How to detect when an SKSpriteNode hits another SKSpriteNode? - ios

I'm trying to make a game where you tilt your phone and try to keep the ball inside the boundary. I can't seem to figure out how to make the ball not go through the boundary. I have the tilt to move the ball working, but it just goes through all my boundaries and I can't seem to figure out how to make the ball stop when it comes in contact with a boundary. Here is my code:
override func didMove(to view: SKView) {
let border = SKPhysicsBody(edgeLoopFrom: self.frame)
self.physicsBody = border
boundary = (self.childNode(withName: "boundry") as! SKSpriteNode) //the boundary is spelled wrong
airplane = SKSpriteNode(imageNamed: "ball image")
airplane.physicsBody = SKPhysicsBody(circleOfRadius: 10)
airplane.position = CGPoint(x: -211.163, y: 367.3)
airplane.size = CGSize(width: 50, height: 50)
airplane.physicsBody?.isDynamic = true
airplane.physicsBody?.affectedByGravity = false
airplane.physicsBody?.allowsRotation = true
airplane.physicsBody?.pinned = false
self.addChild(airplane)
if motionManager.isAccelerometerAvailable {
// 2
motionManager.accelerometerUpdateInterval = 0.01
motionManager.startAccelerometerUpdates(to: .main) {
(data, error) in
guard let data = data, error == nil else {
return
}
// 3
let currentX = self.airplane.position.x
self.destX = currentX + CGFloat(data.acceleration.x * 500)
let currentY = self.airplane.position.y
self.destY = currentY + CGFloat(data.acceleration.y * 500)
}
}
}
override func update(_ currentTime: TimeInterval) {
let action = SKAction.moveTo(x: destX, duration: 1)
let action2 = SKAction.moveTo(y: destY, duration: 1)
airplane.run(action)
airplane.run(action2)
}

In SpriteKit things don't collide unless you give them a set of matching collisionBitMask. ie border.collisionBitMask & airplane.collisionBitMask need to have at least one non zero bit in common. Try setting both to 1 to begin with.

Another thing is that you may need to add a distance constraint to airplane so that it cannot escape from the border if speed is too high.

