SKNodeSkalingProblem.swift

import SpriteKit
import GameplayKit

class GameScene: SKScene {
    static var shared: GameScene?

    var frameCount = 0
    var bigSprite: SKSpriteNode?
    var bigSpriteIsSetup = false
    var spriteTexture: SKTexture?
    var textureAtlas: SKTextureAtlas?

    override func didMove(to view: SKView) {
        GameScene.shared = self
    }

    override func update(_ currentTime: TimeInterval) {
        if !bigSpriteIsSetup {
            spriteTexture = SKTexture(imageNamed: "channel-background")
            bigSprite = SKSpriteNode(texture: spriteTexture)

            bigSprite?.size = frame.size
            bigSprite?.color = .blue
            bigSprite?.colorBlendFactor = 1.0
            bigSprite?.anchorPoint = CGPoint(x: 0.5, y: 0.5)

            bigSprite?.position = CGPoint(x: 100 + -self.size.width / 4, y: -100 + self.size.height / 4)

            bigSprite!.setScale(0.5)
            self.addChild(bigSprite!)
            
            bigSpriteIsSetup = true
        }

        let littleSprite = SKSpriteNode(texture: spriteTexture)
        littleSprite.size = CGSize(width: 10.0, height: 10.0)
        littleSprite.color = .green
        littleSprite.colorBlendFactor = 1.0
        littleSprite.anchorPoint = CGPoint(x: 0.5, y: 0.5)
        littleSprite.zPosition = 2.0

        let x = Int.random(in: Int(-self.bigSprite!.size.width)..<Int(self.bigSprite!.size.width))
        let y = Int.random(in: Int(-self.bigSprite!.size.height)..<Int(self.bigSprite!.size.height))
        littleSprite.position = CGPoint(x: x, y: y)

        let fw = -self.scene!.size.width * 2
        let fh = self.scene!.size.height * 2
        if CGRect(x: 0, y: 0, width: fw, height: fh).contains(littleSprite.position) {
            print("add \(littleSprite.position)")
            bigSprite!.addChild(littleSprite)
        } else {
            print("discard \(littleSprite.position)")
        }

        frameCount += 1
    }
}