// This makes the character turn to face the current movement speed per default.
var autoRotate : boolean = true;
var maxRotationSpeed : float = 360;

private var motor : CharacterMotor;

// Use this for initialization
function Awake () {
  motor = GetComponent(CharacterMotor);
}

// Update is called once per frame
function Update () {
  // Get the input vector from kayboard or analog stick
  var directionVector = new Vector3(Input.GetAxis("Horizontal"), 0, 0);
   
  if (directionVector != Vector3.zero) {
   // Get the length of the directon vector and then normalize it
   // Dividing by the length is cheaper than normalizing when we already have the length anyway
   var directionLength = directionVector.magnitude;
   directionVector = directionVector / directionLength;
    
   // Make sure the length is no bigger than 1
   directionLength = Mathf.Min(1, directionLength);
    
   // Make the input vector more sensitive towards the extremes and less sensitive in the middle
   // This makes it easier to control slow speeds when using analog sticks
   directionLength = directionLength * directionLength;
    
   // Multiply the normalized direction vector by the modified length
   directionVector = directionVector * directionLength;
  }
   
  // Rotate the input vector into camera space so up is camera's up and right is camera's right
  directionVector = Camera.main.transform.rotation * directionVector;
   
  // Rotate input vector to be perpendicular to character's up vector
  var camToCharacterSpace = Quaternion.FromToRotation(-Camera.main.transform.forward, transform.up);
  directionVector = (camToCharacterSpace * directionVector);
   
  // Apply the direction to the CharacterMotor
  motor.inputMoveDirection = directionVector;
  motor.inputJump = Input.GetButton("Jump");
   
  // Set rotation to the move direction  
  if (autoRotate && directionVector.sqrMagnitude > 0.01) {
   var newForward : Vector3 = ConstantSlerp(
    transform.forward,
    directionVector,
    maxRotationSpeed * Time.deltaTime
   );
   newForward = ProjectOntoPlane(newForward, transform.up);
   transform.rotation = Quaternion.LookRotation(newForward, transform.up);
  }
}

function ProjectOntoPlane (v : Vector3, normal : Vector3) {
  return v - Vector3.Project(v, normal);
}

function ConstantSlerp (from : Vector3, to : Vector3, angle : float) {
  var value : float = Mathf.Min(1, angle / Vector3.Angle(from, to));
  return Vector3.Slerp(from, to, value);
}

// Require a cracter controller to be attached to the same game object
@script RequireComponent (CharacterMotor)
@script AddComponentMenu ("Character/Platform Input Controller")