BrechtDeMan@938: /**
BrechtDeMan@938:  * core.js
BrechtDeMan@938:  * 
BrechtDeMan@938:  * Main script to run, calls all other core functions and manages loading/store to backend.
BrechtDeMan@938:  * Also contains all global variables.
BrechtDeMan@938:  */
BrechtDeMan@938: 
BrechtDeMan@938: /* create the web audio API context and store in audioContext*/
BrechtDeMan@938: var audioContext; // Hold the browser web audio API
BrechtDeMan@938: var projectXML; // Hold the parsed setup XML
BrechtDeMan@938: 
BrechtDeMan@938: var testXMLSetups = []; // Hold the parsed test instances
BrechtDeMan@938: var testResultsHolders =[]; // Hold the results from each test for publishing to XML
BrechtDeMan@938: var currentTrackOrder = []; // Hold the current XML tracks in their (randomised) order
BrechtDeMan@938: var currentTestHolder; // Hold any intermediate results during test - metrics
BrechtDeMan@938: var audioEngineContext; // The custome AudioEngine object
BrechtDeMan@938: var projectReturn; // Hold the URL for the return
BrechtDeMan@938: var preTestQuestions = document.createElement('PreTest'); // Store any pre-test question response
BrechtDeMan@938: var postTestQuestions = document.createElement('PostTest'); // Store any post-test question response
BrechtDeMan@938: 
BrechtDeMan@938: // Add a prototype to the bufferSourceNode to reference to the audioObject holding it
BrechtDeMan@938: AudioBufferSourceNode.prototype.owner = undefined;
BrechtDeMan@938: 
BrechtDeMan@938: window.onload = function() {
BrechtDeMan@938: 	// Function called once the browser has loaded all files.
BrechtDeMan@938: 	// This should perform any initial commands such as structure / loading documents
BrechtDeMan@938: 	
BrechtDeMan@938: 	// Create a web audio API context
BrechtDeMan@938: 	// Fixed for cross-browser support
BrechtDeMan@938: 	var AudioContext = window.AudioContext || window.webkitAudioContext;
BrechtDeMan@938: 	audioContext = new AudioContext;
BrechtDeMan@938: 	
BrechtDeMan@938: 	// Create the audio engine object
BrechtDeMan@938: 	audioEngineContext = new AudioEngine();
BrechtDeMan@938: };
BrechtDeMan@938: 
BrechtDeMan@938: function loadProjectSpec(url) {
BrechtDeMan@938: 	// Load the project document from the given URL, decode the XML and instruct audioEngine to get audio data
BrechtDeMan@938: 	// If url is null, request client to upload project XML document
BrechtDeMan@938: 	var r = new XMLHttpRequest();
BrechtDeMan@938: 	r.open('GET',url,true);
BrechtDeMan@938: 	r.onload = function() {
BrechtDeMan@938: 		loadProjectSpecCallback(r.response);
BrechtDeMan@938: 	};
BrechtDeMan@938: 	r.send();
BrechtDeMan@938: };
BrechtDeMan@938: 
BrechtDeMan@938: function loadProjectSpecCallback(response) {
BrechtDeMan@938: 	// Function called after asynchronous download of XML project specification
BrechtDeMan@938: 	var decode = $.parseXML(response);
BrechtDeMan@938: 	projectXML = $(decode);
BrechtDeMan@938: 	
BrechtDeMan@938: 	// Now extract the setup tag
BrechtDeMan@938: 	var xmlSetup = projectXML.find('setup');
BrechtDeMan@938: 	// Detect the interface to use and load the relevant javascripts.
