In the previous recipe, Creating basic animations, you can see that SwiftUI is able to animate the change of common characteristics, such as position, color, size, and so on. But what if the feature we want to animate is not one that is part of the framework?
In this recipe, we'll create a triangular shape whose height is equal to the width times a fraction of the width; when we tap on the triangle, we set that multiplier to a random number, making the height change.
How can we instruct SwiftUI to animate the change of the multiplier? We'll see that the code needed is simple, but that the underlying engine is quite sophisticated.
How to do it…
Tapping on the shape, the multiplier...