Merge pull request #36235 from ymber/mapgen_items

Allow defining anonymous itemgroups in mapgen

data/json/mapgen_palettes/apartment.json

@@ -83,12 +83,19 @@
       "d": { "item": "dresser", "chance": 70, "repeat": [ 1, 3 ] },
       "e": { "item": "fridge", "chance": 70, "repeat": [ 1, 10 ] },
       "j": { "item": "trash", "chance": 65, "repeat": [ 1, 3 ] },
-      "o": [
-        { "item": "magazines", "chance": 30 },
-        { "item": "novels", "chance": 40 },
-        { "item": "alcohol", "chance": 30 },
-        { "item": "manuals", "chance": 20 }
-      ],
+      "o": {
+        "item": {
+          "subtype": "distribution",
+          "entries": [
+            { "group": "magazines" },
+            { "group": "SUS_fiction_bookcase" },
+            {
+              "distribution": [ { "group": "SUS_tailoring_bookcase" }, { "group": "SUS_crafts_bookcase" }, { "group": "SUS_cooking_bookcase" } ]
+            }
+          ]
+        },
+        "chance": 75
+      },
       "O": { "item": "oven", "chance": 70 },
       "p": { "item": "mail", "chance": 30, "repeat": [ 2, 5 ] },
       "r": [ { "item": "dresser", "chance": 30 }, { "item": "jackets", "chance": 60 } ],

doc/MAPGEN.md

@@ -586,7 +586,7 @@ Places a gas pump with gasoline (or sometimes diesel) in it. Values:
 
 ### 2.5.6 "items"
 Places items from an item group. Values:
-- "item": (required, string) the item group to use.
+- "item": (required, string or itemgroup object) the item group to use.
 - "chance": (optional, integer or min/max array) x in 100 chance that a loop will continue to spawn items from the group (which itself may spawn multiple items or not depending on its type, see `ITEM_SPAWN.md`), unless the chance is 100, in which case it will trigger the item group spawn exactly 1 time (see `map::place_items`).
 - "repeat": (optional, integer or min/max array) the number of times to repeat this placement, default is 1.
 

src/mapgen.cpp

@@ -1041,14 +1041,11 @@ class jmapgen_liquid_item : public jmapgen_piece
 class jmapgen_item_group : public jmapgen_piece
 {
     public:
-        std::string group_id;
+        Group_tag group_id;
         jmapgen_int chance;
-        jmapgen_item_group( const JsonObject &jsi ) :
-            group_id( jsi.get_string( "item" ) )
-            , chance( jsi, "chance", 1, 1 ) {
-            if( !item_group::group_is_defined( group_id ) ) {
-                set_mapgen_defer( jsi, "item", "no such item group '" + group_id + "'" );
-            }
+        jmapgen_item_group( const JsonObject &jsi ) : chance( jsi, "chance", 1, 1 ) {
+            JsonValue group = jsi.get_member( "item" );
+            group_id = item_group::load_item_group( group, "collection" );
             repeat = jmapgen_int( jsi, "repeat", 1, 1 );
         }
         void apply( mapgendata &dat, const jmapgen_int &x, const jmapgen_int &y ) const override {