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unitycoder/EasingFunctions.cs

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Created February 18, 2022 16:14
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Revisions

  1. @cjddmut cjddmut revised this gist Feb 10, 2019. 1 changed file with 8 additions and 29 deletions.
    37 changes: 8 additions & 29 deletions EasingFunctions.cs
    View file
    Original file line number Diff line number Diff line change
    @@ -1,11 +1,9 @@
    using UnityEngine;

    /*
    * Created by C.J. Kimberlin (http://cjkimberlin.com)
    * Created by C.J. Kimberlin
    *
    * The MIT License (MIT)
    *
    * Copyright (c) 2015
    * Copyright (c) 2019
    *
    * Permission is hereby granted, free of charge, to any person obtaining a copy
    * of this software and associated documentation files (the "Software"), to deal
    @@ -57,7 +55,9 @@
    * float derivativeValue = derivativeFunc(0, 10, 0.67f);
    */

    public class EasingFunction
    using UnityEngine;

    public static class EasingFunction
    {
    public enum Ease
    {
    @@ -546,7 +546,7 @@ public static float EaseOutSineD(float start, float end, float value)
    public static float EaseInOutSineD(float start, float end, float value)
    {
    end -= start;
    return end * 0.5f * Mathf.PI * Mathf.Cos(Mathf.PI * value);
    return end * 0.5f * Mathf.PI * Mathf.Sin(Mathf.PI * value);
    }
    public static float EaseInExpoD(float start, float end, float value)
    {
    @@ -685,29 +685,7 @@ public static float EaseInOutBackD(float start, float end, float value)

    public static float EaseInElasticD(float start, float end, float value)
    {
    end -= start;

    float d = 1f;
    float p = d * .3f;
    float s;
    float a = 0;

    if (a == 0f || a < Mathf.Abs(end))
    {
    a = end;
    s = p / 4;
    }
    else
    {
    s = p / (2 * Mathf.PI) * Mathf.Asin(end / a);
    }

    float c = 2 * Mathf.PI;

    // From an online derivative calculator, kinda hoping it is right.
    return ((-a) * d * c * Mathf.Cos((c * (d * (value - 1f) - s)) / p)) / p -
    5f * NATURAL_LOG_OF_2 * a * Mathf.Sin((c * (d * (value - 1f) - s)) / p) *
    Mathf.Pow(2f, 10f * (value - 1f) + 1f);
    return EaseOutElasticD(start, end, 1f - value);
    }

    public static float EaseOutElasticD(float start, float end, float value)
    @@ -773,6 +751,7 @@ public static float SpringD(float start, float end, float value)
    end -= start;

    // Damn... Thanks http://www.derivative-calculator.net/
    // TODO: And it's a little bit wrong
    return end * (6f * (1f - value) / 5f + 1f) * (-2.2f * Mathf.Pow(1f - value, 1.2f) *
    Mathf.Sin(Mathf.PI * value * (2.5f * value * value * value + 0.2f)) + Mathf.Pow(1f - value, 2.2f) *
    (Mathf.PI * (2.5f * value * value * value + 0.2f) + 7.5f * Mathf.PI * value * value * value) *
  2. @cjddmut cjddmut revised this gist Apr 17, 2015. 1 changed file with 1 addition and 1 deletion.
    2 changes: 1 addition & 1 deletion EasingFunctions.cs
    View file
    Original file line number Diff line number Diff line change
    @@ -5,7 +5,7 @@
    *
    * The MIT License (MIT)
    *
    * Copyright (c) 2014
    * Copyright (c) 2015
    *
    * Permission is hereby granted, free of charge, to any person obtaining a copy
    * of this software and associated documentation files (the "Software"), to deal
  3. @cjddmut cjddmut created this gist Apr 17, 2015.
    1,128 changes: 1,128 additions & 0 deletions EasingFunctions.cs
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,1128 @@
    using UnityEngine;

