自定义图层/形状内的Swift/ios波浪填充动画

import UIKit
import QuartzCore

class WaveView: UIView {
    
    private let shapeLayer = CAShapeLayer()
    private let animation = CABasicAnimation(keyPath: "path")
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        setupView()
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        setupView()
    }
    
    private func setupView() {
        layer.addSublayer(shapeLayer)
        setupAnimation()
    }
    
    private func setupAnimation() {
        animation.duration = 2.0
        animation.repeatCount = .infinity
        animation.timingFunction = CAMediaTimingFunction(name: .easeInEaseOut)
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        let path = UIBezierPath()
        let width = bounds.width
        let height = bounds.height
        let amplitude: CGFloat = 10.0
        let frequency: CGFloat = 4.0
        
        for x in stride(from: 0, to: width, by: 1) {
            let y = height / 2 + sin(CGFloat(x) * .pi * frequency) * amplitude
            if x == 0 {
                path.move(to: CGPoint(x: x, y: y))
            } else {
                path.addLine(to: CGPoint(x: x, y: y))
            }
        }
        
        shapeLayer.path = path.cgPath
        animation.fromValue = path.cgPath
        animation.toValue = UIBezierPath(arcCenter: CGPoint(x: width / 2, y: height / 2), radius: width / 2, startAngle: -.pi, endAngle: .pi, clockwise: true).cgPath
        
        shapeLayer.add(animation, forKey: "wave")
    }
}