使用iOS中的核心图形绘制带有渐变的外半圆？

import UIKit

class GradientHalfCircleView: UIView {
    
    override func draw(_ rect: CGRect) {
        super.draw(rect)
        
        guard let context = UIGraphicsGetCurrentContext() else { return }
        
        let colors = [UIColor.red.cgColor, UIColor.blue.cgColor]
        let colorSpace = CGColorSpaceCreateDeviceRGB()
        let colorLocations: [CGFloat] = [0.0, 1.0]
        
        guard let gradient = CGGradient(colorsSpace: colorSpace, colors: colors as CFArray, locations: colorLocations) else { return }
        
        let center = CGPoint(x: bounds.midX, y: bounds.midY)
        let radius = min(bounds.width, bounds.height)
        let startAngle = CGFloat(0)
        let endAngle = CGFloat(Double.pi)
        let path = UIBezierPath()
        
        path.addArc(withCenter: center, radius: radius, startAngle: startAngle, endAngle: endAngle, clockwise: true)
        context.drawLinearGradient(gradient, start: CGPoint(x: bounds.midX, y: 0), end: CGPoint(x: bounds.midX, y: bounds.height), options: [])
        context.addPath(path.cgPath)
        context.clip()
        context.fillPath()
    }
}