I had just recently set up collision detection in my game it is doesn't seem to be working. I am very new to spritekit and i would like to know what is happening. Below i will provide you the gamscene class, didMoveToView, a function that is spawning the balls in the view, and my Did begin contact function. Please note that i am working with just the red Ball and the red block right now so they are the only two colliding. Please tell me if theres anything else in the project that you need to see and is not provided below.
import SpriteKit
import GameplayKit
class GameScene: SKScene, SKPhysicsContactDelegate {
var greenBlock = SKSpriteNode ()
var redBlock = SKSpriteNode()
var yellowBlock = SKSpriteNode()
var blueBlock = SKSpriteNode()
var greenBall = SKSpriteNode()
var redBall = SKSpriteNode()
var yellowBall = SKSpriteNode()
var blueBall = SKSpriteNode()
var ball = SKSpriteNode()
var ballSpeedTop = CGVector(dx: 0, dy: 5)
var ballSpeedBottom = CGVector(dx: 0, dy: -5)
This is where i define the numbers for the categoryBitMask
let redBallCategory: UInt32 = 0x1 << 0
let greenBallCategory: UInt32 = 0x1 << 1
let blueBallCategory: UInt32 = 0x1 << 2
let yellowBallCategory: UInt32 = 0x1 << 3
let redBlockCategory: UInt32 = 0x1 << 4
let yellowBlockCategory: UInt32 = 0x1 << 5
let greenBlockCategory: UInt32 = 0x1 << 6
let blueBlockCategory: UInt32 = 0x1 << 7
override func didMove(to view: SKView) {
physicsWorld.contactDelegate = self
Where i am applying the physics bodies to the block.
redBlock = self.childNode(withName: "redBlock") as! SKSpriteNode
redBlock.physicsBody?.categoryBitMask = redBlockCategory
redBlock.physicsBody?.collisionBitMask = redBallCategory
redBlock.physicsBody?.contactTestBitMask = redBallCategory
yellowBlock = self.childNode(withName: "yellowBlock") as! SKSpriteNode
greenBlock = self.childNode(withName: "greenBlock") as! SKSpriteNode
blueBlock = self.childNode(withName: "blueBlock") as! SKSpriteNode
redBlock.physicsBody?.affectedByGravity = false
redBlock.physicsBody?.isDynamic = true
greenBlock.physicsBody?.affectedByGravity = false
greenBlock.physicsBody?.isDynamic = true
blueBlock.physicsBody?.affectedByGravity = false
blueBlock.physicsBody?.isDynamic = false
yellowBlock.physicsBody?.affectedByGravity = false
yellowBlock.physicsBody?.isDynamic = false
initializeGame()
print("hello")
}
func initializeGame (){
Timer.scheduledTimer(timeInterval: TimeInterval(randomBetweenNumbers(firstNum: 2, secondNum: 4)), target: self, selector: #selector(topBall), userInfo: nil, repeats: true)
Timer.scheduledTimer(timeInterval: TimeInterval(randomBetweenNumbers(firstNum: 2, secondNum: 4)), target: self, selector: #selector(bottomBall), userInfo: nil, repeats: true)
}
// top ball spawner
func topBall () -> SKSpriteNode {
let ball: SKSpriteNode?;
if Int(randomBetweenNumbers(firstNum: 0, secondNum: 2)) == 0 {
ball = SKSpriteNode(imageNamed: "redBall")
ball?.name = "redBall"
ball!.physicsBody?.categoryBitMask = redBallCategory
ball!.physicsBody?.collisionBitMask = redBlockCategory
ball!.physicsBody?.contactTestBitMask = redBlockCategory
} else {
ball = SKSpriteNode(imageNamed: "greenBall")
ball?.name = "greenBall"
}
ball!.size = CGSize(width: 30, height: 30)
ball!.anchorPoint = CGPoint(x: 0.5, y: 0.5)
ball!.position = CGPoint(x: 0, y: 0)
ball!.physicsBody = SKPhysicsBody(circleOfRadius: ball!.size.height / 2)
ball!.physicsBody?.affectedByGravity = false
ball!.physicsBody?.isDynamic = true
ball!.zPosition = 2
self.addChild(ball!)
ball!.physicsBody?.applyImpulse(ballSpeedTop)
return ball!
}
the contact function
func didBegin(_ contact: SKPhysicsContact) {
if (contact.bodyA.categoryBitMask == redBallCategory && contact.bodyB.categoryBitMask == redBlockCategory){
print("touched red block")
} else if (contact.bodyB.categoryBitMask == redBallCategory && contact.bodyA.categoryBitMask == redBlockCategory){
print("touched a red block")
}
}
UPDATE::: i found where i went wrong but my problem is not technically solved yet. i had applied the properties of the redBall outside the if statement which meant that the redballs category bit mask, etc. is applied to both balls, i need a way to apply the redBall category bit mask to the redBall when it spawns and a different categorybitmask to the green ball when it spawns.
func topBall () -> SKSpriteNode {
let ball: SKSpriteNode?;
if Int(randomBetweenNumbers(firstNum: 0, secondNum: 2)) == 0 {
ball = SKSpriteNode(imageNamed: "redBall")
ball?.name = "redBall"
} else {
ball = SKSpriteNode(imageNamed: "greenBall")
ball?.name = "greenBall"
}
ball!.size = CGSize(width: 30, height: 30)
ball!.anchorPoint = CGPoint(x: 0.5, y: 0.5)
ball!.position = CGPoint(x: 0, y: 0)
ball!.physicsBody = SKPhysicsBody(circleOfRadius: ball!.size.height / 2)
ball!.physicsBody?.affectedByGravity = false
ball!.physicsBody?.isDynamic = true
ball!.physicsBody?.categoryBitMask = redBallCategory
ball!.physicsBody?.collisionBitMask = redBlockCategory
ball!.physicsBody?.contactTestBitMask = redBlockCategory
ball!.zPosition = 2
self.addChild(ball!)
ball!.physicsBody?.applyImpulse(ballSpeedTop)
return ball!
}
this is how i got it to work but the problem is that i want to apply individual categorybitmasks to the ball depending on wether it is green or red.
