Extend a layer outward to fill gaps

Extend a polygon layer's boundaries outward using Voronoi diagrams, producing a complete coverage layer with no external gaps (coastlines, disputed areas, water bodies).

topo-tools edge-extend example.gpkg example_extended.gpkg

Rerun and overwrite a previous output:

topo-tools edge-extend example.parquet example_extended.parquet --overwrite

This is the standalone primitive edge-match calls per parent group internally; reach for it directly only when a layer needs extending on its own, with no parent/clip layer to fit afterward. If a parent/clip layer exists, use edge-match instead so extend and clip happen in one call.

See edge-extend reference and its explanation page for how the Voronoi extension itself works.