【Swift】AdMobのリワード動画を実装したい

Question

前提・実現したいこと

swiftでspriteKitを使ったゲームを作っています。
AdMobのリワード動画を出したいのですが、呼び出し方が分かりません。
お願いします。

発生している問題・エラーメッセージ

GameViewControllerに書いたGADRewardBasedVideoAd.sharedInstance().present(fromRootViewController: self)を他のswiftファイルのGameSceneで呼び出そうとするとエラーメッセージInstance member 'HINT' cannot be used on type 'GameViewController'; did you mean to use a value of this type instead?が出てしまい呼ぶことが出来ません。

該当のソースコード

GameViewController.swift

import SpriteKit
import GoogleMobileAds

class GameViewController: UIViewController, GADRewardBasedVideoAdDelegate{
    

    
        override func viewDidLoad() {
            super.viewDidLoad()

      
            GADRewardBasedVideoAd.sharedInstance().delegate = self
            GADRewardBasedVideoAd.sharedInstance().load(GADRequest(),
                withAdUnitID: "ca-app-pub-3940256099942544/1712485313")
            
          

            if let view = self.view as! SKView? {
                // Load the SKScene from 'GameScene.sks'
                if let scene = SKScene(fileNamed: "GameTitle") {
                    // Set the scale mode to scale to fit the window
                    scene.scaleMode = .aspectFill
                    
                    // Present the scene
                    view.presentScene(scene)
                }
                
                view.ignoresSiblingOrder = true
                
                view.showsFPS = true
                view.showsNodeCount = true
            }
            
            
             
    }
    
    func HINT() {
       if GADRewardBasedVideoAd.sharedInstance().isReady == true {

         GADRewardBasedVideoAd.sharedInstance().present(fromRootViewController: self)
           }
        
}


        func rewardBasedVideoAd(_ rewardBasedVideoAd: GADRewardBasedVideoAd,
            didRewardUserWith reward: GADAdReward) {
          print("Reward received with currency: (reward.type), amount (reward.amount).")
        }

        func rewardBasedVideoAdDidReceive(_ rewardBasedVideoAd:GADRewardBasedVideoAd) {
          print("Reward based video ad is received.")
        }

        func rewardBasedVideoAdDidOpen(_ rewardBasedVideoAd: GADRewardBasedVideoAd) {
          print("Opened reward based video ad.")
        }

        func rewardBasedVideoAdDidStartPlaying(_ rewardBasedVideoAd: GADRewardBasedVideoAd) {
          print("Reward based video ad started playing.")
        }

        func rewardBasedVideoAdDidCompletePlaying(_ rewardBasedVideoAd: GADRewardBasedVideoAd) {
          print("Reward based video ad has completed.")
        }

        func rewardBasedVideoAdDidClose(_ rewardBasedVideoAd: GADRewardBasedVideoAd) {
          print("Reward based video ad is closed.")
            GADRewardBasedVideoAd.sharedInstance().load(GADRequest(),
                 withAdUnitID: "ca-app-pub-3940256099942544/1712485313")
        }

        func rewardBasedVideoAdWillLeaveApplication(_ rewardBasedVideoAd: GADRewardBasedVideoAd) {
          print("Reward based video ad will leave application.")
        }

        func rewardBasedVideoAd(_ rewardBasedVideoAd: GADRewardBasedVideoAd,
            didFailToLoadWithError error: Error) {
          print("Reward based video ad failed to load.")
        }
}



AppDelegate.swift

class AppDelegate: UIResponder, UIApplicationDelegate{
 
    var window: UIWindow?
  
 
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.
        

        GADMobileAds.sharedInstance().start(completionHandler: nil)
        return true
    }

    func applicationWillResignActive(_ application: UIApplication) {
        // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
        // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
    }

    func applicationDidEnterBackground(_ application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    }

    func applicationWillEnterForeground(_ application: UIApplication) {
        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
    }

    func applicationDidBecomeActive(_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    }


}

GameScene.swift

import AVFoundation
import SpriteKit
import UIKit
import GoogleMobileAds

class GameScene: SKScene {

       hint.position = CGPoint(x:240 , y: 500)
       hint.size = CGSize(width:75, height: 75)
       hint.zPosition = 1
       self.addChild(hint)

    // タッチしたときの処理
     override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        for touch: AnyObject in touches {
            // タッチされた位置にあるものを調べて
            let location = touch.location(in: self)
            let touchNode = self.atPoint(location)
 
            
             if touchNode == hint {  GameViewController.HINT()  }

試したこと

Main.storyboardを使ってGameViewControllerの画面にButtonを設置してHINTとコードを紐付けしたら動画を再生できたのですが、全画面にButtonが出てしまいます。storyboardを使わずに開発をしていたのでstoryboardは使わないようにしたいです。

補足情報（FW/ツールのバージョンなど）

Xcode11.5 Swift5.2.4

Answer 1

GameViewController.swift

let button:UIButton = UIButton(frame: CGRect(x:70, y: 390, width: 130, height: 50))

    override func viewDidLoad() {
        super.viewDidLoad()
        
        
        
        button.setTitleColor(.white, for: .normal)
        button.addTarget(self, action: #selector(pushButton), for: .touchUpInside)

}

@objc func pushButton(sender: UIButton) {

 if GADRewardBasedVideoAd.sharedInstance().isReady == true {
    
    button.isHidden = true
    
    GADRewardBasedVideoAd.sharedInstance().present(fromRootViewController: self)

        }
 

 }

GameScene.swift

 override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    for touch: AnyObject in touches {

        if touchNode == hint {
            self.view!.addSubview(button)
            button.isHidden = false
           }

GameViewControllerにコード上で透明なボタンを作り呼び出したい画面の時だけ呼び出すことでリワード動画を表示することが出来ました。