Add boundaries à la NaturalEarth tiles

data.yml

@@ -51,6 +51,44 @@ Layer:
     properties: 
       "buffer-size": 4
     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
+  - id: boundary
+    Datasource: 
+      dbname: osm
+      extent: -20037508.34,-20037508.34,20037508.34,20037508.34
+      geometry_field: geom
+      geometry_table: ''
+      host: db
+      key_field: ''
+      key_field_as_attribute: ''
+      max_size: 512
+      password: osm
+      port: 5432
+      srid: ''
+      table: |-
+        ( SELECT *
+          FROM (
+              SELECT * FROM boundary_z0 WHERE z(!scale_denominator!) = 0
+              UNION ALL
+              SELECT * FROM boundary_z1 WHERE z(!scale_denominator!) BETWEEN 1 AND 2
+              UNION ALL
+              SELECT * FROM boundary_z3 WHERE z(!scale_denominator!) BETWEEN 3 AND 4
+              UNION ALL
+              SELECT * FROM boundary_z5 WHERE z(!scale_denominator!) BETWEEN 5 AND 6
+              UNION ALL
+              SELECT * FROM boundary_z7 WHERE z(!scale_denominator!) >= 7
+          ) AS admin
+          WHERE geom && !bbox!
+        ) AS data
+      type: postgis
+      user: osm
+    description: Buildings
+    fields: 
+      admin_level: Number
+      class: String
+      scalerank: Number
+    properties: 
+      "buffer-size": 4
+    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
   - id: building
     Datasource: 
       dbname: osm

schema/create_schema.sh

@@ -18,6 +18,7 @@ function main() {
     exec_psql_file "$VT_UTIL_DIR/postgis-vt-util.sql"
     exec_psql_file "layers/water.sql"
     exec_psql_file "layers/building.sql"
+    exec_psql_file "layers/boundary.sql"
 }
 
 main

schema/layers/boundary.sql

@@ -0,0 +1,60 @@
+CREATE OR REPLACE FUNCTION boundary_class(featureclass VARCHAR) RETURNS VARCHAR
+AS $$
+BEGIN
+    RETURN CASE
+        WHEN featureclass ILIKE 'line of control%' THEN 'control'
+        WHEN featureclass ILIKE 'disputed%' THEN 'dispute'
+        WHEN featureclass ILIKE 'lease%' THEN 'lease'
+        WHEN featureclass ILIKE 'overlay%' THEN 'overlay'
+        ELSE 'boundary'
+    END;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE;
+
+CREATE OR REPLACE VIEW boundary_z0 AS (
+    SELECT geom, 0 AS admin_level, scalerank,
+           boundary_class(featurecla) AS class
+    FROM ne_110m_admin_0_boundary_lines_land
+);
+
+CREATE OR REPLACE VIEW boundary_z1 AS (
+    SELECT geom, 0 AS admin_level, scalerank,
+           boundary_class(featurecla) AS class
+    FROM ne_50m_admin_0_boundary_lines_land
+    UNION ALL
+    SELECT geom, 1 AS admin_level, scalerank,
+           boundary_class(featurecla) AS class
+    FROM ne_50m_admin_1_states_provinces_lines
+    WHERE scalerank <= 2
+);
+
+CREATE OR REPLACE VIEW boundary_z3 AS (
+    SELECT geom, 0 AS admin_level, scalerank,
+           boundary_class(featurecla) AS class
+    FROM ne_50m_admin_0_boundary_lines_land
+    UNION ALL
+    SELECT geom, 1 AS admin_level, scalerank,
+           boundary_class(featurecla) AS class
+    FROM ne_50m_admin_1_states_provinces_lines
+);
+
+CREATE OR REPLACE VIEW boundary_z5 AS (
+    SELECT geom, 0 AS admin_level, scalerank,
+           boundary_class(featurecla) AS class
+    FROM ne_10m_admin_0_boundary_lines_land
+    UNION ALL
+    SELECT geom, 1 AS admin_level, scalerank,
+           boundary_class(featurecla) AS class
+    FROM ne_10m_admin_1_states_provinces_lines_shp
+    WHERE scalerank <= 7
+);
+
+CREATE OR REPLACE VIEW boundary_z7 AS (
+    SELECT geom, 0 AS admin_level, scalerank,
+           boundary_class(featurecla) AS class
+    FROM ne_10m_admin_0_boundary_lines_land
+    UNION ALL
+    SELECT geom, 1 AS admin_level, scalerank,
+           boundary_class(featurecla) AS class
+    FROM ne_10m_admin_1_states_provinces_lines_shp
+);