Render natural=shrubbery

Render `natural=shrubbery`. The three `shrubbery:density` values
(`sparse`, `medium`, and `dense`) are reflected in the pattern.

Fixes #4473

project.mml

@@ -64,13 +64,13 @@ Layer:
               way,
               ('landuse_' || (CASE WHEN landuse IN ('forest', 'farmland', 'residential', 'commercial', 'retail', 'industrial',
                                                     'meadow', 'grass', 'village_green', 'vineyard', 'orchard') THEN landuse END)) AS landuse,
-              ('natural_' || (CASE WHEN "natural" IN ('wood', 'sand', 'scree', 'shingle', 'bare_rock', 'heath', 'grassland', 'scrub') THEN "natural" END)) AS "natural",
+              ('natural_' || (CASE WHEN "natural" IN ('wood', 'sand', 'scree', 'shingle', 'bare_rock', 'heath', 'grassland', 'scrub', 'shrubbery') THEN "natural" END)) AS "natural",
               ('wetland_' || (CASE WHEN "natural" IN ('wetland', 'mud') THEN (CASE WHEN "natural" IN ('mud') THEN "natural" ELSE tags->'wetland' END) END)) AS wetland,
               way_area/NULLIF(POW(!scale_denominator!*0.001*0.28,2),0) AS way_pixels,
               way_area
             FROM planet_osm_polygon
             WHERE (landuse IN ('forest', 'farmland', 'residential', 'commercial', 'retail', 'industrial', 'meadow', 'grass', 'village_green', 'vineyard', 'orchard')
-              OR "natural" IN ('wood', 'wetland', 'mud', 'sand', 'scree', 'shingle', 'bare_rock', 'heath', 'grassland', 'scrub'))
+              OR "natural" IN ('wood', 'wetland', 'mud', 'sand', 'scree', 'shingle', 'bare_rock', 'heath', 'grassland', 'scrub', 'shrubbery'))
               AND way_area > 0.01*!pixel_width!::real*!pixel_height!::real
               AND building IS NULL
           ) AS features
@@ -87,7 +87,7 @@ Layer:
       <<: *osm2pgsql
       table: |-
         (SELECT
-            way, name, religion, way_pixels, is_building,
+            way, name, religion, density, way_pixels, is_building,
             COALESCE(aeroway, golf, amenity, wetland, power, landuse, leisure, man_made, "natural", shop, tourism, highway, railway) AS feature
           FROM (SELECT
               way, COALESCE(name, '') AS name,
@@ -107,13 +107,16 @@ Layer:
                                                     'golf_course', 'miniature_golf', 'sports_centre', 'stadium', 'pitch', 'ice_rink',
                                                     'track', 'dog_park', 'fitness_station', 'water_park') THEN leisure END)) AS leisure,
               ('man_made_' || (CASE WHEN man_made IN ('works', 'wastewater_plant', 'water_works') THEN man_made END)) AS man_made,
-              ('natural_' || (CASE WHEN "natural" IN ('beach', 'shoal', 'heath', 'grassland', 'wood', 'sand', 'scree', 'shingle', 'bare_rock', 'scrub') THEN "natural" END)) AS "natural",
+              ('natural_' || (CASE WHEN "natural" IN ('beach', 'shoal', 'heath', 'grassland', 'wood', 'sand', 'scree', 'shingle', 'bare_rock', 'scrub', 'shrubbery') THEN "natural" END)) AS "natural",
               ('wetland_' || (CASE WHEN "natural" IN ('wetland', 'mud') THEN (CASE WHEN "natural" = 'mud' THEN "natural" ELSE tags->'wetland' END) END)) AS wetland,
               ('power_' || (CASE WHEN power IN ('plant', 'substation', 'generator') THEN power END)) AS power,
               ('tourism_' || (CASE WHEN tourism IN ('camp_site', 'caravan_site', 'picnic_site') THEN tourism END)) AS tourism,
               ('highway_' || (CASE WHEN highway IN ('services', 'rest_area') THEN highway END)) AS highway,
               ('railway_' || (CASE WHEN railway = 'station' THEN railway END)) AS railway,
               CASE WHEN religion IN ('christian', 'jewish', 'muslim') THEN religion ELSE 'INT-generic'::text END AS religion,
+              CASE WHEN "natural" = 'shrubbery'
+                THEN tags->'shrubbery:density'
+              END AS density,
               way_area/NULLIF(POW(!scale_denominator!*0.001*0.28,2),0) AS way_pixels,
               CASE WHEN building = 'no' OR building IS NULL THEN 'no' ELSE 'yes' END AS is_building,
               way_area
@@ -126,7 +129,7 @@ Layer:
                              'grave_yard', 'place_of_worship', 'prison', 'clinic', 'ferry_terminal', 'marketplace', 'community_centre', 'social_facility',
                              'arts_centre', 'parking_space', 'bus_station', 'fire_station', 'police')
               OR man_made IN ('works', 'wastewater_plant','water_works')
-              OR "natural" IN ('beach', 'shoal', 'heath', 'mud', 'wetland', 'grassland', 'wood', 'sand', 'scree', 'shingle', 'bare_rock', 'scrub')
+              OR "natural" IN ('beach', 'shoal', 'heath', 'mud', 'wetland', 'grassland', 'wood', 'sand', 'scree', 'shingle', 'bare_rock', 'scrub', 'shrubbery')
               OR power IN ('plant', 'substation', 'generator')
               OR shop IN ('mall')
               OR tourism IN ('camp_site', 'caravan_site', 'picnic_site')
@@ -298,9 +301,13 @@ Layer:
               END AS int_wetland,
             landuse,
             tags->'leaf_type' AS leaf_type,
+            -- Could be extended with wood:density or scrub:density:
+            CASE WHEN "natural" = 'shrubbery'
+                THEN tags->'shrubbery:density'
+              END AS density,
             way_area/NULLIF(POW(!scale_denominator!*0.001*0.28,2),0) AS way_pixels
           FROM planet_osm_polygon
-          WHERE ("natural" IN ('mud', 'wetland', 'wood', 'beach', 'shoal', 'reef', 'scrub') OR landuse IN ('forest', 'salt_pond'))
+          WHERE ("natural" IN ('mud', 'wetland', 'wood', 'beach', 'shoal', 'reef', 'scrub', 'shrubbery') OR landuse IN ('forest', 'salt_pond'))
             AND building IS NULL
             AND way_area > 1*!pixel_width!::real*!pixel_height!::real
           ORDER BY COALESCE(layer,0), way_area DESC
@@ -1527,7 +1534,7 @@ Layer:
                                                     'construction', 'salt_pond', 'military', 'plant_nursery') THEN landuse END,
                 'natural_' || CASE WHEN "natural" IN ('peak', 'volcano', 'saddle', 'cave_entrance') AND way_area IS NULL THEN "natural" END,
                 'natural_' || CASE WHEN "natural" IN ('wood', 'water', 'mud', 'wetland', 'bay', 'spring', 'scree', 'shingle', 'bare_rock', 'sand', 'heath',
-                                                      'grassland', 'scrub', 'beach', 'glacier', 'tree', 'strait', 'cape')
+                                                      'grassland', 'scrub', 'shrubbery', 'beach', 'glacier', 'tree', 'strait', 'cape')
                                                       THEN "natural" END,
                 'waterway_' || CASE WHEN "waterway" IN ('waterfall') AND way_area IS NULL THEN waterway END,
                 'place_' || CASE WHEN place IN ('island', 'islet', 'square') THEN place END,

