Source:

• src/ometeotl_foundations/spatial/geometry.py

Local role: Structural Protocol (PEP 544) that all geometry implementations must satisfy. Decorated with @runtime_checkable so isinstance(obj, Geometry) guards work at runtime.

Big-picture role: The contract between the spatial foundations layer and adapter backends. BoundingBox satisfies it at the foundations layer; the Shapely adapter will wrap shapely.geometry.* objects in a thin class that also satisfies it.

Protocol members

Properties:

• area -> float — area in the native units of the coordinate system; 0 for point/line geometries
• centroid -> Coordinate2D — geometric centroid as a 2-D coordinate
• bounds -> BoundingBox — axis-aligned bounding box of the geometry

Methods:

• contains(other: Geometry) -> bool — True if this geometry fully contains other
• intersects(other: Geometry) -> bool — True if they share any interior area
• touches(other: Geometry) -> bool — True if they share a boundary but their open interiors are disjoint (DE-9IM semantics)
• distance(other: Geometry) -> float — minimum distance; 0.0 if they overlap
• to_dict() -> JsonMap — serialise to a plain dict; the dict must include a "type" discriminator key (e.g. "bounding_box") so downstream callers can dispatch to the correct from_dict

Design notes

• Mutation (union, buffer) is intentionally not on the protocol — those are construction operations handled by SpatialBackend.
• TYPE_CHECKING-only import of BoundingBox avoids a circular import with bounding_box.py.
• BoundingBox satisfies this protocol and its conformance is asserted at import time.

Example:

from ometeotl_foundations.spatial.bounding_box import BoundingBox
from ometeotl_foundations.spatial.geometry import Geometry

box = BoundingBox(0, 0, 10, 10)
assert isinstance(box, Geometry)   # runtime_checkable

# Any object with the right attributes/methods satisfies the protocol

See also:

• BoundingBox — concrete implementation
• SpatialBackend — factory for geometry objects