[SwiftUI] 화면에 구멍 뚫기 - .mask (iOS 15 부터)

struct ContentView: View {
    
    let colors: [Color] = [.red, .blue]
    
    var body: some View {
        
        LinearGradient(colors: colors, startPoint: .leading, endPoint: .trailing)
            .mask {
                Image(systemName: "flag.checkered")
                    .font(.system(size: 128))
            }
            .background(Color.blue.opacity(0.2))
            .ignoresSafeArea()
    }
}