {1,...,40}{%
        \pgfmathsetcounter{density}{\thedensity+20}
        \setcounter{density}{\thedensity}
        \path[coordinate] coordinate(X) at (A){};
        \path[coordinate] (A) -- (B) coordinate[pos=.10](A)
                            -- (C) coordinate[pos=.10](B)
                            -- (D) coordinate[pos=.10](C)
                            -- (X) coordinate[pos=.10](D);
        \draw[fill=\couleur!\thedensity] (A)--(B)--(C)-- (D) -- cycle;
    }
		\ifthenelse{\boolean{rahmen}}{
			\draw [step=2,black, thick] (-6.5cm,-6.5cm) grid (6.5cm,6.5cm);
		}{
			\draw [step=2,transparent] (-6.5cm,-6.5cm) grid (6.5cm,6.5cm);
		}
\end{tikzpicture}