Related

How to spawn images forever? Sprite-Kit

Im trying to create a dodgeball feature in my game and I need to repeatedly spawn a dodgeball and the current code I used (shown below) results in Thread 1: Exception: "Attemped to add a SKNode which already has a parent: name:'(null)' texture:[ 'dodgeball5' (500 x 500)] position:{-140.00019836425781, -55.124687194824219} scale:{1.00, 1.00} size:{30, 30} anchor:{0.5, 0.5} rotation:0.00". What am I doing incorrect?
class ClassicLevelScene: SKScene {
// Right Pointing Cannons
var rightPointingCannon: [SKReferenceNode] = []
// Dodgeball 5 Constants
var dodgeball5 = SKSpriteNode(imageNamed: "dodgeball5")
// Dodgeball SKActions
var dodgeballRepeat = SKAction()
let dodgeballMoveLeft = SKAction.moveBy(x: -400, y: 0, duration: 0.5)
let dodgeballMoveRight = SKAction.moveBy(x: 400, y: 0, duration: 0.5)
let dodgeballMoveDone = SKAction.removeFromParent()
let dodgeballWait = SKAction.wait(forDuration: 1)
var dodgeballLeftSequence = SKAction()
var dodgeballRightSequence = SKAction()
override func didMove(to view: SKView) {
// Cannon Setup
for child in self.children {
if child.name == "rightPointingCannon" {
if let child = child as? SKReferenceNode {
rightPointingCannon.append(child)
dodgeball5.position = child.position
run(SKAction.repeatForever(
SKAction.sequence([
SKAction.run(spawnDodgeball),
SKAction.wait(forDuration: 1.0)
])
))
}
}
}
// Dodgeball Right Sequence
dodgeballRightSequence = SKAction.sequence([dodgeballMoveRight, dodgeballMoveDone, dodgeballWait])
}
func spawnDodgeball() {
dodgeball5.zPosition = -1
dodgeball5.size = CGSize(width: 30, height: 30)
addChild(dodgeball5)
dodgeball5.run(dodgeballRightSequence)
}
}
Assuming single ball and ball can go off screen:
I would actually recommend against cloning the sprite.
Simply reuse it.
Once it's off the screen, you can reset it's position and speed and display it again. No need to create lots of objects, if you only need one.
One SKNode only can have 1 parent at time.
You need to create a new SKSpriteNode or clone the dodgeball5 before to add again on spawnDodgeball()
You can use
addChild(dodgeball5.copy())
instead of
addChild(dodgeball5)
But be make sure dodgeball5 have no parent before.
Your code seems to be unnecessarily complex.
all you need to do is copy() you ball and add it to your scene
Also all of your SKActions don't need to be declared at a class level
And it's not clear why you are creating an array of cannons when only one is instantiated
class ClassicLevelScene: SKScene {
// Dodgeball 5 Constants
var dodgeball5 = SKSpriteNode(imageNamed: "dodgeball5")
override func didMove(to view: SKView) {
setupCannonAndBall()
let dodgeballMoveRight = SKAction.moveBy(x: 400, y: 0, duration: 0.5)
let dodgeballMoveDone = SKAction.removeFromParent()
let dodgeballWait = SKAction.wait(forDuration: 1)
dodgeballRightSequence = SKAction.sequence([dodgeballMoveRight, dodgeballMoveDone, dodgeballWait])
//setup sequences ^ before spawning ball
let spawn = SKAction.run(spawnDodgeball)
let wait = SKAction.wait(forDuration: 1.0)
run(SKAction.repeatForever(SKAction.sequence([spawn, wait])))
}
func setupCannonAndBall() {
if let cannonRef = SKReferenceNode(fileNamed: "rightPointingCannon") {
dodgeball5.position = cannonRef.position
dodgeball5.isHidden = true
dodgeball5.size = CGSize(width: 30, height: 30)
dodgeball5.zPosition = -1
}
}
func spawnDodgeball() {
let dodgeball = dodgeball.copy()
dodgeball.isHidden = false
addChild(dodgeball)
dodgeball.run(dodgeballRightSequence)
}
}