    /*
    * Created by C.J. Kimberlin (http://cjkimberlin.com)
    *
    * The MIT License (MIT)
    *
    * Copyright (c) 2014
    *
    * Permission is hereby granted, free of charge, to any person obtaining a copy
    * of this software and associated documentation files (the "Software"), to deal
    * in the Software without restriction, including without limitation the rights
    * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    * copies of the Software, and to permit persons to whom the Software is
    * furnished to do so, subject to the following conditions:
    *
    * The above copyright notice and this permission notice shall be included in all
    * copies or substantial portions of the Software.
    *
    * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    * SOFTWARE.
    *
    *
    * TERMS OF USE - EASING EQUATIONS
    * Open source under the BSD License.
    * Copyright (c)2001 Robert Penner
    * All rights reserved.
    * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
    * Neither the name of the author nor the names of contributors may be used to endorse or promote products derived from this software without specific prior written permission.
    *
    * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
    * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
    * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    *
    *
    * ============= Description =============
    *
    * Below is an example of how to use the easing functions in the file. There is a getting function that will return the function
    * from an enum. This is useful since the enum can be exposed in the editor and then the function queried during Start().
    *
    * EasingFunction.Ease ease = EasingFunction.Ease.EaseInOutQuad;
    * EasingFunction.EasingFunc func = GetEasingFunction(ease;
    *
    * float value = func(0, 10, 0.67f);
    *
    * EasingFunction.EaseingFunc derivativeFunc = GetEasingFunctionDerivative(ease);
    *
    * float derivativeValue = derivativeFunc(0, 10, 0.67f);
    */

    public class EasingFunction
    {
    public enum Ease
    {
    EaseInQuad = 0,
    EaseOutQuad,
    EaseInOutQuad,
    EaseInCubic,
    EaseOutCubic,
    EaseInOutCubic,
    EaseInQuart,
    EaseOutQuart,
    EaseInOutQuart,
    EaseInQuint,
    EaseOutQuint,
    EaseInOutQuint,
    EaseInSine,
    EaseOutSine,
    EaseInOutSine,
    EaseInExpo,
    EaseOutExpo,
    EaseInOutExpo,
    EaseInCirc,
    EaseOutCirc,
    EaseInOutCirc,
    Linear,
    Spring,
    EaseInBounce,
    EaseOutBounce,
    EaseInOutBounce,
    EaseInBack,
    EaseOutBack,
    EaseInOutBack,
    EaseInElastic,
    EaseOutElastic,
    EaseInOutElastic,
    }

    private const float NATURAL_LOG_OF_2 = 0.693147181f;

    //
    // Easing functions
    //

    public static float Linear(float start, float end, float value)
    {
    return Mathf.Lerp(start, end, value);
    }

    public static float Spring(float start, float end, float value)
    {
    value = Mathf.Clamp01(value);
    value = (Mathf.Sin(value * Mathf.PI * (0.2f + 2.5f * value * value * value)) * Mathf.Pow(1f - value, 2.2f) + value) * (1f + (1.2f * (1f - value)));
    return start + (end - start) * value;
    }

    public static float EaseInQuad(float start, float end, float value)
    {
    end -= start;
    return end * value * value + start;
    }

    public static float EaseOutQuad(float start, float end, float value)
    {
    end -= start;
    return -end * value * (value - 2) + start;
    }

    public static float EaseInOutQuad(float start, float end, float value)
    {
    value /= .5f;
    end -= start;
    if (value < 1) return end * 0.5f * value * value + start;
    value--;
    return -end * 0.5f * (value * (value - 2) - 1) + start;
    }

    public static float EaseInCubic(float start, float end, float value)
    {
    end -= start;
    return end * value * value * value + start;
    }

    public static float EaseOutCubic(float start, float end, float value)
    {
    value--;
    end -= start;
    return end * (value * value * value + 1) + start;
    }

    public static float EaseInOutCubic(float start, float end, float value)
    {
    value /= .5f;
    end -= start;
    if (value < 1) return end * 0.5f * value * value * value + start;
    value -= 2;
    return end * 0.5f * (value * value * value + 2) + start;
    }

    public static float EaseInQuart(float start, float end, float value)
    {
    end -= start;
    return end * value * value * value * value + start;
    }

