ゲームのState管理を簡単にするiOS 9 GameplayKitのクラスとは：iOS SDKとSwiftで始めるゲーム作成入門（5）（2/4 ページ）

import UIKit
import SpriteKit
class Enemy: SKSpriteNode {
    var life = 3
}

class EnemyList {
    private var enemies = [Enemy]()
 
    func enemiesCloseToPoint(point: CGPoint, distance: Double) -> [Enemy] {
        // 略...
    }
 
    func appendEnemy(enemy: Enemy) {
        enemies.append(enemy)
    }
    // 略...
}

class GameScene: SKScene, SKPhysicsContactDelegate {
    // 略...
    func createEnemy() {
        // 略...
        let enemy = Enemy(imageNamed: "Enemy")
        // 略...
    }
    // 略...
}

class GameScene: SKScene, SKPhysicsContactDelegate {
    // 略...
    override func update(currentTime: NSTimeInterval) {
        enemyList.enemiesCloseToPoint(char.frame.origin, distance: 50).forEach {
        $0.life -= 1    
        if $0.life <= 0 {
            $0.physicsBody?.node?.removeFromParent()
            $0.physicsBody?.node?.removeAllActions()
 
            if enemyList.isAllEnemyRemoved() {
                state = .GameClear
 
                let myLabel = SKLabelNode(fontNamed: "HiraginoSans-W6")
                myLabel.text = "ゲームクリア"
                myLabel.fontSize = 45
                myLabel.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame) - 20)
                    addChild(myLabel)
                }
            }
        }
    }
    // 略...
}

import UIKit
import SpriteKit
 
class Char: SKSpriteNode {
    enum State {
        case Attack
        case Wait
    }
    var state: State = .Attack
}

class GameScene: SKScene, SKPhysicsContactDelegate {
// 略...
//    let char = SKSpriteNode(imageNamed: "Char")
let char = Char(imageNamed: "Char")
// 略...
}

class GameScene: SKScene, SKPhysicsContactDelegate {
    // 略...
    override func update(currentTime: NSTimeInterval) {
        // stateが.Attackのときだけ攻撃する
        if char.state == .Attack {
            enemyList.enemiesCloseToPoint(char.frame.origin, distance: 50).forEach {
                $0.life -= 1
                if $0.life <= 0 {
                    $0.physicsBody?.node?.removeFromParent()
                    $0.physicsBody?.node?.removeAllActions()
 
                    if enemyList.isAllEnemyRemoved() {
                        state = .GameClear
 
                        let myLabel = SKLabelNode(fontNamed: "HiraginoSans-W6")
                        myLabel.text = "ゲームクリア"
                        myLabel.fontSize = 45
                        myLabel.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame) - 20)
                        addChild(myLabel)
                    }
                }
                // 敵に攻撃したらstateを.Waitにする
                char.state = .Wait
                // 0.2秒経過したらstateを.Attackに戻す
                performSelector("changeCharStateToAttack", withObject: nil, afterDelay: 0.2)
            }
        }
    }
 
    func changeCharStateToAttack() {
        char.state = .Attack
    }
    // 略...
}