Unity Implementation of the 1€ filter for input smoothing

OneEuroExtensions.cs

using UnityEngine;
using System.Collections;

public struct FloatOneEuroData
{
    public float dx;
    public float edx;
    public float cutoff;
    public float filthatxprev;
    public float dfilthatxprev;
    public bool firstTime;
}
public struct V2OneEuroData
{
    public Vector2 dx;
    public Vector2 edx;
    public float cutoff;
    public Vector2 filthatxprev;
    public Vector2 dfilthatxprev;
    public bool firstTime;
}
public struct V3OneEuroData
{
    public Vector3 dx;
    public Vector3 edx;
    public float cutoff;
    public Vector3 filthatxprev;
    public Vector3 dfilthatxprev;
    public bool firstTime;
}

public static class OneEuroExtensions {

    public static Vector3 identity(this Vector3 v)
    {
        return v;
    }

    static float alpha(float rate, float cutoff)
    {
        float tau = 1 / (2 * Mathf.PI * cutoff);
        float te = 1 / rate;
        return 1 / (1 + tau / te);
    }

    public static float oneEuro(this float input, ref FloatOneEuroData euroData, float minCutoff = 1, float beta = 0.007f, float dCutoff = 1, float rate = 50)
    {
        if (euroData.firstTime)
        {
            euroData.dx = 0;
            euroData.filthatxprev = input;
            euroData.dfilthatxprev = 0;
            euroData.firstTime = false;
        }
        else
        {
            euroData.dx = (input - euroData.filthatxprev) * rate;
        }
        euroData.edx = euroData.dx.filter(alpha(rate, dCutoff), ref euroData.dfilthatxprev);
        euroData.cutoff = minCutoff + beta * Mathf.Abs(euroData.edx);
        return input.filter(alpha(rate, euroData.cutoff), ref euroData.filthatxprev);
    }
    public static Vector2 oneEuro(this Vector2 input, ref V2OneEuroData euroData, float minCutoff = 1, float beta = 0.007f, float dCutoff = 1, float rate = 50)
    {
        if (euroData.firstTime)
        {
            euroData.dx = Vector2.zero;
            euroData.filthatxprev = input;
            euroData.dfilthatxprev = Vector2.zero;
            euroData.firstTime = false;
        }
        else
        {
            euroData.dx = (input - euroData.filthatxprev) * rate;
        }
        euroData.edx = euroData.dx.filter(alpha(rate, dCutoff), ref euroData.dfilthatxprev);
        euroData.cutoff = minCutoff + beta * euroData.edx.magnitude;
        return input.filter(alpha(rate, euroData.cutoff), ref euroData.filthatxprev);
    }
    public static Vector3 oneEuro(this Vector3 input, ref V3OneEuroData euroData, float minCutoff = 1, float beta = 0.007f, float dCutoff = 1, float rate = 50)
    {
        if (euroData.firstTime)
        {
            euroData.dx = Vector3.zero;
            euroData.filthatxprev = input;
            euroData.dfilthatxprev = Vector3.zero;
            euroData.firstTime = false;
        }
        else
        {
            euroData.dx = (input - euroData.filthatxprev) * rate;
        }
        euroData.edx = euroData.dx.filter(alpha(rate, dCutoff), ref euroData.dfilthatxprev);
        euroData.cutoff = minCutoff + beta * euroData.edx.magnitude;
        return input.filter(alpha(rate, euroData.cutoff), ref euroData.filthatxprev);
    }

    static float filter(this float input, float alpha, ref float hatxprev)
    {
        float hatx = input * alpha + hatxprev * (1 - alpha);
        hatxprev = hatx;
        return hatx;
    }
    static Vector2 filter(this Vector2 input, float alpha, ref Vector2 hatxprev)
    {
        Vector2 hatx = input * alpha + hatxprev * (1 - alpha);
        hatxprev = hatx;
        return hatx;
    }
    static Vector3 filter(this Vector3 input, float alpha, ref Vector3 hatxprev)
    {
        Vector3 hatx = input * alpha + hatxprev * (1 - alpha);
        hatxprev = hatx;
        return hatx;
    }
	
}

Wobbly.cs

using UnityEngine;
using System.Collections;

public class Wobbly : MonoBehaviour {

    public GameObject go;
    V3OneEuroData euroData;

	// Use this for initialization
	void Start () {
        euroData.firstTime = true;
	}
	
	// Update is called once per frame
	void Update () {
        this.transform.position = go.transform.position.oneEuro(ref euroData);
	}
}