How to implement a SpriteKit timer? - swift

I am currently trying to implement a timer for my sprite kit game, but I don't get it working. The initial value of the timer always remains the same.
I am assuming I need to update the label somehow/somewhere, but I don't know HOW and WHERE :? I don't get the point. Any ideas?
Here is my code within my GameScene Class
let levelTimerLabel = SKLabelNode(fontNamed: "Chalkduster")
var levelTimerValue: Int = 500
var levelTimer = NSTimer()
func startLevelTimer() {
levelTimerLabel.fontColor = SKColor.blackColor()
levelTimerLabel.fontSize = 40
levelTimerLabel.position = CGPoint(x: size.width/2, y: size.height/2 + 350)
addChild(levelTimerLabel)
levelTimer = NSTimer.scheduledTimerWithTimeInterval(0.5, target: self, selector: Selector("levelCountdown"), userInfo: nil, repeats: true)
levelTimerLabel.text = String(levelTimerValue)
}
func levelCountdown(){
levelTimerValue--
}

I would stick to SKActions for these kind of tasks in SpriteKit due to fact that NSTimer is not affected by scene's, or view's paused state, so it might lead you into troubles. Or at least, it will require from you to implement a pause feature in order to pause your timers in certain situations, like when user pause the scene, or receive a phone call etc. Read more here about SKAction vs NSTimer vs GCD for time related actions in SpriteKit.
import SpriteKit
class GameScene: SKScene {
var levelTimerLabel = SKLabelNode(fontNamed: "ArialMT")
//Immediately after leveTimerValue variable is set, update label's text
var levelTimerValue: Int = 500 {
didSet {
levelTimerLabel.text = "Time left: \(levelTimerValue)"
}
}
override func didMoveToView(view: SKView) {
levelTimerLabel.fontColor = SKColor.blackColor()
levelTimerLabel.fontSize = 40
levelTimerLabel.position = CGPoint(x: size.width/2, y: size.height/2 + 350)
levelTimerLabel.text = "Time left: \(levelTimerValue)"
addChild(levelTimerLabel)
let wait = SKAction.waitForDuration(0.5) //change countdown speed here
let block = SKAction.runBlock({
[unowned self] in
if self.levelTimerValue > 0{
self.levelTimerValue--
}else{
self.removeActionForKey("countdown")
}
})
let sequence = SKAction.sequence([wait,block])
runAction(SKAction.repeatActionForever(sequence), withKey: "countdown")
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
//Stop the countdown action
if actionForKey("countdown") != nil {removeActionForKey("countdown")}
}
}

Sounds like you need to update the label everytime levelTimerValue is changed. The easiest way would be something like this.
func levelCountdown(){
levelTimerValue--
levelTimerLabel.text = String(levelTimerValue)
}

Related

Cannot disable, then reenable touch, after an SKAction animation

I am working on an interactive, animated scene. I want all touches on the scene to be disabled on entry. Then, once the objects (which are subclassed nodes) in the scene finish rotating/moving, I want to re-enable all touches on the screen to allow interaction. I have disabled user interaction using this code:
override func didMove(to view: SKView) {
setupNodes()
view?.isUserInteractionEnabled = false
spinLocations()
}
This is the code, within the scene file, for spinLocations:
func spinLocations() {
var allLocationArrays = [[String : CGPoint]]()
var previousArray = hiddenLocationPositions
for _ in 0...SearchConstant.numSpins {
let freshArray = generateNewLocationArray(previous: previousArray)
allLocationArrays.append(freshArray)
previousArray = freshArray
}
for (item, _) in hiddenLocationPositions {
let node = fgNode.childNode(withName: item) as! LocationNode
node.spin(position: allLocationArrays) // this is function below
}
hiddenLocationPositions = previousArray
}
This is the code for the animations in the node class:
func spin(position: [[String : CGPoint]]) {
var allActions = [SKAction]()
for array in position {
let action = SKAction.move(to: array[self.name!]!, duration: 2.0)
allActions.append(action)
}
let allActionsSeq = SKAction.sequence(allActions)
self.run(SKAction.sequence([SKAction.wait(forDuration: 5.0), allActionsSeq, SKAction.run {
self.position = position[position.count - 1][self.name!]!
},]))
}
This is the code for passing back the touches to the main scene from this class:
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
guard let parent = self.parent else { return }
}
As you can see, touch is not disabled here.
I do not want to add a "waitForDuration" SKAction to the runBlock to change the view status after the previous action; I want the program to determine when the animations are finished executing and then re-enable touches.
In order to do this, I theorised using a completion handler might work, but it only re-enables touches immediately (e.g. handling a handler to spin causes the touches to be detected again). Previously, I also tried to disable the view in the runBlock, but of course, that is run instantaneously. How do I ensure that the touches are re-detected following the animation without using "waitForDuration."?
So, this is a simple example that shows how you can:
1) Disable touches completely
2) Spin a node
3) When node is done with spinning, to enable touches
Here is the code (you can copy/paste it to try how it works):
class Object:SKSpriteNode{
func spin(times:Int,completion:#escaping ()->()) {
let duration = 3.0
let angle = CGFloat(M_PI) * 2.0
let oneRevolution = SKAction.rotate(byAngle: angle , duration: duration)
let spin = SKAction.repeat(oneRevolution, count: times)
let sequence = SKAction.sequence([spin,SKAction.run(completion)])
run(sequence, withKey:"spinning")
}
}
class WelcomeScene: SKScene {
override func didMove(to view: SKView) {
view.isUserInteractionEnabled = false
print("Touches Disabled")
let object = Object(texture: nil, color: .purple, size: CGSize(width: 200, height: 200))
addChild(object)
object.spin(times: 3, completion: {[weak self] in
self?.view?.isUserInteractionEnabled = true
print("Touches Enabled")
})
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
print("touch detected")
}
deinit {
print("Welcome scene deinited")
}
}
Here, you disable touches when scene is loaded, start spinning the object, and you pass a completion block to it... That block of code is used here:
let sequence = SKAction.sequence([spin,SKAction.run(completion)])
So after spinning, that block will be executed. Now, there are different ways to do this...Personally, I would use delegation, but I thought this can be less confusing... I can write an example for delegation too if needed, but basically, what you would do, is to set a scene as a delegate of your custom node, and notify it about spinning is done, so the scene can tell the view to re-enable the touches.

