Why can't I call a function in function update? - ios

Question

Please help me! Im trying to call a function I have declared in the GameScene class, within the update function. But it doesn't recognise the function, I'm wondering if this is something to do with the class or something because I want to run the function every frame (but has to update for each individual spriteCopy, depending on its own movement) to make sure the sprite copies all follow the function and continue to, infinitely.
Thank you in advance for any help.
here is the code for the function that sort of works to an extent:
func touchUp(atPoint pos : CGPoint) {
if let spriteCopy = self.sprite?.copy() as! SKShapeNode? {
spriteCopy.fillColor = UIColor.white
spriteCopy.position = initialTouch
spriteCopy.physicsBody?.restitution = 0.5
spriteCopy.physicsBody?.friction = 0
spriteCopy.physicsBody?.affectedByGravity = false
spriteCopy.physicsBody?.linearDamping = 0
spriteCopy.physicsBody?.angularDamping = 0
spriteCopy.physicsBody?.angularVelocity = 0
spriteCopy.physicsBody?.isDynamic = true
spriteCopy.physicsBody?.categoryBitMask = 1 //active
spriteCopy.isHidden = false
touchUp = pos
xAxisLength = initialTouch.x - touchUp.x
yAxisLength = initialTouch.y - touchUp.y
xUnitVector = xAxisLength / distanceBetweenTouch * power * 300
yUnitVector = yAxisLength / distanceBetweenTouch * power * 300
spriteCopy.physicsBody?.velocity = CGVector(dx: xUnitVector, dy: yUnitVector)
func directionRotation() {
if let body = spriteCopy.physicsBody {
if (body.velocity.speed() > 0.01) {
spriteCopy.zRotation = body.velocity.angle()
}
}
}
directionRotation() //When I run the function with this line, the spriteCopy
//is spawned initially with the right angle (in the direction
//of movement) but doesn't stay updating the angle
sprite?.isHidden = true
self.addChild(spriteCopy)
}
}
and here is the function not being recognised in function update:
override func update(_ currentTime: TimeInterval) {
directionRotation() //this line has error saying "use of unresolved identifier"
// Called before each frame is rendered
}
EDIT: I was thinking maybe there could be a way to spawn multiple spriteCopy's without the "copy()" method that will not restrict the access to the spriteCopy's properties after they have been spawned? Whilst remembering they still must have to be individual SpriteNodes so that the directionRotation function could be applied independently to each of them (FYI: The user can spawn upwards of 50+ sprite nodes)

Answer 1

You have specified local function. You need move out from touchUp function realisation directionRotation
func directionRotation() {
if let body = spriteCopy.physicsBody {
if (body.velocity.speed() > 0.01) {
spriteCopy.zRotation = body.velocity.angle()
}
}
}
func touchUp(atPoint pos : CGPoint) {
...
}
EDIT
I mean you need do some think like this:
func directionRotation(node:SKNode) {
if let body = node.physicsBody {
if (body.velocity.speed() > 0.01) {
node.zRotation = body.velocity.angle()
}
}
}
override func update(_ currentTime: TimeInterval) {
for node in self.children
{
directionRotation(node)
}
}