I just read Metal by Tutorials and SwiftUI by Tutorials, But I don’t figure out how to combine Metal and SwiftUI together. Is There possible to include this part in the next version of this book?
More immediately, you might want to look at
drawingGroup() (https://developer.apple.com/documentation/swiftui/group/3284805-drawinggroup). It uses metal and can improve performance for more complex graphics views.