CrowdControl/Assets/Feel/MMTools/Tools/MMMovement/MMAutoRotate.cs

using UnityEngine;
using System.Collections;

namespace MoreMountains.Tools
{
	/// <summary>
	/// Add this class to a GameObject to make it rotate on itself
	/// </summary>
	[AddComponentMenu("More Mountains/Tools/Movement/MMAutoRotate")]
	public class MMAutoRotate : MonoBehaviour
	{
		public enum UpdateModes { Update, LateUpdate, FixedUpdate }

		[Header("Rotation")]
		/// whether or not this object should be rotating right now
		public bool Rotating = true;
		[MMCondition("Rotating", true)]
		/// the space to apply the rotation in
		public Space RotationSpace = Space.Self;
		/// whether movement should happen at Update, FixedUpdate or LateUpdate
		public UpdateModes UpdateMode = UpdateModes.Update;
		[MMCondition("Rotating", true)]
		/// The rotation speed. Positive means clockwise, negative means counter clockwise.
		public Vector3 RotationSpeed = new Vector3(100f, 0f, 0f);

		[Header("Orbit")]
		/// if this is true, the object will also move around a pivot (only the position is affected, not the rotation)
		public bool Orbiting = false;
		[MMCondition("Orbiting", true)]
		/// if this is true, the orbit plane will rotate along with the parent
		public bool AdditiveOrbitRotation = false;
		/// the pivot to rotate around (if left blank, will be the object itself
		[MMCondition("Orbiting", true)]
		public Transform OrbitCenterTransform;
		/// the pivot (relative to the object's position in local space) to rotate around
		[MMCondition("Orbiting", true)]
		public Vector3 OrbitCenterOffset = Vector3.zero;
		/// the axis around which the object should rotate (don't make it zero)
		[MMCondition("Orbiting", true)]
		public Vector3 OrbitRotationAxis = new Vector3(0f, 1f, 0f);
		/// the speed at which to rotate
		[MMCondition("Orbiting", true)]
		public float OrbitRotationSpeed = 10f;
		/// the radius at which to orbit
		[MMCondition("Orbiting", true)]
		public float OrbitRadius = 3f;
		/// the speed at which the object catches up when orbit radius or axis changes
		[MMCondition("Orbiting", true)]
		public float OrbitCorrectionSpeed = 10f;

		[Header("Settings")]
		/// if this is true, will draw gizmos to show the plane, orbit and direction
		public bool DrawGizmos = true;
		[MMCondition("DrawGizmos", true)]
		/// the color of the orbit disc
		public Color OrbitPlaneColor = new Color(54f, 169f, 225f, 0.02f);
		[MMCondition("DrawGizmos", true)]
		/// the color of the orbit line
		public Color OrbitLineColor = new Color(225f, 225f, 225f, 0.1f);
        
		[HideInInspector]
		public Vector3 _orbitCenter;
		[HideInInspector]
		public Vector3 _worldRotationAxis;
		[HideInInspector]
		public Plane _rotationPlane;
		[HideInInspector]
		public Vector3 _snappedPosition;
		[HideInInspector]
		public Vector3 _radius;

		protected Quaternion _newRotation;
		protected Vector3 _desiredOrbitPosition;
		private Vector3 _previousPosition;

		/// <summary>
		/// On start, we initialize our plane
		/// </summary>
		protected virtual void Start()
		{
			_rotationPlane = new Plane();
		}

		/// <summary>
		/// Makes the object rotate on its center at Update 
		/// </summary>
		protected virtual void Update()
		{
			if (UpdateMode == UpdateModes.Update)
			{
				Rotate();
			}
		}
        
		/// <summary>
		/// Makes the object rotate on its center at FixedUpdate
		/// </summary>
		protected virtual void FixedUpdate()
		{
			if (UpdateMode == UpdateModes.FixedUpdate)
			{
				Rotate();
			}
		}
        
		/// <summary>
		/// Makes the object rotate on its center at LateUpdate
		/// </summary>
		protected virtual void LateUpdate()
		{
			if (UpdateMode == UpdateModes.LateUpdate)
			{
				Rotate();
			}
		}

		/// <summary>
		/// Sets Rotating to true or false
		/// </summary>
		/// <param name="status"></param>
		public virtual void Rotate(bool status)
		{
			Rotating = status;
		}

		/// <summary>
		/// Sets Orbiting to true or false
		/// </summary>
		/// <param name="status"></param>
		public virtual void Orbit(bool status)
		{
			Orbiting = status;
		}

		/// <summary>
		/// Rotates the object
		/// </summary>
		protected virtual void Rotate()
		{
			if (Rotating)
			{
				transform.Rotate(RotationSpeed * Time.deltaTime, RotationSpace);
			}

			if (Orbiting)
			{
				_orbitCenter = OrbitCenterTransform.transform.position + OrbitCenterOffset;
				if (AdditiveOrbitRotation)
				{
					_worldRotationAxis = OrbitCenterTransform.TransformDirection(OrbitRotationAxis);
				}
				else
				{
					_worldRotationAxis = OrbitRotationAxis;
				}
				_rotationPlane.SetNormalAndPosition(_worldRotationAxis.normalized, _orbitCenter);
				_snappedPosition = _rotationPlane.ClosestPointOnPlane(this.transform.position);
				_radius = OrbitRadius * Vector3.Normalize(_snappedPosition - _orbitCenter);
				_newRotation = Quaternion.AngleAxis(OrbitRotationSpeed * Time.deltaTime, _worldRotationAxis);
				_desiredOrbitPosition = _orbitCenter + _newRotation * _radius;
				this.transform.position = Vector3.Lerp(this.transform.position, _desiredOrbitPosition, OrbitCorrectionSpeed * Time.deltaTime);
				_previousPosition = _desiredOrbitPosition;
			}
		}
	}
}