Running into some trouble with my code. I'm trying to make zombies follow my player around with the following code:
class GameScene: SKScene, SKPhysicsContactDelegate {
func Enemies() {
Enemy = SKSpriteNode(imageNamed: "Spaceship")
Enemy.size = CGSize(width: 50, height: 50)
Enemy.color = UIColor(red: 0.9, green: 0.1, blue: 0.1, alpha: 1.0)
Enemy.colorBlendFactor = 1.0
//physics
Enemy.physicsBody = SKPhysicsBody(rectangleOf: Enemy.size)
Enemy.physicsBody?.isDynamic = true
Enemy.physicsBody?.affectedByGravity = false
Enemy.name = "Enemy"
Enemy.position.y = -frame.size.height/2
let positionX = arc4random_uniform(UInt32(frame.size.width))
Enemy.position.x = CGFloat(positionX)
addChild(Enemy)
}
override func didMove(to view: SKView) {
enemyTimer = Timer.scheduledTimer(timeInterval: 0.5, target: self, selector: #selector(GameScene.Enemies), userInfo: nil, repeats: true)
override func update(_ currentTime: TimeInterval) {
Enemy.run(SKAction.move(to: ship.position, duration: 3))
}
If I run this code, I can spawn the zombies, but they will not follow my main player, they will just go to the position that he was at when they were spawned (i.e. zombie spawned at time = 0 will go to the ship position at time = 0, zombie spawned at time = 1 will go to the ship position at time = 1, and so on). However, if I run this code while only spawning one zombie like so:
override func didMove(to view: SKView) {
Enemies()
}
The lone zombie will follow my player around. Any idea why the code works for one zombie, but not for multiple zombies?
I would not recommend constantly adding actions on your update cycle, you are going to suffer from performance loss due to all the things that happen behind the scenes. Instead, use an SKAction.customAction that you would only add to your sprite once.
Here is an example of a custom action that will do what you want, remember only assign it once. (Code is not tested, so may need edits)
let customActionBlock =
{
(node,elapsedTime) in
let dx = ship.x - node.position.x
let dy = ship.y - node.position.y
let angle = atan2(dx,dy)
node.position.x += sin(angle) * speedPerFrame
node.position.y += cos(angle) * speedPerFrame
}
let duration = TimeInterval(Int.max) //want the action to run infinitely
let followPlayer = SKAction.customAction(withDuration:duration,actionBlock:customActionBlock)
Enemy.run(action:followPlayer,withKey:"follow")
Maybe you should removeAllActions() on Enemy before readding an action. It seems that you have actions that take 3 seconds, but you add an action every frame, so it has at most 180 actions for a node at once.
Related
I am trying to write a function where I can increase SKShapeNode radius every second, but don't know how:(
var eRadius: CGFloat = 20
var eCircle = SKShapeNode()
override func didMove(to view: SKView) {
super.didMove(to: view)
eCircle = SKShapeNode(circleOfRadius: eRadius)
eCircle.strokeColor = .black
eCircle.glowWidth = 1.0
eCircle.fillColor = .white
eCircle.fillTexture = SKTexture(imageNamed: "e")
addChild(eCircle)
gameTimer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(addRadius), userInfo: nil, repeats: true)
}
#objc func addRadius(){
eRadius += 1
???? :(
}
Thank you!
Here's a working solution:
import SpriteKit
class GameScene: SKScene {
private var eRadius: CGFloat = 20
private var eCircle = SKShapeNode()
override func didMove(to view: SKView) {
eCircle.strokeColor = .black
eCircle.glowWidth = 1.0
eCircle.fillColor = .white
eCircle.fillTexture = SKTexture(imageNamed: "e")
addChild(eCircle)
run(SKAction.repeatForever(SKAction.sequence([SKAction.run {
self.updateCirclePath()
self.eRadius += 1
}, SKAction.wait(forDuration: 1.0)])))
}
private func updateCirclePath() {
eCircle.path = UIBezierPath(ovalIn: CGRect(x: -eRadius * 0.5, y: -eRadius * 0.5, width: eRadius, height: eRadius)).cgPath
}
}
Basically, you create the circle using a UIBezierPath and then update it as your radius changes. For the updating you should use a forever-repeating SKAction sequence that both sets the path, then changes the radius. I chose to do the path first, then update the radius for the next upcoming turn, for clarity.
You can also do it the opposite way, so run the update function first to set the initial path, then wait one second, after which you change the radius, then update the path based on that radius.
In SpriteKit, you should use SKActions for timers instead of scheduling or dispatch queues. With SKActions, everything conforms to the same game time, which you can then control by pausing and whatever.
Also, there are multiple ways to make a circle using UIBezierPath, including ovals, rounded rectangles and arcs: https://developer.apple.com/documentation/uikit/uibezierpath.
