metamaps--metamaps/app/assets/javascripts/lib/howler.js

1354 lines
38 KiB
JavaScript
Raw Normal View History

2015-09-19 16:02:05 +00:00
/*!
* howler.js v1.1.26
* howlerjs.com
*
* (c) 2013-2015, James Simpson of GoldFire Studios
* goldfirestudios.com
*
* MIT License
*/
(function() {
// setup
var cache = {};
// setup the audio context
var ctx = null,
usingWebAudio = true,
noAudio = false;
try {
if (typeof AudioContext !== 'undefined') {
ctx = new AudioContext();
} else if (typeof webkitAudioContext !== 'undefined') {
ctx = new webkitAudioContext();
} else {
usingWebAudio = false;
}
} catch(e) {
usingWebAudio = false;
}
if (!usingWebAudio) {
if (typeof Audio !== 'undefined') {
try {
new Audio();
} catch(e) {
noAudio = true;
}
} else {
noAudio = true;
}
}
// create a master gain node
if (usingWebAudio) {
var masterGain = (typeof ctx.createGain === 'undefined') ? ctx.createGainNode() : ctx.createGain();
masterGain.gain.value = 1;
masterGain.connect(ctx.destination);
}
// create global controller
var HowlerGlobal = function(codecs) {
this._volume = 1;
this._muted = false;
this.usingWebAudio = usingWebAudio;
this.ctx = ctx;
this.noAudio = noAudio;
this._howls = [];
this._codecs = codecs;
this.iOSAutoEnable = true;
};
HowlerGlobal.prototype = {
/**
* Get/set the global volume for all sounds.
* @param {Float} vol Volume from 0.0 to 1.0.
* @return {Howler/Float} Returns self or current volume.
*/
volume: function(vol) {
var self = this;
// make sure volume is a number
vol = parseFloat(vol);
if (vol >= 0 && vol <= 1) {
self._volume = vol;
if (usingWebAudio) {
masterGain.gain.value = vol;
}
// loop through cache and change volume of all nodes that are using HTML5 Audio
for (var key in self._howls) {
if (self._howls.hasOwnProperty(key) && self._howls[key]._webAudio === false) {
// loop through the audio nodes
for (var i=0; i<self._howls[key]._audioNode.length; i++) {
self._howls[key]._audioNode[i].volume = self._howls[key]._volume * self._volume;
}
}
}
return self;
}
// return the current global volume
return (usingWebAudio) ? masterGain.gain.value : self._volume;
},
/**
* Mute all sounds.
* @return {Howler}
*/
mute: function() {
this._setMuted(true);
return this;
},
/**
* Unmute all sounds.
* @return {Howler}
*/
unmute: function() {
this._setMuted(false);
return this;
},
/**
* Handle muting and unmuting globally.
* @param {Boolean} muted Is muted or not.
*/
_setMuted: function(muted) {
var self = this;
self._muted = muted;
if (usingWebAudio) {
masterGain.gain.value = muted ? 0 : self._volume;
}
for (var key in self._howls) {
if (self._howls.hasOwnProperty(key) && self._howls[key]._webAudio === false) {
// loop through the audio nodes
for (var i=0; i<self._howls[key]._audioNode.length; i++) {
self._howls[key]._audioNode[i].muted = muted;
}
}
}
},
/**
* Check for codec support.
* @param {String} ext Audio file extention.
* @return {Boolean}
*/
codecs: function(ext) {
return this._codecs[ext];
},
/**
* iOS will only allow audio to be played after a user interaction.
* Attempt to automatically unlock audio on the first user interaction.
