foodicator-reloaded/js/game.js

// If we're ready
var ready = false;

// My ID
var myId;

// List of other players
var playerList = {};

// Set up the eureca server
var eurecaServer;

// Client setup function
var eurecaClientSetup = function() {

	// create an instance of eureca.io client
	var eurecaClient = new Eureca.Client();

	// Ready function for getting the server
	eurecaClient.ready(function(proxy) {
		eurecaServer = proxy;
	});

	// export functions can be called on the server side

	// Handshake function to hand over ID
	eurecaClient.exports.handshake = function(id) {
		//create() is moved here to make sure nothing is created before uniq id assignation
		myId = id;
		create();

		state = {
			x: player.sprite.x,
			y: player.sprite.y
		}
		eurecaServer.updateMe(state);

		ready = true;
	}

	// close a connection
	eurecaClient.exports.kill = function(id) {
		var pl = playerList[id];
		// if we have this player
		if (pl) {

			// Kill the player and log
			pl.kill();
			console.log(id, " disconnected ", pl);
		}
	}

	// Spawn another player
	eurecaClient.exports.spawnPlayer = function(i, x, y) {

		if (i == myId) return; // do nothing for me

		// log and create the player
		console.log(i, " connected");
		var player = new Player(i, x, y);

		// add to our list
		playerList[i] = player;
	}

	// Update a player state
	eurecaClient.exports.updateState = function(id, state) {
		var pl = playerList[id];

		// if we have this player update it's pos
		if (pl) {
			pl.sprite.x = state.x;
			pl.sprite.y = state.y;
		}
	}
}

// Create the game
var game = new Phaser.Game(800, 540,
	Phaser.AUTO,
	'', {
		preload: preload,
		create: eurecaClientSetup,
		update: update
	});


// get the length of a vector
function length(vec) {
	return Math.sqrt((vec.x * vec.x) + (vec.y * vec.y));
}

// Normalise a vector
function normalise(vec) {
	var len = length(vec);
	vec.x = (vec.x / len);
	vec.y = (vec.y / len);
}

// Player object
Player = function(id, x, y) {

	// Constants
	this.id = id;
	this.topSpeed = 5;
	this.acceleration = 1.5;
	this.friction = 0.6;
	this.alive = false;

	// varying
	this.velocity = {
		x: 0,
		y: 0
	};

	// Create a sprite
	this.sprite = game.add.sprite(x, y, 'dude');

	// set alive
	this.alive = true;
}

// Update a player
Player.prototype.update = function() {

	// early out if dead
	if (!this.alive) return;

	// control force
	var force = {
		x: 0,
		y: 0
	}

	// Grab the members, javascript is weird?
	var sprite = this.sprite;
	var velocity = this.velocity;
	var topSpeed = this.topSpeed;
	var acceleration = this.acceleration;
	var friction = this.friction;

	// Left and right
	if (controls.left.isDown) {
		//  Move to the left
		force.x = -acceleration;
	} else if (controls.right.isDown) {
		//  Move to the right
		force.x = acceleration;
	}

	// Up and down
	if (controls.up.isDown) {
		//  Move up
		force.y = -acceleration;
	} else if (controls.down.isDown) {
		//  Move down
		force.y = acceleration;
	}

	// Normalise out force
	if (length(force) > 0) {
		normalise(force)

		// Limit to pos
		velocity.x = Math.min(velocity.x + force.x, topSpeed);
		velocity.y = Math.min(velocity.y + force.y, topSpeed);

		// Limit to neg
		velocity.x = Math.max(velocity.x + force.x, -topSpeed);
		velocity.y = Math.max(velocity.y + force.y, -topSpeed);

	} else {

		// if no force, then apply friction
		velocity.x = velocity.x * friction;
		velocity.y = velocity.y * friction;
	}

	// if we have a speed, then update pos and send info to server
	if (length(velocity) > 1) {

		sprite.position.x = sprite.position.x + velocity.x;
		sprite.position.y = sprite.position.y + velocity.y;

		var state = {
			x: sprite.position.x,
			y: sprite.position.y
		}
		eurecaServer.updateMe(state)
	}
}

// Kill a player
Player.prototype.kill = function() {
	// The player and its settings
	this.sprite.kill();
	this.alive = false;
}

// Phaser functions

// preload all assets
function preload() {

	// Set centered
	game.scale.pageAlignHorizontally = true;
	game.scale.pageAlignVertically = true;

	// load the background
	game.load.image("bg", "assets/bg.png");

	// load the background
	game.load.image("options", "assets/options.png");

	// Load the dude  
	game.load.image('dude', 'assets/dude.png', 50, 50);
}

// Create the game
function create() {

	// Add the background sprite
	background = game.add.sprite(0, 0, "bg");

	// create our player
	player = new Player(myId, Math.random() * 100, Math.random() * 100);

	//  Get controls
	controls = game.input.keyboard.createCursorKeys();
}

// On update
function update() {

	// do nothing if not ready yet
	if (!ready) return;

	// update our player
	player.update();

}