Swift - Increase speed of a moving Node using SpriteKit

I am working on a game similar to pong, while starting the game I apply impulse to the ball in random direction, which is at the centre of the screen e.g.
func impulse(){
let randomNum:UInt32 = arc4random_uniform(200)
let someInt:Int = Int(randomNum)
//Ball Impulse
if someInt<49{
ball.physicsBody?.applyImpulse(CGVector(dx: ballSpeed+3, dy: ballSpeed-5))
}else if someInt<99{
ball.physicsBody?.applyImpulse(CGVector(dx: ballSpeed+5, dy: -ballSpeed+5))
}else if someInt<149{
ball.physicsBody?.applyImpulse(CGVector(dx: -ballSpeed-5, dy: -ballSpeed+5))
}else if someInt<200{
ball.physicsBody?.applyImpulse(CGVector(dx: -ballSpeed-3, dy: ballSpeed-5))
}
}
Where ballSpeed is the preset speed of ball.
So is there any way I can gradually increase the velocity of ball with duration while it is in motion? As ball will keep on bouncing around the screen so it is difficult to apply force to it using dx and dy.
EDIT -
I am using above method just to assign a random quadrant/direction to ball at start of the game.
Start, when impulse method is implemented e.g.
Game start image
And I want to increase speed of the ball by a predefined unit over time during gameplay e.g.
Gameplay
Ok, here you go! The ball CONSTANTLY gets faster, no matter what!!! Adjust amount to determine how much the ball gains speed each frame.
class GameScene: SKScene, SKPhysicsContactDelegate {
let ball = SKShapeNode(circleOfRadius: 20)
var initialDY = CGFloat(0)
var initialDX = CGFloat(0)
override func didMove(to view: SKView) {
self.physicsBody = SKPhysicsBody(edgeLoopFrom: frame)
self.physicsWorld.gravity = CGVector.zero
// Configure ball pb:
let pb = SKPhysicsBody(circleOfRadius: 20)
ball.physicsBody = pb
addChild(ball)
pb.applyImpulse(CGVector(dx: 10, dy: 10))
}
override func update(_ currentTime: TimeInterval) {
initialDX = abs(ball.physicsBody!.velocity.dx)
initialDY = abs(ball.physicsBody!.velocity.dy)
}
override func didSimulatePhysics() {
guard let pb = ball.physicsBody else { fatalError() }
// decrease this to adjust the amount of speed gained each frame :)
let amount = CGFloat(5)
// When bouncing off a wall, speed decreases... this corrects that to _increase speed_ off bounces.
if abs(pb.velocity.dx) < abs(initialDX) {
if pb.velocity.dx < 0 { pb.velocity.dx = -initialDX - amount }
else if pb.velocity.dx > 0 { pb.velocity.dx = initialDX + amount }
}
if abs(pb.velocity.dy) < abs(initialDY) {
if pb.velocity.dy < 0 { pb.velocity.dy = -initialDY - amount }
else if pb.velocity.dy > 0 { pb.velocity.dy = initialDY + amount }
}
}
}
you can modify this to only increase speed every 5 seconds with an SKAction.repeatForever(.sequence([.wait(forDuration: TimeInterval, .run( { code } ))) but IMO having it constantly gain speed is a bit more awesome and easier to implement.

