using UnityEngine;
using System.Collections;

public class CameraShaker : MonoBehaviour
{
    public static void AddShake(float amount)
    {
        shake += amount;
    }

    static float shake = 0;
    public static float Shake
    {
        get { return CameraShaker.shake; }
        set { CameraShaker.shake = value; }
    }

    float MaxShake = 10;
    float LinearShakeAmount = 0.066f;
    float ShakeStrength = 10;
    float lerpAmount = 1;
    float shakeBleed = 4;

    Vector3 restingPosition;

    void Start()
    {
        restingPosition = transform.position;
    }

    void Update ()
    {
        Shake -= Time.deltaTime * shakeBleed;
        Shake = Mathf.Max(Shake, 0);
        Shake = Mathf.Min(Shake, MaxShake);
        Vector3 newPos = transform.position;
        float applyShake = Mathf.Log(Shake) + Shake * LinearShakeAmount;
        if (Shake > 0)
        {
            newPos += new Vector3(
                Random.Range(-applyShake * ShakeStrength, applyShake * ShakeStrength),
                Random.Range(-applyShake * ShakeStrength, applyShake * ShakeStrength),
                0);
        }
        transform.position = Vector3.Lerp(restingPosition, newPos,
            Time.deltaTime * Shake * lerpAmount);
    }
}