%!

% procedures

/pagebegin {  
/A exch def
/x A 0 get def
/y A 1 get def
gsave 
72 dup scale 
x y translate
0.5 72 div setlinewidth
} def 

/pageend { 
grestore showpage 
} def 

% array [x y r theta]]
/circle {8 dict begin
/A exch def
/x A 0 get def
/y A 1 get def
/r A 2 get def
/theta A 3  get def
/c 0 def 
/n 64 def
newpath
r c cos mul x add r c sin mul y add moveto
n{
/c c theta n div add def
r c cos mul x add r c sin mul y add lineto
} repeat
end} def

% array [x y a b theta]
/ellipse {9 dict begin
/A exch def
/x A 0 get def
/y A 1 get def
/a A 2 get def
/b A 3  get def
/theta A 4 get def
/c 0 def 
/n 64 def
newpath
a c cos mul x add b c sin mul y add moveto
n{
/c c theta n div add def
a c cos mul x add b c sin mul y add lineto
} repeat
end} def


% colors

/black { 
0 0 0 setrgbcolor
}def

/yellow { 
1 1 0 setrgbcolor 
} def 

/red {
0.5 0 1 setrgbcolor
} def 

/blue {
0 1 1 setrgbcolor
} def 

/white {
1 1 1 setrgbcolor
} def

% Fonts

/largefont {
/Times-Roman findfont
0.32 scalefont
setfont } def

/normalfont {
/Times-Roman findfont
0.22 scalefont
setfont } def

/smallfont {
/Times-Roman findfont
0.16 scalefont
setfont}def

% rotate [x y r theta]
/rotate{ 6 dict begin
/A exch def
/x A 0 get def
/y A 1 get def
/r A 2 get def
/theta A 3 get def
/alpha -90 theta add def
newpath
x y moveto
r alpha sin alpha cos div mul r lineto
stroke
}def

/rotateA{
/A exch def
/x A 0 get def
/y A 1 get def
/r A 2 get def
/theta A 3 get def
x y moveto
r theta cos mul x add r theta sin mul y add lineto
stroke
}def

/polygon { 2 dict begin 
/poly exch def 
/n poly length def 
poly 0 get aload pop moveto 
1 1 n 1 sub { 
/i exch def
poly i get aload pop lineto 
} for 
end} def 

[2 6] pagebegin
black
[[-2 4] [2 4] [2 -2] [-2 -2]] polygon fill

white
[0 0 1 180] circle stroke
1 0 moveto -1 0 lineto stroke
[0 0 1 30] rotate
[0 0 1 45] rotate
[0 0 1 60] rotate
[0 0 1 75] rotate
[0 0 1 90] rotate
[0 0 1 105] rotate
[0 0 1 120] rotate
[0 0 1 135] rotate
[0 0 1 150] rotate

[0 1 15 sin 15 cos div 180] circle stroke
[0 1 30 sin 30 cos div 180] circle stroke
[0 1 45 sin 45 cos div 180] circle stroke
[0 1 60 sin 60 cos div 180] circle stroke

blue
60 sin 60 cos div 1 moveto -60 sin -60 cos div 1 lineto stroke
[0 1 60 sin 60 cos div 30] rotateA
[0 1 60 sin 60 cos div 60] rotateA
[0 1 60 sin 60 cos div 90] rotateA
[0 1 60 sin 60 cos div 120] rotateA
[0 1 60 sin 60 cos div 150] rotateA
pageend