BrechtDeMan@938: 	var interfaceType = xmlSetup[0].attributes['interface'];
BrechtDeMan@938: 	var interfaceJS = document.createElement('script');
BrechtDeMan@938: 	interfaceJS.setAttribute("type","text/javascript");
BrechtDeMan@938: 	if (interfaceType.value == 'APE') {
BrechtDeMan@938: 		interfaceJS.setAttribute("src","ape.js");
BrechtDeMan@938: 		
BrechtDeMan@938: 		// APE comes with a css file
BrechtDeMan@938: 		var css = document.createElement('link');
BrechtDeMan@938: 		css.rel = 'stylesheet';
BrechtDeMan@938: 		css.type = 'text/css';
BrechtDeMan@938: 		css.href = 'ape.css';
BrechtDeMan@938: 		
BrechtDeMan@938: 		document.getElementsByTagName("head")[0].appendChild(css);
BrechtDeMan@938: 	}
BrechtDeMan@938: 	document.getElementsByTagName("head")[0].appendChild(interfaceJS);
BrechtDeMan@938: }
BrechtDeMan@938: 
BrechtDeMan@938: function createProjectSave(destURL) {
BrechtDeMan@938: 	// Save the data from interface into XML and send to destURL
BrechtDeMan@938: 	// If destURL is null then download XML in client
BrechtDeMan@938: 	// Now time to render file locally
BrechtDeMan@938: 	var xmlDoc = interfaceXMLSave();
BrechtDeMan@938: 	if (destURL == "null" || destURL == undefined) {
BrechtDeMan@938: 		var parent = document.createElement("div");
BrechtDeMan@938: 		parent.appendChild(xmlDoc);
BrechtDeMan@938: 		var file = [parent.innerHTML];
BrechtDeMan@938: 		var bb = new Blob(file,{type : 'application/xml'});
BrechtDeMan@938: 		var dnlk = window.URL.createObjectURL(bb);
BrechtDeMan@938: 		var a = document.createElement("a");
BrechtDeMan@938: 		a.hidden = '';
BrechtDeMan@938: 		a.href = dnlk;
BrechtDeMan@938: 		a.download = "save.xml";
BrechtDeMan@938: 		a.textContent = "Save File";
BrechtDeMan@938: 		
BrechtDeMan@938: 		var submitDiv = document.getElementById('download-point');
BrechtDeMan@938: 		submitDiv.appendChild(a);
BrechtDeMan@938: 	}
BrechtDeMan@938: 	return submitDiv;
BrechtDeMan@938: }
BrechtDeMan@938: 
BrechtDeMan@938: function AudioEngine() {
BrechtDeMan@938: 	
BrechtDeMan@938: 	// Create two output paths, the main outputGain and fooGain.
BrechtDeMan@938: 	// Output gain is default to 1 and any items for playback route here
BrechtDeMan@938: 	// Foo gain is used for analysis to ensure paths get processed, but are not heard
BrechtDeMan@938: 	// because web audio will optimise and any route which does not go to the destination gets ignored.
BrechtDeMan@938: 	this.outputGain = audioContext.createGain();
BrechtDeMan@938: 	this.fooGain = audioContext.createGain();
BrechtDeMan@938: 	this.fooGain.gain = 0;
BrechtDeMan@938: 	
BrechtDeMan@938: 	// Use this to detect playback state: 0 - stopped, 1 - playing
BrechtDeMan@938: 	this.status = 0;
BrechtDeMan@938: 	
BrechtDeMan@938: 	// Connect both gains to output
BrechtDeMan@938: 	this.outputGain.connect(audioContext.destination);
BrechtDeMan@938: 	this.fooGain.connect(audioContext.destination);
BrechtDeMan@938: 	
BrechtDeMan@938: 	// Create the timer Object
BrechtDeMan@938: 	this.timer = new timer();
BrechtDeMan@938: 	// Create session metrics
BrechtDeMan@938: 	this.metric = new sessionMetrics(this);
BrechtDeMan@938: 	
BrechtDeMan@938: 	this.loopPlayback = false;
BrechtDeMan@938: 	
BrechtDeMan@938: 	// Create store for new audioObjects
BrechtDeMan@938: 	this.audioObjects = [];
BrechtDeMan@938: 	
BrechtDeMan@938: 	this.play = function(){};
BrechtDeMan@938: 	
BrechtDeMan@938: 	this.stop = function(){};
BrechtDeMan@938: 	
BrechtDeMan@938: 	
BrechtDeMan@938: 	this.newTrack = function(url) {
BrechtDeMan@938: 		// Pull data from given URL into new audio buffer
BrechtDeMan@938: 		// URLs must either be from the same source OR be setup to 'Access-Control-Allow-Origin'
BrechtDeMan@938: 		
BrechtDeMan@938: 		// Create the audioObject with ID of the new track length;
BrechtDeMan@938: 		audioObjectId = this.audioObjects.length;
BrechtDeMan@938: 		this.audioObjects[audioObjectId] = new audioObject(audioObjectId);
BrechtDeMan@938: 
BrechtDeMan@938: 		// AudioObject will get track itself.
BrechtDeMan@938: 		this.audioObjects[audioObjectId].constructTrack(url);
BrechtDeMan@938: 	};
BrechtDeMan@938: 	
BrechtDeMan@938: }
BrechtDeMan@938: 
BrechtDeMan@938: function audioObject(id) {
BrechtDeMan@938: 	// The main buffer object with common control nodes to the AudioEngine
BrechtDeMan@938: 	
BrechtDeMan@938: 	this.id = id;
BrechtDeMan@938: 	this.state = 0; // 0 - no data, 1 - ready
BrechtDeMan@938: 	this.url = null; // Hold the URL given for the output back to the results.
