sample_circle_uniform

vector2  sample_circle_uniform(vector2 u)

u

Pair of numbers between 0 and 1.

Returns a vector2 of length < 1, based on u. Given uniform random u pairs of values in [0,1), the returned vectors will be uniform random and continuous with respect to u inside the unit circle. Specifically, it returns scale*(cos(angle),sin(angle)), where angle is 2*pi*u.x and scale is sqrt(u.y).