33 lines
1.1 KiB
PL/PgSQL
33 lines
1.1 KiB
PL/PgSQL
CREATE OR REPLACE VIEW ice_z0 AS (
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SELECT geom, 'glacier' AS type FROM ne_110m_glaciated_areas
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UNION ALL
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SELECT geom, 'ice_shelf' AS type FROM ne_50m_antarctic_ice_shelves_polys
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);
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CREATE OR REPLACE VIEW ice_z2 AS (
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SELECT geom, 'glacier' AS type FROM ne_50m_glaciated_areas
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UNION ALL
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SELECT geom, 'ice_shelf' AS type FROM ne_50m_antarctic_ice_shelves_polys
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);
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CREATE OR REPLACE VIEW ice_z5 AS (
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SELECT geom, 'glacier' AS type FROM ne_10m_glaciated_areas
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UNION ALL
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SELECT geom, 'ice_shelf' AS type FROM ne_10m_antarctic_ice_shelves_polys
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);
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CREATE OR REPLACE FUNCTION layer_ice(bbox geometry, zoom_level int)
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RETURNS TABLE(geom geometry, class text) AS $$
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SELECT geom, type::text AS class FROM (
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SELECT ST_Simplify(geom, 80000) AS geom, type FROM ice_z0
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WHERE zoom_level BETWEEN 0 AND 1
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UNION ALL
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SELECT * FROM ice_z2
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WHERE zoom_level BETWEEN 2 AND 4
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UNION ALL
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SELECT * FROM ice_z5
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WHERE zoom_level BETWEEN 5 AND 8
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) AS zoom_levels
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WHERE geom && bbox;
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$$ LANGUAGE SQL IMMUTABLE;
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