    public static float EaseOutQuart(float start, float end, float value)
    {
    value--;
    end -= start;
    return -end * (value * value * value * value - 1) + start;
    }

    public static float EaseInOutQuart(float start, float end, float value)
    {
    value /= .5f;
    end -= start;
    if (value < 1) return end * 0.5f * value * value * value * value + start;
    value -= 2;
    return -end * 0.5f * (value * value * value * value - 2) + start;
    }

    public static float EaseInQuint(float start, float end, float value)
    {
    end -= start;
    return end * value * value * value * value * value + start;
    }

    public static float EaseOutQuint(float start, float end, float value)
    {
    value--;
    end -= start;
    return end * (value * value * value * value * value + 1) + start;
    }

    public static float EaseInOutQuint(float start, float end, float value)
    {
    value /= .5f;
    end -= start;
    if (value < 1) return end * 0.5f * value * value * value * value * value + start;
    value -= 2;
    return end * 0.5f * (value * value * value * value * value + 2) + start;
    }

    public static float EaseInSine(float start, float end, float value)
    {
    end -= start;
    return -end * Mathf.Cos(value * (Mathf.PI * 0.5f)) + end + start;
    }

    public static float EaseOutSine(float start, float end, float value)
    {
    end -= start;
    return end * Mathf.Sin(value * (Mathf.PI * 0.5f)) + start;
    }

    public static float EaseInOutSine(float start, float end, float value)
    {
    end -= start;
    return -end * 0.5f * (Mathf.Cos(Mathf.PI * value) - 1) + start;
    }

    public static float EaseInExpo(float start, float end, float value)
    {
    end -= start;
    return end * Mathf.Pow(2, 10 * (value - 1)) + start;
    }

    public static float EaseOutExpo(float start, float end, float value)
    {
    end -= start;
    return end * (-Mathf.Pow(2, -10 * value) + 1) + start;
    }

    public static float EaseInOutExpo(float start, float end, float value)
    {
    value /= .5f;
    end -= start;
    if (value < 1) return end * 0.5f * Mathf.Pow(2, 10 * (value - 1)) + start;
    value--;
    return end * 0.5f * (-Mathf.Pow(2, -10 * value) + 2) + start;
    }

    public static float EaseInCirc(float start, float end, float value)
    {
    end -= start;
    return -end * (Mathf.Sqrt(1 - value * value) - 1) + start;
    }

    public static float EaseOutCirc(float start, float end, float value)
    {
    value--;
    end -= start;
    return end * Mathf.Sqrt(1 - value * value) + start;
    }

    public static float EaseInOutCirc(float start, float end, float value)
    {
    value /= .5f;
    end -= start;
    if (value < 1) return -end * 0.5f * (Mathf.Sqrt(1 - value * value) - 1) + start;
    value -= 2;
    return end * 0.5f * (Mathf.Sqrt(1 - value * value) + 1) + start;
    }

    public static float EaseInBounce(float start, float end, float value)
    {
    end -= start;
    float d = 1f;
    return end - EaseOutBounce(0, end, d - value) + start;
    }

    public static float EaseOutBounce(float start, float end, float value)
    {
    value /= 1f;
    end -= start;
    if (value < (1 / 2.75f))
    {
    return end * (7.5625f * value * value) + start;
    }
    else if (value < (2 / 2.75f))
    {
    value -= (1.5f / 2.75f);
    return end * (7.5625f * (value) * value + .75f) + start;
    }
    else if (value < (2.5 / 2.75))
    {
    value -= (2.25f / 2.75f);
    return end * (7.5625f * (value) * value + .9375f) + start;
    }
    else
    {
    value -= (2.625f / 2.75f);
    return end * (7.5625f * (value) * value + .984375f) + start;
    }
    }

    public static float EaseInOutBounce(float start, float end, float value)
    {
    end -= start;
    float d = 1f;
    if (value < d * 0.5f) return EaseInBounce(0, end, value * 2) * 0.5f + start;
    else return EaseOutBounce(0, end, value * 2 - d) * 0.5f + end * 0.5f + start;
    }

