Add: [Script] ObjectType::ResolveNewGRFID to resolve object id from grfid and grf_local_id

src/script/api/ai_changelog.hpp

@@ -17,6 +17,8 @@
  *
  * This version is not yet released. The following changes are not set in stone yet.
  *
+ * \li AIObjectType::ResolveNewGRFID
+ *
  * \b 12.0
  *
  * API additions:

src/script/api/game_changelog.hpp

@@ -17,6 +17,8 @@
  *
  * This version is not yet released. The following changes are not set in stone yet.
  *
+ * \li GSObjectType::ResolveNewGRFID
+ *
  * \b 12.0
  *
  * API additions:

src/script/api/script_objecttype.cpp

@@ -44,3 +44,11 @@
 
 	return ScriptObject::Command<CMD_BUILD_OBJECT>::Do(tile, object_type, view);
 }
+
+/* static */ ObjectType ScriptObjectType::ResolveNewGRFID(uint32 grfid, uint16 grf_local_id)
+{
+	EnforcePrecondition(INVALID_OBJECT_TYPE, IsInsideBS(grf_local_id, 0x00, NUM_OBJECTS_PER_GRF));
+
+	grfid = BSWAP32(grfid); // Match people's expectations.
+	return _object_mngr.GetID(grf_local_id, grfid);
+}

src/script/api/script_objecttype.hpp

@@ -52,6 +52,15 @@ public:
 	 * @return True if the object was successfully build.
 	 */
 	static bool BuildObject(ObjectType object_type, uint8 view, TileIndex tile);
+
+	/**
+	 * Get a specific object-type from a grf.
+	 * @param grf_id The ID of the NewGRF.
+	 * @param grf_local_id The ID of the object, local to the NewGRF.
+	 * @pre 0x00 <= grf_local_id < NUM_OBJECTS_PER_GRF.
+	 * @return the object-type ID, local to the current game (this diverges from the grf_local_id).
+	 */
+	static ObjectType ResolveNewGRFID(uint32 grfid, uint16 grf_local_id);
 };
 
 #endif /* SCRIPT_OBJECTTYPE_HPP */