%!
% set units to inches
(lenses.inc) run

110 110 scale
0.01 setlinewidth
1 1 translate

% draw the boundary of the picture
newpath
0 0 moveto
4 0 lineto
4 3 lineto
0 3 lineto
closepath
stroke

% restrict all subsequent drawing to inside that boundary by clipping
newpath
0 0 moveto
4 0 lineto
4 3 lineto
0 3 lineto
closepath
clip

% draw the water in the pool
newpath
0 1.5 moveto
4 1.5 lineto
4 3 lineto
0 3 lineto
closepath
0.8 0.9 1 setrgbcolor
fill

newpath
2 0 moveto
2 3 lineto
0 0 0 setrgbcolor
stroke
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%Exaggerated index of refraction%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%Index refraction in Water : Red: 1.331 Yellow: 1.333 Blue: 1.340

2 0 translate
/A 33.69 def


newpath
1 0 moveto
0 A cos A sin div lineto
0 0 0 setrgbcolor
stroke

/nr 1.111 def %Red
newpath
0 A cos A sin div moveto
/r A sin nr div asin def
/l r sin r cos div 1.5 mul def
l -1 mul 3 lineto
1 0 0 setrgbcolor
stroke

/nr 1.555 def % Blue
newpath
0 A cos A sin div moveto
/r A sin nr div asin def
/l r sin r cos div 1.5 mul def
l -1 mul 3 lineto
0 0 1 setrgbcolor
stroke

/nr 1.333 def% Yellow
newpath
0 A cos A sin div moveto
/r A sin nr div asin def
/l r sin r cos div 1.5 mul def
l -1 mul 3 lineto
0.8 1 0.3 setrgbcolor
stroke

0 0 0 setrgbcolor

1 1.3 moveto
/Times-Roman findfont 0.14 scalefont setfont
(air) show
1 1.6 moveto
/Times-Roman findfont 0.14 scalefont setfont
(water) show

0.7 2.5 moveto
/Times-Roman findfont 0.10 scalefont setfont
(Index of refraction(water):) show
1 2.4 moveto
(Red    1.331) show
1 2.3 moveto
(Yellow 1.333) show
1 2.2 moveto
(Blue   1.340) show
showpage