/******************************************************************************
 * Copyright (C) Ultraleap, Inc. 2011-2021.                                   *
 *                                                                            *
 * Use subject to the terms of the Apache License 2.0 available at            *
 * http://www.apache.org/licenses/LICENSE-2.0, or another agreement           *
 * between Ultraleap and you, your company or other organization.             *
 ******************************************************************************/

namespace Leap.Unity.Animation
{

    /// <summary> Utility functions for producing smooth motion. </summary>
    public static class Ease
    {

        public static class Quadratic
        {

            /// <summary> Maps a linear 0-1 animation coefficient "t" to a quadratic in-out 0-1 curve. 
            /// The input is not clamped automatically, but expects a value from 0 to 1. </summary>
            public static float InOut(float t)
            {
                t *= 2F;
                if (t < 1F) return 0.5F * t * t;
                t -= 1F;
                return (-0.5F) * (t * (t - 2F) - 1F);
            }

        }

        public static class Cubic
        {

            /// <summary> Maps a linear 0-1 animation coefficient "t" to a cubic in-out 0-1 curve.
            /// The input is not clamped automatically, but expects a value from 0 to 1. </summary>
            public static float InOut(float t)
            {
                t *= 2F;
                if (t < 1F) return 0.5F * t * t * t;
                t -= 2F;
                return 0.5F * (t * t * t + 2F);
            }

        }

        public static class Quartic
        {

            /// <summary> Maps a linear 0-1 animation coefficient "t" to a quartic in-out 0-1 curve.
            /// The input is not clamped automatically, but expects a value from 0 to 1. </summary>
            public static float InOut(float t)
            {
                t *= 2F;
                if (t < 1F) return 0.5F * t * t * t * t;
                t -= 2F;
                return -0.5F * (t * t * t * t - 2F);
            }

        }

    }

}