swiftUI如何创建气泡效果？

import SwiftUI

struct SpeechBubble: Shape {
    let speechBubbleWidth: CGFloat
    let speechBubbleHeight: CGFloat
    
    func path(in rect: CGRect) -> Path {
        var path = Path()
        
        let speechBubbleRect = CGRect(x: rect.minX, y: rect.minY, width: speechBubbleWidth, height: speechBubbleHeight)
        let speechBubbleRadius: CGFloat = 10
        
        path.move(to: CGPoint(x: speechBubbleRect.midX, y: speechBubbleRect.minY))
        path.addArc(center: CGPoint(x: speechBubbleRect.maxX - speechBubbleRadius, y: speechBubbleRect.minY + speechBubbleRadius), radius: speechBubbleRadius, startAngle: Angle(degrees: -90), endAngle: Angle(degrees: 0), clockwise: false)
        path.addArc(center: CGPoint(x: speechBubbleRect.maxX - speechBubbleRadius, y: speechBubbleRect.maxY - speechBubbleRadius), radius: speechBubbleRadius, startAngle: Angle(degrees: 0), endAngle: Angle(degrees: 90), clockwise: false)
        path.addArc(center: CGPoint(x: speechBubbleRect.minX + speechBubbleRadius, y: speechBubbleRect.maxY - speechBubbleRadius), radius: speechBubbleRadius, startAngle: Angle(degrees: 90), endAngle: Angle(degrees: 180), clockwise: false)
        path.addArc(center: CGPoint(x: speechBubbleRect.minX + speechBubbleRadius, y: speechBubbleRect.minY + speechBubbleRadius), radius: speechBubbleRadius, startAngle: Angle(degrees: 180), endAngle: Angle(degrees: 270), clockwise: false)
        path.closeSubpath()
        
        return path
    }
}

struct ContentView: View {
    var body: some View {
        SpeechBubble(speechBubbleWidth: 200, speechBubbleHeight: 100)
            .foregroundColor(.blue)
            .padding()
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}