% create tikz drawing of a multi mass multi spring system

\tikzstyle{vmline}=[red, dashed,line width=0.4,dash pattern=on 1pt off 1pt]
\tikzstyle{ground}=[pattern=north east lines]
\tikzstyle{mass}=[line width=0.6,red!30!black,fill=red!40!black!10,rounded corners=1,top color=red!40!black!20,bottom color=red!40!black!10,shading angle=20]
\tikzstyle{spring}=[line width=0.8,blue!7!black!80,snake=coil,segment amplitude=5,line cap=round]

\begin{tikzpicture}[scale=2]
    \newcommand{\ticks}[3]
    {
        % x, y coordinates
        \draw[thick] (#1, #2 - 0.1 / 2) --++ (0, 0.1) node[scale=0.8,below=0.2] {#3};
    }
    \tikzmath{
        \hWall = 1.2;
        \wWall = 0.3;
        \lWall = 5;
        \hMass = 0.6;
        \wMass = 1.1;
        \xMass1 = 1.0;
        \xMass2 = 3.0;
        \xAxisYpos = 0;
        \originX1 = 0;
        \originY1 = 0.5;
        \springscale=7;
    }

    % create axis
    \draw[->,thick] (0,\xAxisYpos) --+ (\xMass2 + \wMass, 0) node[right]{$q$};
    % create ticks on x / q axis
    \ticks{\xMass1}{\xAxisYpos}{$q_{1}$}
    \ticks{\xMass2}{\xAxisYpos}{$q_{2}$}

    % create non-moving backgrounds
    \draw[ground] (\originX1, \originY1) ++ (0, 0) --+(\lWall,0) --+(\lWall, \hWall)
    --+ (\lWall - \wWall, \hWall) --+(\lWall - \wWall, \wWall) --+ (\wWall, \wWall)  --+(\wWall, \hWall) --+(0, \hWall) -- cycle;

    % create masses
    \draw[mass] (\originX1, \originY1) ++ (\xMass1, \wWall) rectangle ++ (\wMass,\hMass) node[midway] {$m_{1}$};
    \draw[mass] (\originX1, \originY1) ++ (\xMass2, \wWall) rectangle ++ (\wMass,\hMass) node[midway] {$m_{2}$};

    % create springs
    \draw[spring, segment length=(\xMass1 - \wWall) * \springscale] (\originX1, \originY1) ++
    (\wWall, \wWall + \hMass / 2) --++ (\xMass1 - \wWall, 0) node[midway,above=0.2] {$k_1$};
    \draw[spring, segment length=(\xMass1 - \wWall) * \springscale] (\originX1, \originY1) ++
    (\xMass1 + \wMass, \wWall + \hMass / 2) --++ (\xMass2 - \xMass1 - \wMass, 0) node[midway,above=0.2] {$k_c$};
    \draw[spring, segment length=(\xMass1 - \wWall) * \springscale] (\originX1, \originY1) ++
    (\xMass2 + \wMass, \wWall + \hMass / 2) --++ (\lWall - \xMass2 - \wMass - \wWall, 0) node[midway,above=0.2] {$k_2$};

    % create vertical measurement line 
    \draw[vmline] (\xMass1, \xAxisYpos) --+(0, \originY1 + \wWall);
    \draw[vmline] (\xMass2, \xAxisYpos) --+(0, \originY1 + \wWall);

\end{tikzpicture}
