b@1608: /**
b@1608:  * core.js
b@1608:  * 
b@1608:  * Main script to run, calls all other core functions and manages loading/store to backend.
b@1608:  * Also contains all global variables.
b@1608:  */
b@1608: 
b@1608: /* create the web audio API context and store in audioContext*/
b@1608: var audioContext; // Hold the browser web audio API
b@1608: var projectXML; // Hold the parsed setup XML
b@1608: 
b@1608: var testXMLSetups = []; // Hold the parsed test instances
b@1608: var testResultsHolders =[]; // Hold the results from each test for publishing to XML
b@1608: var currentTrackOrder = []; // Hold the current XML tracks in their (randomised) order
b@1608: var currentTestHolder; // Hold any intermediate results during test - metrics
b@1608: var audioEngineContext; // The custome AudioEngine object
b@1608: var projectReturn; // Hold the URL for the return
b@1608: var preTestQuestions = document.createElement('PreTest'); // Store any pre-test question response
b@1608: var postTestQuestions = document.createElement('PostTest'); // Store any post-test question response
b@1608: 
b@1608: // Add a prototype to the bufferSourceNode to reference to the audioObject holding it
b@1608: AudioBufferSourceNode.prototype.owner = undefined;
b@1608: 
b@1608: window.onload = function() {
b@1608: 	// Function called once the browser has loaded all files.
b@1608: 	// This should perform any initial commands such as structure / loading documents
b@1608: 	
b@1608: 	// Create a web audio API context
b@1608: 	// Fixed for cross-browser support
b@1608: 	var AudioContext = window.AudioContext || window.webkitAudioContext;
b@1608: 	audioContext = new AudioContext;
b@1608: 	
b@1608: 	// Create the audio engine object
b@1608: 	audioEngineContext = new AudioEngine();
b@1608: };
b@1608: 
b@1608: function loadProjectSpec(url) {
b@1608: 	// Load the project document from the given URL, decode the XML and instruct audioEngine to get audio data
b@1608: 	// If url is null, request client to upload project XML document
b@1608: 	var r = new XMLHttpRequest();
b@1608: 	r.open('GET',url,true);
b@1608: 	r.onload = function() {
b@1608: 		loadProjectSpecCallback(r.response);
b@1608: 	};
b@1608: 	r.send();
b@1608: };
b@1608: 
b@1608: function loadProjectSpecCallback(response) {
b@1608: 	// Function called after asynchronous download of XML project specification
b@1608: 	var decode = $.parseXML(response);
b@1608: 	projectXML = $(decode);
b@1608: 	
b@1608: 	// Now extract the setup tag
b@1608: 	var xmlSetup = projectXML.find('setup');
b@1608: 	// Detect the interface to use and load the relevant javascripts.
b@1608: 	var interfaceType = xmlSetup[0].attributes['interface'];
b@1608: 	var interfaceJS = document.createElement('script');
b@1608: 	interfaceJS.setAttribute("type","text/javascript");
b@1608: 	if (interfaceType.value == 'APE') {
b@1608: 		interfaceJS.setAttribute("src","ape.js");
b@1608: 		
b@1608: 		// APE comes with a css file
b@1608: 		var css = document.createElement('link');
b@1608: 		css.rel = 'stylesheet';
b@1608: 		css.type = 'text/css';
b@1608: 		css.href = 'ape.css';
b@1608: 		
b@1608: 		document.getElementsByTagName("head")[0].appendChild(css);
b@1608: 	}
b@1608: 	document.getElementsByTagName("head")[0].appendChild(interfaceJS);
b@1608: }
b@1608: 
b@1608: function createProjectSave(destURL) {
b@1608: 	// Save the data from interface into XML and send to destURL
b@1608: 	// If destURL is null then download XML in client
b@1608: 	// Now time to render file locally
b@1608: 	var xmlDoc = interfaceXMLSave();
b@1608: 	if (destURL == "null" || destURL == undefined) {
b@1608: 		var parent = document.createElement("div");
b@1608: 		parent.appendChild(xmlDoc);
b@1608: 		var file = [parent.innerHTML];
b@1608: 		var bb = new Blob(file,{type : 'application/xml'});
b@1608: 		var dnlk = window.URL.createObjectURL(bb);
b@1608: 		var a = document.createElement("a");
b@1608: 		a.hidden = '';
b@1608: 		a.href = dnlk;
b@1608: 		a.download = "save.xml";
b@1608: 		a.textContent = "Save File";
b@1608: 		
b@1608: 		var submitDiv = document.getElementById('download-point');
b@1608: 		submitDiv.appendChild(a);
b@1608: 	}
b@1608: 	return submitDiv;
b@1608: }
b@1608: 
b@1608: function AudioEngine() {
b@1608: 	
b@1608: 	// Create two output paths, the main outputGain and fooGain.
