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using System ;
namespace MLEM.Misc {
/// <summary>
/// This class contains a set of easing functions, adapted from <see href="https://easings.net"/>.
/// These can be used for ui elements or any other kind of animations.
/// By default, each function takes an input that ranges between 0 and 1, and produces an output that roughly ranges between 0 and 1. To change this behavior, you can use <see cref="ScaleInput"/> and <see cref="ScaleOutput"/>.
/// </summary>
public static class Easings {
/// <summary><see href="https://easings.net/#easeInSine"/></summary>
public static readonly Easing InSine = p = > 1 - ( float ) Math . Cos ( p * Math . PI / 2 ) ;
/// <summary><see href="https://easings.net/#easeOutSine"/></summary>
public static readonly Easing OutSine = p = > ( float ) Math . Sin ( p * Math . PI / 2 ) ;
/// <summary><see href="https://easings.net/#easeInOutSine"/></summary>
public static readonly Easing InOutSine = p = > - ( ( float ) Math . Cos ( p * Math . PI ) - 1 ) / 2 ;
/// <summary><see href="https://easings.net/#easeInQuad"/></summary>
public static readonly Easing InQuad = p = > p * p ;
/// <summary><see href="https://easings.net/#easeOutQuad"/></summary>
public static readonly Easing OutQuad = p = > 1 - ( 1 - p ) * ( 1 - p ) ;
/// <summary><see href="https://easings.net/#easeInOutQuad"/></summary>
public static readonly Easing InOutQuad = p = > p < 0.5F ? 2 * p * p : 1 - ( - 2 * p + 2 ) * ( - 2 * p + 2 ) / 2 ;
/// <summary><see href="https://easings.net/#easeInCubic"/></summary>
public static readonly Easing InCubic = p = > p * p * p ;
/// <summary><see href="https://easings.net/#easeOutCubic"/></summary>
public static readonly Easing OutCubic = p = > 1 - ( 1 - p ) * ( 1 - p ) * ( 1 - p ) ;
/// <summary><see href="https://easings.net/#easeInOutCubic"/></summary>
public static readonly Easing InOutCubic = p = > p < 0.5F ? 4 * p * p * p : 1 - ( - 2 * p + 2 ) * ( - 2 * p + 2 ) * ( - 2 * p + 2 ) / 2 ;
/// <summary><see href="https://easings.net/#easeInExpo"/></summary>
public static readonly Easing InExpo = p = > p = = 0 ? 0 : ( float ) Math . Pow ( 2 , 10 * p - 10 ) ;
/// <summary><see href="https://easings.net/#easeOutExpo"/></summary>
public static readonly Easing OutExpo = p = > p = = 1 ? 1 : 1 - ( float ) Math . Pow ( 2 , - 10 * p ) ;
/// <summary><see href="https://easings.net/#easeInOutExpo"/></summary>
public static readonly Easing InOutExpo = p = > p = = 0 ? 0 : p = = 1 ? 1 : p < 0.5F ? ( float ) Math . Pow ( 2 , 20 * p - 10 ) / 2 : ( 2 - ( float ) Math . Pow ( 2 , - 20 * p + 10 ) ) / 2 ;
/// <summary><see href="https://easings.net/#easeInCirc"/></summary>
public static readonly Easing InCirc = p = > 1 - ( float ) Math . Sqrt ( 1 - p * p ) ;
/// <summary><see href="https://easings.net/#easeOutCirc"/></summary>
public static readonly Easing OutCirc = p = > ( float ) Math . Sqrt ( 1 - ( p - 1 ) * ( p - 1 ) ) ;
/// <summary><see href="https://easings.net/#easeInOutCirc"/></summary>
public static readonly Easing InOutCirc = p = > p < 0.5F ? ( 1 - ( float ) Math . Sqrt ( 1 - 2 * p * ( 2 * p ) ) ) / 2 : ( ( float ) Math . Sqrt ( 1 - ( - 2 * p + 2 ) * ( - 2 * p + 2 ) ) + 1 ) / 2 ;
/// <summary><see href="https://easings.net/#easeInBack"/></summary>
public static readonly Easing InBack = p = > 2.70158F * p * p * p - 1.70158F * p * p ;
/// <summary><see href="https://easings.net/#easeOutBack"/></summary>
public static readonly Easing OutBack = p = > 1 + 2.70158F * ( p - 1 ) * ( p - 1 ) * ( p - 1 ) + 1.70158F * ( p - 1 ) * ( p - 1 ) ;
/// <summary><see href="https://easings.net/#easeInOutBack"/></summary>
public static readonly Easing InOutBack = p = > p < 0.5 ? 2 * p * ( 2 * p ) * ( ( 2.594909F + 1 ) * 2 * p - 2.594909F ) / 2 : ( ( 2 * p - 2 ) * ( 2 * p - 2 ) * ( ( 2.594909F + 1 ) * ( p * 2 - 2 ) + 2.594909F ) + 2 ) / 2 ;
