pub fn circle_contour(
circle: &CircleProfile,
) -> Result<ContourProfile, GeomError>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.