gistfile1.txt

import SpriteKit

struct Level {
    enum CollisionTypes: UInt32 {
        case player = 1
        case wall = 2
        case star = 4
        case vortex = 8
        case teleport = 16
        case finish = 32
    }
    
    var levelLabel: SKLabelNode!
    
    var levelFileName = "level1.txt"
    var maxLevels = 9
    var levelNodesArray = [SKSpriteNode]()
    
    var level = 1 {
        didSet {
            levelLabel.text = "Level: \(level)"
            levelFileName = "level\(level).txt"
        }
    }
    
    var isLevelFinished = false
    let wallImageName = "block"
    let vortexImageName = "vortex"
    let starImageName = "star"
    let teleportImageName = "teleport"
    let finishImageName = "finish"
    let nextLevelLabelName = "nextLevel"
    
    var teleportNodes: [String: SKSpriteNode?] = [:]
    var teleportStartNode: SKSpriteNode!
    var teleportEndNode: SKSpriteNode!
    var startNodeKey = "teleportStart"
    var endNodeKey = "teleportEnd"
    var isSecondPass: Bool = false
    
    let playerBallSize = 64
    
    
    func loadLevelFile() -> [String] {
        print("start loading level with \(levelFileName)")
        guard let levelURL = Bundle.main.url(forResource: levelFileName, withExtension: nil) else {
            fatalError("Could not find \(levelFileName) in the app bundle")
        }
        
        guard let levelString = try? String(contentsOf: levelURL) else {
            fatalError("Failed to load \(levelFileName) from the app bundle")
        }
        
        return levelString.components(separatedBy: "\n")
    }
    
    mutating func displayLevel(_ lines: [String]) {
        print("in displayLevel, level = \(level)")
        for (row, line) in lines.reversed().enumerated() {
            for (column, letter) in line.enumerated() {
                let position = CGPoint(x: (playerBallSize * column) + (playerBallSize / 2), y: (playerBallSize * row) + (playerBallSize / 2))
                
                switch letter {
                case "x":
                    loadWall(at: position)
                case "v":
                    loadVortex(at: position)
                case "s":
                    loadStar(at: position)
                case "t":
                    loadTeleport(at: position)
                case "f":
                    loadFinish(at: position)
                case " ":
                    let _ = "foo"
                    // nop
                default:
                    fatalError("Unknown level symbol found: \(letter) at row \(row), col \(column) - Level file is invalid")
                }
            }
        }
        print("end displayLevel")
    }

    mutating func loadWall(at position: CGPoint) {
        let node = SKSpriteNode(imageNamed: wallImageName)
        node.name = wallImageName
        node.position = position
        node.zPosition = 0
        
        node.physicsBody = SKPhysicsBody(rectangleOf: node.size)
        node.physicsBody?.isDynamic = false
        node.physicsBody?.categoryBitMask = CollisionTypes.wall.rawValue
        
        addChild(node)
        levelNodesArray.insert(node, at: 0)
    }
    
    mutating func loadVortex(at position: CGPoint) {
        let node = SKSpriteNode(imageNamed: vortexImageName)
        node.name = vortexImageName
        node.position = position
        node.zPosition = 0
        node.run(SKAction.repeatForever(SKAction.rotate(byAngle: .pi, duration: 1)))
        node.physicsBody = SKPhysicsBody(circleOfRadius: node.size.width / 2)
        node.physicsBody?.isDynamic = false
        
        node.physicsBody?.categoryBitMask = CollisionTypes.vortex.rawValue
        node.physicsBody?.contactTestBitMask = CollisionTypes.player.rawValue
        node.physicsBody?.collisionBitMask = 0

        addChild(node)
        levelNodesArray.insert(node, at: 0)
    }
    
    mutating func loadStar(at position: CGPoint) {
        let node = SKSpriteNode(imageNamed: starImageName)
        node.name = starImageName
        node.position = position
        node.zPosition = 0
        
        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
        
        addChild(node)
        levelNodesArray.insert(node, at: 0)
    }
    
    mutating func loadFinish(at position: CGPoint) {
        let node = SKSpriteNode(imageNamed: finishImageName)
        node.name = finishImageName
        node.position = position
        node.zPosition = 0
        
        node.physicsBody = SKPhysicsBody(circleOfRadius: node.size.width / 2)
        node.physicsBody?.isDynamic = false
        
        node.physicsBody?.categoryBitMask = CollisionTypes.finish.rawValue
        node.physicsBody?.contactTestBitMask = CollisionTypes.player.rawValue
        node.physicsBody?.collisionBitMask = 0
        
        addChild(node)
        levelNodesArray.insert(node, at: 0)
    }

    mutating func loadTeleport(at position: CGPoint) {
        let node = SKSpriteNode(imageNamed: teleportImageName)
        
        node.name = teleportImageName  // default name
        node.position = position
        node.zPosition = 0
        
        let scaleDown = SKAction.scale(to: 0.7, duration: 0.75)
        let scaleUp = SKAction.scale(to: 1.0, duration: 0.75)
        let sequence = SKAction.sequence([scaleDown, scaleUp])
        node.run(SKAction.repeatForever(sequence))
        
        node.physicsBody = SKPhysicsBody(circleOfRadius: node.size.width / 2)
        node.physicsBody?.isDynamic = false
        
        node.physicsBody?.categoryBitMask = CollisionTypes.teleport.rawValue
        node.physicsBody?.contactTestBitMask = CollisionTypes.player.rawValue
        node.physicsBody?.collisionBitMask = 0
        
        
        if teleportNodes[startNodeKey] != nil && isSecondPass {
            node.name = endNodeKey
            teleportNodes[endNodeKey] = node
            addChild(node)
            levelNodesArray.insert(node, at: 0)
        } else {
            print("    teleportNodes[startNodeKey] is nil or isSecondPass is false -- not end node scenario")
        }
        
        if teleportNodes[startNodeKey] == nil && isSecondPass == false {
            node.name = startNodeKey
            teleportNodes[startNodeKey] = node
            isSecondPass = true
            addChild(node)
            levelNodesArray.insert(node, at: 0)
        } else {
            print("    start node already exists or isSecondPass is true - not start node scenario")
        }
    }
}

In the methods:

• loadWall
• loadVortex
• loadStar
• loadFinish
• loadTeleport

Each method creates a new SKSpriteNode, sets some properties for the node, then tries calls addNode() on the node.
I get a compile-time error on all the 'addChild()' of "Cannot find 'addChild' in scope"
I can't figure out why I'm getting the error.