Ellipse.random will return a uniformly distributed random point from anywhere within the ellipse.

Author: photonstorm

README.md

@@ -303,8 +303,9 @@ Version 2.4 - "Katar" - in dev
 * onDragUpdate is a new signal that is dispatched whenever a Game object enabled for input and drag is moved by a pointer (i.e. during a drag event). See the `Phaser.InputHandler.enableDrag` docs for parameter details and the new Phaser Example.
 * Rectangle.resize allows you to resize a Rectangle to the new given dimensions without altering its position.
 * Cache.getJSON has a new parameter: `clone`. If set it will return a clone of the object stored in the Cache rather than a reference to it.
-* Circle.random will return a random point from anywhere within the circle.
+* Circle.random will return a uniformly distributed random point from anywhere within the circle.
 * Line.random will return a random point from anywhere on the Line segment.
+* Ellipse.random will return a uniformly distributed random point from anywhere within the ellipse.
 
 ### Updates
 

src/geom/Circle.js

@@ -70,12 +70,11 @@ Phaser.Circle.prototype = {
     },
 
     /**
-    * Returns a random point from anywhere within this circle.
-    * The point is uniformly distributed within bounds.
+    * Returns a uniformly distributed random point from anywhere within this Circle.
     * 
     * @method Phaser.Circle#random
     * @param {Phaser.Point|object} [out] - A Phaser.Point, or any object with public x/y properties, that the values will be set in.
-    *     If no object is provided a new Phaser.Point object will be created. In high performance areas avoid this by re-using an object.
+    *     If no object is provided a new Phaser.Point object will be created. In high performance areas avoid this by re-using an existing object.
     * @return {Phaser.Point} An object containing the random point in its `x` and `y` properties.
     */
     random: function (out) {

src/geom/Ellipse.js

@@ -137,6 +137,7 @@ Phaser.Ellipse.prototype = {
 
     /**
     * Return true if the given x/y coordinates are within this Ellipse object.
+    * 
     * @method Phaser.Ellipse#contains
     * @param {number} x - The X value of the coordinate to test.
     * @param {number} y - The Y value of the coordinate to test.
@@ -148,6 +149,31 @@ Phaser.Ellipse.prototype = {
 
     },
 
+    /**
+    * Returns a uniformly distributed random point from anywhere within this Ellipse.
+    * 
+    * @method Phaser.Ellipse#random
+    * @param {Phaser.Point|object} [out] - A Phaser.Point, or any object with public x/y properties, that the values will be set in.
+    *     If no object is provided a new Phaser.Point object will be created. In high performance areas avoid this by re-using an existing object.
+    * @return {Phaser.Point} An object containing the random point in its `x` and `y` properties.
+    */
+    random: function (out) {
+
+        if (typeof out === 'undefined') { out = new Phaser.Point(); }
+
+        var p = Math.random() * Math.PI * 2;
+        var r = Math.random();
+
+        out.x = Math.sqrt(r) * Math.cos(p);
+        out.y = Math.sqrt(r) * Math.sin(p);
+
+        out.x = this.x + (out.x * this.width / 2.0);
+        out.y = this.y + (out.y * this.height / 2.0);
+
+        return out;
+
+    },
+
     /**
     * Returns a string representation of this object.
     * @method Phaser.Ellipse#toString

typescript/phaser.d.ts

@@ -814,6 +814,7 @@ declare module Phaser {
         copyFrom(source: any): Phaser.Ellipse;
         copyTo(dest: any): any;
         getBounds(): Phaser.Rectangle;
+        random(out?: Phaser.Point): Phaser.Point;
         setTo(x: number, y: number, width: number, height: number): Phaser.Ellipse;
         toString(): string;