raygeo.geo.algo.offset

Polygon offsetting operations for geometry data.

Provides concentric inward offset generation for adaptive clearing and pocketing toolpath generation.

Functions

compute_inset_region()

compute_inset_region(
    boundary: Sequence[tuple[float, float]],
    radius: float,
    obstacles: Sequence[Sequence[tuple[float, float]]] = [],
) -> tuple[list[list[tuple[float, float]]], float]

Compute the inset region: boundary shrunk by radius, minus obstacle buffers (each obstacle expanded by radius).

Parameter	Type	Description
boundary	Sequence[tuple[float, float]]	Outer boundary polygon as a list of (x, y) points.
radius	float	Inset / expansion radius.
obstacles	Sequence[Sequence[tuple[float, float]]] = []	List of obstacle polygons (default []).
Returns	tuple[list[list[tuple[float, float]]], float]	(region_polygons, total_area).
Complexity		O((n + m) log(n + m)) where n and m are boundary and obstacle point counts

Inset region: boundary shrunk, obstacles removed. Left: simple. Right: with central obstacle.

Multi-obstacle inset: the region splits into multiple disconnected polygons.

Mixed convex/concave boundary + L-shaped island: verifies Round inset arcs at all joint types.

concentric_offsets()

concentric_offsets(
    geom: geo.Geometry,
    step: float,
    max_passes: int = 10,
    min_area: float = 1,
) -> list[geo.Geometry]

Generate concentric inward offsets of a geometry.

Each successive offset shrinks the boundary by step. Stops early when the enclosed area drops below min_area or max_passes is reached. Returns offsets outermost-first.

Parameter	Type	Description
geom	geo.Geometry	A closed geometry.
step	float	Inward offset distance per pass.
max_passes	int = 10	Maximum number of offset passes (default 10).
min_area	float = 1	Minimum area to stop at (default 1.0).
Returns	list[geo.Geometry]	List of offset geometries, outermost first.
Complexity		O(n * p) time, O(n) space where n is the number of contour vertices and p the number of passes

Concentric inward offsets for adaptive clearing / pocketing

find_deepest_cores()

find_deepest_cores(
    regions: Sequence[geo.types.Polygon],
    step_over: float,
) -> list[geo.types.Point]

Find the deepest (most open) regions of a polygon set.

Iteratively offsets each polygon inward by step_over until all polygons collapse. Returns the centroids of the final polygons.

Parameter	Type	Description
regions	Sequence[geo.types.Polygon]	List of polygons to search.
step_over	float	Inward offset distance per iteration.
Returns	list[geo.types.Point]	List of (x, y) centroid points.
Complexity		O(n * k) where k is the number of iterations

Deepest-core detection: finds max clearance in valid tool area — best helical-entry for the pocket

Multi-island pocket: clockwise contours are islands; core is deepest point in largest valid region.

Central-island (annular): ring of valid tool area; deepest core is max clearance, never in island.

offset_contour_group()

offset_contour_group(
    solid_path: Sequence[geo.types.Point],
    hole_paths: Sequence[Sequence[geo.types.Point]],
    offset: float,
    join_style: geo.shape.polygon.JoinStyle = raygeo.geo.shape.polygon.JoinStyle.Miter,
) -> list[geo.types.Polygon]

Offset a solid contour with its hole contours.

Offsets the solid outward (or inward for negative offset) while offsetting holes in the opposite direction and subtracting them from the solid result.

Parameter	Type	Description
solid_path	Sequence[geo.types.Point]	Outer boundary polygon as (x, y) points.
hole_paths	Sequence[Sequence[geo.types.Point]]	List of hole polygons.
offset	float	Offset distance (positive to inflate, negative to deflate).
join_style	geo.shape.polygon.JoinStyle = raygeo.geo.shape.polygon.JoinStyle.Miter	Corner join style (default: JoinStyle.Miter).
Returns	list[geo.types.Polygon]	Offset polygon(s) with holes subtracted.
Complexity		O(n log n)