/// <summary><see href="https://easings.net/#easeInElastic"/></summary>
public static readonly Easing InElastic = p = > p = = 0 ? 0 : p = = 1 ? 1 : - ( float ) Math . Pow ( 2 , 10 * p - 10 ) * ( float ) Math . Sin ( ( p * 10 - 10.75 ) * 2.094395F ) ;
/// <summary><see href="https://easings.net/#easeOutElastic"/></summary>
public static readonly Easing OutElastic = p = > p = = 0 ? 0 : p = = 1 ? 1 : ( float ) Math . Pow ( 2 , - 10 * p ) * ( float ) Math . Sin ( ( p * 10 - 0.75 ) * 2.0943951023932F ) + 1 ;
/// <summary><see href="https://easings.net/#easeInOutElastic"/></summary>
public static readonly Easing InOutElastic = p = > p = = 0 ? 0 : p = = 1 ? 1 : p < 0.5 ? - ( ( float ) Math . Pow ( 2 , 20 * p - 10 ) * ( float ) Math . Sin ( ( 20 * p - 11.125 ) * 1.39626340159546F ) ) / 2 : ( float ) Math . Pow ( 2 , - 20 * p + 10 ) * ( float ) Math . Sin ( ( 20 * p - 11.125 ) * 1.39626340159546F ) / 2 + 1 ;
/// <summary><see href="https://easings.net/#easeInBounce"/></summary>
public static readonly Easing InBounce = p = > 1 - OutBounce ( 1 - p ) ;
/// <summary><see href="https://easings.net/#easeOutBounce"/></summary>
public static readonly Easing OutBounce = p = > {
const float n1 = 7.5625F ;
const float d1 = 2.75F ;
if ( p < 1 / d1 ) {
return n1 * p * p ;
} else if ( p < 2 / d1 ) {
return n1 * ( p - = 1.5F / d1 ) * p + 0.75F ;
} else if ( p < 2.5 / d1 ) {
return n1 * ( p - = 2.25F / d1 ) * p + 0.9375F ;
} else {
return n1 * ( p - = 2.625F / d1 ) * p + 0.984375F ;
}
} ;
/// <summary><see href="https://easings.net/#easeInOutBounce"/></summary>
public static readonly Easing InOutBounce = p = > p < 0.5 ? ( 1 - OutBounce ( 1 - 2 * p ) ) / 2 : ( 1 + OutBounce ( 2 * p - 1 ) ) / 2 ;
/// <summary>
/// Scales the input of an easing function, which is usually between 0 and 1, to a given minimum and maximum.
/// Note that the minimum needs to be smaller than the maximum.
/// </summary>
/// <param name="easing">The easing function to scale</param>
/// <param name="min">The minimum input value</param>
/// <param name="max">The maximum input value</param>
/// <returns>The scaled easing function</returns>
public static Easing ScaleInput ( this Easing easing , float min , float max ) {
return p = > easing ( ( p - min ) / ( max - min ) ) ;
}
/// <summary>
/// Scales the output of an easing function, which is usually between 0 and 1, to a given minimum and maximum.
/// Note that the minimum needs to be smaller than the maximum.
/// </summary>
/// <param name="easing">The easing function to scale</param>
/// <param name="min">The minimum output value</param>
/// <param name="max">The maximum output value</param>
/// <returns>The scaled easing function</returns>
public static Easing ScaleOutput ( this Easing easing , float min , float max ) {
return p = > easing ( p ) * ( max - min ) + min ;
}
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/// <summary>
/// Causes the easing functino to play fully, and then play fully in reverse, in the span between an input of 0 and 1.
/// In some places, this behavior is also called "auto-reversing".
/// </summary>
/// <param name="easing">The easing function to play in reverse as well</param>
/// <returns>An auto-reversing version of the easing function</returns>
public static Easing AndReverse ( this Easing easing ) {
return p = > p < = 0.5F ? easing ( p * 2 ) : easing ( 1 - ( p - 0.5F ) * 2 ) ;
}
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/// <summary>
/// A delegate method used by <see cref="Easings"/>.
/// </summary>
/// <param name="percentage">The percentage into the easing function. Either between 0 and 1, or, if <see cref="Easings.ScaleInput"/> was used, between an arbitary set of values.</param>
public delegate float Easing ( float percentage ) ;
}
}