ScreenShake.cs

// ScreenShake.cs
// Last edited 5:35 PM 04/21/2015 by Aaron Freedman

using Assets.PrototypingKit.Patterns;
using UnityEngine;

namespace Assets.PrototypingKit
{
    public class ScreenShake : Singleton<ScreenShake>
    {
        private float activeTime;
        private Transform camPos;
        private float intensity;
        private Vector3 originalPosition;
        public bool shake;
        public bool useLerp;
        private float startTime;
        private Vector3 target;

        //TODO: this screenshake method doesn't work for movable cameras attached to an object

        private void Start()
        {
            originalPosition = Camera.main.gameObject.transform.position;
            camPos = GetComponent<Camera>().gameObject.transform;
            target = originalPosition;
            shake = false;
        }

        private void Update()
        {
            if (shake)
            {
                if (Time.time > startTime + activeTime)
                {
                    StopShake();
                }
                else
                {
                    Shake();
                }
            }

            camPos.position = useLerp ? Vector3.Lerp(camPos.position, target, 10 * Time.deltaTime) : target;
        }

        public void Shake()
        {
            target = new Vector3(originalPosition.x + Random.Range(-intensity, intensity),
                                 originalPosition.y + Random.Range(-intensity, intensity), originalPosition.z);
        }

        public void StartShake(float time, float _intensity)
        {
            shake = true;
            activeTime = time;
            startTime = Time.time;
            intensity = _intensity;
        }

        public void StopShake()
        {
            ResetPosition();
        }

        public void ResetPosition()
        {
            target = originalPosition;
        }
    }
}