mixins: fix duplicate spawn events for large gameobjects

runelite-mixins/src/main/java/net/runelite/mixins/RSTileMixin.java

@@ -76,6 +76,9 @@ public abstract class RSTileMixin implements RSTile
 	@Shadow("clientInstance")
 	private static RSClient client;
 
+	@Inject
+	private static RSGameObject lastGameObject;
+
 	@Inject
 	private static RSDeque[][][] lastGroundItems = new RSDeque[Constants.MAX_Z][Constants.SCENE_SIZE][Constants.SCENE_SIZE];
 
@@ -234,12 +237,26 @@ public abstract class RSTileMixin implements RSTile
 		// Update previous object to current
 		previousGameObjects[idx] = current;
 
+		// Last game object
+		RSGameObject last = lastGameObject;
+
+		// Update last game object
+		lastGameObject = current;
+
 		// Duplicate event, return
 		if (current == previous)
 		{
 			return;
 		}
 
+		if (current != null && current == last)
+		{
+			// When >1 tile objects are added to the scene, the same GameObject is added to
+			// multiple tiles. We keep lastGameObject to prevent duplicate spawn events from
+			// firing for these objects.
+			return;
+		}
+
 		// actors, projectiles, and graphics objects are added and removed from the scene each frame as GameObjects,
 		// so ignore them.
 		boolean currentInvalid = false, prevInvalid = false;