* Concept from: http://paulbakaus.com/tutorials/html5/web-audio-on-ios/
* @return {Howler}
*/
_enableiOSAudio: function() {
var self = this;
// only run this on iOS if audio isn't already eanbled
if (ctx && (self._iOSEnabled || !/iPhone|iPad|iPod/i.test(navigator.userAgent))) {
return;
}
self._iOSEnabled = false;
// call this method on touch start to create and play a buffer,
// then check if the audio actually played to determine if
// audio has now been unlocked on iOS
var unlock = function() {
// create an empty buffer
var buffer = ctx.createBuffer(1, 1, 22050);
var source = ctx.createBufferSource();
source.buffer = buffer;
source.connect(ctx.destination);
// play the empty buffer
if (typeof source.start === 'undefined') {
source.noteOn(0);
} else {
source.start(0);
}
// setup a timeout to check that we are unlocked on the next event loop
setTimeout(function() {
if ((source.playbackState === source.PLAYING_STATE || source.playbackState === source.FINISHED_STATE)) {
// update the unlocked state and prevent this check from happening again
self._iOSEnabled = true;
self.iOSAutoEnable = false;
// remove the touch start listener
window.removeEventListener('touchstart', unlock, false);
}
}, 0);
};
// setup a touch start listener to attempt an unlock in
window.addEventListener('touchstart', unlock, false);
return self;
}
};
// check for browser codec support
var audioTest = null;
var codecs = {};
if (!noAudio) {
audioTest = new Audio();
codecs = {
mp3: !!audioTest.canPlayType('audio/mpeg;').replace(/^no$/, ''),
opus: !!audioTest.canPlayType('audio/ogg; codecs="opus"').replace(/^no$/, ''),
ogg: !!audioTest.canPlayType('audio/ogg; codecs="vorbis"').replace(/^no$/, ''),
wav: !!audioTest.canPlayType('audio/wav; codecs="1"').replace(/^no$/, ''),
aac: !!audioTest.canPlayType('audio/aac;').replace(/^no$/, ''),
m4a: !!(audioTest.canPlayType('audio/x-m4a;') || audioTest.canPlayType('audio/m4a;') || audioTest.canPlayType('audio/aac;')).replace(/^no$/, ''),
mp4: !!(audioTest.canPlayType('audio/x-mp4;') || audioTest.canPlayType('audio/mp4;') || audioTest.canPlayType('audio/aac;')).replace(/^no$/, ''),
weba: !!audioTest.canPlayType('audio/webm; codecs="vorbis"').replace(/^no$/, '')
};
}
// allow access to the global audio controls
var Howler = new HowlerGlobal(codecs);
// setup the audio object
var Howl = function(o) {
var self = this;
// setup the defaults
self._autoplay = o.autoplay || false;
self._buffer = o.buffer || false;
self._duration = o.duration || 0;
self._format = o.format || null;
self._loop = o.loop || false;
self._loaded = false;
self._sprite = o.sprite || {};
self._src = o.src || '';
self._pos3d = o.pos3d || [0, 0, -0.5];
self._volume = o.volume !== undefined ? o.volume : 1;
self._urls = o.urls || [];
self._rate = o.rate || 1;
// allow forcing of a specific panningModel ('equalpower' or 'HRTF'),
// if none is specified, defaults to 'equalpower' and switches to 'HRTF'
// if 3d sound is used
self._model = o.model || null;
// setup event functions
self._onload = [o.onload || function() {}];
self._onloaderror = [o.onloaderror || function() {}];
self._onend = [o.onend || function() {}];
self._onpause = [o.onpause || function() {}];
self._onplay = [o.onplay || function() {}];
self._onendTimer = [];
// Web Audio or HTML5 Audio?
self._webAudio = usingWebAudio && !self._buffer;
// check if we need to fall back to HTML5 Audio
self._audioNode = [];
if (self._webAudio) {
self._setupAudioNode();
}
// automatically try to enable audio on iOS
if (typeof ctx !== 'undefined' && ctx && Howler.iOSAutoEnable) {
Howler._enableiOSAudio();
}
// add this to an array of Howl's to allow global control
Howler._howls.push(self);
// load the track
self.load();
};
// setup all of the methods
Howl.prototype = {
/**
* Load an audio file.
