change spring icon to a simple outlined dit and move to separate layer

amenity-points.mss

@@ -929,13 +929,14 @@
     point-file: url('symbols/poi_cave.p.16.png');
     point-placement: interior;
   }
-
+/*
   [feature = 'natural_spring'][zoom >= 14] {
     marker-file: url('symbols/spring.svg');
     marker-placement: interior;
     marker-clip: false;
+    marker-fill: @water-color;
   }
-
+*/
   [feature = 'power_generator']['generator:source' = 'wind'],
   [feature = 'power_generator'][power_source = 'wind'] {
     [zoom >= 15] {

project.mml

@@ -318,6 +318,31 @@
       },
       "advanced": {}
     },
+    {
+      "name": "springs",
+      "srs-name": "900913",
+      "geometry": "point",
+      "id": "springs",
+      "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",
+      "Datasource": {
+        "extent": "-20037508,-20037508,20037508,20037508",
+        "table": "(SELECT\n     St_Centroid(way) AS way, \"natural\"\n   FROM planet_osm_polygon\n   WHERE \"natural\" IN ('spring')\n UNION ALL\n SELECT\n     way, \"natural\"\n   FROM planet_osm_point\n   WHERE \"natural\" IN ('spring')\n) AS springs",
+        "geometry_field": "way",
+        "type": "postgis",
+        "key_field": "",
+        "dbname": "gis"
+      },
+      "extent": [
+        -180,
+        -85.05112877980659,
+        180,
+        85.05112877980659
+      ],
+      "properties": {
+        "minzoom": 14
+      },
+      "advanced": {}
+    },
     {
       "name": "water-lines",
       "srs-name": "900913",

project.yaml

@@ -301,6 +301,26 @@ Layer:
     properties:
       minzoom: 4
     advanced: {}
+  - id: "springs"
+    name: "springs"
+    geometry: "point"
+    <<: *extents
+    Datasource:
+      <<: *osm2pgsql
+      table: |-
+        (SELECT
+             St_Centroid(way) AS way, "natural"
+           FROM planet_osm_polygon
+           WHERE "natural" IN ('spring')
+         UNION ALL
+         SELECT
+             way, "natural"
+           FROM planet_osm_point
+           WHERE "natural" IN ('spring')
+        ) AS springs
+    properties:
+      minzoom: 14
+    advanced: {}
   - id: "water-lines"
     name: "water-lines"
     class: "water-lines"

water-features.mss

@@ -162,3 +162,15 @@
     }
   }
 }
+
+#springs {
+  [natural = 'spring'][zoom >= 14] {
+    marker-file: url('symbols/spring_small.svg');
+    [zoom >= 15] {
+      marker-file: url('symbols/spring.svg');
+    }
+    marker-placement: interior;
+    marker-clip: false;
+    marker-fill: @water-color;
+  }
+}