GKStateMachine
玩家进入GameScene场景中 -> 通过GKStateMachine进入到指定的游戏状态GKState
在GameScene场景中 -> 根据不同的逻辑调用GKStateMachine -> 在各个不同的游戏状态GKState之间进行切换
源码如下：
一、GameScene.swft
import SpriteKit
import GameplayKit
class GameScene: SKScene,SKPhysicsContactDelegate {
//MARK: - StateMachine 场景中各个舞台State
lazy var stateMachine:GKStateMachine = GKStateMachine(states: [
WaitingState(scene: self),
PlayState(scene: self),
GameOverState(scene: self)])
override func didMove(to view: SKView) {
stateMachine.enter(MenuState.self) // 进入MenuState
}
func restartGame(){
let newScene = GameScene(fileNamed: "GameScene")!
newScene.size = CGSize(width: SCENE_WIDTH, height: SCENE_HEIGHT)
newScene.anchorPoint = CGPoint(x: 0, y: 0)
newScene.scaleMode = .aspectFill
let transition = SKTransition.crossFade(withDuration: TimeInterval(0.5))
view?.presentScene(newScene, transition:transition)
//reload GameScene 直接进入游戏状态;
newScene.stateMachine.enter(PlayState.self)
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
guard let touch = touches.first else {
return
}
// 当 physicsWorld.body(at: touchLocation)为nil时
// 采用atPoint 取得场景中的的精灵
let touchLocation = touch.location(in: self) ///获得点击的位置
let nodeAtPoint = self.atPoint(touchLocation) //返回SKNode
/// 判断目前的GameScene场景舞台是哪个state
switch stateMachine.currentState {
case is WaitingState:
/// 判断是否是点击了PlayButton
if nodeAtPoint.name == "playButton" {
stateMachine.enter(PlayState.self)
}
if nodeAtPoint.name == "learnTemp" {
print("weird")
UIApplication.shared.open(URL(string: "http://www.iFIERO.com")!, options: convertToUIApplicationOpenExternalURLOptionsKeyDictionary([:]), completionHandler: { (error) in
print("jump to http://www.iFiero.com")
})
}
case is PlayState:
//挑战：判断是否是点击了暂停按钮 PauseButton
// if nodeAtPoint.name == "pauseButton" {
// stateMachine.enter(PauseState.self)
// }
break;
case is GameOverState:
if nodeAtPoint.name == "tapToPlay" {
restartGame()
}
default:
break;
}
}
//MARK: - 时时更新
override func update(_ currentTime: TimeInterval) {
/// 获取时间差
if lastUpdateTimeInterval == 0 {
lastUpdateTimeInterval = currentTime
}
dt = currentTime - lastUpdateTimeInterval
lastUpdateTimeInterval = currentTime
stateMachine.update(deltaTime: dt) // 调用所有State内的update方法
}
}
二、MenuState.swft
//
// MenuState.swift
// Copyright © 2018 iFiero. All rights reserved.
//
import SpriteKit
import GameplayKit
class MenuState:GKState {
// 必须引入场景(如:GameScene)
unowned let scene:GameScene
// 执行didEnter前，可在init()初始化代码
init(scene:SKScene){
self.scene = scene as! GameScene
super.init()
print("Menu State")
}
// 进入当前状态时触发
override func didEnter(from previousState: GKState?) {
}
// 离开当前状态时触发
override func willExit(to nextState: GKState) {
}
/* 返回一个布尔值
* 该值指示当前处于该状态的状态机是否允许转换到指定状态
* 通俗点讲就是：如果stateMachine(状态机)的状态是PlayState,那么就从MenuState状态转到PlayState状态
*/
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
return stateClass is PlayState.Type
}
// Execute Update Per Frame,游戏运行过程中的每一帧都会执行
// 但须在GameScene update内调用stateMachine.update()
override func update(deltaTime seconds: TimeInterval) {
}
}
三、PlayingState.swft
import SpriteKit
import GameplayKit
class PlayState:GKState {
unowned let scene:GameScene
init(scene:SKScene){
self.scene = scene as! GameScene
super.init()
print("Play State")
}
override func didEnter(from previousState: GKState?) {
}
// 挑战:创建游戏暂停GKState状态 PauseState.swift
// return (stateClass == PauseState.self) || (stateClass == GameOverState.self)
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
return stateClass is GameOverState.Type
}
// Excute Update Per Frame
override func update(deltaTime seconds: TimeInterval) {
// update 用于判断球的速度是否过快，如果太快了则设置linearDamping的阻力
}
}
四、GameOverState.swft
import SpriteKit
import GameplayKit
class GameOverState:GKState {
unowned let scene:GameScene
init(scene:SKScene){
self.scene = scene as! GameScene
super.init()
}
override func didEnter(from previousState: GKState?) {
print("GameOver State 游戏结束")
}
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
return stateClass is PlayState.Type
// return (stateClass == PlayState.self) || (stateClass == MenuState.self)
}
}
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