Type Property


Ease-in pacing, which causes an animation to begin slowly and then speed up as it progresses.


static let easeIn: CAMediaTimingFunctionName


This is a Bézier timing function with the control points (0.42,0.0) and (1.0,1.0).

Listing 1 shows how to create a basic animation object using ease-in interpolation.

Listing 1

Creating a basic animation with an ease-in timing function

 let verticalAnimation = CABasicAnimation(keyPath: "position.y")
 verticalAnimation.fromValue = 310
 verticalAnimation.toValue = 10
 verticalAnimation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseIn)

A layer animated with the animation created by the code above and with linearly interpolated horizontal movement would describe a path similar to Figure 1.

Figure 1

Path taken using ease-in timing function

Path taken using ease-in timing function