The shape of the fillet is controlled by a set of coordinates for a series of two or more connected lines. The fillet is tangential to the start point of the first line and to the end point of the last line. When more than two sets of coordinates are supplied, the fillet passes through the mid-points of the intermediate lines. An individual fillet always lies within the area bounded by the start, end, and control points.

Refer to function "GpiPolyFillet" in the Presentation Manager Programming Reference for more information.