    public static float EaseInBack(float start, float end, float value)
    {
    end -= start;
    value /= 1;
    float s = 1.70158f;
    return end * (value) * value * ((s + 1) * value - s) + start;
    }

    public static float EaseOutBack(float start, float end, float value)
    {
    float s = 1.70158f;
    end -= start;
    value = (value) - 1;
    return end * ((value) * value * ((s + 1) * value + s) + 1) + start;
    }

    public static float EaseInOutBack(float start, float end, float value)
    {
    float s = 1.70158f;
    end -= start;
    value /= .5f;
    if ((value) < 1)
    {
    s *= (1.525f);
    return end * 0.5f * (value * value * (((s) + 1) * value - s)) + start;
    }
    value -= 2;
    s *= (1.525f);
    return end * 0.5f * ((value) * value * (((s) + 1) * value + s) + 2) + start;
    }

    public static float EaseInElastic(float start, float end, float value)
    {
    end -= start;

    float d = 1f;
    float p = d * .3f;
    float s;
    float a = 0;

    if (value == 0) return start;

    if ((value /= d) == 1) return start + end;

    if (a == 0f || a < Mathf.Abs(end))
    {
    a = end;
    s = p / 4;
    }
    else
    {
    s = p / (2 * Mathf.PI) * Mathf.Asin(end / a);
    }

    return -(a * Mathf.Pow(2, 10 * (value -= 1)) * Mathf.Sin((value * d - s) * (2 * Mathf.PI) / p)) + start;
    }

    public static float EaseOutElastic(float start, float end, float value)
    {
    end -= start;

    float d = 1f;
    float p = d * .3f;
    float s;
    float a = 0;

    if (value == 0) return start;

    if ((value /= d) == 1) return start + end;

    if (a == 0f || a < Mathf.Abs(end))
    {
    a = end;
    s = p * 0.25f;
    }
    else
    {
    s = p / (2 * Mathf.PI) * Mathf.Asin(end / a);
    }

    return (a * Mathf.Pow(2, -10 * value) * Mathf.Sin((value * d - s) * (2 * Mathf.PI) / p) + end + start);
    }

    public static float EaseInOutElastic(float start, float end, float value)
    {
    end -= start;

    float d = 1f;
    float p = d * .3f;
    float s;
    float a = 0;

    if (value == 0) return start;

    if ((value /= d * 0.5f) == 2) return start + end;

    if (a == 0f || a < Mathf.Abs(end))
    {
    a = end;
    s = p / 4;
    }
    else
    {
    s = p / (2 * Mathf.PI) * Mathf.Asin(end / a);
    }

    if (value < 1) return -0.5f * (a * Mathf.Pow(2, 10 * (value -= 1)) * Mathf.Sin((value * d - s) * (2 * Mathf.PI) / p)) + start;
    return a * Mathf.Pow(2, -10 * (value -= 1)) * Mathf.Sin((value * d - s) * (2 * Mathf.PI) / p) * 0.5f + end + start;
    }

    //
    // These are derived functions that the motor can use to get the speed at a specific time.
    //
    // The easing functions all work with a normalized time (0 to 1) and the returned value here
    // reflects that. Values returned here should be divided by the actual time.
    //
    // TODO: These functions have not had the testing they deserve. If there is odd behavior around
    // dash speeds then this would be the first place I'd look.

    public static float LinearD(float start, float end, float value)
    {
    return end - start;
    }

    public static float EaseInQuadD(float start, float end, float value)
    {
    return 2f * (end - start) * value;
    }

    public static float EaseOutQuadD(float start, float end, float value)
    {
    end -= start;
    return -end * value - end * (value - 2);
    }

    public static float EaseInOutQuadD(float start, float end, float value)
    {
    value /= .5f;
    end -= start;

    if (value < 1)
    {
    return end * value;
    }

    value--;

    return end * (1 - value);
    }

    public static float EaseInCubicD(float start, float end, float value)
    {
    return 3f * (end - start) * value * value;
    }

    public static float EaseOutCubicD(float start, float end, float value)
    {
    value--;
    end -= start;
    return 3f * end * value * value;
    }

