EasingFunction (diozero - Core 1.3.0 API)

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
```
@FunctionalInterface
public interface EasingFunction
```
See easings.net for examples. See also Understanding Easing (Explaining Penner?s equations).

Implemented as a functional interface so that implementations can use method references rather than inheritance, makes it easier to refer to ease in, ease out and ease in-out variants.

- Method Summary
  
  All Methods Instance Methods Abstract Methods
  Modifier and Type Method Description
  
  float ease(float t, float b, float c, float d)

- Method Detail
  - ease
```
float ease(float t,
           float b,
           float c,
           float d)
```
    Parameters:
    
    t - (time) is the current time (or position) of the tween. This can be seconds or frames, steps, seconds, ms, whatever ? as long as the unit is the same as is used for the total time [3].
    
    b - (begin) is the beginning value of the property.
    
    c - (change) is the change between the beginning and destination value of the property.
    
    d - (duration) is the total time of the tween.
    
    Returns:
    
    Next value