ScreenShake

using UnityEngine;
using System.Collections;

// based on http://unitytipsandtricks.blogspot.com/2013/05/camera-shake.html
public class CameraShake : MonoBehaviour
{
    public float duration = 2f;
    public float speed = 20f;
    public float magnitude = 2f;
    public AnimationCurve damper = new AnimationCurve(new Keyframe(0f, 1f), new Keyframe(0.9f, .33f, -2f, -2f), new Keyframe(1f, 0f, -5.65f, -5.65f));
    public bool testPosition = false;
    public bool shake = false;
    public bool testProjection = false;

    Vector3 originalPos;
    Quaternion originalRot;
    CameraScript mainCamera;


    void OnEnable()
    {
        if (originalPos == Vector3.zero )
        {

        }
        mainCamera = GetComponent<CameraScript>();
        originalPos = transform.localPosition;
        originalRot = transform.localRotation;
    }


    void Update()
    {
        if (shake)
        {
            shake = false;
            StopAllCoroutines();
            StartCoroutine(ShakeRotation(transform, originalRot, duration, speed, magnitude, damper));
        }
    }

    public void Shake(float duration, float speed, float magnitude)
    {
        StopAllCoroutines();
        StartCoroutine(ShakeRotation(transform, originalRot, duration, speed, magnitude, damper));
    }

    public void ShakeAnimation(float duration, float speed, float magnitude)
    {
        StopAllCoroutines();
        StartCoroutine(ShakeRotationAnimation(transform, originalRot, duration, speed, magnitude, damper));
    }

    IEnumerator ShakePosition(Transform transform, Vector3 originalPosition, float duration, float speed, float magnitude, AnimationCurve damper = null)
    {
        float elapsed = 0f;
        while (elapsed < duration)
        {
            elapsed += Time.deltaTime;
            float damperedMag = (damper != null) ? (damper.Evaluate(elapsed / duration) * magnitude) : magnitude;
            float x = (Mathf.PerlinNoise(Time.time * speed, 0f) * damperedMag) - (damperedMag / 2f);
            float y = (Mathf.PerlinNoise(0f, Time.time * speed) * damperedMag) - (damperedMag / 2f);
            transform.localPosition = new Vector3(originalPosition.x + x, originalPosition.y + y, originalPosition.z);
            yield return null;
        }
        transform.localPosition = originalPosition;
    }


    IEnumerator ShakeRotation(Transform transform, Quaternion originalRotation, float duration, float speed, float magnitude, AnimationCurve damper = null)
    {
        Vector3 originalEuler = mainCamera.rot.eulerAngles;
        float elapsed = 0f;
        while (elapsed < duration)
        {
            originalEuler = mainCamera.rot.eulerAngles;
            elapsed += Time.deltaTime;
            float damperedMag = (damper != null) ? (damper.Evaluate(elapsed / duration) * magnitude) : magnitude;
            float x = (Mathf.PerlinNoise(Time.time * speed, 0f) * damperedMag) - (damperedMag / 2f);
            float y = (Mathf.PerlinNoise(0f, Time.time * speed) * damperedMag) - (damperedMag / 2f);
            float z = (Mathf.PerlinNoise(0.5f, Time.time * speed * 0.5f) * damperedMag) - (damperedMag / 2f);
            transform.localRotation = Quaternion.Euler(new Vector3(originalEuler.x + x, originalEuler.y + y, originalEuler.z + z));
            yield return null;
        }
        transform.localRotation = mainCamera.rot;
    }

    IEnumerator ShakeRotationAnimation(Transform transform, Quaternion originalRotation, float duration, float speed, float magnitude, AnimationCurve damper = null)
    {
        Vector3 originalEuler = mainCamera.transform.rotation.eulerAngles;
        float elapsed = 0f;
        while (elapsed < duration)
        {
            originalEuler = mainCamera.transform.rotation.eulerAngles;
            elapsed += Time.deltaTime;
            float damperedMag = (damper != null) ? (damper.Evaluate(elapsed / duration) * magnitude) : magnitude;
            float x = (Mathf.PerlinNoise(Time.time * speed, 0f) * damperedMag) - (damperedMag / 2f);
            float y = (Mathf.PerlinNoise(0f, Time.time * speed) * damperedMag) - (damperedMag / 2f);
            float z = (Mathf.PerlinNoise(0.5f, Time.time * speed * 0.5f) * damperedMag) - (damperedMag / 2f);
            transform.localRotation = Quaternion.Euler(new Vector3(originalEuler.x + x, originalEuler.y + y, originalEuler.z + z));
            yield return null;
        }
        transform.localRotation = mainCamera.rot;
    }


    IEnumerator ShakeCameraProjection(Camera camera, float duration, float speed, float magnitude, AnimationCurve damper = null)
    {
        float elapsed = 0f;
        while (elapsed < duration)
        {
            elapsed += Time.deltaTime;
            float damperedMag = (damper != null) ? (damper.Evaluate(elapsed / duration) * magnitude) : magnitude;
            float x = (Mathf.PerlinNoise(Time.time * speed, 0f) * damperedMag) - (damperedMag / 2f);
            float y = (Mathf.PerlinNoise(0f, Time.time * speed) * damperedMag) - (damperedMag / 2f);
            // offset camera obliqueness - http://answers.unity3d.com/questions/774164/is-it-possible-to-shake-the-screen-rather-than-sha.html
            float frustrumHeight = 2 * camera.nearClipPlane * Mathf.Tan(camera.fieldOfView * 0.5f * Mathf.Deg2Rad);
            float frustrumWidth = frustrumHeight * camera.aspect;
            Matrix4x4 mat = camera.projectionMatrix;
            mat[0, 2] = 2 * x / frustrumWidth;
            mat[1, 2] = 2 * y / frustrumHeight;
            camera.projectionMatrix = mat;
            yield return null;
        }
        camera.ResetProjectionMatrix();
    }

}