SpriteKit: calculate angle of joystick and change sprite based on that - ios

Question

I am making a RPG Birds-eye style game with SpriteKit. I made a joystick because a D-Pad does not give the player enough control over his character.
I cannot wrap my brain around how I would calculate the neccessary data needed to change the Sprite of my character based on the angle of the joystick thumb Node.
Here is my code I am using
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
let location = touch.location(in: self)
if isTracking == false && base.contains(location) {
isTracking = true
}
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
let location: CGPoint = touch.location(in: self)
if isTracking == true {
let v = CGVector(dx: location.x - base.position.x, dy: location.y - DPad.position.y)
let angle = atan2(v.dy, v.dx)
let deg = angle * CGFloat(180 / Double.pi)
let Length:CGFloat = base.frame.size.height / 2
let xDist: CGFloat = sin(angle - 1.57079633) * Length
let yDist: CGFloat = cos(angle - 1.57079633) * Length
print(xDist,yDist)
xJoystickDelta = location.x * base.position.x / CGFloat(Double.pi)
yJoystickDelta = location.y * base.position.y / CGFloat(Double.pi)
if base.contains(location) {
thumbNode.position = location
} else {
thumbNode.position = CGPoint(x: base.position.x - xDist, y: base.position.y + yDist)
}
}
}
}
Update method
override func update(_ currentTime: TimeInterval) {
// Called before each frame is rendered
if xJoystickDelta > 0 && yJoystickDelta < 0 {
print("forward")
}
}
The way I have set up right now tests the positive or negative state of the Joystick position in a cross method based on where the thumb Node is inside of the four marked sections below
I dont want it to do that
How can I set it up so that it changes the sprite based on where the thumb node is actually pointing inside my joysticks base like so.
I have been struggling with this for 3 days now so any help would be appreciated.

Answer 1

That looks far too complicated. Just compare the x and y components
of the difference vector v. Something like this:
if v.dx > abs(v.dy) {
// right
} else if v.dx < -abs(v.dy) {
// left
} else if v.dy < 0 {
// up
} else if v.dy > 0 {
// down
}