Added Vector2.angle method

Author: photonstorm

v3/src/math/Vector2.js

@@ -50,6 +50,20 @@ var Vector2 = new Class({
         return this;
     },
 
+    angle: function () {
+
+        // computes the angle in radians with respect to the positive x-axis
+
+        var angle = Math.atan2(this.y, this.x);
+
+        if (angle < 0)
+        {
+            angle += 2 * Math.PI;
+        }
+
+        return angle;
+    },
+
     add: function (src)
     {
         this.x += src.x;