* @return {Howl}
*/
load: function() {
var self = this,
url = null;
// if no audio is available, quit immediately
if (noAudio) {
self.on('loaderror');
return;
}
// loop through source URLs and pick the first one that is compatible
for (var i=0; i<self._urls.length; i++) {
var ext, urlItem;
if (self._format) {
// use specified audio format if available
ext = self._format;
} else {
// figure out the filetype (whether an extension or base64 data)
urlItem = self._urls[i];
ext = /^data:audio\/([^;,]+);/i.exec(urlItem);
if (!ext) {
ext = /\.([^.]+)$/.exec(urlItem.split('?', 1)[0]);
}
if (ext) {
ext = ext[1].toLowerCase();
} else {
self.on('loaderror');
return;
}
}
if (codecs[ext]) {
url = self._urls[i];
break;
}
}
if (!url) {
self.on('loaderror');
return;
}
self._src = url;
if (self._webAudio) {
loadBuffer(self, url);
} else {
var newNode = new Audio();
// listen for errors with HTML5 audio (http://dev.w3.org/html5/spec-author-view/spec.html#mediaerror)
newNode.addEventListener('error', function () {
if (newNode.error && newNode.error.code === 4) {
HowlerGlobal.noAudio = true;
}
self.on('loaderror', {type: newNode.error ? newNode.error.code : 0});
}, false);
self._audioNode.push(newNode);
// setup the new audio node
newNode.src = url;
newNode._pos = 0;
newNode.preload = 'auto';
newNode.volume = (Howler._muted) ? 0 : self._volume * Howler.volume();
// setup the event listener to start playing the sound
// as soon as it has buffered enough
var listener = function() {
// round up the duration when using HTML5 Audio to account for the lower precision
self._duration = Math.ceil(newNode.duration * 10) / 10;
// setup a sprite if none is defined
if (Object.getOwnPropertyNames(self._sprite).length === 0) {
self._sprite = {_default: [0, self._duration * 1000]};
}
if (!self._loaded) {
self._loaded = true;
self.on('load');
}
if (self._autoplay) {
self.play();
}
// clear the event listener
newNode.removeEventListener('canplaythrough', listener, false);
};
newNode.addEventListener('canplaythrough', listener, false);
newNode.load();
}
return self;
},
/**
* Get/set the URLs to be pulled from to play in this source.
* @param {Array} urls Arry of URLs to load from
* @return {Howl} Returns self or the current URLs
*/
urls: function(urls) {
var self = this;
if (urls) {
self.stop();
self._urls = (typeof urls === 'string') ? [urls] : urls;
self._loaded = false;
self.load();
return self;
} else {
return self._urls;
}
},
/**
* Play a sound from the current time (0 by default).
* @param {String} sprite (optional) Plays from the specified position in the sound sprite definition.
* @param {Function} callback (optional) Returns the unique playback id for this sound instance.
* @return {Howl}
*/
play: function(sprite, callback) {
var self = this;
// if no sprite was passed but a callback was, update the variables
if (typeof sprite === 'function') {
callback = sprite;
}
// use the default sprite if none is passed
if (!sprite || typeof sprite === 'function') {
sprite = '_default';
}
// if the sound hasn't been loaded, add it to the event queue
if (!self._loaded) {
self.on('load', function() {
self.play(sprite, callback);
});
return self;
}
// if the sprite doesn't exist, play nothing
if (!self._sprite[sprite]) {
if (typeof callback === 'function') callback();
return self;
}
// get the node to playback
self._inactiveNode(function(node) {
// persist the sprite being played
node._sprite = sprite;
// determine where to start playing from
var pos = (node._pos > 0) ? node._pos : self._sprite[sprite][0] / 1000;
// determine how long to play for
var duration = 0;
if (self._webAudio) {
duration = self._sprite[sprite][1] / 1000 - node._pos;
if (node._pos > 0) {
pos = self._sprite[sprite][0] / 1000 + pos;
}
} else {
duration = self._sprite[sprite][1] / 1000 - (pos - self._sprite[sprite][0] / 1000);
}
// determine if this sound should be looped
var loop = !!(self._loop || self._sprite[sprite][2]);
// set timer to fire the 'onend' event
var soundId = (typeof callback === 'string') ? callback : Math.round(Date.now() * Math.random()) + '',
timerId;
(function() {
var data = {
id: soundId,
sprite: sprite,
loop: loop
};
timerId = setTimeout(function() {
// if looping, restart the track
