Enumerated

import UIKit
import SpriteKit
import Foundation


enum CollisionTypes: UInt32 {
  case player = 1
  case wall = 2
  case star = 4
  case rig = 3
}

final class GameScene: SKScene, SKPhysicsContactDelegate {
  private var player: SKSpriteNode!
  private var lastTouchPosition: CGPoint?
  private var scoreLabel: SKLabelNode!
  private var score = 0 {
    didSet {
      scoreLabel.text = "Score: \(score)"
    }

  private var items = [String]()
  private var teleportDestination = [CGPoint]()
  override func didMove(to view: SKView) {
    createScoreLabel()
    loadLevel()
    createPlayer()
    physicsWorld.gravity = .zero
    physicsWorld.contactDelegate = self
    let rightRect = CGRect(x: self.frame.size.width, y: 0, width: 1, height: self.frame.size.height)
   let right = SKNode()
   right.physicsBody = SKPhysicsBody(edgeLoopFrom: rightRect)
   self.addChild(right)
   right.name = "right"
   right.physicsBody?.categoryBitMask = CollisionTypes.rig.rawValue
   right.physicsBody?.contactTestBitMask = CollisionTypes.player.rawValue
    right.physicsBody?.collisionBitMask = CollisionTypes.wall.rawValue
 }
override func update(_ currentTime: TimeInterval) {
  if let lastTouchPosition = lastTouchPosition {
   let diff = CGPoint(x: lastTouchPosition.x - player.position.x, y: lastTouchPosition.y - player.position.y)
   physicsWorld.gravity = CGVector(dx: diff.x / 200, dy: diff.y / 200)
   }
 }
private func loadLevel() {
   let itm:CGFloat = frame.size.width/12
   guard let levelURL = Bundle.main.url(forResource: "level1", withExtension: "txt") else {
   fatalError("Could't find")
}
  guard let levelString = try? String(contentsOf: levelURL) else {
   fatalError("Could't load")
}
  let lines = levelString.components(separatedBy: "\n")
  for (row, line) in lines.reversed().enumerated() {
   for (column, letter) in line.enumerated() {
      let position = CGPoint(x: (Int(itm) * column) + 16, y: (Int(itm) * row) + Int(self.frame.height) / 8)
      if letter == "a" {
       createBlock(in: position)
 }else if letter == "s" {
      createStar(in: position)
  }else if letter == "y" {
    createfild(in: position)
  }
 }
 }
 }
 private func createBlock(in position: CGPoint) {
  let node = SKSpriteNode(imageNamed: "Field0")
  node.name = "block"
  items.append(node.name!)
  node.position = position
  node.physicsBody = SKPhysicsBody(rectangleOf: node.size)
  node.physicsBody?.categoryBitMask = CollisionTypes.wall.rawValue
  node.physicsBody?.isDynamic = false
  addChild(node)
  node.setScale(1.05)
 }
 private func createScoreLabel() {
  scoreLabel = SKLabelNode(fontNamed: "AvenirNext-Bold")
  scoreLabel.text = "Score: 0"
  scoreLabel.horizontalAlignmentMode = .left
  scoreLabel.position = CGPoint(x: 16, y: 16)
  scoreLabel.zPosition = 2
  addChild(scoreLabel)
 }
  private func createPlayer() {
  player = SKSpriteNode(imageNamed: "player")
  player.position = CGPoint(x: frame.size.width/12 + player.size.width * 0.38, y: frame.height - 70 )
  player.zPosition = 1
  player.physicsBody = SKPhysicsBody(circleOfRadius: player.size.width / 2)
  player.physicsBody?.allowsRotation = false
  player.physicsBody?.linearDamping = 0.8
  player.physicsBody?.categoryBitMask = CollisionTypes.player.rawValue
  player.physicsBody?.contactTestBitMask = CollisionTypes.star.rawValue
  player.physicsBody?.collisionBitMask = CollisionTypes.wall.rawValue
  addChild(player)
    player.setScale(0.55)
 }
  private func createStar(in position: CGPoint) {
   let node = SKSpriteNode(imageNamed: "star")
   node.name = "star"
  items.append(node.name!)
   node.physicsBody = SKPhysicsBody(circleOfRadius: node.size.width / 2)
   node.physicsBody?.isDynamic = false
   node.physicsBody?.categoryBitMask = CollisionTypes.star.rawValue
   node.physicsBody?.contactTestBitMask = CollisionTypes.player.rawValue
   node.physicsBody?.collisionBitMask = 0
   node.position = position
   addChild(node)
  node.setScale(0.5)
}
private func createfild(in position: CGPoint) {
  let node = SKSpriteNode(imageNamed: "Field2")
  node.name = "fild"
 items.append(node.name!)
  node.physicsBody = SKPhysicsBody(circleOfRadius: node.size.width / 2)
  node.physicsBody?.isDynamic = false
  node.physicsBody?.categoryBitMask = CollisionTypes.star.rawValue
  node.physicsBody?.contactTestBitMask = CollisionTypes.player.rawValue
  node.physicsBody?.collisionBitMask = 0
  node.position = position
  addChild(node)
  node.setScale(1.05)
}
 private func playerCollided(with node: SKNode) {
  if node.name == "star" {
  node.removeFromParent()
  score += 1
 }
}
  private func ballCollided(with node: SKNode) {
   if node.name == "right" {
   node.removeFromParent()
  let gameOverScene = GameScene(size: self.frame.size)
   self.view?.presentScene(gameOverScene)
 }
 }
 func didBegin(_ contact: SKPhysicsContact) {
 guard let nodeA = contact.bodyA.node else { return }
 guard let nodeB = contact.bodyB.node else { return }
 if nodeA == player {
  playerCollided(with: nodeB)
} else if nodeB == player {
 playerCollided(with: nodeA)
  ballCollided(with: nodeA)
  }
}
override func touchesBegan(_ touches: Set, with event: UIEvent?) {
 guard let touch = touches.first else { return }
  let location = touch.location(in: self)
  lastTouchPosition = location
}
  override func touchesMoved(_ touches: Set, with event: UIEvent?) {
  guard let touch = touches.first else { return }
  let location = touch.location(in: self)
 lastTouchPosition = location
}
 override func touchesEnded(_ touches: Set, with event: UIEvent?) {
lastTouchPosition = nil
 }
}
///////
level1.txt
a aaaaaaaaay
a        a
aaaaaaaa aaa
as         a
a  aa aayaaa
aaaaa     sa
a     aaaaaa
aaaaa aaaaaa
aaaaa aaaaaa
asaaa     sa
a aaa aaaaaa
a     yaaaaa
aaaaa
aaaaasaaaaaa
yaaaaaaaaaaa
//////