Rotate 2D Texture negative positive degrees touch

Hello,

I am working on a kind of wheel which you can rotate 360 degrees with your fingers. The positive degrees are working nicely. But the problem is, how can i make it, so when your finger goes to the left, the degrees goes negative?

Thanks in advance, Flux

Code:

 public var texture : Texture2D = null; 
 public var size : Vector2 = new Vector2(128, 128); 
 
 private var angle : float = 0; 
 private var pos : Vector2 = new Vector2(0, 0); 
 private var rect : Rect; 
 private var pivot : Vector2; 
 private var rotating : boolean = false; 
 private var initialMouseAngle : float; 
 
 function Start() { 
     UpdateSettings(); 
 } 
 
 function UpdateSettings() { 
    pos = new Vector2(180, Screen.height - texture.height + 350); 
    rect = new Rect(pos.x - size.x * 0.5f, pos.y - size.y * 0.5f, size.x, size.y); 
    pivot = new Vector2(rect.xMin + rect.width * 0.5f, rect.yMin + rect.height * 0.5f);
 } 
 
 function OnGUI() { 
    if (Application.isEditor) { UpdateSettings(); } 
     
     
    if(Input.touchCount > 0) {  
         var touch : Touch = Input.GetTouch(0); 
         var guiMouse : Vector2 = Vector2(touch.position.x, touch.position.y); 
         guiMouse.y = Screen.height - guiMouse.y; 
          
         if ((touch.phase == TouchPhase.Began) && rect.Contains(guiMouse)) { 
          var v2T : Vector2 = (guiMouse - pivot); 
          initialMouseAngle = Mathf.Atan2(v2T.y, v2T.x) - angle * Mathf.Deg2Rad; 
          rotating = true; 
         }
         else if ((touch.phase == TouchPhase.Moved) & rotating) { 
          var v2T2 : Vector2 = (guiMouse - pivot); 
          angle = (Mathf.Atan2 (v2T2.y, v2T2.x) - initialMouseAngle)  * Mathf.Rad2Deg;     
          if(angle < 0) {
             angle += 360;  
              Debug.Log(angle);
          }
         } 
         else if ((touch.phase == TouchPhase.Ended)) { 
          rotating = false; 
          angle = 0; 
         }
    } 
     
     angle = Mathf.Clamp(angle, -360, 360);
     GUI.Label(Rect(100, 30, 100, 30), angle.ToString());
     
     var matrixBackup : Matrix4x4 = GUI.matrix; 
     GUIUtility.RotateAroundPivot(angle, pivot); 
     GUI.DrawTexture(rect, texture); 
     GUI.matrix = matrixBackup; 
 }