Optimize the UIImageView

ReadMe.md

After reading "High Performance iOS Apps" Chapter7. UIImageView, and lookiing for some information in google.
Image Resizing Techniques I try to enhancements with resize image related code in a custom UIImageView (AutoDownsampingImageView).

See the orign code OptimizationImageView.swift

// just use   
let imageView: AutoDownsampingImageView = AutoDownsampingImageView()   
imageView.image = image

OptimizationImageView.swift

//  DownsampingImageView
//
//  Created by Woody on 2022/1/28.
//

import UIKit

fileprivate var WidthScale: (_ r: CGFloat, _ l: CGFloat)-> CGFloat = {
    return Scale($0, $1)
}

fileprivate var HeightScale: (_ r: CGFloat, _ l: CGFloat)-> CGFloat = {
    return Scale($0, $1)
}

fileprivate var Scale: (_ r: CGFloat, _ l: CGFloat)-> CGFloat = {
    return $0 / $1
}

extension UIImage {
    
    func resizeImageIfNeed(for size: CGSize)-> UIImage {
        guard needResizeimage(for: size) else { return self }
        return resizeImage(for: size)
    }
    
    func needResizeimage(for size: CGSize)-> Bool {
        let orign: CGSize = self.size
        return  WidthScale(orign.width, size.width) >= 0.5 || HeightScale(orign.height, size.height) >= 0.5
    }
    
    func resizeImage(for size: CGSize)-> UIImage {
        #if DEBUG
        print("\(#function) is Action")
        #endif
        let render = UIGraphicsImageRenderer(size: size)
        return render.image { ctx in self.draw(in: .init(origin: .zero, size: size))}
    }
}

extension UIImageView {
    func resizeImageIfNeed() {
        self.image = image?.resizeImage(for: bounds.size)
    }
}

class AutoDownsampingImageView: UIImageView {
    override var bounds: CGRect {
        didSet {
            resizeImageIfNeed()
        }
    }
}