From f321cab77ed6e250bab59ef354f20eb5bc444911 Mon Sep 17 00:00:00 2001
From: photonstorm <rdavey@gmail.com>
Date: Tue, 11 Mar 2014 01:23:41 +0000
Subject: [PATCH] The physics configuration object can now be used to start
 physics systems specifically.

---
 examples/wip/physics config.js | 108 +++++++++++++++++++++++++++++++++
 src/physics/Physics.js         |  31 +++++++++-
 2 files changed, 138 insertions(+), 1 deletion(-)
 create mode 100644 examples/wip/physics config.js

diff --git a/examples/wip/physics config.js b/examples/wip/physics config.js
new file mode 100644
index 000000000..444528029
--- /dev/null
+++ b/examples/wip/physics config.js	
@@ -0,0 +1,108 @@
+//  Here we'll use a Physics Configuration object to specify which physics systems should be started with the game.
+
+var physicsConfig = {
+
+    arcade: true,
+    ninja: false,
+    p2: true
+
+};
+
+var game = new Phaser.Game(800, 600, Phaser.AUTO, 'phaser-example', { preload: preload, create: create, update: update, render: render }, false, false, physicsConfig);
+
+function preload() {
+
+    game.load.image('atari', 'assets/sprites/atari130xe.png');
+    game.load.spritesheet('bullets', 'assets/sprites/balls.png', 17, 17);
+
+}
+
+var atari;
+var balls;
+
+function create() {
+
+    game.stage.backgroundColor = '#2d2d2d';
+
+    balls = game.add.group();
+
+    balls.createMultiple(250, 'bullets', 0, false);
+
+    atari = game.add.sprite(300, 450, 'atari');
+
+    game.physics.arcade.gravity.y = 400;
+
+    //  Enable physics on everything added to the world so far (the true parameter makes it recurse down into children)
+    game.physics.arcade.enable(game.world, true);
+
+    atari.body.gravityScale.y = 0;
+    atari.body.immovable = true;
+
+    cursors = game.input.keyboard.createCursorKeys();
+
+    game.time.events.loop(150, fire, this);
+
+}
+
+function fire() {
+
+    var ball = balls.getFirstExists(false);
+
+    if (ball)
+    {
+        ball.frame = game.rnd.integerInRange(0,6);
+        ball.exists = true;
+        ball.reset(game.world.randomX, 0);
+
+        ball.body.bounce.y = 0.8;
+    }
+
+}
+
+function reflect(a, ball) {
+
+    if (ball.y > (atari.y + 5))
+    {
+        return true;
+    }
+    else
+    {
+        ball.body.velocity.x = atari.body.velocity.x;
+        ball.body.velocity.y *= -(ball.body.bounce.y);
+
+        return false;
+    }
+
+}
+
+function update() {
+
+    game.physics.arcade.collide(atari, balls, null, reflect, this);
+
+    atari.body.velocity.x = 0;
+
+    if (cursors.left.isDown)
+    {
+        atari.body.velocity.x = -200;
+    }
+    else if (cursors.right.isDown)
+    {
+        atari.body.velocity.x = 200;
+    }
+
+    balls.forEachAlive(checkBounds, this);
+
+}
+
+function checkBounds(ball) {
+
+    if (ball.y > 600)
+    {
+        ball.kill();
+    }
+
+}
+
+function render() {
+
+}
diff --git a/src/physics/Physics.js b/src/physics/Physics.js
index 1f02ea674..bdd477ce5 100644
--- a/src/physics/Physics.js
+++ b/src/physics/Physics.js
@@ -20,6 +20,8 @@
 */
 Phaser.Physics = function (game, config) {
 
+    config = config || {};
+
     /**
     * @property {Phaser.Game} game - Local reference to game.
     */
@@ -33,7 +35,7 @@ Phaser.Physics = function (game, config) {
     /**
     * @property {Phaser.Physics.Arcade} arcade - The Arcade Physics system.
     */
-    this.arcade = new Phaser.Physics.Arcade(game);
+    this.arcade = null;
 
     /**
     * @property {Phaser.Physics.P2} p2 - The P2.JS Physics system.
@@ -55,6 +57,8 @@ Phaser.Physics = function (game, config) {
     */
     this.chipmunk = null;
 
+    this.parseConfig();
+
 };
 
 /**
@@ -89,6 +93,31 @@ Phaser.Physics.CHIPMUNK = 5;
 
 Phaser.Physics.prototype = {
 
+    /**
+    * Parses the Physics Configuration object passed to the Game constructor and starts any physics systems specified within.
+    *
+    * @method Phaser.Physics#parseConfig
+    */
+    parseConfig: function () {
+
+        if ((!this.config.hasOwnProperty('arcade') || this.config['arcade'] === true) && Phaser.Physics.hasOwnProperty('Arcade'))
+        {
+            //  If Arcade isn't specified, we create it automatically if we can
+            this.arcade = new Phaser.Physics.Arcade(this.game);
+        }
+
+        if (this.config.hasOwnProperty('ninja') && this.config['ninja'] === true && Phaser.Physics.hasOwnProperty('Ninja'))
+        {
+            this.ninja = new Phaser.Physics.Ninja(this.game);
+        }
+
+        if (this.config.hasOwnProperty('p2') && this.config['p2'] === true && Phaser.Physics.hasOwnProperty('P2'))
+        {
+            this.p2 = new Phaser.Physics.P2(this.game, this.config);
+        }
+
+    },
+
     /**
     * This will create an instance of the requested physics simulation.
     * Phaser.Physics.Arcade is running by default, but all others need activating directly.