if (!self._webAudio && loop) {
self.stop(data.id).play(sprite, data.id);
}
// set web audio node to paused at end
if (self._webAudio && !loop) {
self._nodeById(data.id).paused = true;
self._nodeById(data.id)._pos = 0;
// clear the end timer
self._clearEndTimer(data.id);
}
// end the track if it is HTML audio and a sprite
if (!self._webAudio && !loop) {
self.stop(data.id);
}
// fire ended event
self.on('end', soundId);
}, duration * 1000);
// store the reference to the timer
self._onendTimer.push({timer: timerId, id: data.id});
})();
if (self._webAudio) {
var loopStart = self._sprite[sprite][0] / 1000,
loopEnd = self._sprite[sprite][1] / 1000;
// set the play id to this node and load into context
node.id = soundId;
node.paused = false;
refreshBuffer(self, [loop, loopStart, loopEnd], soundId);
self._playStart = ctx.currentTime;
node.gain.value = self._volume;
if (typeof node.bufferSource.start === 'undefined') {
loop ? node.bufferSource.noteGrainOn(0, pos, 86400) : node.bufferSource.noteGrainOn(0, pos, duration);
} else {
loop ? node.bufferSource.start(0, pos, 86400) : node.bufferSource.start(0, pos, duration);
}
} else {
if (node.readyState === 4 || !node.readyState && navigator.isCocoonJS) {
node.readyState = 4;
node.id = soundId;
node.currentTime = pos;
node.muted = Howler._muted || node.muted;
node.volume = self._volume * Howler.volume();
setTimeout(function() { node.play(); }, 0);
} else {
self._clearEndTimer(soundId);
(function(){
var sound = self,
playSprite = sprite,
fn = callback,
newNode = node;
var listener = function() {
sound.play(playSprite, fn);
// clear the event listener
newNode.removeEventListener('canplaythrough', listener, false);
};
newNode.addEventListener('canplaythrough', listener, false);
})();
return self;
}
}
// fire the play event and send the soundId back in the callback
self.on('play');
if (typeof callback === 'function') callback(soundId);
return self;
});
return self;
},
/**
* Pause playback and save the current position.
* @param {String} id (optional) The play instance ID.
* @return {Howl}
*/
pause: function(id) {
var self = this;
// if the sound hasn't been loaded, add it to the event queue
if (!self._loaded) {
self.on('play', function() {
self.pause(id);
});
return self;
}
// clear 'onend' timer
self._clearEndTimer(id);
var activeNode = (id) ? self._nodeById(id) : self._activeNode();
if (activeNode) {
activeNode._pos = self.pos(null, id);
if (self._webAudio) {
// make sure the sound has been created
if (!activeNode.bufferSource || activeNode.paused) {
return self;
}
activeNode.paused = true;
if (typeof activeNode.bufferSource.stop === 'undefined') {
activeNode.bufferSource.noteOff(0);
} else {
activeNode.bufferSource.stop(0);
}
} else {
activeNode.pause();
}
}
self.on('pause');
return self;
},
/**
* Stop playback and reset to start.
* @param {String} id (optional) The play instance ID.
* @return {Howl}
*/
stop: function(id) {
var self = this;
// if the sound hasn't been loaded, add it to the event queue
if (!self._loaded) {
self.on('play', function() {
self.stop(id);
});
return self;
}
// clear 'onend' timer
self._clearEndTimer(id);
var activeNode = (id) ? self._nodeById(id) : self._activeNode();
if (activeNode) {
activeNode._pos = 0;
if (self._webAudio) {
// make sure the sound has been created
if (!activeNode.bufferSource || activeNode.paused) {
return self;
}
activeNode.paused = true;
if (typeof activeNode.bufferSource.stop === 'undefined') {
activeNode.bufferSource.noteOff(0);
} else {
activeNode.bufferSource.stop(0);
}
} else if (!isNaN(activeNode.duration)) {
activeNode.pause();
activeNode.currentTime = 0;
}
}
return self;
},
/**
* Mute this sound.
* @param {String} id (optional) The play instance ID.
* @return {Howl}
*/
mute: function(id) {
var self = this;
// if the sound hasn't been loaded, add it to the event queue
if (!self._loaded) {
self.on('play', function() {
self.mute(id);
});
return self;
}
var activeNode = (id) ? self._nodeById(id) : self._activeNode();
if (activeNode) {
if (self._webAudio) {
activeNode.gain.value = 0;
} else {
activeNode.muted = true;
}
}
return self;
},
/**
* Unmute this sound.
* @param {String} id (optional) The play instance ID.
