raygeo.geo.algo.offset_exact

Exact offsetting of closed line-and-arc contours.

Offsets boundaries keeping lines and arcs exact, so an arc wall comes out as an arc rather than a chord approximation.

Functions

offset_exact()

offset_exact(
    geometry: geo.Geometry,
    offset: float,
    tolerance: float = 0.1,
) -> list[geo.Geometry]

Offset the closed line-and-arc contours of a geometry exactly.

Every closed subpath takes part: counter-clockwise loops bound material, clockwise ones bound holes. Lines and arcs stay exact (arc walls come out as arcs); other curves are followed as line chains within tolerance. Open subpaths are ignored. A positive offset grows the region, a negative one shrinks it.

Parameter	Type	Description
geometry	geo.Geometry	geometry whose closed subpaths are offset.
offset	float	offset distance; positive grows the region.
tolerance	float = 0.1	line-chain tolerance for non-line-and-arc curves.
Returns	list[geo.Geometry]	the offset closed loops, one geometry per loop.
Complexity		O(n^2) in the number of boundary pieces.

Exact offsets of a rounded rectangle: input arcs stay arcs, new corners roll on arcs.

Every closed subpath takes part: growing the region moves the island's boundary inwards.

A spline boundary is followed as a line chain, mitered while that stays within the tolerance.