#http://www-gap.dcs.st-and.ac.uk/~history/Curves/Watts.html

vertices = 2000

t = from 0 to (2*PI)

a = rand2(5, 20)
c = rand2(a, 20)
b = rand2(sqrt(c*c + a*a), 20)

r = sqrt( b*b - [a*sin(t) + sqrt(c*c - a*a*cos(t)*cos(t))]^2 )

x = r*sin(t)
y = r*cos(t)