* @return {Howl}
*/
unmute: function(id) {
var self = this;
// if the sound hasn't been loaded, add it to the event queue
if (!self._loaded) {
self.on('play', function() {
self.unmute(id);
});
return self;
}
var activeNode = (id) ? self._nodeById(id) : self._activeNode();
if (activeNode) {
if (self._webAudio) {
activeNode.gain.value = self._volume;
} else {
activeNode.muted = false;
}
}
return self;
},
/**
* Get/set volume of this sound.
* @param {Float} vol Volume from 0.0 to 1.0.
* @param {String} id (optional) The play instance ID.
* @return {Howl/Float} Returns self or current volume.
*/
volume: function(vol, id) {
var self = this;
// make sure volume is a number
vol = parseFloat(vol);
if (vol >= 0 && vol <= 1) {
self._volume = vol;
// if the sound hasn't been loaded, add it to the event queue
if (!self._loaded) {
self.on('play', function() {
self.volume(vol, id);
});
return self;
}
var activeNode = (id) ? self._nodeById(id) : self._activeNode();
if (activeNode) {
if (self._webAudio) {
activeNode.gain.value = vol;
} else {
activeNode.volume = vol * Howler.volume();
}
}
return self;
} else {
return self._volume;
}
},
/**
* Get/set whether to loop the sound.
* @param {Boolean} loop To loop or not to loop, that is the question.
* @return {Howl/Boolean} Returns self or current looping value.
*/
loop: function(loop) {
var self = this;
if (typeof loop === 'boolean') {
self._loop = loop;
return self;
} else {
return self._loop;
}
},
/**
* Get/set sound sprite definition.
* @param {Object} sprite Example: {spriteName: [offset, duration, loop]}
* @param {Integer} offset Where to begin playback in milliseconds
* @param {Integer} duration How long to play in milliseconds
* @param {Boolean} loop (optional) Set true to loop this sprite
* @return {Howl} Returns current sprite sheet or self.
*/
sprite: function(sprite) {
var self = this;
if (typeof sprite === 'object') {
self._sprite = sprite;
return self;
} else {
return self._sprite;
}
},
/**
* Get/set the position of playback.
* @param {Float} pos The position to move current playback to.
* @param {String} id (optional) The play instance ID.
* @return {Howl/Float} Returns self or current playback position.
*/
pos: function(pos, id) {
var self = this;
// if the sound hasn't been loaded, add it to the event queue
if (!self._loaded) {
self.on('load', function() {
self.pos(pos);
});
return typeof pos === 'number' ? self : self._pos || 0;
}
// make sure we are dealing with a number for pos
pos = parseFloat(pos);
var activeNode = (id) ? self._nodeById(id) : self._activeNode();
if (activeNode) {
if (pos >= 0) {
self.pause(id);
activeNode._pos = pos;
self.play(activeNode._sprite, id);
return self;
} else {
return self._webAudio ? activeNode._pos + (ctx.currentTime - self._playStart) : activeNode.currentTime;
}
} else if (pos >= 0) {
return self;
} else {
// find the first inactive node to return the pos for
for (var i=0; i<self._audioNode.length; i++) {
if (self._audioNode[i].paused && self._audioNode[i].readyState === 4) {
return (self._webAudio) ? self._audioNode[i]._pos : self._audioNode[i].currentTime;
}
}
}
},
/**
* Get/set the 3D position of the audio source.
* The most common usage is to set the 'x' position
* to affect the left/right ear panning. Setting any value higher than
* 1.0 will begin to decrease the volume of the sound as it moves further away.
* NOTE: This only works with Web Audio API, HTML5 Audio playback
* will not be affected.
* @param {Float} x The x-position of the playback from -1000.0 to 1000.0
* @param {Float} y The y-position of the playback from -1000.0 to 1000.0
* @param {Float} z The z-position of the playback from -1000.0 to 1000.0
* @param {String} id (optional) The play instance ID.
* @return {Howl/Array} Returns self or the current 3D position: [x, y, z]
*/
pos3d: function(x, y, z, id) {
var self = this;
// set a default for the optional 'y' & 'z'
y = (typeof y === 'undefined' || !y) ? 0 : y;
z = (typeof z === 'undefined' || !z) ? -0.5 : z;
// if the sound hasn't been loaded, add it to the event queue
if (!self._loaded) {
self.on('play', function() {
self.pos3d(x, y, z, id);
});
return self;
}
if (x >= 0 || x < 0) {
if (self._webAudio) {
var activeNode = (id) ? self._nodeById(id) : self._activeNode();
if (activeNode) {
self._pos3d = [x, y, z];
activeNode.panner.setPosition(x, y, z);
activeNode.panner.panningModel = self._model || 'HRTF';
}
}
} else {
return self._pos3d;
}
return self;
},
/**
* Fade a currently playing sound between two volumes.
