}

	// Update the histogram.
	h := &d.hist
	lbFloat, lf := math.Modf(l * mudDegree)
	lb := int(lbFloat)
	if lb >= mudDegree {
		lb, lf = mudDegree-1, 1
	}
	if l == r {
		h[lb] += area
	} else {
		rbFloat, rf := math.Modf(r * mudDegree)
		rb := int(rbFloat)
		if rb >= mudDegree {
			rb, rf = mudDegree-1, 1
		}
		if lb == rb {
			h[lb] += area