raygeo.geo.algo.polylabel

Functions

find_largest_circle()

find_largest_circle(
    shell: Sequence[tuple[float, float]],
    holes: Sequence[Sequence[tuple[float, float]]] = [],
    precision: float = 0.5,
) -> tuple[tuple[float, float], float] | None

Find the centre and radius of the largest inscribed circle.

Parameter	Type	Description
shell	Sequence[tuple[float, float]]	Outer boundary polygon.
holes	Sequence[Sequence[tuple[float, float]]] = []	List of hole polygons to exclude (default []).
precision	float = 0.5	Desired precision (default 0.5).
Returns	tuple[tuple[float, float], float] | None	((x, y), radius) or None for degenerate polygons.

find_largest_circle returns the centre and radius of the largest inscribed circle — the entry point and its clearance for helical versus ramp decisions

polylabel()

polylabel(
    shell: Sequence[tuple[float, float]],
    holes: Sequence[Sequence[tuple[float, float]]] = [],
    precision: float = 0.5,
) -> tuple[float, float] | None

Find the pole of inaccessibility of a polygon (with optional holes).

Uses the Polylabel algorithm (Mapbox): a priority-queue of grid cells repeatedly subdivided until the cell radius drops below precision.

Parameter	Type	Description
shell	Sequence[tuple[float, float]]	Outer boundary polygon.
holes	Sequence[Sequence[tuple[float, float]]] = []	List of hole polygons to exclude (default []).
precision	float = 0.5	Desired precision (default 0.5).
Returns	tuple[float, float] | None	(x, y) of the most interior point, or None for degenerate polygons.
Complexity		O(n log n) where n is the number of cells explored.

Polylabel: priority-queue cell refinement finds the point farthest from the boundary — the pole of inaccessibility

Multi-island pocket: the pole of inaccessibility sits in the largest valid region, farthest from all boundaries

Central-island pocket (annular): the pole of inaccessibility sits at the centre of the ring