Codes for Equiangular spiral

to main
cs ht
bernoulli.spiral 200
end

to bernoulli.spiral :side
if :side<2 [stop]
setpensize [1 1]
bernoulli.polygon :side
setpensize [2 2]
arc2 90 :side
bernoulli.spiral (tau-1)*:side
end

to bernoulli.polygon :side
repeat 2[fd :side rt 90 fd tau*:side rt 90]
end

to tau
op .5*(1+sqrt 5)
end