Add gridrank attribute

layers/poi/layer.sql

@@ -1,8 +1,13 @@
-CREATE OR REPLACE FUNCTION layer_poi(bbox geometry, zoom_level integer)
-RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text, class text, subclass text) AS $$
-    SELECT id, geometry, name, NULLIF(name_en, ''), poi_class(subclass) AS class, subclass
+CREATE OR REPLACE FUNCTION layer_poi(bbox geometry, zoom_level integer, pixel_width numeric)
+RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text, class text, subclass text, gridrank bigint) AS $$
+    SELECT id, geometry, name, NULLIF(name_en, ''), poi_class(subclass) AS class, subclass,
+        row_number() OVER (
+            PARTITION BY LabelGrid(geometry, 100 * pixel_width)
+            ORDER BY poi_class_rank(poi_class(subclass)) ASC, length(name) DESC
+        ) AS gridrank
     FROM osm_poi_point
     WHERE geometry && bbox
+      AND zoom_level >= 14
       AND name <> ''
-      AND (zoom_level >= 14);
+    ORDER BY gridrank;
 $$ LANGUAGE SQL IMMUTABLE;