Spawning the Power-up Star at random

We still need to add the Power-p Star into the world. We can randomly spawn a Star every ten encounters to add some extra excitement. Follow these steps to add the Star logic:

1. Add a new instance of the Star class as a constant on the GameScene class:

           let powerUpStar = Star() 
   

2. Anywhere inside the GameScene didMove function, add the Star as a child of the GameScene and position it:

           // Place the star out of the way for now: 
           self.addChild(powerUpStar) 
           powerUpStar.position = CGPoint(x: -2000, y: -2000) 
   

3. Inside the GameScene didSimulatePhysics function, update your new encounter code as follows (new code in bold):

           // Check to see if we should set a new encounter: 
           if player.position.x > nextEncounterSpawnPosition { 
               encounterManager.placeNextEncounter( 
                   currentXPos: nextEncounterSpawnPosition) 
               nextEncounterSpawnPosition += 1200 ...