Fractional Brownian motion: sums octaves of a noise source at increasing
frequency and decreasing amplitude - the workhorse for natural-looking
heightmaps and clouds. Given a source in [-1, 1], returns a value in [-1, 1].
Parameters
sample: (frequency:number)=>number
receives an octave frequency, returns the base noise scaled by it
Fractional Brownian motion: sums octaves of a noise source at increasing frequency and decreasing amplitude - the workhorse for natural-looking heightmaps and clouds. Given a source in [-1, 1], returns a value in [-1, 1].