%!Postscript File
%
% % ------------------------------------------------------
% % These are unit definitions.  They define conversion factors for
% % common units like mils, inches, millimeters, etc.
% % ------------------------------------------------------
/mil { 0.072 mul } def
/in { 72 mul } def
/mm { 2.83464567 mul } def
%
% ------------------------------------------------------
% The Golden Ratio
% ------------------------------------------------------
/phi 1.618034 def

% ------------------------------------------------------
% 19mm tile width fits fairly well into an A4 sheet
% and is a good size for fridge magnets. (20mm is just
% a smidgin too big for A4)
% ------------------------------------------------------
/tilesize 19 mm def

% ------------------------------------------------------
% According to the theory of Penrose tiling, the
% thick:thin tile ratio should be approximately 16:10
% so here we have 99:63, making each sheet good for
% making patterns with only a few tiles left over.
% ------------------------------------------------------
/thinrows 7 def
/thincols 9 def
/thickrows 11 def
/thickcols 9 def

% ------------------------------------------------------
% This probably should be left as zero.
% ------------------------------------------------------
/tilegap 0 mm def

% ------------------------------------------------------
% If you increase this size you'll have to change the
% radius of the arcs or they'll collide on the thin
% tiles.
% ------------------------------------------------------
/linewidth 1 mm def

% ------------------------------------------------------
% Arc colours in RGB format
% ------------------------------------------------------
/colour1 {1 0 0} def % small radius
/colour2 {0 0 1} def % large radius
/colour3 {0 0 0} def % bisectors (not currently used
                     % because they collide with the
                     % arcs on the thin tile))

%/colour2 {1 0.843 0} def % gold
%/colour1 {0.753 0.753 0.753} def % silver


% ------------------------------------------------------
% ------------------------------------------------------
% Little below here should need changing
% ------------------------------------------------------

% ------------------------------------------------------
% draw a tile (args: <rotation> <x origin> <y origin>)
% ------------------------------------------------------
/tile {
   gsave
   translate
   0 mm setlinewidth
   newpath
   0 0 moveto
   tilesize 0 rlineto
   dup neg rotate
   %-54 rotate
   0 tilesize rlineto
   rotate
   %54 rotate
   tilesize neg 0 rlineto
   closepath
   stroke
   grestore

} def

% ------------------------------------------------------
% draw alignment arcs for thick tiles
%    (args: <x origin> <y origin>)
% ------------------------------------------------------
/thickarcs {
   gsave
   translate
   36 rotate

   % arc 1
   linewidth setlinewidth
   colour1 setrgbcolor
   newpath
   0 0
      tilesize 5 phi div div
      -36 36 arc
   stroke

   % outlines
   0 mm setlinewidth
   colour3 setrgbcolor
   newpath
   0 0
      tilesize 5 phi div div linewidth 2 div add
      -36 36 arc
   stroke
   newpath
   0 0
      tilesize 5 phi div div linewidth 2 div sub
      -36 36 arc
   stroke

   % arc 2
   linewidth setlinewidth
   colour2 setrgbcolor
   newpath
   tilesize phi div tilesize add 0
      tilesize 0.75 mul
      144 216 arc
   stroke

   0 mm setlinewidth
   colour3 setrgbcolor
   newpath
   tilesize phi div tilesize add 0
      tilesize 0.75 mul linewidth 2 div add
      144 216 arc
   stroke

   % outlines
   newpath
   tilesize phi div tilesize add 0
      tilesize 0.75 mul linewidth 2 div sub
      144 216 arc
   stroke

   -36 rotate
   grestore

} def
%
% ------------------------------------------------------
% draw alignment arcs for tin tiles
%    (args: <x origin> <y origin>)
% ------------------------------------------------------
/thinarcs {
   gsave
   translate
   18 rotate

   %newpath
   %0 0 moveto
   %0 10 lineto
   %stroke

   % ------------------------------------------------
   % arc 1
   linewidth setlinewidth
   colour1 setrgbcolor
   newpath
   0 0
      tilesize 5 phi div div
      18 162  arc
   stroke

   % outlines
   colour3 setrgbcolor
   0 mm setlinewidth
   newpath
   0 0
      tilesize 5 phi div div linewidth 2 div sub
      18 162  arc
   stroke
   newpath
   0 0
      tilesize 5 phi div div linewidth 2 div add
      18 162 arc
   stroke

   % ------------------------------------------------
   % arc 2
   linewidth setlinewidth
   colour2 setrgbcolor
   newpath
   %tilesize 108 sin mul  0
   0 tilesize phi div
      tilesize 4 div
      198 -18  arc
   stroke

   % outlines
   colour3 setrgbcolor
   0 mm setlinewidth
   newpath
   0 tilesize phi div
      tilesize 4 div linewidth 2 div sub
      198 -18  arc
   stroke
   newpath
   0 tilesize phi div
      tilesize 4 div linewidth 2 div add
      198 -18  arc
   stroke

   % ------------------------------------------------
   -18 rotate
   grestore

} def

% ------------------------------------------------------
% % draw Robinson bisectors
% % ------------------------------------------------------
/bisector {
   gsave
   translate
   linewidth 2 div setlinewidth
   colour3 setrgbcolor
   tilesize 0 moveto
   36 rotate
   tilesize 0 rmoveto
   -36 rotate
   0 0 lineto
   stroke
   grestore
} def

% ------------------------------------------------------
% draw tiles centred on A4 sheet
% ------------------------------------------------------
210 mm tilesize 36 cos mul tilesize thincols mul add sub 2 div
297 mm tilesize 72 sin mul thickrows mul tilesize 36 sin mul thinrows mul add sub 2 div
translate

% ------------------------------------------------------
% draw thin tiles
% ------------------------------------------------------
0 1 thincols 1 sub {
   /xp exch tilesize tilegap add mul def
   0 1 thinrows 1 sub {
      /yp exch tilesize 36 sin mul tilegap add mul def
      18 xp tilesize add yp thinarcs
      54 xp yp tile
      %xp yp bisector
   } for
} for
% ------------------------------------------------------
% draw thick tiles
% ------------------------------------------------------
0 thinrows tilesize 36 sin mul tilegap add thinrows mul translate
0 1 thickcols 1 sub {
   /xp exch tilesize tilegap add mul def
   0 1 thickrows 1 sub {
      /yp exch tilesize 72 sin mul tilegap add mul def
      xp yp thickarcs
      18 xp yp tile
      %xp yp bisector
   } for
} for

% ------------------------------------------------------
% annotation
% ------------------------------------------------------
/Times-Roman findfont
12 scalefont
setfont
thincols tilesize 72 sin mul tilegap add mul tilesize 1.2 mul add tilesize 2 div moveto
90 rotate
(Penrose P3 Tiles for the fridge. Print these on A4 magnetic sheet and cut them along the thin lines.) show
0 0 rmoveto
/Times-Roman findfont
6 scalefont
setfont
(    [ChrisG 2017]) show

showpage

% that's all