%%
%% A DANTE-Edition example
%%
%% Example 33-03-17 on page 693.
%%
%% 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}
\begin{pspicture}(-5,-3)(5,3)
\pnode(-1,-2.5){A} \pnode(1,-2.5){B} \pnode(1,2.5){C} \pnode(-1,2.5){D}
\uput[-135](A){A} \uput[-45](B){B} \uput[45](C){C} \uput[135](D){D}
\pspolygon[fillcolor=lightgray,fillstyle=solid,linecolor=blue](A)(B)(C)(D)
\refractionRay(-3,-3)(-2,-2)(D)(A){1}{1.5}{END}% 1.
\psset{linecolor=red,linewidth=2pt,arrowsize=5pt,arrows=->}
\arrowLine(-3,-3)(END){2} \ABinterCD(END)(END')(C)(B){Out}
\arrowLine(END)(Out){1} \refractionRay(END)(Out)(C)(B){1.5}{1}{Q}
\arrowLine(Q)(Q'){1} \psOutLine[length=2](Q)(Q'){End}
\refractionRay(-3,0)(-2,0)(A)(D){1}{1.5}{END}% 2.
\psset{linecolor=green,linewidth=2pt,arrowsize=5pt,arrows=->}
\arrowLine(-3,0)(END){2} \ABinterCD(END)(END')(C)(B){Out}
\arrowLine(END)(Out){1} \refractionRay(END)(Out)(C)(B){1.5}{1}{Q}
\arrowLine(Q)(Q'){1} \psOutLine[length=2](Q)(Q'){End}
\refractionRay(-3,3)(-2,2)(D)(A){1}{1.5}{END}% 3.
\psset{linecolor=blue,linewidth=2pt,arrowsize=5pt,arrows=->}
\arrowLine(-3,3)(END){2} \ABinterCD(END)(END')(C)(B){Out}
\arrowLine(END)(Out){1} \refractionRay(END)(Out)(C)(B){1.5}{1}{Q}
\arrowLine(Q)(Q'){1} \psOutLine[length=2](Q)(Q'){End}
\end{pspicture}
\end{document}
