pub fn circle_contour(circle: &CircleProfile) -> GeomResult<ContourProfile>Expand description
A circle profile, and its bore when it has a wall thickness, as exact contours of four quarter arcs each (#111).
Four quarters, not one full turn: contour lowering refuses a segment of half a turn or more (ADR 0053), and a quarter keeps every arc’s endpoints on the axes, where the seams of revolved and extruded walls sit.