%%
%% A DANTE-Edition example
%%
%% Example 33-03-19 on page 694.
%%
%% Copyright (C) 2011 Herbert Voss
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3
%% of this license or (at your option) any later version.
%%
%% See
http://www.latex-project.org/lppl.txt for details.
%%
%%
%% ====
% Show page(s) 1
%%
\documentclass[]{article}
\pagestyle{empty}
\setlength\textwidth{375.57637pt}
\setlength\parindent{0pt}
\usepackage{pst-optic}
\begin{document}
\psset{unit=0.75}
\begin{pspicture}(-8,-2)(8,5.75)
\pnode(-8,1.5){A}\pnode(8,1.5){B}
\uput[45](A){A}\uput[135](B){B}
\pnode(0,0){START}
\psframe[fillcolor=lightgray,fillstyle=solid,linecolor=blue](-8,-1.5)(B)
\psset{linecolor=red,arrowsize=3pt,arrows=->}
\multido{\n=20+5}{29}{%
\refractionRay(START)(1;\n)(A)(B){1.5}{1}{END}
\arrowLine(START)(END){2}\arrowLine(END)(END'){1}
\psOutLine[length=3](END)(END'){Q}\arrowLine(END')(Q){3} }
\end{pspicture}
\end{document}
