How to add a 30 second timer to end a game round? - swift

Question

I am currently experimenting with some code that I found on the internet about a game where you have to click on one set of items and avoid clicking on the other. I am currently trying to add a timer to the game so that it lasts of a total of 30 seconds but I am really struggling to do so as I am quite inexperienced with this programming language.
import UIKit
import QuartzCore
import SceneKit
class GameViewController: UIViewController, SCNSceneRendererDelegate {
var gameView:SCNView!
var SceneGame:SCNScene!
var NodeCamera:SCNNode!
var targetCreationTime:TimeInterval = 0
override func viewDidLoad() {
super.viewDidLoad()
View_in()
initScene()
initCamera()
}
func View_in(){
gameView = self.view as! SCNView
gameView.allowsCameraControl = true
gameView.autoenablesDefaultLighting = true
gameView.delegate = self
}
func initScene (){
SceneGame = SCNScene()
gameView.scene = SceneGame
gameView.isPlaying = true
}
func initCamera(){
NodeCamera = SCNNode()
NodeCamera.camera = SCNCamera()
NodeCamera.position = SCNVector3(x:0, y:5, z:10)
SceneGame.rootNode.addChildNode(NodeCamera)
}
func createTarget(){
let geometry:SCNGeometry = SCNPyramid( width: 1, height: 1, length: 1)
let randomColor = arc4random_uniform(2
) == 0 ? UIColor.green : UIColor.red
geometry.materials.first?.diffuse.contents = randomColor
let geometryNode = SCNNode(geometry: geometry)
geometryNode.physicsBody = SCNPhysicsBody(type: .dynamic, shape: nil)
if randomColor == UIColor.red {
geometryNode.name = "enemy"
}else{
geometryNode.name = "friend"
}
SceneGame.rootNode.addChildNode(geometryNode)
let randomDirection:Float = arc4random_uniform(2) == 0 ? -1.0 : 1.0
let force = SCNVector3(x: randomDirection, y: 15, z: 0)
geometryNode.physicsBody?.applyForce(force, at: SCNVector3(x: 0.05, y: 0.05, z: 0.05), asImpulse: true)
}
func renderer(_ renderer: SCNSceneRenderer, updateAtTime time: TimeInterval) {
if time > targetCreationTime{
createTarget()
targetCreationTime = time + 0.6
}
cleanUp()
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
let touch = touches.first!
let location = touch.location(in: gameView)
let hitList = gameView.hitTest(location, options: nil)
if let hitObject = hitList.first{
let node = hitObject.node
if node.name == "friend" {
node.removeFromParentNode()
self.gameView.backgroundColor = UIColor.black
}else {
node.removeFromParentNode()
self.gameView.backgroundColor = UIColor.red
}
}
}
func cleanUp() {
for node in SceneGame.rootNode.childNodes {
if node.presentation.position.y < -2 {
node.removeFromParentNode()
}
}
}
override var shouldAutorotate: Bool {
return true
}
override var prefersStatusBarHidden: Bool {
return true
}
override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
if UIDevice.current.userInterfaceIdiom == .phone {
return .allButUpsideDown
} else {
return .all
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Release any cached data, images, etc that aren't in use.
}
}

Answer 1

You could use a Timer object, documented here. Just set up the timer when you want the game to start, probably once you've finished all your initializations. When you set up the timer, just wait for it to call back to your code when it finishes and run whatever logic you want to use to terminate your game.

Answer 2

EDIT
Create a variable representing the time you want your game will end:
var time: CGFloat = 60
Then, add an SCNAction to your scene so that each second it will decrease this variable value, for example in the viewDidLoad:
//One second before decrease the time
let wait = SCNAction.wait(forDuration: 1)
//This is the heart of this answer
// An action that reduce the time and when it is less than 1 (it reached zero) do whatever you want
let reduceTime = SCNAction.run{ _ in
self.time -= 1
if self.time < 1 {
// Do whatever you want
// for example show a game over scene or something else
}
}
}
SceneGame.rootNode.run(SCNAction.repeatForever(SCNAction.sequence([wait,reduceTime])))
If you want, you can show the remaining time by using SKLabel on an HUD, which is an SKScene used as overlay.
You can check this tutorial for how to create an HUD
As well, you can use an SCNText, this is the documentation about it