How to set ball's random position in Spritekit? - ios

Question

I am making a game where there are two balls on the scene, but the user is going to tap on the correct ball. However, when user taps on the correct ball, I want to set a random position for my second ball that when the user taps on the correct ball, I want to also want the second ball to move randomly.
Here is my code for setting up the random positions of the ball:
let currentBall = SKShapeNode(circleOfRadius: CGFloat(size))
let shape = SKShapeNode()
currentBall.fillColor = pickColor()
//Rectangle
shape.path = UIBezierPath(roundedRect: CGRect(x: 64, y: 64, width: 160,height: 160), cornerRadius: 50).cgPath
shape.fillColor = pickColor()
self.addChild(shape)
func randomBallPosition() -> CGPoint {
let xPosition = view!.scene!.frame.midX - viewMidX + CGFloat(arc4random_uniform(UInt32(viewMidX*2)))
let yPosition = view!.scene!.frame.midY - viewMidY + CGFloat(arc4random_uniform(UInt32(viewMidY*2)))
return CGPoint(x: xPosition, y: yPosition)
}
func handleTap() {
currentBall.position = randomBallPosition()
shape.position = randomBallPosition()
}

Answer 1

The issue is that you're setting the exact same position, which you have used for the first ball. As far as I understand both ball should appear at random independent positions. You should create a function to return a new position and call it for each ball:
class MyScene: SKScene {
var currentBall: SKShapeNode!
var shape: SKShapeNode!
override func didMove(to view: SKView) {
super.didMove(to: view)
let currentBall = SKShapeNode(circleOfRadius: CGFloat(size))
currentBall.fillColor = pickColor()
let shape = SKShapeNode()
shape.path = UIBezierPath(roundedRect: CGRect(x: 64, y: 64, width: 160,height: 160), cornerRadius: 50).cgPath
shape.fillColor = pickColor()
self.addChild(shape)
}
func handleTap() {
//your code here, except that you don't create new nodes, just modify existing ones
//at some point you will change balls' positions like this:
currentBall.position = randomBallPosition()
secondBall.position = randomBallPosition()
}
func randomBallPosition() -> CGPoint {
let xPosition = CGFloat(arc4random_uniform(UInt32((view?.bounds.maxX)! + 1)))
let yPosition = CGFloat(arc4random_uniform(UInt32((view?.bounds.maxY)! + 1)))
return CGPoint(x: xPosition, y: yPosition)
}
}
Hope this helps