BrechtDeMan@938: 	this.metric = new metricTracker();
BrechtDeMan@938: 	
BrechtDeMan@938: 	// Create a buffer and external gain control to allow internal patching of effects and volume leveling.
BrechtDeMan@938: 	this.bufferNode = undefined;
BrechtDeMan@938: 	this.outputGain = audioContext.createGain();
BrechtDeMan@938: 	
BrechtDeMan@938: 	// Default output gain to be zero
BrechtDeMan@938: 	this.outputGain.gain.value = 0.0;
BrechtDeMan@938: 	
BrechtDeMan@938: 	// Connect buffer to the audio graph
BrechtDeMan@938: 	this.outputGain.connect(audioEngineContext.outputGain);
BrechtDeMan@938: 	
BrechtDeMan@938: 	// the audiobuffer is not designed for multi-start playback
BrechtDeMan@938: 	// When stopeed, the buffer node is deleted and recreated with the stored buffer.
BrechtDeMan@938: 	this.buffer;
BrechtDeMan@938: 	
BrechtDeMan@938: 	this.play = function(startTime) {
BrechtDeMan@938: 		this.bufferNode = audioContext.createBufferSource();
BrechtDeMan@938: 		this.bufferNode.connect(this.outputGain);
BrechtDeMan@938: 		this.bufferNode.buffer = this.buffer;
BrechtDeMan@938: 		this.bufferNode.loop = audioEngineContext.loopPlayback;
BrechtDeMan@938: 		this.bufferNode.start(startTime);
BrechtDeMan@938: 	};
BrechtDeMan@938: 	
BrechtDeMan@938: 	this.stop = function() {
BrechtDeMan@938: 		this.bufferNode.stop(0);
BrechtDeMan@938: 		this.bufferNode = undefined;
BrechtDeMan@938: 	};
BrechtDeMan@938: 
BrechtDeMan@938: 	this.constructTrack = function(url) {
BrechtDeMan@938: 		var request = new XMLHttpRequest();
BrechtDeMan@938: 		this.url = url;
BrechtDeMan@938: 		request.open('GET',url,true);
BrechtDeMan@938: 		request.responseType = 'arraybuffer';
BrechtDeMan@938: 		
BrechtDeMan@938: 		var audioObj = this;
BrechtDeMan@938: 		
BrechtDeMan@938: 		// Create callback to decode the data asynchronously
BrechtDeMan@938: 		request.onloadend = function() {
BrechtDeMan@938: 			audioContext.decodeAudioData(request.response, function(decodedData) {
BrechtDeMan@938: 				audioObj.buffer = decodedData;
BrechtDeMan@938: 				audioObj.state = 1;
BrechtDeMan@938: 			}, function(){
BrechtDeMan@938: 				// Should only be called if there was an error, but sometimes gets called continuously
BrechtDeMan@938: 				// Check here if the error is genuine
BrechtDeMan@938: 				if (audioObj.state == 0 || audioObj.buffer == undefined) {
BrechtDeMan@938: 					// Genuine error
BrechtDeMan@938: 					console.log('FATAL - Error loading buffer on '+audioObj.id);
BrechtDeMan@938: 				}
BrechtDeMan@938: 			});
BrechtDeMan@938: 		};
BrechtDeMan@938: 		request.send();
BrechtDeMan@938: 	};
BrechtDeMan@938: 	
BrechtDeMan@938: }
BrechtDeMan@938: 
BrechtDeMan@938: function timer()
BrechtDeMan@938: {
BrechtDeMan@938: 	/* Timer object used in audioEngine to keep track of session timings
BrechtDeMan@938: 	 * Uses the timer of the web audio API, so sample resolution
BrechtDeMan@938: 	 */
BrechtDeMan@938: 	this.testStarted = false;
BrechtDeMan@938: 	this.testStartTime = 0;
BrechtDeMan@938: 	this.testDuration = 0;
BrechtDeMan@938: 	this.minimumTestTime = 0; // No minimum test time
BrechtDeMan@938: 	this.startTest = function()
BrechtDeMan@938: 	{
BrechtDeMan@938: 		if (this.testStarted == false)
BrechtDeMan@938: 		{
BrechtDeMan@938: 			this.testStartTime = audioContext.currentTime;
BrechtDeMan@938: 			this.testStarted = true;
BrechtDeMan@938: 			this.updateTestTime();
BrechtDeMan@938: 			audioEngineContext.metric.initialiseTest();
BrechtDeMan@938: 		}
BrechtDeMan@938: 	};