    public static float EaseInOutCubicD(float start, float end, float value)
    {
    value /= .5f;
    end -= start;

    if (value < 1)
    {
    return (3f / 2f) * end * value * value;
    }

    value -= 2;

    return (3f / 2f) * end * value * value;
    }

    public static float EaseInQuartD(float start, float end, float value)
    {
    return 4f * (end - start) * value * value * value;
    }

    public static float EaseOutQuartD(float start, float end, float value)
    {
    value--;
    end -= start;
    return -4f * end * value * value * value;
    }

    public static float EaseInOutQuartD(float start, float end, float value)
    {
    value /= .5f;
    end -= start;

    if (value < 1)
    {
    return 2f * end * value * value * value;
    }

    value -= 2;

    return -2f * end * value * value * value;
    }

    public static float EaseInQuintD(float start, float end, float value)
    {
    return 5f * (end - start) * value * value * value * value;
    }

    public static float EaseOutQuintD(float start, float end, float value)
    {
    value--;
    end -= start;
    return 5f * end * value * value * value * value;
    }

    public static float EaseInOutQuintD(float start, float end, float value)
    {
    value /= .5f;
    end -= start;

    if (value < 1)
    {
    return (5f / 2f) * end * value * value * value * value;
    }

    value -= 2;

    return (5f / 2f) * end * value * value * value * value;
    }

    public static float EaseInSineD(float start, float end, float value)
    {
    return (end - start) * 0.5f * Mathf.PI * Mathf.Sin(0.5f * Mathf.PI * value);
    }

    public static float EaseOutSineD(float start, float end, float value)
    {
    end -= start;
    return (Mathf.PI * 0.5f) * end * Mathf.Cos(value * (Mathf.PI * 0.5f));
    }

    public static float EaseInOutSineD(float start, float end, float value)
    {
    end -= start;
    return end * 0.5f * Mathf.PI * Mathf.Cos(Mathf.PI * value);
    }
    public static float EaseInExpoD(float start, float end, float value)
    {
    return (10f * NATURAL_LOG_OF_2 * (end - start) * Mathf.Pow(2f, 10f * (value - 1)));
    }

    public static float EaseOutExpoD(float start, float end, float value)
    {
    end -= start;
    return 5f * NATURAL_LOG_OF_2 * end * Mathf.Pow(2f, 1f - 10f * value);
    }

    public static float EaseInOutExpoD(float start, float end, float value)
    {
    value /= .5f;
    end -= start;

    if (value < 1)
    {
    return 5f * NATURAL_LOG_OF_2 * end * Mathf.Pow(2f, 10f * (value - 1));
    }

    value--;

    return (5f * NATURAL_LOG_OF_2 * end) / (Mathf.Pow(2f, 10f * value));
    }

    public static float EaseInCircD(float start, float end, float value)
    {
    return ((end - start) * value) / Mathf.Sqrt(1f - value * value);
    }

    public static float EaseOutCircD(float start, float end, float value)
    {
    value--;
    end -= start;
    return (-end * value) / Mathf.Sqrt(1f - value * value);
    }

    public static float EaseInOutCircD(float start, float end, float value)
    {
    value /= .5f;
    end -= start;

    if (value < 1)
    {
    return (end * value) / (2f * Mathf.Sqrt(1f - value * value));
    }

    value -= 2;

    return (-end * value) / (2f * Mathf.Sqrt(1f - value * value));
    }

    public static float EaseInBounceD(float start, float end, float value)
    {
    end -= start;
    float d = 1f;

    return EaseOutBounceD(0, end, d - value);
    }

    public static float EaseOutBounceD(float start, float end, float value)
    {
    value /= 1f;
    end -= start;

    if (value < (1 / 2.75f))
    {
    return 2f * end * 7.5625f * value;
    }
    else if (value < (2 / 2.75f))
    {
    value -= (1.5f / 2.75f);
    return 2f * end * 7.5625f * value;
    }
    else if (value < (2.5 / 2.75))
    {
    value -= (2.25f / 2.75f);
    return 2f * end * 7.5625f * value;
    }
    else
    {
    value -= (2.625f / 2.75f);
    return 2f * end * 7.5625f * value;
    }
    }

