adapt = function adapt(delta, numPoints, firstTime) {
	var k = 0;
	delta = firstTime ? floor(delta / damp) : delta >> 1;
	delta += floor(delta / numPoints);
	for (; /* no initialization */delta > baseMinusTMin * tMax >> 1; k += base) {
		delta = floor(delta / baseMinusTMin);
	}
	return floor(k + (baseMinusTMin + 1) * delta / (delta + skew));
}
Bias adaptation function as per section 3.4 of RFC 3492.
https://tools.ietf.org/html/rfc3492#section-3.4
@private