Line
A polyline / polygon ring stored as flat primitive arrays rather than one Point object per vertex — dense WFS/OSM geometry is mostly thousands of vertices per ring, and the object-per- vertex graph was the dominant decode-time allocation (the GC-pressure source). xy is interleaved [lon0, lat0, lon1, lat1, …] in degrees (size 2 * vertexCount); z is the per-vertex altitude in meters parallel to the vertices, or null for a 2D ring (clamp to ground). The closing vertex may or may not be present.
Properties
Functions
Envelope-center (longitude, latitude) of this geometry — a deterministic representative point. Used to assign a feature to a single tile (the one containing its center), so a geometry that straddles a tile boundary renders in exactly one tile instead of every tile its envelope touches.