小编inv*_*ngo的帖子

import SpriteKit

class GameScene: SKScene 
{    
    let player = SKSpriteNode(imageNamed: "Gun")

    override func didMoveToView(view: SKView) 
    {    
        backgroundColor = SKColor.whiteColor()    
        player.position = CGPoint(x: size.width * 0.1, y: size.height * 0.5)
        addChild(player)
    }
}

func random() -> CGFloat 
{
    return CGFloat(Float(arc4random()) / 0xFFFFFFFF)
}

func random(#min: CGFloat, max: CGFloat) -> CGFloat 
{
    return random() * (max - min) + min
}

func addMonster() 
{        
    let monster = SKSpriteNode(imageNamed: "monster")        
    let actualY = random(min: monster.size.height/2, monster.size.height - monster.size.height/2)

    monster.position = CGPoint(x: monster.size.width + …