Swiftui PKCanvasView上的手指和铅笔宽度不同

我试图建立一个应用程序的能力，使用苹果铅笔和手指输入绘制。然而，当我将工具的宽度设置为足够小的数字（1）时，铅笔输入显示正确，但当我使用手指时，它会绘制更粗的线。我希望在铅笔和手指之间切换时宽度一致。任何帮助都将不胜感激。Bellow是最小可复制代码

import Foundation
import SwiftUI
import PencilKit

struct ContentView: View {
    var body: some View {
        CanvasRepresentable()
    }
}

struct CanvasRepresentable: UIViewRepresentable {

    class Coordinator: NSObject, PKCanvasViewDelegate {
        var parent: CanvasRepresentable
        init(_ parent: CanvasRepresentable) {
            self.parent = parent

        }

        func canvasViewDrawingDidChange(_ canvasView: PKCanvasView) {
        }

    }


    func makeCoordinator() -> Coordinator {

        return Coordinator(self)

    }

    func makeUIView(context: Context) -> PKCanvasView {
        let c = PKCanvasView()
        c.isOpaque = false
        c.allowsFingerDrawing = true
        c.delegate = context.coordinator
        c.tool = PKInkingTool(.pen, color: .black, width: 1)
        return c

    }

    func updateUIView(_ uiView: PKCanvasView, context: Context) {
        let tool = uiView.tool as! PKInkingTool
        print(tool.width)
    }

}