Add SpriteNodes and Remove Based on Time or click using SpriteKit

I am new to swift and looking to build my first basic game. The game I have in mind involves sprites generating at random and then disappearing based on time or a click if the click is within the time allocated. So far I have created the basic framework and am still messing around with design. My problem comes in where I can't seem to remove the sprite based on time (its generating fine). Any help is appreciated and thanks in advance😊
Below is the framework I've built up so far.
import SpriteKit
var one = SKSpriteNode()
class GameScene: SKScene {
override func didMoveToView(view: SKView) {
/* Setup your scene here */
let myFunction = SKAction.runBlock({()in self.addOne()})
let wait = SKAction.waitForDuration(5)
let remove = SKAction.runBlock({() in self.removeOne()})
self.runAction(SKAction.sequence([myFunction, wait, remove]))
}
func addOne() {
let oneTexture = SKTexture(imageNamed: "blue button 10.png")
let one = SKSpriteNode(texture: oneTexture)
one.position = CGPoint(x: CGRectGetMidX(self.frame) - 100, y: CGRectGetMidY(self.frame) + 250)
one.zPosition = 1
self.addChild(one)
}
func removeOne() {
one.removeFromParent()
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
/* Called when a touch begins */
}
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
}
}
It doesn't disappear because your create a new SpiteNode, but try to remove the old one, do it like this:
var one : SKSpriteNode! //instead of creating it without data, just define the type(not necessary, but I would do it)
class GameScene: SKScene {
override func didMoveToView(view: SKView) {
/* Setup your scene here */
let myFunction = SKAction.runBlock({()in self.addOne()})
let wait = SKAction.waitForDuration(5)
let remove = SKAction.runBlock({() in self.removeOne()})
self.runAction(SKAction.sequence([myFunction, wait, remove]))
}
func addOne() {
let oneTexture = SKTexture(imageNamed: "blue button 10.png")
one = SKSpriteNode(texture: oneTexture) //removed the let, so you dont create a new "one"
one.position = CGPoint(x: CGRectGetMidX(self.frame) - 100, y: CGRectGetMidY(self.frame) + 250)
one.zPosition = 1
self.addChild(one)
}
func removeOne() {
one.removeFromParent()
}
}

Attemped to add a SKNode which already has a parent swift

I am creating a game and i keep getting this error for my bullet spawn method linked with a joystick. I want to repetitively spawn nodes when the joystick is active Here is how i am creating a firing method
override func didMoveToView(view: SKView) {
if fireWeapon == true {
NSTimer.scheduledTimerWithTimeInterval(0.25, target: self,
selector: Selector ("spawnBullet1"), userInfo: nil, repeats: true)
}
}
func spawnBullet1(){
self.addChild(bullet1)
bullet1.position = CGPoint (x: hero.position.x , y:hero.position.y)
bullet1.xScale = 0.5
bullet1.yScale = 0.5
bullet1.physicsBody = SKPhysicsBody(rectangleOfSize: bullet1.size)
bullet1.physicsBody?.categoryBitMask = PhysicsCategory.bullet1
bullet1.physicsBody?.contactTestBitMask = PhysicsCategory.enemy1
bullet1.physicsBody?.affectedByGravity = false
bullet1.physicsBody?.dynamic = false
}
override func touchesBegan(touches: Set<UITouch>, withEvent
event:UIEvent?) {
for touch in touches {
let location = touch.locationInNode(self)
let node = nodeAtPoint(location)
if (CGRectContainsPoint(joystick.frame, location)) {
stickActive = true
if stickActive == true {
fireWeapon = true
}
the first bullet launches as planned and works great however, every time the second bullet launches the app crashes and i get the error. can someone tell me an alternative way to create a fire rate
Instead of self.addChild(bullet1) you need something like self.addChild(SKSpriteNode(imageNamed: "bullet.png"))
This because you need to create a new bullet every time you fire, you do not want to move the same bullet every single time.