    public static float EaseInOutBounceD(float start, float end, float value)
    {
    end -= start;
    float d = 1f;

    if (value < d * 0.5f)
    {
    return EaseInBounceD(0, end, value * 2) * 0.5f;
    }
    else
    {
    return EaseOutBounceD(0, end, value * 2 - d) * 0.5f;
    }
    }

    public static float EaseInBackD(float start, float end, float value)
    {
    float s = 1.70158f;

    return 3f * (s + 1f) * (end - start) * value * value - 2f * s * (end - start) * value;
    }

    public static float EaseOutBackD(float start, float end, float value)
    {
    float s = 1.70158f;
    end -= start;
    value = (value) - 1;

    return end * ((s + 1f) * value * value + 2f * value * ((s + 1f) * value + s));
    }

    public static float EaseInOutBackD(float start, float end, float value)
    {
    float s = 1.70158f;
    end -= start;
    value /= .5f;

    if ((value) < 1)
    {
    s *= (1.525f);
    return 0.5f * end * (s + 1) * value * value + end * value * ((s + 1f) * value - s);
    }

    value -= 2;
    s *= (1.525f);
    return 0.5f * end * ((s + 1) * value * value + 2f * value * ((s + 1f) * value + s));
    }

    public static float EaseInElasticD(float start, float end, float value)
    {
    end -= start;

    float d = 1f;
    float p = d * .3f;
    float s;
    float a = 0;

    if (a == 0f || a < Mathf.Abs(end))
    {
    a = end;
    s = p / 4;
    }
    else
    {
    s = p / (2 * Mathf.PI) * Mathf.Asin(end / a);
    }

    float c = 2 * Mathf.PI;

    // From an online derivative calculator, kinda hoping it is right.
    return ((-a) * d * c * Mathf.Cos((c * (d * (value - 1f) - s)) / p)) / p -
    5f * NATURAL_LOG_OF_2 * a * Mathf.Sin((c * (d * (value - 1f) - s)) / p) *
    Mathf.Pow(2f, 10f * (value - 1f) + 1f);
    }

    public static float EaseOutElasticD(float start, float end, float value)
    {
    end -= start;

    float d = 1f;
    float p = d * .3f;
    float s;
    float a = 0;

    if (a == 0f || a < Mathf.Abs(end))
    {
    a = end;
    s = p * 0.25f;
    }
    else
    {
    s = p / (2 * Mathf.PI) * Mathf.Asin(end / a);
    }

    return (a * Mathf.PI * d * Mathf.Pow(2f, 1f - 10f * value) *
    Mathf.Cos((2f * Mathf.PI * (d * value - s)) / p)) / p - 5f * NATURAL_LOG_OF_2 * a *
    Mathf.Pow(2f, 1f - 10f * value) * Mathf.Sin((2f * Mathf.PI * (d * value - s)) / p);
    }

    public static float EaseInOutElasticD(float start, float end, float value)
    {
    end -= start;

    float d = 1f;
    float p = d * .3f;
    float s;
    float a = 0;

    if (a == 0f || a < Mathf.Abs(end))
    {
    a = end;
    s = p / 4;
    }
    else
    {
    s = p / (2 * Mathf.PI) * Mathf.Asin(end / a);
    }

    if (value < 1)
    {
    value -= 1;

    return -5f * NATURAL_LOG_OF_2 * a * Mathf.Pow(2f, 10f * value) * Mathf.Sin(2 * Mathf.PI * (d * value - 2f) / p) -
    a * Mathf.PI * d * Mathf.Pow(2f, 10f * value) * Mathf.Cos(2 * Mathf.PI * (d * value - s) / p) / p;
    }

    value -= 1;

    return a * Mathf.PI * d * Mathf.Cos(2f * Mathf.PI * (d * value - s) / p) / (p * Mathf.Pow(2f, 10f * value)) -
    5f * NATURAL_LOG_OF_2 * a * Mathf.Sin(2f * Mathf.PI * (d * value - s) / p) / (Mathf.Pow(2f, 10f * value));
    }

    public static float SpringD(float start, float end, float value)
    {
    value = Mathf.Clamp01(value);
    end -= start;

