﻿using UnityEngine;
using System.Collections;
[AddComponentMenu("Camera/Simple Smooth Mouse Look ")]
public class SmoothLookAt : MonoBehaviour {

	Vector2 _mouseAbsolute;
	Vector2 _smoothMouse;
	
	public Vector2 clampInDegrees = new Vector2(360, 180);
	public bool lockCursor;
	public Vector2 sensitivity = new Vector2(2, 2);
	public Vector2 smoothing = new Vector2(3, 3);
	public Vector2 targetDirection;
	public Vector2 targetCharacterDirection;
	
	// Assign this if there's a parent object controlling motion, such as a Character Controller.
	// Yaw rotation will affect this object instead of the camera if set.
	public GameObject characterBody;
	
	void Start()
	{
		// Set target direction to the camera's initial orientation.
		targetDirection = transform.localRotation.eulerAngles;
		
		// Set target direction for the character body to its inital state.
		if (characterBody) targetCharacterDirection = characterBody.transform.localRotation.eulerAngles;
	}
	
	void Update()
	{
		// Ensure the cursor is always locked when set
		Screen.lockCursor = lockCursor;
		
		// Allow the script to clamp based on a desired target value.
		var targetOrientation = Quaternion.Euler(targetDirection);
		var targetCharacterOrientation = Quaternion.Euler(targetCharacterDirection);
		
		// Get raw mouse input for a cleaner reading on more sensitive mice.
		var mouseDelta = new Vector2(Input.GetAxisRaw("Mouse X"), Input.GetAxisRaw("Mouse Y"));
		
		// Scale input against the sensitivity setting and multiply that against the smoothing value.
		mouseDelta = Vector2.Scale(mouseDelta, new Vector2(sensitivity.x * smoothing.x, sensitivity.y * smoothing.y));
		
		// Interpolate mouse movement over time to apply smoothing delta.
		_smoothMouse.x = Mathf.Lerp(_smoothMouse.x, mouseDelta.x, 1f / smoothing.x);
		_smoothMouse.y = Mathf.Lerp(_smoothMouse.y, mouseDelta.y, 1f / smoothing.y);
		
		// Find the absolute mouse movement value from point zero.
		_mouseAbsolute += _smoothMouse;
		
		// Clamp and apply the local x value first, so as not to be affected by world transforms.
		if (clampInDegrees.x < 360)
			_mouseAbsolute.x = Mathf.Clamp(_mouseAbsolute.x, -clampInDegrees.x * 0.5f, clampInDegrees.x * 0.5f);
		
		var xRotation = Quaternion.AngleAxis(-_mouseAbsolute.y, targetOrientation * Vector3.right);
		transform.localRotation = xRotation;
		
		// Then clamp and apply the global y value.
		if (clampInDegrees.y < 360)
			_mouseAbsolute.y = Mathf.Clamp(_mouseAbsolute.y, -clampInDegrees.y * 0.5f, clampInDegrees.y * 0.5f);
		
		transform.localRotation *= targetOrientation;
		
		// If there's a character body that acts as a parent to the camera
		if (characterBody)
		{
			var yRotation = Quaternion.AngleAxis(_mouseAbsolute.x, characterBody.transform.up);
			characterBody.transform.localRotation = yRotation;
			characterBody.transform.localRotation *= targetCharacterOrientation;
		}
		else
		{
			var yRotation = Quaternion.AngleAxis(_mouseAbsolute.x, transform.InverseTransformDirection(Vector3.up));
			transform.localRotation *= yRotation;
		}
	}
}
