Use ClearTables scheme for classes

layers/transportation/class.sql

@@ -0,0 +1,34 @@
+CREATE OR REPLACE FUNCTION brunnel(is_bridge BOOL, is_tunnel BOOL, is_ford BOOL) RETURNS TEXT AS $$
+    SELECT CASE
+        WHEN is_bridge THEN 'bridge'
+        WHEN is_tunnel THEN 'tunnel'
+        WHEN is_ford THEN 'ford'
+        ELSE NULL
+    END;
+$$ LANGUAGE SQL IMMUTABLE STRICT;
+
+-- The classes for highways are derived from the classes used in ClearTables
+-- https://github.com/ClearTables/ClearTables/blob/master/transportation.lua
+CREATE OR REPLACE FUNCTION highway_class(highway TEXT) RETURNS TEXT AS $$
+    SELECT CASE
+        WHEN highway IN ('motorway', 'motorway_link') THEN 'motorway'
+        WHEN highway IN ('trunk', 'trunk_link') THEN 'trunk'
+        WHEN highway IN ('primary', 'primary_link') THEN 'primary'
+        WHEN highway IN ('secondary', 'secondary_link') THEN 'secondary'
+        WHEN highway IN ('tertiary', 'tertiary_link') THEN 'tertiary'
+        WHEN highway IN ('unclassified', 'residential', 'living_street', 'road') THEN 'minor'
+        WHEN highway IN ('service', 'track') THEN highway
+        WHEN highway IN ('pedestrian', 'path', 'footway', 'cycleway', 'steps') THEN 'path'
+        ELSE NULL
+    END;
+$$ LANGUAGE SQL IMMUTABLE STRICT;
+
+-- The classes for railways are derived from the classes used in ClearTables
+-- https://github.com/ClearTables/ClearTables/blob/master/transportation.lua
+CREATE OR REPLACE FUNCTION railway_class(railway TEXT) RETURNS TEXT AS $$
+    SELECT CASE
+        WHEN railway IN ('rail', 'narrow_gauge', 'preserved', 'funicular') THEN 'rail'
+        WHEN railway IN ('subway', 'light_rail', 'monorail', 'tram') THEN 'transit'
+        ELSE NULL
+    END;
+$$ LANGUAGE SQL IMMUTABLE STRICT;

layers/transportation/layer.sql

@@ -8,81 +8,104 @@ $$ LANGUAGE SQL IMMUTABLE STRICT;
 CREATE OR REPLACE FUNCTION layer_transportation(bbox geometry, zoom_level int)
 RETURNS TABLE(osm_id bigint, geometry geometry, class text, subclass text, ramp int, oneway int, brunnel TEXT) AS $$
     SELECT
-		osm_id, geometry,
-		CASE
-            WHEN highway <> '' THEN to_highway_class(highway)
-            WHEN railway <> '' THEN railway_class(railway, service)
+        osm_id, geometry,
+        CASE
+            WHEN highway <> '' THEN highway_class(highway)
+            WHEN railway <> '' THEN railway_class(railway)
         END AS class,
         COALESCE(NULLIF(highway,''), NULLIF(railway, '')) AS subclass,
+        -- All links are considered as ramps as well
         CASE WHEN highway_is_link(highway) THEN 1 ELSE is_ramp::int END AS ramp,
         is_oneway::int AS oneway,
-        to_brunnel(is_bridge, is_tunnel, is_ford) AS brunnel
-	FROM (
+        brunnel(is_bridge, is_tunnel, is_ford) AS brunnel
+    FROM (
+        -- etldoc: ne_10m_global_roads ->  layer_transportation:z4z6
+        SELECT
+            NULL::bigint AS osm_id, geometry,
+            highway, NULL AS railway, NULL AS service,
+            FALSE AS is_bridge, FALSE AS is_tunnel, FALSE AS is_ford,
+            FALSE AS is_ramp, FALSE AS is_oneway,
+            0 AS z_order
+        FROM ne_10m_global_roads
+        WHERE zoom_level BETWEEN 4 AND 6 AND scalerank <= 1 + zoom_level
+        UNION ALL
 