    // Damn... Thanks http://www.derivative-calculator.net/
    return end * (6f * (1f - value) / 5f + 1f) * (-2.2f * Mathf.Pow(1f - value, 1.2f) *
    Mathf.Sin(Mathf.PI * value * (2.5f * value * value * value + 0.2f)) + Mathf.Pow(1f - value, 2.2f) *
    (Mathf.PI * (2.5f * value * value * value + 0.2f) + 7.5f * Mathf.PI * value * value * value) *
    Mathf.Cos(Mathf.PI * value * (2.5f * value * value * value + 0.2f)) + 1f) -
    6f * end * (Mathf.Pow(1 - value, 2.2f) * Mathf.Sin(Mathf.PI * value * (2.5f * value * value * value + 0.2f)) + value
    / 5f);

    }

    public delegate float Function(float s, float e, float v);

    /// <summary>
    /// Returns the function associated to the easingFunction enum. This value returned should be cached as it allocates memory
    /// to return.
    /// </summary>
    /// <param name="easingFunction">The enum associated with the easing function.</param>
    /// <returns>The easing function</returns>
    public static Function GetEasingFunction(Ease easingFunction)
    {
    if (easingFunction == Ease.EaseInQuad)
    {
    return EaseInQuad;
    }

    if (easingFunction == Ease.EaseOutQuad)
    {
    return EaseOutQuad;
    }

    if (easingFunction == Ease.EaseInOutQuad)
    {
    return EaseInOutQuad;
    }

    if (easingFunction == Ease.EaseInCubic)
    {
    return EaseInCubic;
    }

    if (easingFunction == Ease.EaseOutCubic)
    {
    return EaseOutCubic;
    }

    if (easingFunction == Ease.EaseInOutCubic)
    {
    return EaseInOutCubic;
    }

    if (easingFunction == Ease.EaseInQuart)
    {
    return EaseInQuart;
    }

    if (easingFunction == Ease.EaseOutQuart)
    {
    return EaseOutQuart;
    }

    if (easingFunction == Ease.EaseInOutQuart)
    {
    return EaseInOutQuart;
    }

    if (easingFunction == Ease.EaseInQuint)
    {
    return EaseInQuint;
    }

    if (easingFunction == Ease.EaseOutQuint)
    {
    return EaseOutQuint;
    }

    if (easingFunction == Ease.EaseInOutQuint)
    {
    return EaseInOutQuint;
    }

    if (easingFunction == Ease.EaseInSine)
    {
    return EaseInSine;
    }

    if (easingFunction == Ease.EaseOutSine)
    {
    return EaseOutSine;
    }

    if (easingFunction == Ease.EaseInOutSine)
    {
    return EaseInOutSine;
    }

    if (easingFunction == Ease.EaseInExpo)
    {
    return EaseInExpo;
    }

    if (easingFunction == Ease.EaseOutExpo)
    {
    return EaseOutExpo;
    }

    if (easingFunction == Ease.EaseInOutExpo)
    {
    return EaseInOutExpo;
    }

    if (easingFunction == Ease.EaseInCirc)
    {
    return EaseInCirc;
    }

    if (easingFunction == Ease.EaseOutCirc)
    {
    return EaseOutCirc;
    }

    if (easingFunction == Ease.EaseInOutCirc)
    {
    return EaseInOutCirc;
    }

    if (easingFunction == Ease.Linear)
    {
    return Linear;
    }

    if (easingFunction == Ease.Spring)
    {
    return Spring;
    }

    if (easingFunction == Ease.EaseInBounce)
    {
    return EaseInBounce;
    }

    if (easingFunction == Ease.EaseOutBounce)
    {
    return EaseOutBounce;
    }

    if (easingFunction == Ease.EaseInOutBounce)
    {
    return EaseInOutBounce;
    }

