beginfig(1); path p; nbor := (sqrt(5)+1)/2 ; psi := 137.5 ; iter := 1000 ; c := 5 ; r := 0; for i=iter downto 0: t := sqrt(i) ; r := (r + psi) mod 360; cv:= cosd((i/iter)*90); p := ((0,0)--(t,1)--(t+1,0)--(t,-1)-- cycle) rotated r; fill p scaled c withcolor (1,cv,0); draw p scaled c; endfor; endfig; end