Degree from point?

Questions & Answers
1

I want to calculate the degree of a touch location away from the centre of my screen. Currently I have this code:

var myVector : Vector3; 
var myAngle : float;    

    function Update () {
        if ( iPhoneInput.touchCount > 0 ){
            for(var touch : iPhoneTouch in iPhoneInput.touches) { 
                    myVector = new Vector3(240, 160, 0);
                    myAngle = Vector3.Angle(myVector, touch.position);  
            }
        } 
    }

The problem is that it doesn't really work. The degree's it comes up with are wrong and even if you do a full 360 loop around the point it doesn't exceed 50 at any point, does anyone have any idea why?

3

Daniel's answer is technically correct but will only give you 0-180 degrees.

If you want an angle that goes from -180-180 (i.e a full circle), you can use `atan2`.

I.e.

var myAngle : float;

function Update () {
    var midScreenPoint = new Vector2 (Screen.width * 0.5, Screen.height * 0.5);
    var dir = Vector3.Normalize (Input.mousePosition - midScreenPoint);
    myAngle = Mathf.Atan2( dir.y, dir.x ); // myAngle is in radians
}
2

How's this work for you?

var myAngle : float;

function Update () {
    var midScreenPoint = new Vector2 (Screen.width * 0.5, Screen.height * 0.5);
    var dir = Vector3.Normalize (Input.mousePosition - midScreenPoint);
    myAngle = Vector3.Angle (Vector3.up, dir);
}