    if (easingFunction == Ease.EaseInBack)
    {
    return EaseInBack;
    }

    if (easingFunction == Ease.EaseOutBack)
    {
    return EaseOutBack;
    }

    if (easingFunction == Ease.EaseInOutBack)
    {
    return EaseInOutBack;
    }

    if (easingFunction == Ease.EaseInElastic)
    {
    return EaseInElastic;
    }

    if (easingFunction == Ease.EaseOutElastic)
    {
    return EaseOutElastic;
    }

    if (easingFunction == Ease.EaseInOutElastic)
    {
    return EaseInOutElastic;
    }

    return null;
    }

    /// <summary>
    /// Gets the derivative function of the appropriate easing function. If you use an easing function for position then this
    /// function can get you the speed at a given time (normalized).
    /// </summary>
    /// <param name="easingFunction"></param>
    /// <returns>The derivative function</returns>
    public static Function GetEasingFunctionDerivative(Ease easingFunction)
    {
    if (easingFunction == Ease.EaseInQuad)
    {
    return EaseInQuadD;
    }

    if (easingFunction == Ease.EaseOutQuad)
    {
    return EaseOutQuadD;
    }

    if (easingFunction == Ease.EaseInOutQuad)
    {
    return EaseInOutQuadD;
    }

    if (easingFunction == Ease.EaseInCubic)
    {
    return EaseInCubicD;
    }

    if (easingFunction == Ease.EaseOutCubic)
    {
    return EaseOutCubicD;
    }

    if (easingFunction == Ease.EaseInOutCubic)
    {
    return EaseInOutCubicD;
    }

    if (easingFunction == Ease.EaseInQuart)
    {
    return EaseInQuartD;
    }

    if (easingFunction == Ease.EaseOutQuart)
    {
    return EaseOutQuartD;
    }

    if (easingFunction == Ease.EaseInOutQuart)
    {
    return EaseInOutQuartD;
    }

    if (easingFunction == Ease.EaseInQuint)
    {
    return EaseInQuintD;
    }

    if (easingFunction == Ease.EaseOutQuint)
    {
    return EaseOutQuintD;
    }

    if (easingFunction == Ease.EaseInOutQuint)
    {
    return EaseInOutQuintD;
    }

    if (easingFunction == Ease.EaseInSine)
    {
    return EaseInSineD;
    }

    if (easingFunction == Ease.EaseOutSine)
    {
    return EaseOutSineD;
    }

    if (easingFunction == Ease.EaseInOutSine)
    {
    return EaseInOutSineD;
    }

    if (easingFunction == Ease.EaseInExpo)
    {
    return EaseInExpoD;
    }

    if (easingFunction == Ease.EaseOutExpo)
    {
    return EaseOutExpoD;
    }

    if (easingFunction == Ease.EaseInOutExpo)
    {
    return EaseInOutExpoD;
    }

    if (easingFunction == Ease.EaseInCirc)
    {
    return EaseInCircD;
    }

    if (easingFunction == Ease.EaseOutCirc)
    {
    return EaseOutCircD;
    }

    if (easingFunction == Ease.EaseInOutCirc)
    {
    return EaseInOutCircD;
    }

    if (easingFunction == Ease.Linear)
    {
    return LinearD;
    }

    if (easingFunction == Ease.Spring)
    {
    return SpringD;
    }

    if (easingFunction == Ease.EaseInBounce)
    {
    return EaseInBounceD;
    }

    if (easingFunction == Ease.EaseOutBounce)
    {
    return EaseOutBounceD;
    }

    if (easingFunction == Ease.EaseInOutBounce)
    {
    return EaseInOutBounceD;
    }

    if (easingFunction == Ease.EaseInBack)
    {
    return EaseInBackD;
    }

    if (easingFunction == Ease.EaseOutBack)
    {
    return EaseOutBackD;
    }

    if (easingFunction == Ease.EaseInOutBack)
    {
    return EaseInOutBackD;
    }

    if (easingFunction == Ease.EaseInElastic)
    {
    return EaseInElasticD;
    }

    if (easingFunction == Ease.EaseOutElastic)
    {
    return EaseOutElasticD;
    }

    if (easingFunction == Ease.EaseInOutElastic)
    {
    return EaseInOutElasticD;
    }

    return null;
    }
    }