问如何在SwiftUI中动画化核心图像过滤器

EN

struct ContentView: View {
    
    @State private var animate = false

    var body: some View {
        VStack {
            PixellatedImage(imageName: "yoga", scale: animate ? 100 : 1)
                .scaledToFit()
        }
        .padding()
        .onAppear {
            withAnimation(Animation.linear(duration: 3.0).repeatForever()) {
                self.animate.toggle()
            }
        }
    }
}


struct PixellatedImage: View, Animatable {
    
    let imageName: String
    var scale: CGFloat
    
    var animatableData: CGFloat {
        get { scale }
        set { scale = newValue }
    }
    
    var body: some View {
        Image(uiImage: pixellatedImage(imageName: imageName, scale: scale))
            .resizable()
    }
}


func pixellatedImage(imageName: String, scale: Double) -> UIImage {
    if let inputImage = UIImage(named: imageName) {
        let context = CIContext(options: nil)
        
        if let currentFilter = CIFilter(name: "CIPixellate") {
            let beginImage = CIImage(image: inputImage)
            currentFilter.setValue(beginImage, forKey: kCIInputImageKey)
            currentFilter.setValue(scale, forKey: kCIInputScaleKey)
            
            if let output = currentFilter.outputImage {
                if let cgimg = context.createCGImage(output, from: output.extent) {
                    let processedImage = UIImage(cgImage: cgimg)
                    return processedImage
                }
            }
        }
    }
    return UIImage() // empty default instead of nil
}