Module center_line

Centre-line profiles: offset an open path into a closed boundary.

The area a centre line denotes is the set of points within a half-width of its path. This module resolves that into an explicit ring by walking the flattened path out one side and back the other.

Offsetting is done on the FLATTENED path rather than on the exact curves. A true exact offset of a spline is a different curve type, not the same curve moved sideways, so producing one here would either be wrong or would need a curve representation the kernel does not have. Flattening first keeps the approximation in one place and under the caller’s chord budget, which is the same contract every other curved profile already accepts.

Functions

center_line_rings

Resolve a centre-line profile into a closed ring.