Cropping an image from the top in Swift - swift

Question

I am trying to crop this image, which is a SKSpriteNode:
I am trying to crop this image from the top, so that I maintain the bottom semi circle of this shape. For instance, it'd be cropped to this:
So I use these two methods to accomplish this task:
func recalculateScore() {
currentScore -= decreaseRate
let image = UIImage(cgImage: (vial.texture?.cgImage())!)
vial.texture = SKTexture(image: cropBottomImage(image: image))
}
func cropBottomImage(image: UIImage) -> UIImage {
let height = CGFloat(image.size.height / 3)
let rect = CGRect(x: 0, y: image.size.height - height, width: image.size.width, height: height)
return cropImage(image: image, toRect: rect)
}
func cropImage(image:UIImage, toRect rect:CGRect) -> UIImage {
let imageRef:CGImage = image.cgImage!.cropping(to: rect)!
let croppedImage:UIImage = UIImage(cgImage:imageRef)
return croppedImage
}
However, this leads to this result:
It is as if it was being compressed. I think my issue might be in this line:
let rect = CGRect(x: 0, y: image.size.height - height, width: image.size.width, height: height)
Does the CGRect coordinate of (0,0) lie within the top most left corner? I am a bit confused on what the x and y parameters for the CGRect mean?

Answer 1

Resize your sprite, what is happening is the cropped texture is stretching to fill the sprite, and since you only crop vertically, it will only stretch vertically
func recalculateScore() {
currentScore -= decreaseRate
let image = UIImage(cgImage: (vial.texture?.cgImage())!)
vial.texture = SKTexture(image: cropBottomImage(image: image))
vial.size = vial.texture.size
}