Computing area filling contours for surfaces defined by piecewise polynomials (Q1094858)

Noting that the graphical kernel system allows one to color the interior of a polygon with one command, the author presents a method of polygonal approximation of contour lines (or indeed any curve given by its elevation over the xy plane) with an automatic stepsize control depending on the curvature of the line. The curvature being unavailable in most cases, the author takes a step along the tangent and then along the normal until he reaches the curves by one-dimensional search. The ratio of the two lengths measures the curvature and controls the stepsize.