/* * Copyright 2019-2022 Bytes & Brains * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ --| # PostGIS Region Functions --@ availability: 4.0.0 CREATE OR REPLACE FUNCTION h3_polygon_to_cells(multi geometry, resolution integer) RETURNS SETOF h3index AS $$ SELECT h3_polygon_to_cells(exterior, holes, resolution) FROM ( SELECT -- extract exterior ring of each polygon ST_MakePolygon(ST_ExteriorRing(poly))::polygon exterior, -- extract holes of each polygon (SELECT array_agg(hole) FROM ( SELECT ST_MakePolygon(ST_InteriorRingN( poly, generate_series(1, ST_NumInteriorRings(poly)) ))::polygon AS hole ) q_hole ) holes -- extract single polygons from multipolygon FROM ( select (st_dump(multi)).geom as poly ) q_poly GROUP BY poly ) h3_polygon_to_cells; $$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE CALLED ON NULL INPUT; -- NOT STRICT --@ availability: 4.0.0 CREATE OR REPLACE FUNCTION h3_polygon_to_cells(multi geography, resolution integer) RETURNS SETOF h3index AS $$ SELECT h3_polygon_to_cells($1::geometry, $2) $$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE CALLED ON NULL INPUT; -- NOT STRICT