DE Blockkennzeichen: make shield size depend on length of label

Author: Nakaner

signals.mml

@@ -227,6 +227,12 @@ Layer:
             way,
             railway,
             ref,
+            array_to_string(ref_multiline, E'\n') AS ref_multiline,
+            array_length(ref_multiline, 1) AS height,
+            (
+              SELECT MAX(char_length(ref_ml))
+                FROM unnest(ref_multiline) AS u(ref_ml)
+            ) AS width,
             COALESCE(
               tags->'railway:signal:combined',
               tags->'railway:signal:main',
@@ -343,7 +349,7 @@ Layer:
             tags->'railway:signal:crossing:type' AS crossing_type,
             tags->'railway:signal:ring:type' AS ring_type,
             tags->'railway:signal:whistle:type' AS whistle_type
-          FROM openrailwaymap_osm_point
+          FROM openrailwaymap_osm_signals
           WHERE
             railway = 'signal'
             AND "signal_direction" IS NOT NULL

signals.mss

@@ -695,19 +695,25 @@ Format details:
   /* DE block marker ("Blockkennzeichen) */
   /***************************************/
   ["feature"="DE-ESO:blockkennzeichen"] {
-    [zoom<16] {
+    [zoom<16],
+    [zoom>=16][zoom<17][height > 1],
+    [zoom>=16][zoom<17][width > 2],
+    [zoom>=17][height > 2],
+    [zoom>=17][width > 4] {
       marker-file: url('symbols/de/blockkennzeichen.svg');
       marker-allow-overlap: true;
       marker-width: 14;
       marker-height: 14;
     }
 
-    [zoom>=16] {
-      shield-file: url('symbols/de/blockkennzeichen.svg');
-      shield-name: [ref];
+    [zoom>=16][height <= 1][width <= 2],
+    [zoom>=17][height <= 2][width <= 4] {
+      shield-file: url('symbols/flex/de/blockkennzeichen-[width]x[height].svg');
+      shield-name: [ref_multiline];
       shield-fill: black;
-      shield-face-name: @bold-fonts;
+      shield-face-name: @book-fonts;
       shield-size: 10;
+      shield-allow-overlap: true;
     }
   }
 

sql/osm_carto_views.sql

@@ -49,3 +49,14 @@ CREATE OR REPLACE VIEW openrailwaymap_osm_point AS
     tags->'railway:signal:speed_limit_distant:speed' AS "signal_speed_limit_distant_speed",
     tags AS tags
   FROM planet_osm_point;
+
+CREATE OR REPLACE VIEW openrailwaymap_osm_signals AS
+  SELECT
+    osm_id,
+    way,
+    railway,
+    ref,
+    string_to_array(ref, ' ') AS ref_multiline,
+    tags->'railway:signal:direction'   AS "signal_direction",
+    tags AS tags
+  FROM planet_osm_point;