albumId loading fix

source/funkin/play/song/Song.hx

@@ -256,7 +256,7 @@ class Song implements IPlayStateScriptedClass implements IRegistryEntry<SongMeta
    * List the album IDs for each variation of the song.
    * @return A map of variation IDs to album IDs.
    */
-  public function listAlbums():Map<String, String>
+  public function listAlbums(variation:String):Map<String, String>
   {
     var result:Map<String, String> = new Map<String, String>();
 
@@ -275,6 +275,20 @@ class Song implements IPlayStateScriptedClass implements IRegistryEntry<SongMeta
     return result;
   }
 
+  /**
+   * Input a difficulty ID and a variation ID, and get the album ID.
+   * @param diffId
+   * @param variation
+   * @return String
+   */
+  public function getAlbumId(diffId:String, variation:String):String
+  {
+    var diff:Null<SongDifficulty> = getDifficulty(diffId, variation);
+    if (diff == null) return '';
+
+    return diff.album ?? '';
+  }
+
   /**
    * Populate the difficulty data from the provided metadata.
    * Does not load chart data (that is triggered later when we want to play the song).

source/funkin/ui/freeplay/FreeplayState.hx

@@ -567,7 +567,7 @@ class FreeplayState extends MusicBeatSubState
 
       albumRoll.playIntro();
       var daSong = grpCapsules.members[curSelected].freeplayData;
-      albumRoll.albumId = daSong?.data.listAlbums().get(currentDifficulty);
+      albumRoll.albumId = daSong?.data.getAlbumId(currentDifficulty, currentVariation);
 
       if (!fromCharSelect)
       {
@@ -1788,7 +1788,7 @@ class FreeplayState extends MusicBeatSubState
     }
 
     // Set the album graphic and play the animation if relevant.
-    var newAlbumId:Null<String> = daSong?.data.listAlbums().get(currentVariation);
+    var newAlbumId:Null<String> = daSong?.data.getAlbumId(currentDifficulty, currentVariation);
     if (albumRoll.albumId != newAlbumId)
     {
       albumRoll.albumId = newAlbumId;