EaseTo

The easing action is a lot like the moveTo except you can specify an EasingFunction. With built in easing functions like EasingFunctionsEasingFunctions.EaseInOutCubic you can make things look really smooth.

https://easings.net/ is a great site to visualize easing functions

EaseTo

This method will move an actor to the specified x and y position over the specified duration using a given EasingFunctions. This method is part of the actor 'Action' fluent API allowing action chaining.

const actor = new ex.Actor({...})
// Move to (100, 100) in world coordinates over 1000ms using EaseInOutCubic
label.actions.easeTo(ex.vec(100, 100), 1000, ex.EasingFunctions.EaseInOutCubic)

Custom Easing Functions

As long as you implement the easing function interface

The Standard easing functions for motion in Excalibur, defined on a domain of [0, duration] and a range from [+startValue,+endValue] given a time, the function will return a value from positive startValue to positive endValue.

export interface EasingFunction {
  (
    currentTime: number,
    startValue: number,
    endValue: number,
    duration: number
  ): number
}

There is a helper to wrap your easing functions and make them reversible EasingFunctions.CreateReversibleEasingFunction