BrechtDeMan@938: 	this.stopTest = function()
BrechtDeMan@938: 	{
BrechtDeMan@938: 		if (this.testStarted)
BrechtDeMan@938: 		{
BrechtDeMan@938: 			this.testDuration = this.getTestTime();
BrechtDeMan@938: 			this.testStarted = false;
BrechtDeMan@938: 		} else {
BrechtDeMan@938: 			console.log('ERR: Test tried to end before beginning');
BrechtDeMan@938: 		}
BrechtDeMan@938: 	};
BrechtDeMan@938: 	this.updateTestTime = function()
BrechtDeMan@938: 	{
BrechtDeMan@938: 		if (this.testStarted)
BrechtDeMan@938: 		{
BrechtDeMan@938: 			this.testDuration = audioContext.currentTime - this.testStartTime;
BrechtDeMan@938: 		}
BrechtDeMan@938: 	};
BrechtDeMan@938: 	this.getTestTime = function()
BrechtDeMan@938: 	{
BrechtDeMan@938: 		this.updateTestTime();
BrechtDeMan@938: 		return this.testDuration;
BrechtDeMan@938: 	};
BrechtDeMan@938: }
BrechtDeMan@938: 
BrechtDeMan@938: function sessionMetrics(engine)
BrechtDeMan@938: {
BrechtDeMan@938: 	/* Used by audioEngine to link to audioObjects to minimise the timer call timers;
BrechtDeMan@938: 	 */
BrechtDeMan@938: 	this.engine = engine;
BrechtDeMan@938: 	this.lastClicked = -1;
BrechtDeMan@938: 	this.data = -1;
BrechtDeMan@938: 	this.initialiseTest = function(){};
BrechtDeMan@938: }
BrechtDeMan@938: 
BrechtDeMan@938: function metricTracker()
BrechtDeMan@938: {
BrechtDeMan@938: 	/* Custom object to track and collect metric data
BrechtDeMan@938: 	 * Used only inside the audioObjects object.
BrechtDeMan@938: 	 */
BrechtDeMan@938: 	
BrechtDeMan@938: 	this.listenedTimer = 0;
BrechtDeMan@938: 	this.listenStart = 0;
BrechtDeMan@938: 	this.initialPosition = -1;
BrechtDeMan@938: 	this.movementTracker = [];
BrechtDeMan@938: 	this.wasListenedTo = false;
BrechtDeMan@938: 	this.wasMoved = false;
BrechtDeMan@938: 	this.hasComments = false;
BrechtDeMan@938: 	
BrechtDeMan@938: 	this.initialised = function(position)
BrechtDeMan@938: 	{
BrechtDeMan@938: 		if (this.initialPosition == -1) {
BrechtDeMan@938: 			this.initialPosition = position;
BrechtDeMan@938: 		}
BrechtDeMan@938: 	};
BrechtDeMan@938: 	
BrechtDeMan@938: 	this.moved = function(time,position)
BrechtDeMan@938: 	{
BrechtDeMan@938: 		this.wasMoved = true;
BrechtDeMan@938: 		this.movementTracker[this.movementTracker.length] = [time, position];
BrechtDeMan@938: 	};
BrechtDeMan@938: 	
BrechtDeMan@938: 	this.listening = function(time)
BrechtDeMan@938: 	{
BrechtDeMan@938: 		if (this.listenStart == 0)
BrechtDeMan@938: 		{
BrechtDeMan@938: 			this.wasListenedTo = true;
BrechtDeMan@938: 			this.listenStart = time;
BrechtDeMan@938: 		} else {
BrechtDeMan@938: 			this.listenedTimer += (time - this.listenStart);
BrechtDeMan@938: 			this.listenStart = 0;
BrechtDeMan@938: 		}
BrechtDeMan@938: 	};
BrechtDeMan@938: }
BrechtDeMan@938: 
BrechtDeMan@938: function randomiseOrder(input)
BrechtDeMan@938: {
BrechtDeMan@938: 	// This takes an array of information and randomises the order
BrechtDeMan@938: 	var N = input.length;
BrechtDeMan@938: 	var K = N;
BrechtDeMan@938: 	var holdArr = [];
BrechtDeMan@938: 	for (var n=0; n<N; n++)
BrechtDeMan@938: 	{
BrechtDeMan@938: 		// First pick a random number
BrechtDeMan@938: 		var r = Math.random();
BrechtDeMan@938: 		// Multiply and floor by the number of elements left
BrechtDeMan@938: 		r = Math.floor(r*input.length);
BrechtDeMan@938: 		// Pick out that element and delete from the array
BrechtDeMan@938: 		holdArr.push(input.splice(r,1)[0]);
BrechtDeMan@938: 	}
BrechtDeMan@938: 	return holdArr;
BrechtDeMan@938: }