Merge pull request phaserjs#150 from beeglebug/master

added getMagnitude, setMagnitude, normalize and isZero methods to Point

Author: photonstorm

src/geom/Point.js

@@ -215,9 +215,7 @@ Phaser.Point.prototype = {
     * @return {number} The distance between this Point object and the destination Point object.
     */
     distance: function (dest, round) {
-
         return Phaser.Point.distance(this, dest, round);
-        
     },
 
     /**
@@ -244,6 +242,51 @@ Phaser.Point.prototype = {
         return Phaser.Point.rotate(this, x, y, angle, asDegrees, distance);
     },
 
+    /**
+     * Calculates the length of the vector
+     * @method Phaser.Point#getMagnitude
+     * @return {number} the length of the vector
+     */
+    getMagnitude: function() {
+        return Math.sqrt((this.x * this.x) + (this.y * this.y));
+    },
+
+    /**
+     * Alters the length of the vector without changing the direction
+     * @method Phaser.Point#getMagnitude
+     * @param {number} magnitude the desired magnitude of the resulting vector
+     * @return {Phaser.Point} the modified original vector
+     */
+    setMagnitude: function(magnitude) {
+        return this.normalize().multiply(magnitude, magnitude);
+    },
+
+    /**
+     * Alters the vector so that its length is 1, but it retains the same direction
+     * @method Phaser.Point#normalize
+     * @return {Phaser.Point} the modified original vector
+     */
+    normalize: function() {
+
+        if(!this.isZero()) {
+            var m = this.getMagnitude();
+            this.x /= m;
+            this.y /= m;
+        }
+
+        return this;
+
+    },
+
+    /**
+     * Determine if this point is at 0,0
+     * @method Phaser.Point#isZero
+     * @return {boolean} True if this Point is 0,0, otherwise false
+     */
+    isZero: function() {
+        return (this.x === 0 && this.y === 0);
+    },
+
     /**
     * Returns a string representation of this object.
     * @method Phaser.Point#toString