This algorithm is relatively simple and consists of the following steps:
1. Select the first vertex of every two contours.
2. Calculate the distance that joins them and create a point belonging to the initial contour line(s) (linear interpolation).
3. Determine the least distance from a vertex on a contour line to another contour line. The following step are used to do this:
a) Start from the current points on both contour lines.
b) The distance from the next point on contour line 1 to the same point on contour line 2 is calculated. Then the distance from the next point on contour line 2 to the same point on contour line 1 is calculated. Finally, distance between the next points on contour line 1 and contour line 2 are calculated. In other words, three distances are calculated.
c) A decision is made on which of the three distances is smallest. This distance will determine whether the advance occurs on the vertices of contour line 1, contour line 2 or both in this step.
4. After determining the advance, the process is repeated from point 2 with the two new vertices selected until the last vertex of both polylines is reached.
TcpMDT