How do can I make things collide and do things when they do?

Question

I have been trying to do this for ages, what I would like to do is, I have a rocket and missiles coming down in my Scene and I want a very very simple explanation on how to do this so when the missiles collide with the rocket it will run a function in your code just call the function "func" and I am not very familiar with SKPhysicsBody and enums so please explain those as well please (This is in swift spriteKit). Thanks in Advance.

Answer 1

I would comment but i don't have enough reputation XD. I have watched a tutorial on youtube that explains you how to remove with collision. https://www.youtube.com/watch?v=ylIIy5EbsWQ

 func didBeginContact(contact: SKPhysicsContact!){

    // Body1 and 2 depend on the categoryBitMask << 0 und << 1
    var firstBody:SKPhysicsBody
    var secondBody:SKPhysicsBody

    if (contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask){
        firstBody = contact.bodyA
        secondBody = contact.bodyB
    }else{
        firstBody = contact.bodyB
        secondBody = contact.bodyA
    }

    torpedoDidCollideWithAlien(contact.bodyA.node as SKSpriteNode, alien: contact.bodyB.node as SKSpriteNode)


}

func torpedoDidCollideWithAlien(torpedo:SKSpriteNode, alien:SKSpriteNode){
    println("HIT")
    torpedo.removeFromParent()
    alien.removeFromParent()
    aliensDestroyed++

    if (aliensDestroyed > 30){
        var transition:SKTransition = SKTransition.flipHorizontalWithDuration(0.5)
        var gameOverScene:SKScene = GameOverScene(size: self.size, won: true)
        self.view.presentScene(gameOverScene, transition: transition)
    }
}