下面通过一个样例演示如何实现飞行道具的生成，以及道具碰撞拾取。
样例说明：1，屏幕从右到左不断地生成苹果飞过来（苹果高度随机）2，点击屏幕可以让熊猫跳跃3，熊猫碰到苹果，苹果消失运行效果：
样例代码：苹果工厂类 AppleFactory.swift
| 1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071 | import SpriteKit class AppleFactory:SKNode{ //定义苹果纹理 let appleTexture = SKTexture(imageNamed: "apple") //游戏场景的狂赌 var sceneWidth :CGFloat = 0.0 //定义苹果数组 var arrApple = [SKSpriteNode]() //定时器 var timer = NSTimer() func onInit(width:CGFloat) { self.sceneWidth = width //启动的定时器 timer = NSTimer.scheduledTimerWithTimeInterval( 0.2, target: self, selector: "createApple", userInfo: nil, repeats: true) } //创建苹果类 func createApple(){ //通过随机数来随机生成苹果 //算法是，随机生成0-9的数，当随机数大于8的时候声称苹果 //也就是说，有1/10的几率生成苹果 //这样游戏场景中的苹果就不会整整齐齐以相同间隔出现了 let random = arc4random() % 10 if random > 8 { //生成苹果 let apple = SKSpriteNode(texture: appleTexture) //设置物理体 apple.physicsBody = SKPhysicsBody(rectangleOfSize: apple.size) //弹性设为0 apple.physicsBody?.restitution = 0 //物理体标识 apple.physicsBody?.categoryBitMask = BitMaskType.apple //不受物理效果影响 apple.physicsBody?.dynamic = false //设置中心点 apple.anchorPoint = CGPointMake(0, 0) //z轴深度 apple.zPosition = 40 //设定位置 let theY = CGFloat(arc4random()%200 + 200) apple.position = CGPointMake(sceneWidth+apple.frame.width , theY) //加入数组 arrApple.append(apple) //加入场景 self.addChild(apple) } } //苹果移动方法 func move(speed:CGFloat){ for apple in arrApple { apple.position.x -= speed } //移出屏幕外时移除苹果 if arrApple.count > 0 && arrApple[0].position.x < -20{ arrApple[0].removeFromParent() arrApple.removeAtIndex(0) } } //重置方法 func reSet(){ //移除所有子对象 self.removeAllChildren() //清空苹果数组 arrApple.removeAll(keepCapacity: false) }} |
熊猫类 Panda.swift
| 123456789101112131415161718192021222324252627282930313233 | import SpriteKit class Panda: SKSpriteNode { //定义纹理 let pandaTexture = SKTexture(imageNamed: "panda") init() { //执行父类的构造方法 super.init(texture:pandaTexture,color:SKColor.whiteColor(),size:pandaTexture.size()) //设置中心点 self.anchorPoint = CGPointMake(0, 0) self.physicsBody = SKPhysicsBody(rectangleOfSize:pandaTexture.size()) self.physicsBody?.dynamic = true self.physicsBody?.allowsRotation = false //弹性 self.physicsBody?.restitution = 0 self.physicsBody?.categoryBitMask = BitMaskType.panda self.physicsBody?.contactTestBitMask = BitMaskType.scene|BitMaskType.apple self.physicsBody?.collisionBitMask = BitMaskType.scene } required init(coder aDecoder: NSCoder) { fatalError("init(coder:) has not been implemented") } //跳 func jump (){ //施加一个向上的力，让小人跳起来 self.physicsBody?.velocity = CGVectorMake(0, 700) }} |
碰撞标识类 – BitMaskType.swift
| 1234567891011 | class BitMaskType { class var panda:UInt32{ return 1<<0 } class var apple:UInt32{ return 1<<1 } class var scene:UInt32{ return 1<<2 }} |
主场景 – GameScene.swift
| 1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162 | import SpriteKit class GameScene: SKScene,SKPhysicsContactDelegate { lazy var appleFactory = AppleFactory() lazy var panda = Panda() //移动速度 var moveSpeed:CGFloat = 15 //吃到的苹果数 var appleNum = 0 override func didMoveToView(view: SKView) { //物理世界代理 self.physicsWorld.contactDelegate = self //重力设置 self.physicsWorld.gravity = CGVectorMake(0, -5) //设置物理体 self.physicsBody = SKPhysicsBody(edgeLoopFromRect: self.frame) //设置种类标示 self.physicsBody?.categoryBitMask = BitMaskType.scene //是否响应物理效果 self.physicsBody?.dynamic = false //场景的背景颜色 let skyColor = SKColor(red:113/255,green:197/255,blue:207/255,alpha:1) self.backgroundColor = skyColor //给小人定一个初始位置 panda.position = CGPointMake(200, 400) //将小人显示在场景中 self.addChild(panda) //苹果工厂 appleFactory.onInit(self.frame.width) self.addChild( appleFactory ) } override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) { panda.jump() } override func update(currentTime: CFTimeInterval) { appleFactory.move(moveSpeed) } //碰撞检测方法 func didBeginContact(contact: SKPhysicsContact) { //熊猫和苹果碰撞 if (contact.bodyA.categoryBitMask | contact.bodyB.categoryBitMask) == (BitMaskType.apple | BitMaskType.panda){ //苹果计数加1 self.appleNum++ //如果碰撞体A是苹果，隐藏碰撞体A，反之隐藏碰撞体B //（因为苹果出了屏幕都会被移除，所以这里隐藏就可以了） if contact.bodyA.categoryBitMask == BitMaskType.apple { contact.bodyA.node?.hidden = true }else{ contact.bodyB.node?.hidden = true } } }} |
源码下载：
EatApple.zip
