polygon.ps

%!PS-Adobe-3.0 EPSF-3.0
%%Pages: 1
%%BoundingBox: 0 0 720 720
%%EndComments

/inch { 72 mul } def
/invertgray { 1 currentgray sub setgray } def

/makepoints { % nsides
  4 dict begin
    /n exch def
    /array n 2 mul array def
    0 1 n 1 sub {
      /idx exch def
      /angle idx 360 mul n div def
      array idx 2 mul angle cos put
      array idx 2 mul 1 add angle sin put
    } for
    array
  end
} def

/nsides 50 def
/points nsides makepoints def

/point { % index
  1 dict begin
    /idx exch 2 mul def
    points idx get
    points idx 1 add get
  end
} def

5 inch dup translate
4 inch dup scale
90 rotate

1 512 div setlinewidth
1 16 div setgray

newpath
2 2 moveto -2 2 lineto -2 -2 lineto 2 -2 lineto
closepath fill

invertgray
newpath
0 point moveto
1 1 nsides 1 sub { point lineto } for
closepath
fill
invertgray

1 1 128 div sub dup scale
2 dict begin
  0 1 nsides 1 sub {
    /i exch def
    0 1 nsides 1 sub {
      /j exch def
      i j ne {
        newpath
        i point moveto
        j point lineto
        stroke
      } if
    } for
  } for
end

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