-		-- etldoc: ne_10m_global_roads ->  layer_transportation:z4z6
-		SELECT
-			NULL::bigint AS osm_id, geometry, highway, NULL AS railway, NULL AS service,
-			FALSE AS is_bridge, FALSE AS is_tunnel, FALSE AS is_ford, FALSE AS is_ramp, FALSE AS is_oneway,
-			0 AS z_order
-		FROM ne_10m_global_roads
-		WHERE zoom_level BETWEEN 4 AND 6 AND scalerank <= 1 + zoom_level
-		UNION ALL
-
-		-- etldoc: osm_transportation_linestring_gen4  ->  layer_transportation:z7z8
-		SELECT osm_id, geometry, highway, railway, service, is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
+        -- etldoc: osm_transportation_linestring_gen4  ->  layer_transportation:z7z8
+        SELECT
+            osm_id, geometry, highway, railway, service,
+            is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
         FROM osm_transportation_linestring_gen4
-		WHERE zoom_level BETWEEN 7 AND 8
-		UNION ALL
+        WHERE zoom_level BETWEEN 7 AND 8
+        UNION ALL
 
-		-- etldoc: osm_transportation_linestring_gen3  ->  layer_transportation:z9
-		SELECT osm_id, geometry, highway, railway, service, is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
+        -- etldoc: osm_transportation_linestring_gen3  ->  layer_transportation:z9
+        SELECT
+            osm_id, geometry, highway, railway, service,
+            is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
         FROM osm_transportation_linestring_gen3
-		WHERE zoom_level = 9
-		UNION ALL
+        WHERE zoom_level = 9
+        UNION ALL
 
-		-- etldoc: osm_transportation_linestring_gen2  ->  layer_transportation:z10
-		SELECT osm_id, geometry, highway, railway, service, is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
+        -- etldoc: osm_transportation_linestring_gen2  ->  layer_transportation:z10
+        SELECT
+            osm_id, geometry, highway, railway, service,
+            is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
         FROM osm_transportation_linestring_gen2
-		WHERE zoom_level = 10
-		UNION ALL
+        WHERE zoom_level = 10
+        UNION ALL
 
-		-- etldoc: osm_transportation_linestring_gen1  ->  layer_transportation:z11
-		SELECT osm_id, geometry, highway, railway, service, is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
+        -- etldoc: osm_transportation_linestring_gen1  ->  layer_transportation:z11
+        SELECT
+            osm_id, geometry, highway, railway, service,
+            is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
         FROM osm_transportation_linestring_gen1
-		WHERE zoom_level = 11
-		UNION ALL
+        WHERE zoom_level = 11
+        UNION ALL
 
-		-- etldoc: osm_transportation_linestring       ->  layer_transportation:z12
-		SELECT osm_id, geometry, highway, railway, service, is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
+        -- etldoc: osm_transportation_linestring       ->  layer_transportation:z12
+        SELECT
+            osm_id, geometry, highway, railway, service,
+            is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
         FROM osm_transportation_linestring
-		WHERE zoom_level = 12
-            AND (to_highway_class(highway) NOT IN ('minor_road', 'path') OR highway IN ('unclassified', 'residential'))
-            AND NOT highway_is_link(highway)
+        WHERE zoom_level = 12
+            AND (
+                highway_class(highway) NOT IN ('track', 'path', 'minor')
+                OR highway IN ('unclassified', 'residential')
+            )
             AND NOT is_area
         UNION ALL
 
-		-- etldoc: osm_transportation_linestring       ->  layer_transportation:z13
-		SELECT osm_id, geometry, highway, railway, service, is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
+        -- etldoc: osm_transportation_linestring       ->  layer_transportation:z13
+        SELECT osm_id, geometry, highway, railway, service, is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
         FROM osm_transportation_linestring
-		WHERE zoom_level = 13
-            AND (to_highway_class(highway) <> 'path' OR railway_class(railway, service) = 'rail')
+        WHERE zoom_level = 13
+            AND (
+                highway_class(highway) NOT IN ('track', 'path')
+                OR (railway='rail' AND service = '')
+            )
             AND NOT is_area
         UNION ALL
 
