%
% keys.tex -- template for standalon tikz images
%
% (c) 2021 Prof Dr Andreas Müller, OST Ostschweizer Fachhochschule
%
\documentclass[tikz]{standalone}
\usepackage{amsmath}
\usepackage{times}
\usepackage{txfonts}
\usepackage{pgfplots}
\usepackage{csvsimple}
\usetikzlibrary{arrows,intersections,math}
\begin{document}
\def\skala{1}
\begin{tikzpicture}[>=latex,thick,scale=\skala]
\definecolor{darkgreen}{rgb}{0,0.6,0}
\def\s{0.5}
\def\punkt#1#2{({(#1)*\s},{(#2)*\s})}
\def\wort#1#2#3{
	\fill[color=#3] \punkt{#1}{#2} rectangle \punkt{(#1+1)}{(#2+4)};
	\draw \punkt{#1}{#2} rectangle \punkt{(#1+1)}{(#2+4)};
}

\def\summe{
	\foreach \x in {0,3,...,21}{
		\draw[->] \punkt{(\x+0.5)}{-0.1} -- \punkt{(\x+0.5)}{-2.1};
		\draw \punkt{(\x+0.5)}{-2.5} circle[radius={0.3*\s}];
		\draw \punkt{(\x+0.5-0.2)}{-2.5} 
			--
			\punkt{(\x+0.5+0.2)}{-2.5};
		\draw \punkt{(\x+0.5)}{-2.5+0.2} 
			--
			\punkt{(\x+0.5)}{-2.5-0.2};
		\draw[->] \punkt{(\x+0.5)}{-2.9} -- \punkt{(\x+0.5)}{-4.9};
	}
	\foreach \x in {0,3,...,18}{
		\draw[->] \punkt{(\x+1.1)}{-7} -- \punkt{(\x+2)}{-7}
			-- \punkt{(\x+2)}{-2.5} -- \punkt{(\x+3.1)}{-2.5};
	}
	\fill[color=white]
		\punkt{(9+1.25)}{-5.5}
		rectangle
		\punkt{(9+2.75)}{-4.00};
	\draw
		\punkt{(9+1.25)}{-5.5}
		rectangle
		\punkt{(9+2.75)}{-4.00};
	\node at \punkt{(9+2)}{-4.75} {$S$};
}

\def\blocks#1{
	\foreach \x in {0,3,...,21}{
		\wort{\x}{0}{#1}
	}
}

\def\schlange#1{
	\draw[->] \punkt{22.1}{2} -- \punkt{23}{2}
		-- \punkt{23}{-1.0} -- \punkt{-3}{-1.0}
		-- \punkt{-3}{-8} -- \punkt{-1}{-8} -- \punkt{-1}{-2.5}
		-- \punkt{0.1}{-2.5};
	;
	\fill[color=white] \punkt{-3.75}{-1.75} rectangle \punkt{-2.25}{-3.25};
	\draw \punkt{-3.75}{-1.75} rectangle \punkt{-2.25}{-3.25};
	\node at \punkt{-3}{-2.5} {$\pi$};

	\fill[color=white] \punkt{-3.75}{-3.75} rectangle \punkt{-2.25}{-5.25};
	\draw \punkt{-3.75}{-3.75} rectangle \punkt{-2.25}{-5.25};
	\node at \punkt{-3}{-4.5} {$S$};

	\fill[color=white] \punkt{-3.75}{-5.75} rectangle \punkt{-2.25}{-7.25};
	\draw \punkt{-3.75}{-5.75} rectangle \punkt{-2.25}{-7.25};
	\node at \punkt{-3}{-6.5} {$r_{#1}$};
}

\begin{scope}
	\blocks{blue!20}
	\foreach \x in {0,...,7}{
		\node at \punkt{(3*\x+0.5)}{2} {$K_\x$};
	}
	\schlange{1}
	\summe
\end{scope}

\begin{scope}[yshift=-4.5cm]
	\blocks{darkgreen!20}
	\foreach \x in {8,...,15}{
		\node at \punkt{(3*(\x-8)+0.5)}{2} {$K_{\x}$};
	}
	\schlange{2}
	\summe
\end{scope}

\begin{scope}[yshift=-9cm]
	\blocks{darkgreen!20}
	\foreach \x in {16,...,23}{
		\node at \punkt{(3*(\x-16)+0.5)}{2} {$K_{\x}$};
	}
	\schlange{3}
	\summe
\end{scope}

\begin{scope}[yshift=-13.5cm]
	\blocks{darkgreen!20}
	\foreach \x in {24,...,31}{
		\node at \punkt{(3*(\x-24)+0.5)}{2} {$K_{\x}$};
	}
	\foreach \x in {0,3,...,21}{
		\draw[->,color=gray]
			\punkt{(\x+0.5)}{-0.1} -- \punkt{(\x+0.5)}{-2.1};
		\node[color=gray] at \punkt{(\x+0.5)}{-2.1} [below] {$\vdots$};
	}
	\draw[color=gray] \punkt{22.1}{2} -- \punkt{23}{2}
		-- \punkt{23}{-1.0} -- \punkt{-3}{-1.0}
		-- \punkt{-3}{-2.1};
	\node[color=gray] at \punkt{-3}{-2.1} [below] {$\vdots$};
\end{scope}

\end{tikzpicture}
\end{document}