AquaWaveShape.swift

struct AquaWaveShape: Shape {
  func path(in rect: CGRect) -> Path {
    Path {
      path in
      path.move(to: CGPoint(x: rect.minX, y: rect.maxY * 0.9))
      path.addQuadCurve(to: CGPoint(x: rect.maxX * 0.25, y: rect.midY),
                        control: CGPoint(x: rect.minX, y: rect.midY))
      path.addLine(to: CGPoint(x: rect.maxX * 0.75, y: rect.midY))
      path.addQuadCurve(to: CGPoint(x: rect.maxX, y: rect.maxY * 0.1),
                        control: CGPoint(x: rect.maxX, y: rect.midY))
      path.addLine(to: CGPoint(x: rect.maxX, y: rect.minY))
      path.addLine(to: CGPoint(x: rect.minX, y: rect.minY))
      path.addLine(to: CGPoint(x: rect.minX, y: rect.maxY))
    }
  }
}

struct AquaWaveView: View {
  var body: some View {
    ZStack {
      LinearGradient(gradient: Gradient(colors: [.gray, .white]),
                     startPoint: .top, endPoint: .bottom)
      Color.aquaLightGray
        .mask(AquaWaveShape())
    }
  }
}