b@1608: 	// Output gain is default to 1 and any items for playback route here
b@1608: 	// Foo gain is used for analysis to ensure paths get processed, but are not heard
b@1608: 	// because web audio will optimise and any route which does not go to the destination gets ignored.
b@1608: 	this.outputGain = audioContext.createGain();
b@1608: 	this.fooGain = audioContext.createGain();
b@1608: 	this.fooGain.gain = 0;
b@1608: 	
b@1608: 	// Use this to detect playback state: 0 - stopped, 1 - playing
b@1608: 	this.status = 0;
b@1608: 	
b@1608: 	// Connect both gains to output
b@1608: 	this.outputGain.connect(audioContext.destination);
b@1608: 	this.fooGain.connect(audioContext.destination);
b@1608: 	
b@1608: 	// Create the timer Object
b@1608: 	this.timer = new timer();
b@1608: 	// Create session metrics
b@1608: 	this.metric = new sessionMetrics(this);
b@1608: 	
b@1608: 	this.loopPlayback = false;
b@1608: 	
b@1608: 	// Create store for new audioObjects
b@1608: 	this.audioObjects = [];
b@1608: 	
b@1608: 	this.play = function(){};
b@1608: 	
b@1608: 	this.stop = function(){};
b@1608: 	
b@1608: 	
b@1608: 	this.newTrack = function(url) {
b@1608: 		// Pull data from given URL into new audio buffer
b@1608: 		// URLs must either be from the same source OR be setup to 'Access-Control-Allow-Origin'
b@1608: 		
b@1608: 		// Create the audioObject with ID of the new track length;
b@1608: 		audioObjectId = this.audioObjects.length;
b@1608: 		this.audioObjects[audioObjectId] = new audioObject(audioObjectId);
b@1608: 
b@1608: 		// AudioObject will get track itself.
b@1608: 		this.audioObjects[audioObjectId].constructTrack(url);
b@1608: 	};
b@1608: 	
b@1608: }
b@1608: 
b@1608: function audioObject(id) {
b@1608: 	// The main buffer object with common control nodes to the AudioEngine
b@1608: 	
b@1608: 	this.id = id;
b@1608: 	this.state = 0; // 0 - no data, 1 - ready
b@1608: 	this.url = null; // Hold the URL given for the output back to the results.
b@1608: 	this.metric = new metricTracker();
b@1608: 	
b@1608: 	// Create a buffer and external gain control to allow internal patching of effects and volume leveling.
b@1608: 	this.bufferNode = undefined;
b@1608: 	this.outputGain = audioContext.createGain();
b@1608: 	
b@1608: 	// Default output gain to be zero
b@1608: 	this.outputGain.gain.value = 0.0;
b@1608: 	
b@1608: 	// Connect buffer to the audio graph
b@1608: 	this.outputGain.connect(audioEngineContext.outputGain);
b@1608: 	
b@1608: 	// the audiobuffer is not designed for multi-start playback
b@1608: 	// When stopeed, the buffer node is deleted and recreated with the stored buffer.
b@1608: 	this.buffer;
b@1608: 	
b@1608: 	this.play = function(startTime) {
b@1608: 		this.bufferNode = audioContext.createBufferSource();
b@1608: 		this.bufferNode.connect(this.outputGain);
b@1608: 		this.bufferNode.buffer = this.buffer;
b@1608: 		this.bufferNode.loop = audioEngineContext.loopPlayback;
b@1608: 		this.bufferNode.start(startTime);
b@1608: 	};
b@1608: 	
b@1608: 	this.stop = function() {
b@1608: 		this.bufferNode.stop(0);
b@1608: 		this.bufferNode = undefined;
b@1608: 	};
b@1608: 
b@1608: 	this.constructTrack = function(url) {
b@1608: 		var request = new XMLHttpRequest();
b@1608: 		this.url = url;
b@1608: 		request.open('GET',url,true);
b@1608: 		request.responseType = 'arraybuffer';
b@1608: 		
b@1608: 		var audioObj = this;
b@1608: 		
b@1608: 		// Create callback to decode the data asynchronously
b@1608: 		request.onloadend = function() {
b@1608: 			audioContext.decodeAudioData(request.response, function(decodedData) {
b@1608: 				audioObj.buffer = decodedData;
b@1608: 				audioObj.state = 1;
b@1608: 			}, function(){
