Adding Scene Scrolling and Game Control - Beginning Swift Games Development for iOS - page 52

the player to it. First, add the following declaration of the foregroundNode immedi-
ately after the declaration of the backgroundNode :
let foregroundNode : SKSpriteNode?
Next, create and add the following foregroundNode instance directly after where you
added the backgroundNode to the scene:
foregroundNode = SKSpriteNode()
addChild(foregroundNode!)
Now find the location in the init() method where you added the playerNode and
orbNode to the scene and change the addChild() invocations to the following:
foregroundNode!.addChild(playerNode!)
foregroundNode!.addChild(orbNode!)
Once you have the playerNode and orbNode added to the new foregroundNode ,
find where you are setting the position of the playerNode and change its position
property using the following CGPoint :
playerNode!.position = CGPoint(x: self.size.width / 2.0, y:
180.0)
Now find where you are setting the playerNode.physicsBody.dynamic property
and turn off the player's dynamic volume.
playerNode!.physicsBody!.dynamic = false
You are doing this so the player does not fall off the screen if you don't tap the screen in
time. Next, add the following new property to the GameScene immediately after the
definition of the orbNode :
var impulseCount = 4
Now change the touchesBegan() method to match the following:
override func touchesBegan(touches: NSSet, withEvent event:
UIEvent) {
if !playerNode!.physicsBody!.dynamic {