File:Triple-Spiral-labyrinth.svg

SVG version of Image:Triple-Spiral-labyrinth.png .

Converted from the following PostScript code:

%!
/archimdouble{
%%%%%%%%%%%%%%%%
% PostScript program to display an Archimedean spiral by approximating
% it with Bezier curves.  Can display a double spiral (two spirals
% rotated by 180 degrees with respect to each other).
%%%  Parameters:
                 % centerx = horizontal coordinate of center of spiral
                 % centery = vertical coordinate of center of spiral
                 % rotf = degrees to rotate
/sepwid 110 def  % width separating successive turnings of spiral
                 % (half this if double spiral is selected)
                 % incrm = insert a curve point every these degrees
/sweeps swp2 def % number of 360 degree turnings to show
                 % double - 0 to display single spiral, else double
%%%  Procedures:
/pi 3.1415926535898 def/radians 57.295779513082 def
/sepwid sepwid pi div 2 div def
gsave centerx centery translate rotf rotate colx setgray
/aspiral{/prevbezy 0 def/first 1 def
    lower incrm sweeps 360 mul{7{dup}repeat
        phase add cos/costh exch def
        phase add sin/sinth exch def
        costh mul radians div/thcosth exch def
        sinth mul radians div/thsinth exch def
        thcosth sepwid mul/x exch def
        thsinth sepwid mul/y exch def
        /slope sinth thcosth add costh thsinth sub div def
        sinth 0 gt sinth 0 eq costh -1 eq and or{/flag -1 def}{/flag 1
            def}ifelse
        /A exch def A 49.29348 lt A 180 gt A 196.273450852 lt and A 360
            gt A 368.8301 lt and A 540 gt A 545.9907 lt and A 720 gt A
            724.5217 lt and A 900 gt A 903.6281968 lt and or or or or
            or{/flag flag neg def}if
        incrm sub 3{dup}repeat phase add cos sepwid mul mul radians div
            /prevx exch def phase add sin sepwid mul mul radians div
            /prevy exch def
        incrm add 3{dup}repeat phase add cos sepwid mul mul radians div
            /nextx exch def phase add sin sepwid mul mul radians div
            /nexty exch def
        /prevdist x prevx sub dup mul y prevy sub dup mul add sqrt pi
            div def
        /nextdist x nextx sub dup mul y nexty sub dup mul add sqrt pi
            div def
        /normaliz slope slope mul 1 add sqrt def
        0 eq{0 0 moveto/prevbezx phase cos nextdist mul def/first 0 def
            }{first 1 eq{x y moveto/first 0 def}{prevbezx prevbezy x 1
            flag mul normaliz div prevdist mul sub y slope flag mul
            normaliz div prevdist mul sub x y curveto}ifelse
        /prevbezx x 1 flag mul normaliz div nextdist mul add def
        /prevbezy y slope flag mul normaliz div nextdist mul add def}
        ifelse}
    for stroke}def
/phase bascphase def single 0 ne{aspiral}if
double 0 ne{/sweeps swp1 def/phase 180 def aspiral}if grestore
%%%%%%%%%%%%%%%%
}def
gsave
18 0 translate .45 dup scale 110 3 div setlinewidth -2 rotate
304 550 280 0 360 arc fill 
927.334 550 280 0 360 arc fill
615.667 1089.823 280 0 360 arc fill
304 550 330 240 60 arc fill 
927.334 550 330 0 180 arc fill
615.667 1089.823 330 120 300 arc fill
1 setlinecap/colx{0}def/bascphase -60 def/single 1 def
/incrm 15 def/lower 840 def/double 0 def/swp2 1126 360 div def
/centerx 304 def/centery 550 def/rotf 0 def archimdouble
/swp2 1141 360 div def
/centerx 927.334 def/centery 550 def/rotf 120 def archimdouble
/centerx 615.667 def/centery 1089.823 def/rotf 240 def archimdouble
/colx{1}def/lower 0 def/double 1 def/bascphase 0 def
/swp1 2.67 def/swp2 3 def
/centerx 304 def/centery 550 def/rotf 0 def archimdouble
/swp1 2.51 def
/centerx 927.334 def/centery 550 def/rotf 120 def archimdouble
/swp1 2.67 def
/centerx 615.667 def/centery 1089.823 def/rotf 240 def archimdouble
/lower 1110 def/swp2 3.18 def/double 0 def archimdouble
/lower 930 def/swp1 990 360 div def/double 1 def/single 0 def
/centerx 927.334 def/centery 550 def/rotf 120 def archimdouble
%/single 1 def/double 0 def/lower 1034.015 def/bascphase 60 def/swp2
%1068 360 div def/incrm 16.202 def
%/centerx 304 def/centery 550 def/rotf 0 def archimdouble
%/centerx 927.334 def/centery 550 def/rotf 120 def archimdouble
%/centerx 615.667 def/centery 1089.823 def/rotf 240 def archimdouble
grestore .1 dup scale 1 setgray 3024.28 2721.715 moveto 
3004.37 2848.93 2960.58 2991.93 2905.98 3108.51 curveto
2850.54 3226.91 2767.21 3353.88 2680.91 3452.13 curveto
2801.03 3405.76 2946.77 3372.19 3075.04 3361.18 curveto
3205.3 3350 3356.92 3358.67 3485.155 3384.29 curveto
3384.94 3303.44 3282.99 3194.02 3209.32 3088.44 curveto
3134.51 2981.23 3066.22 2845.58 3024.28 2721.715 curveto
closepath fill showpage
%EOF