getLengths( divisions = this.arcLengthDivisions ) {

		if ( this.cacheArcLengths &&
			( this.cacheArcLengths.length === divisions + 1 ) &&
			! this.needsUpdate ) {

			return this.cacheArcLengths;

		}

		this.needsUpdate = false;

		const cache = [];
		let current, last = this.getPoint( 0 );
		let sum = 0;

		cache.push( 0 );

		for ( let p = 1; p <= divisions; p ++ ) {

			current = this.getPoint( p / divisions );
			sum += current.distanceTo( last );
			cache.push( sum );
			last = current;

		}

		this.cacheArcLengths = cache;

		return cache; // { sums: cache, sum: sum }; Sum is in the last element.

	}
Returns an array of cumulative segment lengths of the curve.

@param {number} [divisions=this.arcLengthDivisions] - The number of divisions.
@return {Array<number>} An array holding the cumulative segment lengths.