\documentclass[crop,tikz]{standalone}
\input{common-headers}

\begin{document}

\begin{tikzpicture}[%
  shader/.style={draw,fill=white,nearly opaque, minimum size=1.5cm,%
    align=center, node distance=5mm},
  prgrbl/.style={shader,opaque,thick,font=\bfseries},
  prgrbo/.style={prgrbl,dashed},
  f/.tip={Fast Triangle[cap angle=120]},
  >/.tip={Triangle Cap[cap angle=120] . f f}, % Normal tips
  >-</.tip={>[reversed]}                      % Reversed tips
  ]
  \node[shader] (S1) at (0,0)    {Vertex\\ Specification};
  \node[prgrbl,right=of S1] (S2) {Vertex\\ Shader};
  \node[prgrbo,right=of S2] (S3) {Tessellation};
  \node[prgrbo,right=of S3] (S4) {Geometry\\ Shader};
  \node[shader,right=of S4] (S5) {Vertex\\ Post-Processing};
  \node[shader,below=of S5] (S6) {Primitive\\ Assembly};
  \node[shader,left =of S6] (S7) {Rasterization};
  \node[prgrbo,left =of S7] (S8) {Fragment\\ Shader};
  \node[shader,left =of S8] (S9) {Per-Sample\\ Operations};
  \begin{scope}[on background layer]
    \draw[line width=1cm, >->,black!40,rounded corners]
    ($(S1.center) + (-3cm,0)$) to (S5.center)%
    to (S6.center) to ($(S9.center) + (-3cm,0)$);
  \end{scope}
\end{tikzpicture}

\end{document}