SpriteKit joint: follow the body

I've been asked to simplify this question, so that's what I'm doing.
I'm struggling in SpriteKit's physic joints (and possibly physic body properties). I tried every single subclass and many configurations but seams like nothing works or I'm doing something wrong.
I'm developing Snake game. User controls head of snake which should move at constant speed ahead and user can turn it clockwise or anticlockwise. All the remaining snake's pieces should follow the head - they should travel exactly the same path that head was some time ago.
I think for this game the Pin joint should be the answer, which anchor point is exactly in the centre between elements.
Unfortunately the result is not perfect. The structure should make the perfect circle, but it doesn't. I'm attaching the code, and gif showing the current effect. Is anyone experience enough to give me any suggestion what properties of physic body and or joints should are apply here for desired effect?
My code:
class GameScene: SKScene {
private var elements = [SKNode]()
override func didMove(to view: SKView) {
physicsWorld.gravity = CGVector(dx: 0, dy: 0)
let dummyTurnNode = SKNode()
dummyTurnNode.position = CGPoint(x: size.width / 2 - 50, y: size.height / 2)
let dummyTurnBody = SKPhysicsBody(circleOfRadius: 1)
dummyTurnBody.isDynamic = false
dummyTurnNode.physicsBody = dummyTurnBody
addChild(dummyTurnNode)
for index in 0..<5 {
let element = SKShapeNode(circleOfRadius: 10)
let body = SKPhysicsBody(circleOfRadius: 10)
body.linearDamping = 0
// body.mass = 0
element.physicsBody = body
element.position = CGPoint(x: size.width / 2, y: size.height / 2 - 30 * CGFloat(index))
elements.append(element)
addChild(element)
let label = SKLabelNode(text: "A")
label.fontSize = 10
label.fontName = "Helvetica-Bold"
element.addChild(label)
if index == 0 {
element.fillColor = UIColor.blue()
body.velocity = CGVector(dx: 0, dy: 30)
let dummyTurnJoint = SKPhysicsJointPin.joint(withBodyA: dummyTurnBody, bodyB: body, anchor: dummyTurnNode.position)
physicsWorld.add(dummyTurnJoint)
} else {
body.linearDamping = 1
element.fillColor = UIColor.red()
let previousElement = elements[index - 1]
let connectingJoint = SKPhysicsJointPin.joint(withBodyA: previousElement.physicsBody!, bodyB: body, anchor: CGPoint(x: size.width / 2, y: size.height / 2 - 30 * CGFloat(index) + CGFloat(15)))
physicsWorld.add(connectingJoint)
}
}
}
override func update(_ currentTime: TimeInterval) {
let head = elements.first!.physicsBody!
var velocity = head.velocity
velocity.normalize()
velocity.multiply(30)
head.velocity = velocity
}
}
extension CGVector {
var rwLength: CGFloat {
let xSq = pow(dx, 2)
let ySq = pow(dy, 2)
return sqrt(xSq + ySq)
}
mutating func normalize() {
dx /= rwLength
dy /= rwLength
}
mutating func multiply(_ factor: CGFloat) {
dx *= factor
dy *= factor
}
}
"All the remaining snake's pieces should follow the head - they should travel exactly the same path that head was some time ago."
You should note that with Physics joints you are likely going to have variance no matter what you do. Even if you have it close to perfect you'll have rounding errors under the hood making the path not exact.
If all the tail parts are equal you can also use a different approach, this is something I've done for a comet tail. Basically the idea is that you have an array of tail objects and per-frame move move the last tail-object always to the same position as the head-object. If the head-object has a higher z-position the tail is drawn below it.
If you need to keep your tail in order you could vary the approach by storing an array of head-positions (per-frame path) and then place the tail objects along that path in your per-frame update call to the snake.
See my code below for example:
These are you head-object variables:
var tails = [SKEmitterNode]()
var tailIndex = 0
In your head init function instantiate the tail objects:
for _ in 0...MAX_TAIL_INDEX
{
if let remnant = SKEmitterNode(fileNamed: "FireTail.sks")
{
p.tails.append(remnant)
}
}
Call the below per-frame:
func drawTail()
{
if tails.count > tailIndex
{
tails[tailIndex].resetSimulation()
tails[tailIndex].particleSpeed = velocity() / 4
tails[tailIndex].emissionAngle = zRotation - CGFloat(M_PI_2) // opposite direction
tails[tailIndex].position = position
tailIndex = tailIndex < MAX_TAIL_INDEX ? tailIndex + 1 : 0
}
}
The resulting effect is actually really smooth when you call it from the scene update() function.

Swift: Detect when SKSpriteNode has even touched

I have a game where an object falls from the top of the screen to the bottom randomly. I want to have it to where if the object is tapped, I can tell it to do something, like add points to the score.
Can you help me try to figure this out? I'll be on to answer any questions if you happen to have any. Here is the code I'm using:
class GameSceneTest: SKScene, SKPhysicsContactDelegate {
override func didMoveToView(view: SKView) {
backgroundColor = SKColor.clearColor()
physicsWorld.gravity = CGVectorMake(0, 0)
physicsWorld.contactDelegate = self
//Change duration
runAction(SKAction.repeatActionForever(SKAction.sequence([SKAction.runBlock(addObject), SKAction.waitForDuration(1)])
))
//AddMusicHere
}
func random() -> CGFloat {
return CGFloat(Float(arc4random()) / 0xFFFFFFFF)
}
func random(min min: CGFloat, max: CGFloat) -> CGFloat {
return random() * (max - min) + min
}
func add Object() {
let Object = SKSpriteNode(imageNamed: "Object\(arc4random_uniform(6) + 1).png")
Object.userInteractionEnabled = true
Object.size = CGSize(width: 50, height: 50)
Object.physicsBody = SKPhysicsBody(rectangleOfSize: Object.size)
Object.physicsBody?.dynamic = true
//Determine where to spawn gem across y axis
let actually = random(min: Object.size.width/2, max: size.width - Object.size.width/2)
//Position Object slightly off screen along right edge
//and along random y axis point
//Object.position = CGPoint(x: size.width + Object.size.width/2 , y: actually)
Object.position = CGPoint(x: actually, y: size.height + Object.size.height/2)
//Add the Object to the scene
addChild(Object)
//Determines speed of Object (edit later to where speed depends on type of Object)
let actualDuration = random(min: CGFloat(4), max: CGFloat(5))
//Create the Actions
let actionMove = SKAction.moveTo(CGPoint(x: actually, y: gem.size.height/2), duration: NSTimeInterval(actualDuration))
let actionMoveDone = SKAction.removeFromParent()
let loseAction = SKAction.runBlock() {
let reveal = SKTransition.flipHorizontalWithDuration(0.5) //Change to flipe vertical
let gameOverScene = GameOverScene(size: self.size, won: false)
self.view?.presentScene(gameOverScene, transition: reveal)
}
Object.runAction(SKAction.sequence([actionMove, loseAction, actionMoveDone]))
}
Take a look at "Moving The Cards Around The Board" in the following tutorial: Ray Wenderlicht SpriteKit Tutorial.
Then read a bit more around handling touch events in iOS (e.g. Handling Touches...).
Then try something in code and if you get stuck post a more specific question - because this one is a little too general.