I am struggling with one issue. Global declaration of my sprite so that I can interact with it. In this game, I have created a local sprite called enemy featured below:
func spawnEnemy() {
let enemy = SKSpriteNode(imageNamed: "as")
let yPosition = CGFloat(frame.maxY - enemy.size.height)
let getXvalue = GKRandomDistribution(lowestValue: Int(frame.minX + enemy.size.width), highestValue: Int(frame.maxX - enemy.size.width))
let xPosition = CGFloat(getXvalue.nextInt())
enemy.position = CGPoint(x: xPosition, y: yPosition)
enemy.name = "asteroid"
enemy.zPosition = 100
addChild(enemy)
let animationDuration:TimeInterval = 6
var actionArray = [SKAction]()
actionArray.append(SKAction.move(to: CGPoint(x: xPosition, y: 0), duration: animationDuration))
actionArray.append(SKAction.self.removeFromParent())
enemy.run(SKAction.sequence(actionArray))
}
I want to tap the enemy to make it disappear from the screen. The variable is declared locally and not globally so the touchesBegan function does not "see" enemy. However, when I move the statement:
let enemy = SKSpriteNode(imageNamed: "as")
outside of local declaration and into global. It works until the code tries to spawn in another enemy and i get an error of "Tried to add an SKNode who already has a parent" This is the code I have running in my view did load:
run(SKAction.repeatForever(SKAction.sequence([SKAction.run{self.spawnEnemy()
}, SKAction.wait(forDuration: 1.0)])))
Every time it spawns a new enemy it crashes and says that the SKNode already has a parent which i understand. However, for my game to function I need the player to be able to touch the individual instance of that enemy and remove it. Hence my code for
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
let touch = touches.first
if let location = touch?.location(in:self) {
let nodesArray = self.nodes(at:location)
if nodesArray.first?.name == "asteroid" {
print("Test")
enemy.removeFromParent()
print("Test Completed")
}
}
}
Now the error says unresolved use of "enemy" because the enemy is not global. I have been going back and forth on this issue for quite some time. If anyone has any potential solution or work around I would be very grateful, and thank you for your help.
Move your enemies to their own class and handle the touch for each of those enemies in their own class. This cleans up your GameScene and keeps your code more organized. You can now add as many instances of enemy as you want.
FYI not related to this question but somethings to consider after you get this working
when game over or level change or win make sure you have a clean up function to remove all enemies
you should strongly consider recycling your objects vs creating them on the fly...better performance
try to separate as much code to your objects class as possible
class enemy: SKSpriteNode {
init() {
super.init(texture: nil, color: .clear, size: CGSize.zero)
setup()
}
func setup() {
isUserInteractionEnabled = true
name = "asteroid"
zPosition = 100
let image = SKSpriteNode(imageNamed: "as")
imagine.zPosition = 1
addChild(image)
self.size = image.size
animate()
}
func animate() {
let animationDuration: TimeInterval = 6
let move = SKAction.move(to: CGPoint(x: xPosition, y: 0), duration: animationDuration)
let remover = SKAction.self.removeFromParent()
run(SKAction.sequence(move, remover))
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
removeFromParent()
}
}
class GameScene: SKScene {
override func didMove(to view: SKView) {
let sequence = SKAction.sequence([SKAction.run{ self.spawnEnemy()
}, SKAction.wait(forDuration: 1.0)])
run(SKAction.repeatForever(sequence))
}
func spawnEnemy() {
let enemy = Enemy()
let yPosition = CGFloat(frame.maxY - enemy.size.height)
let getXvalue = GKRandomDistribution(lowestValue: Int(frame.minX + enemy.size.width), highestValue: Int(frame.maxX - enemy.size.width))
let xPosition = CGFloat(getXvalue.nextInt())
enemy.position = CGPoint(x: xPosition, y: yPosition)
addChild(enemy)
}
}
I created a project where I have a ball and when the view loads, it falls down, which is good. I'm trying to get the ball to jump back up and fall down again when the Spritenode is tapped.
--This Question was edited--
Originally, I was able to get it to work when sprite.userInteractionEnabled = false. I had to turn this statement true in order to get the score to change.
Now I can't get the balls to fall and be tapped to jump. When I turn ball.physicsBody?.dynamic = true, the balls will fall due to gravity. How do I tap the sprite itself and make it jump.