b@1608: 				// Should only be called if there was an error, but sometimes gets called continuously
b@1608: 				// Check here if the error is genuine
b@1608: 				if (audioObj.state == 0 || audioObj.buffer == undefined) {
b@1608: 					// Genuine error
b@1608: 					console.log('FATAL - Error loading buffer on '+audioObj.id);
b@1608: 				}
b@1608: 			});
b@1608: 		};
b@1608: 		request.send();
b@1608: 	};
b@1608: 	
b@1608: }
b@1608: 
b@1608: function timer()
b@1608: {
b@1608: 	/* Timer object used in audioEngine to keep track of session timings
b@1608: 	 * Uses the timer of the web audio API, so sample resolution
b@1608: 	 */
b@1608: 	this.testStarted = false;
b@1608: 	this.testStartTime = 0;
b@1608: 	this.testDuration = 0;
b@1608: 	this.minimumTestTime = 0; // No minimum test time
b@1608: 	this.startTest = function()
b@1608: 	{
b@1608: 		if (this.testStarted == false)
b@1608: 		{
b@1608: 			this.testStartTime = audioContext.currentTime;
b@1608: 			this.testStarted = true;
b@1608: 			this.updateTestTime();
b@1608: 			audioEngineContext.metric.initialiseTest();
b@1608: 		}
b@1608: 	};
b@1608: 	this.stopTest = function()
b@1608: 	{
b@1608: 		if (this.testStarted)
b@1608: 		{
b@1608: 			this.testDuration = this.getTestTime();
b@1608: 			this.testStarted = false;
b@1608: 		} else {
b@1608: 			console.log('ERR: Test tried to end before beginning');
b@1608: 		}
b@1608: 	};
b@1608: 	this.updateTestTime = function()
b@1608: 	{
b@1608: 		if (this.testStarted)
b@1608: 		{
b@1608: 			this.testDuration = audioContext.currentTime - this.testStartTime;
b@1608: 		}
b@1608: 	};
b@1608: 	this.getTestTime = function()
b@1608: 	{
b@1608: 		this.updateTestTime();
b@1608: 		return this.testDuration;
b@1608: 	};
b@1608: }
b@1608: 
b@1608: function sessionMetrics(engine)
b@1608: {
b@1608: 	/* Used by audioEngine to link to audioObjects to minimise the timer call timers;
b@1608: 	 */
b@1608: 	this.engine = engine;
b@1608: 	this.lastClicked = -1;
b@1608: 	this.data = -1;
b@1608: 	this.initialiseTest = function(){};
b@1608: }
b@1608: 
b@1608: function metricTracker()
b@1608: {
b@1608: 	/* Custom object to track and collect metric data
b@1608: 	 * Used only inside the audioObjects object.
b@1608: 	 */
b@1608: 	
b@1608: 	this.listenedTimer = 0;
b@1608: 	this.listenStart = 0;
b@1608: 	this.initialPosition = -1;
b@1608: 	this.movementTracker = [];
b@1608: 	this.wasListenedTo = false;
b@1608: 	this.wasMoved = false;
b@1608: 	this.hasComments = false;
b@1608: 	
b@1608: 	this.initialised = function(position)
b@1608: 	{
b@1608: 		if (this.initialPosition == -1) {
b@1608: 			this.initialPosition = position;
b@1608: 		}
b@1608: 	};
b@1608: 	
b@1608: 	this.moved = function(time,position)
b@1608: 	{
b@1608: 		this.wasMoved = true;
b@1608: 		this.movementTracker[this.movementTracker.length] = [time, position];
b@1608: 	};
b@1608: 	
b@1608: 	this.listening = function(time)
b@1608: 	{
b@1608: 		if (this.listenStart == 0)
b@1608: 		{
b@1608: 			this.wasListenedTo = true;
b@1608: 			this.listenStart = time;
b@1608: 		} else {
b@1608: 			this.listenedTimer += (time - this.listenStart);
b@1608: 			this.listenStart = 0;
b@1608: 		}
b@1608: 	};
b@1608: }
b@1608: 
b@1608: function randomiseOrder(input)
b@1608: {
b@1608: 	// This takes an array of information and randomises the order
b@1608: 	var N = input.length;
b@1608: 	var K = N;
b@1608: 	var holdArr = [];
b@1608: 	for (var n=0; n<N; n++)
b@1608: 	{
b@1608: 		// First pick a random number
b@1608: 		var r = Math.random();
b@1608: 		// Multiply and floor by the number of elements left
b@1608: 		r = Math.floor(r*input.length);
b@1608: 		// Pick out that element and delete from the array
b@1608: 		holdArr.push(input.splice(r,1)[0]);
b@1608: 	}
b@1608: 	return holdArr;
b@1608: }