Is it possible to run action on a child when parent is paused

I want to make the child node disappear while the parent is paused.
var plats: SKNode = SKNode();
var bigBox: SKSpriteNode!;
override func didMoveToView(view: SKView) {
// Set anchor point
self.anchorPoint = CGPointMake(0.5, 0.5);
bigBox = SKSpriteNode(color: UIColor.redColor(), size: CGSizeMake(100, 100));
bigBox.zPosition = 1;
plats.addChild(bigBox);
var smallBox: SKSpriteNode = SKSpriteNode(color: UIColor.greenColor(), size: CGSizeMake(50, 50));
smallBox.zPosition = 2;
bigBox.addChild(smallBox);
self.addChild(plats);
}
// Pause the plats when touch is detected and try to run the action on the child
override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
// Here I pause the parent
plats.paused = true;
// Get the child node
let smallBox: SKSpriteNode = bigBox.children[0] as! SKSpriteNode;
println(smallBox);
smallBox.paused = false;
println(smallBox.paused); // return false but the action is never trigger
// This part is never run, if I set plats.paused = false it will work but I dont that
let scaleUp = SKAction.scaleTo(0.4, duration: 0.1);
smallBox.runAction(scaleUp, completion: {
self.bigBox.removeAllActions();
self.bigBox.removeFromParent();
println("done");
});
}
Thats is all the code, you can paste and try to see that it dosent work
xcode ver: 6.3
swift ver: 1.2
Once you pause a node, the node and all of its descendants are paused. In other words you cannot pause a parent node and one of its children keep going.

Increasing/Decreasing waitForDuration( )?

I am wondering if its possible to increase withForDuration( ) with a variable. Heres how I am trying to do it in short. This is also SpriteKit, and this is my first time with it so I am still a little unsure. While this snippet of code works to change the float it doesn't actually change the waitForDuration(difficulty)
var timer: NSTimer!
var difficulty = 1.0
override func didMoveToView(view: SKView) {
backgroundColor = SKColor.whiteColor()
player.position = CGPoint(x: size.width * 0.5, y: size.height * 0.25)
player.physicsBody = SKPhysicsBody(circleOfRadius: player.size.width/2)
player.physicsBody?.dynamic = true
addChild(player)
physicsWorld.gravity = CGVectorMake(0, 0)
physicsWorld.contactDelegate = self
var timer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: "increaseDifficulty", userInfo: nil, repeats: true)
runAction(SKAction.repeatActionForever(
SKAction.sequence([
SKAction.runBlock(addEnemy),
SKAction.waitForDuration(difficulty)
])
))
}
func increaseDifficulty() {
difficulty -= 0.1
}
One way to do this is to use the completionHandler of the runAction function. For example.
func addEnemyWithChangingDifficulty() {
let waitAction = SKAction.waitForDuration(difficulty)
let addEnemyAction = SKAction.runBlock { () -> Void in
self.addEnemy()
}
runAction(SKAction.sequence([addEnemyAction,waitAction]), completion: { () -> Void in
self.addEnemyWithChangingDifficulty()
})
}
Another way would be to use the update function to track the waitDuration.
var lastAddedTime : CFTimeInterval = 0
override func update(currentTime: CFTimeInterval) {
if currentTime - lastAddedTime > CFTimeInterval(difficulty) {
addEnemy()
lastAddedTime = currentTime
}
}
You're not getting your intended effect because the value of 'difficulty' is captured in the first declaration of your SKAction and it never refers to the outside declaration again.
Two ways to solve this:
Instead of doing SKAction.repeatActionForever(), dump the SKAction.sequence() in increaseDifficulty. You'll have to tweak the numbers a bit to make it work, but NSTimer is already running on repeat, you can use that instead.
The second way (not 100% sure about this) is to put the '&' symbol in front of difficulty. This passes difficulty by reference rather by value, which should give you the intended effect. I'm just not sure if Swift allows this, but in C++ that's what we can do.