NEWS

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wkpool 0.3.0 (2026-03-05)

• Removed as_decido() which wasn't fully worked out.

• Fixed wkpool() which never worked before.

• Added check_wkpool helper function.

wkpool 0.2.0

Round-trip to wk

• arcs_to_wkt() / arcs_to_wkb() — arcs become linestrings
• cycles_to_wkt() / cycles_to_wkb() — cycles become polygons, with hole nesting
• segments_to_wkt() / segments_to_wkb() — raw segments as linestrings, multilinestring, or points

Arc-node topology

• vertex_degree() counts segments touching each vertex
• find_nodes() identifies branch points and endpoints (degree ≠ 2)
• find_arcs() extracts maximal segment sequences between nodes
• as_arcs() returns wkpool with .arc column for arc membership
• arc_node_summary() reports arc/node structure statistics

Arcs are the "uninterrupted lines" — sequences of segments passing only through degree-2 vertices. Useful for line simplification, network extraction, and efficient storage.

wkpool 0.1.0

Initial release. Vertex pool topology for wk-handleable geometry.

Core functions

• establish_topology() converts any wk-handleable geometry to segments + vertex pool
• merge_coincident() discovers shared vertices (exact or tolerance-based)
• pool_vertices(), pool_segments(), pool_feature() access the structure
• pool_combine() merges multiple pools with proper index remapping
• pool_compact() removes unreferenced vertices

Topology discovery

• find_shared_edges() finds edges shared by multiple features
• find_internal_boundaries() finds edges traversed in opposite directions (true shared boundaries)
• find_neighbours() builds adjacency from shared edges or vertices
• topology_report() summarizes vertex/edge sharing

Cycle and winding analysis

• find_cycles() discovers closed rings from segment connectivity
• cycle_signed_area() computes signed area (shoelace formula)
• classify_cycles() identifies outer rings vs holes by winding
• reverse_cycle() flips winding direction
• hole_points() extracts hole centroids for triangulation
• Convention support: "sf" (default) or "ogc" winding rules

Triangulation export

• as_pslg() exports to RTriangle format (P, S matrices)
• as_decido() exports to decido format (0-indexed)

vctrs integration

• wkpool is a vctrs rcrd: subset, combine operations work
• plot.wkpool() for quick visualization

Design principles

• Segments are the atomic primitive — the waist of the hourglass
• Observe, don't correct — represent truth, fixing is separate
• Minted .vx integers for stable vertex identity
• Feature provenance tracked via .feature