Trying to delay spawn nodes using waitForDuration in didMoveToView with SpriteKit Scene (SWIFT) but not working

I'm trying to stop my nodes from falling just for a second or two at the start of my game. So my problem is when I push start the nodes are already halfway down the screen. I also tried changing how high the nodes start but it seems like a costly solution since I want to be careful not to let my FPS get too low. In my code I am trying to do this in the didMoveToView and I am using waitForDuration but it doesn't work.
Example Image of Nodes Falling Down
Any SpriteKit masters know what I should do? I'm using Swift.
Here is my code:
override func didMoveToView(view: SKView) {
let wait = SKAction.waitForDuration(2.5)
let run = SKAction.runBlock {
self.spawnNumbers()
}
numContainer.runAction(SKAction.sequence([wait, run]))
}
func spawnNumbers() {
let minValue = self.size.width / 8
let maxValue = self.size.width - 36
let spawnPoint = CGFloat(arc4random_uniform(UInt32(maxValue - minValue)))
let action = SKAction.moveToY(-300, duration: 2)
numContainer = SKSpriteNode(imageNamed: "Circle")
numContainer.name = "Circle"
numContainer.size = CGSize(width: 72, height: 72)
numContainer.anchorPoint = CGPointMake(0, 0)
numContainer.position = CGPoint(x: spawnPoint, y: self.size.height)
numContainer.runAction(SKAction.repeatActionForever(action))
numContainer.zPosition = 2
let numberLabel = SKLabelNode(fontNamed: "AvenirNext-Bold")
numberLabel.text = "\(numToTouch)"
numberLabel.name = "Label"
numberLabel.zPosition = -1
numberLabel.position = CGPointMake(CGRectGetMidX(numContainer.centerRect) + 36, CGRectGetMidY(numContainer.centerRect) + 36)
numberLabel.horizontalAlignmentMode = .Center
numberLabel.verticalAlignmentMode = .Center
numberLabel.fontColor = UIColor.whiteColor()
numberLabel.fontSize = 28
addChild(numContainer)
numContainer.addChild(numberLabel)
numContainerArray.append(numContainer)
numToTouch += 1
}
I think you have to cast the 2.5 seconds to an NSTimeInterval:
let wait = SKAction.waitForDuration(NSTimeInterval(2.5))
You could also try putting the actions in the init function for your scene:
override init (size: CGSize) {
super.init(size: size)
//your code from before
}
Also, not sure if it matters, but this is what I normally do and it works,
let wait = SKAction.waitForDuration(NSTimeInterval(2.5))
let action = SKAction.runBlock({() in self.spawnNumbers()})
let actionThenWait = SKAction.sequence([wait, action])
self.runAction(actionThenWait)

Resources