openmaptiles/layers/place/city.sql

30 wiersze
1.3 KiB
PL/PgSQL

CREATE OR REPLACE FUNCTION layer_city(bbox geometry, zoom_level int, pixel_width numeric)
RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text, class city_class, scalerank int) AS $$
SELECT osm_id, geometry, name, name_en, place, scalerank
FROM osm_city_point
WHERE geometry && bbox
AND ((zoom_level = 2 AND scalerank = 0)
OR (zoom_level BETWEEN 3 AND 7 AND scalerank < zoom_level)
)
UNION ALL
SELECT osm_id, geometry, name, name_en, place, scalerank FROM (
SELECT osm_id, geometry, name, name_en, place, scalerank,
row_number() OVER (
PARTITION BY LabelGrid(geometry, 150 * pixel_width)
ORDER BY place ASC NULLS LAST,
population DESC NULLS LAST,
length(name) DESC
) AS gridrank
FROM osm_city_point
WHERE geometry && bbox
AND ((zoom_level BETWEEN 8 AND 9 AND place <= 'town'::city_class)
OR (zoom_level = 10 AND place <= 'village'::city_class)
OR (zoom_level BETWEEN 11 AND 13 AND place <= 'suburb'::city_class)
OR (zoom_level >= 14)
)
) AS ranked_places
WHERE (zoom_level = 8 AND gridrank <= 4)
OR (zoom_level BETWEEN 9 AND 12 AND gridrank <= 9)
OR (zoom_level >= 13);
$$ LANGUAGE SQL IMMUTABLE;