GameScene.swift (For those who want to try the code for themselves.)
import SpriteKit
class GameScene: SKScene {
var ball: Ball!
private var score = 0 {
didSet { scoreLabel.text = "\(score)" }
}
override func didMoveToView(view: SKView) {
let ball = Ball()
scoreLabel = SKLabelNode(fontNamed:"Geared-Slab")
scoreLabel.fontColor = UIColor.blackColor()
scoreLabel.position = CGPoint( x: self.frame.midX, y: 3 * self.frame.size.height / 4 )
scoreLabel.fontSize = 100.0
scoreLabel.zPosition = 100
scoreLabel.text = String(score)
self.addChild(scoreLabel)
ball.position = CGPoint(x:self.size.width / 2.0, y: 440)
addChild(ball)
ball.physicsBody = SKPhysicsBody(circleOfRadius: 120)
ball.physicsBody?.dynamic = true
ball.physicsBody?.allowsRotation = false
ball.physicsBody?.restitution = 3
ball.physicsBody?.friction = 0
ball.physicsBody?.angularDamping = 0
ball.physicsBody?.linearDamping = 0
ball.physicsBody?.usesPreciseCollisionDetection = true
}
class Ball: SKSpriteNode {
init() {
let texture = SKTexture(imageNamed: "Ball")
super.init(texture: texture, color: .clearColor(), size: texture.size())
userInteractionEnabled = true
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
let scene = self.scene as! GameScene
scene.score += 1
}
Before, it was a SKNode being tapped using CGVectorMake(impulse, velocity) now, it's a SKSpriteNode, and I tried using SKAction, but it either does not work, or I'm putting it in the wrong place(touches begin).
I tested your code and it seems that using firstBall.userInteractionEnabled = true is the cause. Without it, it should work. I did some research (here for example), but can't figure out what's the reason of this behavior with userInteractionEnabled. Or for what reason do you use userInteractionEnabled?
Update due to update of question
First ball.physicsBody?.restitution = 3 defines the bounciness of the physics body. The default value is 0.2 and the property must be between 0.0 ans 1.0. So if you set it to 3.0 it will cause some unexpected effects. I just deleted it to use the default value of 0.2.
Second, to make the ball jump after tap and increase the score I put
physicsBody?.velocity = CGVectorMake(0, 600)
physicsBody?.applyImpulse(CGVectorMake(0, 1100))
in the touchesBegan method of the Ball class
Result
I'm trying to get my "Player" (A circle in the middle) to increase in size once the screen is touched by running a timer.
Once the timer is over 0 seconds, it increases in size. Once the timer is over 3 seconds, it decreases to its original scale size and once the timer is over 7 seconds, it resets and this repeats forever.
What am I doing wrong?
import SpriteKit
class GameScene: SKScene {
var Center = SKSpriteNode()
var Player = SKSpriteNode()
var timer = NSTimer()
var seconds = 0
override func didMoveToView(view: SKView) {
Center = SKSpriteNode(imageNamed: "Center")
Center.size = CGSize(width: 80, height: 80)
Center.position = CGPoint(x: CGRectGetMidX(self.frame), y: CGRectGetMidY(self.frame))
self.addChild(Center)
Player = SKSpriteNode(imageNamed: "Player")
Player.size = CGSize(width: 80, height: 80)
Player.position = CGPoint(x: frame.size.width / 2, y: frame.size.height / 2)
self.addChild(Player)
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
timer = NSTimer.scheduledTimerWithTimeInterval(4.0, target: self, selector: #selector(GameScene.playerScaleUp), userInfo: nil, repeats: true)
}
func playerScaleUp(){
if seconds > 0{
Player.runAction(SKAction.scaleBy(4, duration: 2))
}
}
func playerScaleDown(){
if seconds > 3{
Player.runAction(SKAction.scaleBy(-4, duration: 2))
}
}
func resetScale(){
if seconds > 7{
timer.invalidate()
}
}
override func update(currentTime: CFTimeInterval) {
}
}
This can be done in a few different ways:
1) Using SKActions (which my example uses)
2) Using update: method and its passed currentTime parameter
3) Using NSTimer which I wouldn't recommend because it is not affected by scene's, view's or node's paused state, so it can lead you into troubles in the future. Read more in this StackOverflow answer
4) Well, probably some more, but I will stop here.
My example uses SKAction. This means that I don't really check how much time is passed, but rather I organize actions into sequences (where actions are executed sequentially) and into groups (where actions are organized parallel). Means I use SKActions like I am playing with LEGO's :)
Here is the code ...I left debugging code intentionally, because it can help you to learn how you can use SKActions in different situations.
