Update README.md

README.md

@@ -3,7 +3,6 @@
 **Neumorphic** shadow example:
 
 ```swift
-
 let view = SurfaceView()
 view.frame = ...
 view.layer.cornerRadius = ...
@@ -15,3 +14,25 @@ addSubview(view)
 The cast shadows moves accordingly to the device horizontal axis.
 
 <img src="docs_/button.gif" width=140 alt="screen" />
+
+
+**Convex/Concave** shadow example:
+
+
+```swift
+view.backgroundColor = systemBackground()
+let surface = SurfaceView()
+surface.frame = CGRect(x: 100, y: 100, width: 96, height: 32)
+surface.layer.cornerRadius = 16
+surface.surfaceLayer.shadow = Shadow(preset: .concave2)
+view.addSubview(surface)
+
+let button = SurfaceView()
+button.frame = CGRect(x: 0, y: 0, width: 48, height: 32)
+button.layer.cornerRadius = 16
+button.surfaceLayer.shadow = Shadow(preset: .convex1)
+button.backgroundColor = .white
+surface.addSubview(button)
+```
+
+<img src="docs_/switch.gif" width=140 alt="screen" />