差值算法

原文链接：https://blog.csdn.net/cartzhang/article/details/50680237

插值

第一考虑的就是插值。 
插值，内插和外推插值。插值算法，有多种，5点，7点，二次插值等，不一一列举。 
游戏的帧率在DK2上75fps,这帧率插值，需要至少有2秒数据，再加上硬件数据的抖动，个人觉得这不算是个好的方案。

缓动函数

在ITween中有个缓动曲线函数。 
这个不错啊！我们来细说下。

1.先看看各种函数都长啥样？

截图： 

2.网址介绍

相关网址啊： 
http://easings.net/zh-cn#

说明网址上的各个图都是可以点开，动态的哦。

http://robertpenner.com/easing/easing_demo.html 
这个也是可以看看每个曲线的样子。真是方便啊！！

 

3.在看看所有曲线种类。

可以在ITween中找到EaseType.

    /// 

    /// The type of easing to use based on Robert Penner's open source easing equations (http://www.robertpenner.com/easing_terms_of_use.html).
    /// 
    public enum EaseType{
        easeInQuad,
        easeOutQuad,
        easeInOutQuad,
        easeInCubic,
        easeOutCubic,
        easeInOutCubic,
        easeInQuart,
        easeOutQuart,
        easeInOutQuart,
        easeInQuint,
        easeOutQuint,
        easeInOutQuint,
        easeInSine,
        easeOutSine,
        easeInOutSine,
        easeInExpo,
        easeOutExpo,
        easeInOutExpo,
        easeInCirc,
        easeOutCirc,
        easeInOutCirc,
        linear,
        spring,
        /* GFX47 MOD START */
        //bounce,
        easeInBounce,
        easeOutBounce,
        easeInOutBounce,
        /* GFX47 MOD END */
        easeInBack,
        easeOutBack,
        easeInOutBack,
        /* GFX47 MOD START */
        //elastic,
        easeInElastic,
        easeOutElastic,
        easeInOutElastic,
        /* GFX47 MOD END */
        punch
    }

•  

根据需要各区所需啊！！不一定要全部都带上。

4. 函数代码：

ITween中这个代码比较长，代码中更多的是算法。 
代码在ITween.cs中，就不一一贴上来。

缓动曲线代码

我需要的只有这些曲线，其他的不需要，就摘了出来，写成了静态函数，这样方便在需要时候直接调用。

/**************************************************************************
Copyright:@cartzhang
Author: cartzhang
Date:
Description:
**************************************************************************/
using UnityEngine;
using System.Collections;

public enum EaseType:int
{
    easeInQuad,
    //easeOutQuad,
    easeInOutQuad,
    easeInCubic,
    //easeOutCubic,
    easeInOutCubic,
    easeInQuart,
    //easeOutQuart,
    easeInOutQuart,
    easeInQuint,
    //easeOutQuint,
    easeInOutQuint,
    //easeInSine,
    //easeOutSine,
    //easeInOutSine,
    easeInExpo,
    //easeOutExpo,
    easeInOutExpo,
    //easeInCirc,
    //easeOutCirc,
    easeInOutCirc,
    //linear,
    //spring,
    ///* GFX47 MOD START */
    bounce,
    //easeInBounce,
    //easeOutBounce,
    //easeInOutBounce,
    ///* GFX47 MOD END */
    //easeInBack,
    //easeOutBack,
    //easeInOutBack,
    ///* GFX47 MOD START */
    elastic,
    //easeInElastic,
    //easeOutElastic,
    //easeInOutElastic,
    ///* GFX47 MOD END */
    //punch
}

public class DataAlgorithm
{

    #region Easing Curves

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

    public static float clerp(float start, float end, float value)
    {
        float min = 0.0f;
        float max = 360.0f;
        float half = Mathf.Abs((max - min) / 2.0f);
        float retval = 0.0f;
        float diff = 0.0f;
        if ((end - start) < -half)
        {
            diff = ((max - start) + end) * value;
            retval = start + diff;
        }
        else if ((end - start) > half)
        {
            diff = -((max - end) + start) * value;
            retval = start + diff;
        }
        else retval = start + (end - start) * value;
        return retval;
    }

    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 / 2 * value * value + start;
        value--;
        return -end / 2 * (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 / 2 * value * value * value + start;
        value -= 2;
        return end / 2 * (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 / 2 * value * value * value * value + start;
        value -= 2;
        return -end / 2 * (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 / 2 * value * value * value * value * value + start;
        value -= 2;
        return end / 2 * (value * value * value * value * value + 2) + start;
    }

    public static float easeInSine(float start, float end, float value)
    {
        end -= start;
        return -end * Mathf.Cos(value / 1 * (Mathf.PI / 2)) + end + start;
    }

    public static float easeOutSine(float start, float end, float value)
    {
        end -= start;
        return end * Mathf.Sin(value / 1 * (Mathf.PI / 2)) + start;
    }

    public static float easeInOutSine(float start, float end, float value)
    {
        end -= start;
        return -end / 2 * (Mathf.Cos(Mathf.PI * value / 1) - 1) + start;
    }

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

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

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

    /* GFX47 MOD START */
    public static float easeInBounce(float start, float end, float value)
    {
        end -= start;
        float d = 1f;
        return end - easeOutBounce(0, end, d - value) + start;
    }
    /* GFX47 MOD END */

    /* GFX47 MOD START */
    //public static float bounce(float start, float end, float value){
    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;
        }
    }
    /* GFX47 MOD END */

    /* GFX47 MOD START */
    public static float easeInOutBounce(float start, float end, float value)
    {
        end -= start;
        float d = 1f;
        if (value < d / 2) return easeInBounce(0, end, value * 2) * 0.5f + start;
        else return easeOutBounce(0, end, value * 2 - d) * 0.5f + end * 0.5f + start;
    }
    /* GFX47 MOD END */

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

    public static float punch(float amplitude, float value)
    {
        float s = 9;
        if (value == 0)
        {
            return 0;
        }
        if (value == 1)
        {
            return 0;
        }
        float period = 1 * 0.3f;
        s = period / (2 * Mathf.PI) * Mathf.Asin(0);
        return (amplitude * Mathf.Pow(2, -10 * value) * Mathf.Sin((value * 1 - s) * (2 * Mathf.PI) / period));
    }

    /* GFX47 MOD START */
    public static float easeInElastic(float start, float end, float value)
    {
        end -= start;

        float d = 1f;
        float p = d * .3f;
        float s = 0;
        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;
    }
    /* GFX47 MOD END */

    /* GFX47 MOD START */
    //public static float elastic(float start, float end, float value){
    public static float easeOutElastic(float start, float end, float value)
    {
        /* GFX47 MOD END */
        //Thank you to rafael.marteleto for fixing this as a port over from Pedro's UnityTween
        end -= start;

        float d = 1f;
        float p = d * .3f;
        float s = 0;
        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) * Mathf.Sin((value * d - s) * (2 * Mathf.PI) / p) + end + start);
    }

    /* GFX47 MOD START */
    public static float easeInOutElastic(float start, float end, float value)
    {
        end -= start;

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

        if (value == 0) return start;

        if ((value /= d / 2) == 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;
    }
    /* GFX47 MOD END */

    #endregion

}