Merge pull request phaserjs#5092 from samme/feature/Vector2-methods

Add Phaser.Math.Vector2 methods

Author: photonstorm

src/math/Vector2.js

@@ -8,6 +8,7 @@
 //  and [vecmath](https://github.com/mattdesl/vecmath) by mattdesl
 
 var Class = require('../utils/Class');
+var FuzzyEqual = require('../math/fuzzy/Equal');
 
 /**
  * @classdesc
@@ -187,6 +188,22 @@ var Vector2 = new Class({
         return ((this.x === v.x) && (this.y === v.y));
     },
 
+    /**
+     * Check whether this Vector is approximately equal to a given Vector.
+     *
+     * @method Phaser.Math.Vector2#fuzzyEquals
+     * @since 3.23.0
+     *
+     * @param {Phaser.Math.Vector2} v - The vector to compare with this Vector.
+     * @param {number} [epsilon=0.0001] - The tolerance value.
+     *
+     * @return {boolean} Whether both absolute differences of the x and y components are smaller than `epsilon`.
+     */
+    fuzzyEquals: function (v, epsilon)
+    {
+        return (FuzzyEqual(this.x, v.x, epsilon) && FuzzyEqual(this.y, v.y, epsilon));
+    },
+
     /**
      * Calculate the angle between this Vector and the positive x-axis, in radians.
      *
@@ -209,6 +226,21 @@ var Vector2 = new Class({
         return angle;
     },
 
+    /**
+     * Set the angle of this Vector.
+     *
+     * @method Phaser.Math.Vector2#setAngle
+     * @since 3.23.0
+     *
+     * @param {number} angle - The angle, in radians.
+     *
+     * @return {Phaser.Math.Vector2} This Vector2.
+     */
+    setAngle: function (angle)
+    {
+        return this.setToPolar(angle, this.length());
+    },
+
     /**
      * Add a given Vector to this Vector. Addition is component-wise.
      *
@@ -379,6 +411,21 @@ var Vector2 = new Class({
         return Math.sqrt(x * x + y * y);
     },
 
+    /**
+     * Set the length (or magnitude) of this Vector.
+     *
+     * @method Phaser.Math.Vector2#setLength
+     * @since 3.23.0
+     *
+     * @param {number} length
+     *
+     * @return {Phaser.Math.Vector2} This Vector2.
+     */
+    setLength: function (length)
+    {
+        return this.normalize().scale(length);
+    },
+
     /**
      * Calculate the length of this Vector squared.
      *
@@ -440,6 +487,24 @@ var Vector2 = new Class({
         return this;
     },
 
+    /**
+     * Rotate this Vector to its perpendicular, in the negative direction.
+     *
+     * @method Phaser.Math.Vector2#normalizeLeftHand
+     * @since 3.23.0
+     *
+     * @return {Phaser.Math.Vector2} This Vector2.
+     */
+    normalizeLeftHand: function ()
+    {
+        var x = this.x;
+
+        this.x = this.y;
+        this.y = x * -1;
+
+        return this;
+    },
+
     /**
      * Calculate the dot product of this Vector and the given Vector.
      *
@@ -554,6 +619,78 @@ var Vector2 = new Class({
         this.y = 0;
 
         return this;
+    },
+
+    /**
+     * Limit the length (or magnitude) of this Vector.
+     *
+     * @method Phaser.Math.Vector2#limit
+     * @since 3.23.0
+     *
+     * @param {number} max - The maximum length.
+     *
+     * @return {Phaser.Math.Vector2} This Vector2.
+     */
+    limit: function (max)
+    {
+        var len = this.length();
+
+        if (len && len > max)
+        {
+            this.scale(max / len);
+        }
+
+        return this;
+    },
+
+    /**
+     * Reflect this Vector off a line defined by a normal.
+     *
+     * @method Phaser.Math.Vector2#reflect
+     * @since 3.23.0
+     *
+     * @param {Phaser.Math.Vector2} normal - A vector perpendicular to the line.
+     *
+     * @return {Phaser.Math.Vector2} This Vector2.
+     */
+    reflect: function (normal)
+    {
+        normal = normal.clone().normalize();
+
+        return this.subtract(normal.scale(2 * this.dot(normal)));
+    },
+
+    /**
+     * Reflect this Vector across another.
+     *
+     * @method Phaser.Math.Vector2#mirror
+     * @since 3.23.0
+     *
+     * @param {Phaser.Math.Vector2} axis - A vector to reflect across.
+     *
+     * @return {Phaser.Math.Vector2} This Vector2.
+     */
+    mirror: function (axis)
+    {
+        return this.reflect(axis).negate();
+    },
+
+    /**
+     * Rotate this Vector by an angle amount.
+     *
+     * @method Phaser.Math.Vector2#rotate
+     * @since 3.23.0
+     *
+     * @param {number} delta - The angle to rotate by, in radians.
+     *
+     * @return {Phaser.Math.Vector2} This Vector2.
+     */
+    rotate: function (delta)
+    {
+        var cos = Math.cos(delta);
+        var sin = Math.sin(delta);
+
+        return this.set(cos * this.x - sin * this.y, sin * this.x + cos * this.y);
     }
 
 });