How can I change the touch offset of a sprite in SpriteKit? - swift

Question

When I touch the player mallet (Air Hockey), I want to make it so the mallet moves slightly above the touch. This way the mallet will be more visible in the game. I have found some solutions but am having a hard time implementing properly in my function.
Here is a sample of my touchesMoved() function:
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?)
{
bottomTouchIsActive = true
var releventTouch:UITouch!
//convert set to known type
let touchSet = touches
//get array of touches so we can loop through them
let orderedTouches = Array(touchSet)
for touch in orderedTouches
{
//if we've not yet found a relevent touch
if releventTouch == nil
{
//look for a touch that is in the activeArea (Avoid touches by opponent)
if activeArea.contains(touch.location(in: parent!))
{
isUserInteractionEnabled = true
releventTouch = touch
}
else
{
releventTouch = nil
}
}
}
if (releventTouch != nil)
{
//get touch position and relocate player
let location = releventTouch!.location(in: parent!)
position = location
//find old location and use pythagoras to determine length between both points
let oldLocation = releventTouch!.previousLocation(in: parent!)
let xOffset = location.x - oldLocation.x
let yOffset = location.y - oldLocation.y
let vectorLength = sqrt(xOffset * xOffset + yOffset * yOffset)
//get eleapsed and use to calculate speed6A
if lastTouchTimeStamp != nil
{
let seconds = releventTouch.timestamp - lastTouchTimeStamp!
let velocity = 0.01 * Double(vectorLength) / seconds
//to calculate the vector, the velcity needs to be converted to a CGFloat
let velocityCGFloat = CGFloat(velocity)
//calculate the impulse
let directionVector = CGVector(dx: velocityCGFloat * xOffset / vectorLength, dy: velocityCGFloat * yOffset / vectorLength)
//pass the vector to the scene (so it can apply an impulse to the puck)
delegate?.bottomForce(directionVector, fromBottomPlayer: self)
delegate?.bottomTouchIsActive(bottomTouchIsActive, fromBottomPlayer: self)
}
//update latest touch time for next calculation
lastTouchTimeStamp = releventTouch.timestamp
}
}

Answer 1

Is the position var, which you take from the touch location, used to set the position of the mallet? If it is, then if you want the mallet above the touch, why not do something like position.y += 50 immediately after position = location to move it up by 50 points?
Alternatively, you might find it more logical to set the mallet's anchorPoint property (https://developer.apple.com/documentation/spritekit/skspritenode/1519877-anchorpoint and https://developer.apple.com/documentation/spritekit/skspritenode/using_the_anchor_point_to_move_a_sprite) to be somewhere other than the default poisition (the centre of the sprite) e.g. the point that corresponds to the part of the handle of the mallet where one would normally hold it.