Areas topic
The area generator produces an area defined by a topline and a baseline as in an area chart. Typically, the two lines share the same x-values (x0 = x1), differing only in y-value (y0 and y1); most commonly, y0 is defined as a constant representing zero (the y scale’s output for zero). The topline is defined by x1 and y1 and is rendered first; the baseline is defined by x0 and y0 and is rendered second with the points in reverse order. With a curveLinear curve, this produces a clockwise polygon. See also radial areas.