Swift SpriteKit contain nodes within screen width - swift

Question

I have randomly spawning nodes moving vertically down the view.
Here is the code for doing this:
let meteTexture = SKTexture(imageNamed: "redmete.png")
let movementAmount = arc4random() % UInt32(self.frame.width)
let meteOffset = CGFloat(movementAmount) - self.frame.width / 2
let meteTime = arc4random_uniform(4) + 3;
let moveMete = SKAction.move(by: CGVector(dx: 0, dy: -2 * self.frame.height), duration: TimeInterval(meteTime))
redmete = SKSpriteNode(texture: meteTexture)
redmete.position = CGPoint(x: self.frame.midX + meteOffset, y: self.frame.midY + self.frame.height / 2)
My only problem is that as the meteOffset uses the centre of the sprite therefore it can occasionally spawn so 50% or so is out of the view.
I have tried
let movementAmount = arc4random() % UInt32(self.frame.width - meteTexture.size().width / 2)
I've also tried
let meteOffset = CGFloat(movementAmount) - meteTexture.size().width / 2 - self.frame.width / 2
But neither keep the whole of the sprite within the view. How can I do this?

Answer 1

You will want the initial position to be between the sub range of your frame height that is inset by half the height of the meteor.
You would need to have :
let meteorHeight = meteTexture.size().height
let verticalRange = self.frame.height - meteorHeight
let randomXPosition = meteorHeight/2 + arc4random() % verticalRange
Same goes for the horizontal position (if you want that to be random as well) :
let meteorWidth = meteTexture.size().width
let horizontalRange = self.frame.width - meteorWidth
let randomYPosition = meteorWidth/2 + arc4random() % horizontalRange
You can then set the position directly with the random XY coordinates
redmete.position = CGPoint(x:randomXPosition, y:randomYPosition)
If you don't want the meteor to appear too close to the edges, you can reduce the value of the verticalRange and horizontalRange further by subtracting a fixed offset or multiplying by a fraction.

Answer 2

SOLVED:
let meteTexture = SKTexture(imageNamed: "redmete.png")
let movementAmount = arc4random() % UInt32(self.frame.width / 2)
let meteOffset = CGFloat(movementAmount) + meteTexture.size().width/2 - self.frame.width / 2
let meteTime = arc4random_uniform(4) + 3;
let moveMete = SKAction.move(by: CGVector(dx: 0, dy: -2 * self.frame.height), duration: TimeInterval(meteTime))
redmete = SKSpriteNode(texture: meteTexture)
redmete.position = CGPoint(x: self.frame.midX + meteOffset, y: self.frame.midY + self.frame.height / 2)