91 lines
2.4 KiB
JavaScript
91 lines
2.4 KiB
JavaScript
/* Copyright 2010-2017 Will Scullin <scullin@scullinsteel.com>
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*
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* Permission to use, copy, modify, distribute, and sell this software and its
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* documentation for any purpose is hereby granted without fee, provided that
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* the above copyright notice appear in all copies and that both that
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* copyright notice and this permission notice appear in supporting
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* documentation. No representations are made about the suitability of this
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* software for any purpose. It is provided "as is" without express or
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* implied warranty.
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*/
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/*globals debug: false */
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/*exported Audio */
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/*
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* Audio Handling
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*/
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function Audio(io) {
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var sound = true;
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var _samples = [];
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var audioContext;
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var AudioContext = window.AudioContext || window.webkitAudioContext;
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var audioNode;
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var started = false;
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if (AudioContext) {
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audioContext = new AudioContext();
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audioNode = audioContext.createScriptProcessor(4096, 1, 1);
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audioNode.onaudioprocess = function(event) {
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var data = event.outputBuffer.getChannelData(0);
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var sample = _samples.shift();
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var idx = 0;
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var len = data.length;
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if (sample) {
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len = Math.min(sample.length, len);
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for (; idx < len; idx++) {
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data[idx] = sample[idx];
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}
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}
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for (; idx < data.length; idx++) {
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data[idx] = 0.0;
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}
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};
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audioNode.connect(audioContext.destination);
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}
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function _initAudio(io) {
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if (audioContext) {
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debug('Using Webkit Audio');
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io.sampleRate(audioContext.sampleRate);
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io.addSampleListener(function(sample) {
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if (sound) {
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_samples.push(sample);
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while (_samples.length > 5) {
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_samples.shift();
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}
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}
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});
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}
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}
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_initAudio(io);
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return {
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autoStart: function () {
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if (audioContext && !started) {
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_samples = [];
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audioContext.resume();
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started = true;
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}
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},
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start: function () {
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if (audioContext) {
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_samples = [];
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audioContext.resume();
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}
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},
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enable: function(enable) {
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sound = enable;
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}
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};
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}
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