style/landcover.mss

@@ -8,6 +8,8 @@
 @allotments: #c9e1bf;   // Lch(87,20,135)
 @orchard: #aedfa3; // also vineyard, plant_nursery
 @hedge: @forest;       // Lch(80,30,135)
+@shrubbery: @scrub;
+@shrubbery-barrier: @forest;
 
 // --- "Base" landuses ---
 
@@ -530,6 +532,15 @@
     [way_pixels >= 64] { polygon-gamma: 0.3;  }
   }
 
+  [feature = 'natural_shrubbery'][zoom >= 5] {
+    polygon-fill: @shrubbery;
+    [density = 'dense'] {
+      polygon-fill: @shrubbery-barrier;
+    }
+    [way_pixels >= 4]  { polygon-gamma: 0.75; }
+    [way_pixels >= 64] { polygon-gamma: 0.3;  }
+  }
+
   [feature = 'wetland_swamp'][zoom >= 5] {
     polygon-fill: @forest;
     [way_pixels >= 4]  { polygon-gamma: 0.75; }
@@ -792,6 +803,20 @@
       polygon-pattern-file: url('symbols/scrub.png');
       polygon-pattern-alignment: global;
     }
+    [natural = 'shrubbery'] {
+      [density = 'sparse'] {
+        polygon-pattern-file: url('symbols/shrubbery/sparse.png');
+        polygon-pattern-alignment: global;
+      }
+      [density = 'medium'] {
+        polygon-pattern-file: url('symbols/shrubbery/medium.png');
+        polygon-pattern-alignment: global;
+      }
+      [density = 'dense'] {
+        polygon-pattern-file: url('symbols/shrubbery/dense.png');
+        polygon-pattern-alignment: global;
+      }
+    }
   }
 
   //Also landuse = forest, converted in the SQL