raygeo.geo.algo.fillet

Pure-geometry fillet operations.

Domain-neutral utilities for creating circular fillet arcs, appending them to polylines, and trimming to safe spans.

• create_fillet_polyline — circular arc tangent to a direction.
• append_end_fillets — fillet both ends of an open polyline.
• trim_to_safe_fillet_span — longest sub-span whose end fillets avoid obstacles.

Functions

append_end_fillets()

append_end_fillets(
    polyline: Sequence[tuple[float, float]],
    radius: float,
    sweep_angle: float,
    side: float,
) -> list[tuple[float, float]]

Append fillet arcs to both ends of an open polyline.

A reversed fillet is added at the start and a forward fillet at the end, producing a smooth rounded path.

Parameter	Type	Description
polyline	Sequence[tuple[float, float]]	Input open polyline.
radius	float	Fillet radius.
sweep_angle	float	Arc sweep angle in radians.
side	float	Offset side (+1 left, -1 right).
Returns	list[tuple[float, float]]	Full polyline with fillets.

append_end_fillets rounds both ends of an open polyline with reversed-start / forward-end fillet arcs

create_fillet_polyline()

create_fillet_polyline(
    p: tuple[float, float],
    dir: tuple[float, float],
    radius: float,
    sweep_angle: float,
    side: float,
    reverse: bool,
) -> tuple[tuple[float, float], list[tuple[float, float]]]

Create a circular fillet arc tangent to dir at p.

side selects the offset side (+1 = left of dir, -1 = right). When reverse is True the arc curls back opposite to dir.

Parameter	Type	Description
p	tuple[float, float]	Start point (x, y).
dir	tuple[float, float]	Tangent direction vector (dx, dy).
radius	float	Fillet radius.
sweep_angle	float	Arc sweep angle in radians.
side	float	Offset side (+1 left, -1 right).
reverse	bool	Whether the arc is reversed.
Returns	tuple[tuple[float, float], list[tuple[float, float]]]	(center, polyline) — arc centre and fillet vertices.

create_fillet_polyline generates circular fillet arcs of arbitrary sweep angle, tangent to a direction at a point

create_fillet_polyline with side=+1 (left) and side=-1 (right) of the direction vector

fillet_arc_ends()

fillet_arc_ends(
    arc: Sequence[tuple[float, float]],
    pocket_boundary: Sequence[tuple[float, float]],
    islands: Sequence[Sequence[tuple[float, float]]] = [],
    tool_radius: float = 3,
    wall_margin: float = 0,
) -> list[tuple[float, float]]

Round both ends of a cutting arc with quarter-circle fillets.

The arc is trimmed to the longest sub-arc whose tool sweep (arc + end fillets of tool_radius) does not collide with pocket_boundary or islands. A 90° fillet of tool_radius is then appended at each end.

Parameter	Type	Description
arc	Sequence[tuple[float, float]]	Cutting arc vertices (open polyline).
pocket_boundary	Sequence[tuple[float, float]]	Outer boundary of the pocket.
islands	Sequence[Sequence[tuple[float, float]]] = []	List of island (hole) polygons (default []).
tool_radius	float = 3	Tool / fillet radius in mm (default 3.0).
wall_margin	float = 0	Extra clearance past tangency (default 0.0).
Returns	list[tuple[float, float]]	Filleted arc as an open polyline.

fillet_arc_ends trims the arc to the longest safe sub-arc and appends quarter-circle fillets at each end

find_safe_sweep_end()

find_safe_sweep_end(
    arc: Sequence[tuple[float, float]],
    pocket_boundary: Sequence[tuple[float, float]],
    islands: Sequence[Sequence[tuple[float, float]]] = [],
    tool_radius: float = 3,
    wall_margin: float = 0,
) -> tuple[tuple[float, float], tuple[float, float]] | None

Find the longest safe sub-arc by iterative sweep shortening.

Returns the two points (enter, exit) delimiting the longest sub-arc of arc whose tool sweep (arc + end fillets of tool_radius) does not collide with pocket_boundary or islands. Shortens from each end until the sweep is clear. Returns None when no usable safe sub-arc remains.

Parameter	Type	Description
arc	Sequence[tuple[float, float]]	Cutting arc vertices (open polyline).
pocket_boundary	Sequence[tuple[float, float]]	Outer boundary of the pocket.
islands	Sequence[Sequence[tuple[float, float]]] = []	List of island (hole) polygons (default []).
tool_radius	float = 3	Tool radius in mm (default 3.0).
wall_margin	float = 0	Extra clearance past tangency (default 0.0).
Returns	tuple[tuple[float, float], tuple[float, float]] | None

find_safe_sweep_end returns the (enter, exit) points delimiting the longest sub-arc whose tool sweep avoids islands

trim_to_safe_fillet_span()

trim_to_safe_fillet_span(
    polyline: Sequence[tuple[float, float]],
    outer_boundary: Sequence[tuple[float, float]],
    inner_obstacles: Sequence[Sequence[tuple[float, float]]] = [],
    radius: float = 3,
    margin: float = 0,
) -> tuple[tuple[float, float], tuple[float, float]] | None

Find the longest sub-span whose end fillets avoid obstacles.

Shortens from each end until the sweep is clear. Returns (enter, exit) or None.

Parameter	Type	Description
polyline	Sequence[tuple[float, float]]	Open polyline to trim.
outer_boundary	Sequence[tuple[float, float]]	Outer boundary polygon.
inner_obstacles	Sequence[Sequence[tuple[float, float]]] = []	List of obstacle polygons (default []).
radius	float = 3	Fillet radius (default 3.0).
margin	float = 0	Extra clearance past tangency (default 0.0).
Returns	tuple[tuple[float, float], tuple[float, float]] | None

trim_to_safe_fillet_span finds the longest sub-span whose end fillets do not collide with obstacles (red)