-		-- etldoc: osm_transportation_linestring       ->  layer_transportation:z14_
-		SELECT osm_id, geometry, highway, railway, service, is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
+        -- etldoc: osm_transportation_linestring       ->  layer_transportation:z14_
+        SELECT osm_id, geometry, highway, railway, service, is_bridge, is_tunnel, is_ford, is_ramp, is_oneway, z_order
         FROM osm_transportation_linestring
-		WHERE zoom_level >= 14 AND NOT is_area
+        WHERE zoom_level >= 14 AND NOT is_area
         UNION ALL
 
-        -- NOTE: We limit the selection of polys because we need to be careful to net get false positives here because
-        -- it is possible that closed linestrings appear both as highway linestrings and as polygon
+        -- NOTE: We limit the selection of polys because we need to be
+        -- careful to net get false positives here because
+        -- it is possible that closed linestrings appear both as
+        -- highway linestrings and as polygon
         -- etldoc: osm_transportation__polygon          ->  layer_transportation:z13
         -- etldoc: osm_transportation__polygon          ->  layer_transportation:z14_
-		SELECT osm_id, geometry, highway, NULL AS railway, NULL AS service, FALSE AS is_bridge, FALSE AS is_tunnel, FALSE AS is_ford, FALSE AS is_ramp, FALSE AS is_oneway, z_order
+        SELECT
+            osm_id, geometry,
+            highway, NULL AS railway, NULL AS service,
+            FALSE AS is_bridge, FALSE AS is_tunnel, FALSE AS is_ford,
+            FALSE AS is_ramp, FALSE AS is_oneway, z_order
         FROM osm_transportation_polygon
         -- We do not want underground pedestrian areas for now
-		WHERE zoom_level >= 13 AND is_area AND COALESCE(layer, 0) >= 0
+        WHERE zoom_level >= 13 AND is_area AND COALESCE(layer, 0) >= 0
     ) AS zoom_levels
     WHERE geometry && bbox
     ORDER BY z_order ASC;

layers/transportation/transportation.yaml

@@ -31,7 +31,7 @@ layer:
     srid: 900913
     query: (SELECT geometry, class, subclass, oneway, ramp, brunnel FROM layer_transportation(!bbox!, z(!scale_denominator!))) AS t
 schema:
-  - ./types.sql
+  - ./class.sql
   - ./ne_global_roads.sql
   - ./layer.sql
 datasources:

layers/transportation/types.sql

@@ -1,29 +0,0 @@
-CREATE OR REPLACE FUNCTION to_brunnel(is_bridge BOOL, is_tunnel BOOL, is_ford BOOL) RETURNS TEXT AS $$
-    SELECT CASE
-        WHEN is_bridge THEN 'bridge'
-        WHEN is_tunnel THEN 'tunnel'
-        WHEN is_ford THEN 'ford'
-        ELSE NULL
-    END;
-$$ LANGUAGE SQL IMMUTABLE STRICT;
-
-CREATE OR REPLACE FUNCTION to_highway_class(highway TEXT) RETURNS TEXT AS $$
-    SELECT CASE
-        WHEN highway IN ('motorway', 'motorway_link') THEN 'motorway'
-        -- A major class is helpful in styling - one can still differentiate on a finer level using the subclass
-        WHEN highway IN ('trunk', 'trunk_link',
-                         'primary', 'primary_link',
-                         'secondary', 'secondary_link',
-                         'tertiary', 'tertiary_link') THEN 'major_road'
-        WHEN highway IN ('unclassified', 'residential', 'living_street', 'road', 'track', 'service') THEN 'minor_road'
-        WHEN highway IN ('pedestrian', 'path', 'footway', 'cycleway', 'steps') THEN 'path'
-        ELSE NULL
-    END;
-$$ LANGUAGE SQL IMMUTABLE STRICT;
-
-CREATE OR REPLACE FUNCTION railway_class(railway text, service text) RETURNS TEXT AS $$
-    SELECT CASE
-        WHEN railway='rail' AND service='' THEN 'rail'
-        ELSE 'minor_rail'
-    END;
-$$ LANGUAGE SQL IMMUTABLE;