spawn enemy from the side Sprite-kit

Question

I'm working on my game but I face a problem when I try spawn the enemy from the said I can spawn them only from the top and bottom of the scene I don't know why

This is my timer:

override func didMoveToView(view: SKView) {
    initialzeGame()
    NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: Selector("spawnEnemy"), userInfo: nil, repeats: true)
}

And this is the rest:

func randomBetweenNumbers(firstNum: CGFloat, secondNum: CGFloat) -> CGFloat {
    return CGFloat(arc4random()) / CGFloat(UINT32_MAX) * abs(firstNum + secondNum) + min(firstNum, secondNum)
}

func spawnEnemy() {
    //supposed to pick random point within the screen width

    let Pos = randomBetweenNumbers(0, secondNum: frame.height )
    //let PosTwo = randomBetweenNumbers(0, secondNum: frame.height )

    let enemy = SKSpriteNode(imageNamed: "zombie") //create a new enemy each time
    enemy.position = CGPointMake(CGFloat(Pos), self.frame.size.width/16)
    enemy.physicsBody = SKPhysicsBody(circleOfRadius: 7)
    enemy.physicsBody?.affectedByGravity = true
    enemy.physicsBody?.categoryBitMask = 0
    enemy.physicsBody?.contactTestBitMask = 1
    enemy.size = CGSize(width: 80, height: 70)
    let enmyact = SKAction.moveTo(hero.position, duration: 2)
    enemy.runAction(enmyact)
    addChild(enemy)
}

are you sure the enemy is not just spawning in an area that is being cropped, also, you want to use frame.width, not frame.height, since height > then width, your enemies again are in an area that is not on screen — Knight0fDragon
@AliMahdi This : enemy.physicsBody?.affectedByGravity = true in conjunction with this : enemy.runAction(enmyact) will produce very weird results. I am not sure how you didn't noticed that already by yourself ? Enemy has a dynamic body, affected by gravity, means, the physics world will apply certain force to this body (and pull it in certain direction). Also, at the same time, you are using SKAction to move enemies where you want. This will break physics simulation, and you will have a buggy enemy movement. I guess, you want to make enemies unaffected by gravity. — Whirlwind

Price Ringo Price Ringo · Accepted Answer · 2016-03-07T16:24:44

Reverse the arguments in CGPointMake.

  enemy.position = CGPointMake(self.frame.size.width/16, CGFloat(Pos))

spawn enemy from the side Sprite-kit

1 Answers