Spawn enemies does not work good in spritekit / swift

Question

I want to sequentially spawn enemies. So wrote a code for that, but can't understand why just two of first enemies appears on right position, and the rest of them spawn on wrong positions. Here is the code:

func addDoor() {
    for i in 0...1 {
        let doorSprite = SKSpriteNode(imageNamed: "Door")
        doorSprite.name = "door\(i)"
        if i == 0 {
            doorSprite.position = CGPointMake(self.frame.size.width / 2.0 - 40.0 - doorSprite.frame.size.width, self.frame.size.height - doorSprite.frame.size.height / 2.0)
        } else {
            doorSprite.position = CGPointMake(self.frame.size.width / 2.0 + 40.0 + doorSprite.frame.size.width, self.frame.size.height - doorSprite.frame.size.height / 2.0)
        }
        gameLayer.addChild(doorSprite)
    }
}

func enemySpawn() {
    for i in 0..<15 {
        let sprite = Enemy(imageNamed: "Enemy")
        sprite.name = "enemy\(i)"

        let randDoor = Int(arc4random_uniform(2))

            if randDoor == 0 {
                if let door = gameLayer.childNodeWithName("door\(randDoor)") {
                    sprite.position = CGPointMake((door.position.x - door.frame.size.width / 2.0) + spawnPoint(UInt32(door.frame.size.width - sprite.frame.size.width)) + sprite.frame.size.width / 2.0, door.position.y)
                }
            } else {
                if let door = homeLayer.childNodeWithName("door\(randDoor)") {
                    sprite.position = CGPointMake((door.position.x - door.frame.size.width / 2.0) + spawnPoint(UInt32(door.frame.size.width - sprite.frame.size.width)) + sprite.frame.size.width / 2.0, door.position.y)
                }
            }
        }

        enemiesLayer.runAction(SKAction.waitForDuration(NSTimeInterval(i)), completion: {
            self.enemiesLayer.addChild(sprite)
        })

    }
}

func spawnPoint(num: UInt32) -> CGFloat {
    let randomSpawn: CGFloat = CGFloat(arc4random_uniform(num))
    return randomSpawn
}

It isn't possible to tell from your code what the 'right' or 'wrong' positions would be. — tebs1200
First method adds two doors in the scene. Then i want to spawn sequentially enemies on one of these doors. So in the second function only adds two enemies to the doors, and the rest of them appears in CGPointMake(0.0, 0.0), it should appears where doors stay, though. — Nurassyl Nuridin
Something wrong, where optional binding in 'if let door = gameLayer.childNodeWithName("door(randDoor)")' — Nurassyl Nuridin

tebs1200 tebs1200 · Accepted Answer · 2016-01-27T12:11:43

For one thing, the logic in both the if and else blocks is exactly the same.

I'm not quite sure what you're trying to do here or how the randDoor variable is supposed to be used, but the whole if - else block isn't doing anything.

Spawn enemies does not work good in spritekit / swift

1 Answers