Add water name layer

docker-compose.yml

@@ -19,6 +19,11 @@ services:
     env_file: .env
     links:
     - postgres
+  import-lakelines:
+    image: "openmaptiles/import-lakelines"
+    env_file: .env
+    links:
+    - postgres
   import-osm:
     image: "openmaptiles/import-osm"
     env_file: .env

layers/water_name/layer.sql

@@ -0,0 +1,10 @@
+CREATE OR REPLACE FUNCTION layer_water_name(bbox geometry, zoom_level integer)
+RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text, class text) AS $$
+    SELECT osm_id, geometry, name, name_en, 'lake'::text AS class
+    FROM osm_water_lakeline
+    WHERE geometry && bbox
+      AND name <> ''
+      AND ((zoom_level BETWEEN 10 AND 13 AND LineLabel(zoom_level, NULLIF(name, ''), geometry))
+        OR (zoom_level >= 14))
+    ORDER BY ST_Length(geometry) DESC;
+$$ LANGUAGE SQL IMMUTABLE;

layers/water_name/merge_lakelines.sql

@@ -0,0 +1,9 @@
+CREATE TABLE IF NOT EXISTS osm_water_lakeline AS (
+	SELECT wp.osm_id,
+		ll.wkb_geometry AS geometry,
+		name, name_en
+    FROM osm_water_polygon AS wp
+    INNER JOIN lake_centerline ll ON wp.osm_id = ll.osm_id
+);
+
+CREATE INDEX IF NOT EXISTS osm_water_lakeline_geometry_idx ON osm_water_lakeline USING gist(geometry);

layers/water_name/water_name.yaml

@@ -0,0 +1,18 @@
+layer:
+  id: "water_name"
+  description: |
+      OSM lakelines.
+  buffer_size: 8
+  srs: +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over
+  fields:
+    class: String
+  datasource:
+    geometry_field: geometry
+    srid: 900913
+    query: (SELECT geometry, name, name_en, class FROM layer_water_name(!bbox!, z(!scale_denominator!))) AS t
+schema:
+  - ./merge_lakelines.sql
+  - ./layer.sql
+datasources:
+  - type: imposm3
+    mapping_file: ../water/mapping.yaml

openmaptiles.yaml

@@ -8,6 +8,7 @@ tileset:
     #- layers/housenumber/housenumber.yaml
     - layers/place/place.yaml
     - layers/railway/railway.yaml
+    - layers/water_name/water_name.yaml
     - layers/water/water.yaml
     - layers/waterway/waterway.yaml
     - layers/landcover/landcover.yaml