maxi_webAudio.js

// Temporary patch until all browsers support unprefixed context.
AudioContext = AudioContext || webkitAudioContext;

// var context;
var context = new AudioContext();
// context = new (window.AudioContext || window.webkitAudioContext)();

var source;
var jsProcessor = 0;
var analyser;

var output = 0;
var bufferLoader;

var myBufferData = new Module.VectorDouble();//this data will be used to make an envelope. Value and time to value in ms.
var sampleIsLoaded = false;

// var vectorTools = new Module.vectorTools();
// init() once the page has finished loading.
window.onload = init;

function setup(){
    console.log("non-overrided setup");
    // setNumOutputChannels(3);
}

// this will be overriden in the users script
function play(){
    // output = 0;
    // console.log("non-overrided play happening");
}

// use to set num channels and set output as an array
// not currently working!
function setNumOutputChannels(numChannelsOut_){

    if(numChannelsOut_ > 1){
        OutputIsArray(true, numChannelsOut_);
    } else {
        OutputIsArray(false, numChannelsOut_);
    }

    source.disconnect();
    jsProcessor.disconnect();
    analyser.disconnect();

    initAudio(numChannelsOut_);

}

function OutputIsArray(isArray, numChannelsOut_){
    if(isArray){
        output = new Array(numChannelsOut_);

        for(var i = 0; i < numChannelsOut_; i++){
            output[i] = 0;
        }
    } else {
        output = 0;
    }
}

var outputErrorLogged = false;
// function handling audio processing
// called byjsProcessor
function process(event) {
    var numChannels = event.outputBuffer.numberOfChannels;
    var outputLength = event.outputBuffer.getChannelData(0).length;
    // console.log(numChannels);

    for (var i = 0; i < outputLength; ++i) {
        play();

        if(output instanceof Array){
            for (var channel = 0; channel < numChannels; channel++) {
                event.outputBuffer.getChannelData(channel)[i] = output[channel];
            }
        }
        else
        {
         for (var channel = 0; channel < numChannels; channel++) {
            event.outputBuffer.getChannelData(channel)[i] = output;
        }
    }
}
}

// var myArrayBuffer = audioCtx.createBuffer(2, 4096, context.sampleRate);

function initAudio(numChannels) {
    source = context.createBufferSource();

    jsProcessor = context.createScriptProcessor(4096, numChannels, numChannels);
    jsProcessor.onaudioprocess = process;

    analyser = context.createAnalyser();
    analyser.fftSize = 2048;

    // // Connect the processing graph: source -> jsProcessor -> analyser -> destination
    source.connect(jsProcessor);
    jsProcessor.connect(analyser);
    analyser.connect(context.destination);
}


function init() {
    initAudio(2);
    setup();
}

// function loadSampleBuffers(url){
//   bufferLoader = new BufferLoader(
//     context,
//     [url],
//     finishedLoading
//     );

//   bufferLoader.load();

// // var sources = [];
// //   for(var i = 0; i < urls.length; i++){
// //     var sourceI = context.createBufferSource();
// //     sourceI.buffer = bufferList[i];
// // }
// }

function loadSample(url, samplePlayer) {
    var data = [];

    samplePlayer.clear();

    sampleIsLoaded = false;
    // Load asynchronously
    var request = new XMLHttpRequest();
    request.addEventListener("load", transferComplete);
    request.open("GET", url, true);

    request.responseType = "arraybuffer";

    request.onload = function() {
        context.decodeAudioData(
            request.response,
            function(buffer) {
                // source.buffer = buffer;
                // source.loop = true;
                // source.start(0);
                data = buffer.getChannelData(0);

                if(data){
                    Module.vectorTools.clearVectorDbl(myBufferData);

                    for(var n = 0; n < data.length; n++){
                        myBufferData.push_back(data[n]);
                    }

                    samplePlayer.setSample(myBufferData);
                    sampleIsLoaded = true;
                }

            },

            function(buffer) {
                console.log("Error decoding source!");
            }
            );
    };

    request.send();

}

function transferComplete(evt) {
  console.log("The transfer is complete.");
}

// function playSound(buffer) {
//   var source = context.createBufferSource(); // creates a sound source
//   source.buffer = buffer;                    // tell the source which sound to play
//   source.connect(context.destination);       // connect the source to the context's destination (the speakers)
//   source.start(0);                           // play the source now
//                                              // note: on older systems, may have to use deprecated noteOn(time);
//                                          }