class GameScene: SKScene, SKPhysicsContactDelegate {
let player = SKSpriteNode(color: .blackColor(), size: CGSize(width: 50, height: 50))
var timePassed = 0.0 {
didSet {
self.label.text = String(format: "%.1f",timePassed)
}
}
let label = SKLabelNode(fontNamed: "ArialMT")
override func didMoveToView(view: SKView) {
/* Debugging - Not really needed, I added it just because of a better example */
let wait = SKAction.waitForDuration(0.1)
let updateLabel = SKAction.runBlock({[unowned self] in self.timePassed += wait.duration})
self.label.position = CGPoint(x: frame.midX, y: frame.midY+100.0)
addChild(self.label)
let timerSequence = SKAction.sequence([updateLabel, wait])
self.runAction(SKAction.repeatActionForever(timerSequence), withKey: "counting")
//This is used later, at the end of scaleUpAndDownSequence to reset the timer
let resetTimer = SKAction.runBlock({[unowned self] in self.timePassed = 0.0})
/* End Debugging */
self.player.position = CGPoint(x: frame.midX, y: frame.midY)
addChild(self.player)
let waitBeforeScaleToOriginalSize = SKAction.waitForDuration(3.0)
let waitBeforeRestart = SKAction.waitForDuration(4.0)
let scaleUp = SKAction.scaleTo(2.0, duration: 1)
let scaleDown = SKAction.scaleTo(1.0, duration: 1)
let scaleUpGroup = SKAction.group([waitBeforeScaleToOriginalSize, scaleUp])
let scaleDownGroup = SKAction.group([scaleDown, waitBeforeRestart])
//One cycle, scale up, scale down, reset timer
let scaleUpAndDownSequence = SKAction.sequence([scaleUpGroup, scaleDownGroup, resetTimer])
let loop = SKAction.repeatActionForever(scaleUpAndDownSequence)
self.player.runAction(loop, withKey: "scalingUpAndDown")
}
}
So here, I have two groups of actions:
1) scaleUpGroup
2) scaleDownGroup
scaleUpGroup group of actions has two actions in it: a scaleUp action, and an action which says how much to wait before the scale down action should occur. Because we want scaling up to happen immediately, we run it in parallel with the waitBeforeScaleToOriginalSize.
Same logic goes for scaleDownGroup. When scaleUpGroup is finished (its duration is determined by the longest action in the group) we start scaleDownGroup which scales down the player to its default size, and waits certain amount of time to repeat the whole thing.
Here is the result:
I start an animation on touch ( I've removed that code) and as you can see, scale up animation starts immediately, then after 3 seconds the player get scaled down to its original size, and after 4 seconds the whole animation repeats (player gets scaled up again etc).
I started working with SKS files to create games in swift, and in this game im trying to get enemies to spawn randomly within the width of the phone screen as opposed to all over the sks file scene
override func didMoveToView(view: SKView) {
self.physicsWorld.contactDelegate = self
NSTimer.scheduledTimerWithTimeInterval(0.2, target: self, selector: Selector("spawnEnemy"), userInfo: nil, repeats: true)
}
func spawnEnemy(){
//supposed to pick random point within the screen width
let xPos = Int.random(self.frame.width)
enemy = SKSpriteNode(imageNamed: "enemy")
enemy.position = CGPointMake(CGFloat(xpos), self.frame.size.height/2)
enemy.physicsBody = SKPhysicsBody(circleOfRadius: 7)
enemy.physicsBody?.affectedByGravity = true
enemy.physicsBody?.categoryBitMask = 0
enemy.physicsBody?.contactTestBitMask = 1
addChild(self.enemy)
}
Anyways, I wrote an example for you :)
So, here is how your example should look in order to work:
override func didMoveToView(view: SKView) {
self.physicsWorld.contactDelegate = self
NSTimer.scheduledTimerWithTimeInterval(0.2, target: self, selector: Selector("spawnEnemy"), userInfo: nil, repeats: true)
}
func randomBetweenNumbers(firstNum: CGFloat, secondNum: CGFloat) -> CGFloat{
return CGFloat(arc4random()) / CGFloat(UINT32_MAX) * abs(firstNum - secondNum) + min(firstNum, secondNum)
}
func spawnEnemy(){
//supposed to pick random point within the screen width
let xPos = randomBetweenNumbers(0, secondNum: frame.width )
let enemy = SKSpriteNode(imageNamed: "enemy") //create a new enemy each time
enemy.position = CGPointMake(CGFloat(xPos), self.frame.size.height/2)
enemy.physicsBody = SKPhysicsBody(circleOfRadius: 7)
enemy.physicsBody?.affectedByGravity = true
enemy.physicsBody?.categoryBitMask = 0
enemy.physicsBody?.contactTestBitMask = 1
addChild(enemy)
}
Method randomBetweenNumbers is borrowed from here.
And, this is another way of how you can spawn enemies by using SKAction:
override func didMoveToView(view: SKView) {
self.physicsWorld.contactDelegate = self
let wait = SKAction .waitForDuration(1, withRange: 0.5)
let spawn = SKAction.runBlock({
self.spawnEnemy()
})
let spawning = SKAction.sequence([wait,spawn])
self.runAction(SKAction.repeatActionForever(spawning), withKey:"spawning")
}
Method spawnEnemy remains the same in both cases. To stop spawning you can remove an action for certain key ("spawning" in this case). You can do it like this:
if((self.actionForKey("spawning")) != nil){
self.removeActionForKey("spawning")
}