* @param {Number} from The volume to fade from (0.0 to 1.0).
* @param {Number} to The volume to fade to (0.0 to 1.0).
* @param {Number} len Time in milliseconds to fade.
* @param {Function} callback (optional) Fired when the fade is complete.
* @param {String} id (optional) The play instance ID.
* @return {Howl}
*/
fade: function(from, to, len, callback, id) {
var self = this,
diff = Math.abs(from - to),
dir = from > to ? 'down' : 'up',
steps = diff / 0.01,
stepTime = len / steps;
// if the sound hasn't been loaded, add it to the event queue
if (!self._loaded) {
self.on('load', function() {
self.fade(from, to, len, callback, id);
});
return self;
}
// set the volume to the start position
self.volume(from, id);
for (var i=1; i<=steps; i++) {
(function() {
var change = self._volume + (dir === 'up' ? 0.01 : -0.01) * i,
vol = Math.round(1000 * change) / 1000,
toVol = to;
setTimeout(function() {
self.volume(vol, id);
if (vol === toVol) {
if (callback) callback();
}
}, stepTime * i);
})();
}
},
/**
* [DEPRECATED] Fade in the current sound.
* @param {Float} to Volume to fade to (0.0 to 1.0).
* @param {Number} len Time in milliseconds to fade.
* @param {Function} callback
* @return {Howl}
*/
fadeIn: function(to, len, callback) {
return this.volume(0).play().fade(0, to, len, callback);
},
/**
* [DEPRECATED] Fade out the current sound and pause when finished.
* @param {Float} to Volume to fade to (0.0 to 1.0).
* @param {Number} len Time in milliseconds to fade.
* @param {Function} callback
* @param {String} id (optional) The play instance ID.
* @return {Howl}
*/
fadeOut: function(to, len, callback, id) {
var self = this;
return self.fade(self._volume, to, len, function() {
if (callback) callback();
self.pause(id);
// fire ended event
self.on('end');
}, id);
},
/**
* Get an audio node by ID.
* @return {Howl} Audio node.
*/
_nodeById: function(id) {
var self = this,
node = self._audioNode[0];
// find the node with this ID
for (var i=0; i<self._audioNode.length; i++) {
if (self._audioNode[i].id === id) {
node = self._audioNode[i];
break;
}
}
return node;
},
/**
* Get the first active audio node.
* @return {Howl} Audio node.
*/
_activeNode: function() {
var self = this,
node = null;
// find the first playing node
for (var i=0; i<self._audioNode.length; i++) {
if (!self._audioNode[i].paused) {
node = self._audioNode[i];
break;
}
}
// remove excess inactive nodes
self._drainPool();
return node;
},
/**
* Get the first inactive audio node.
* If there is none, create a new one and add it to the pool.
* @param {Function} callback Function to call when the audio node is ready.
*/
_inactiveNode: function(callback) {
var self = this,
node = null;
// find first inactive node to recycle
for (var i=0; i<self._audioNode.length; i++) {
if (self._audioNode[i].paused && self._audioNode[i].readyState === 4) {
// send the node back for use by the new play instance
callback(self._audioNode[i]);
node = true;
break;
}
}
// remove excess inactive nodes
self._drainPool();
if (node) {
return;
}
// create new node if there are no inactives
var newNode;
if (self._webAudio) {
newNode = self._setupAudioNode();
callback(newNode);
} else {
self.load();
newNode = self._audioNode[self._audioNode.length - 1];
// listen for the correct load event and fire the callback
var listenerEvent = navigator.isCocoonJS ? 'canplaythrough' : 'loadedmetadata';
var listener = function() {
newNode.removeEventListener(listenerEvent, listener, false);
callback(newNode);
};
newNode.addEventListener(listenerEvent, listener, false);
}
},
/**
* If there are more than 5 inactive audio nodes in the pool, clear out the rest.
*/
_drainPool: function() {
var self = this,
inactive = 0,
i;
// count the number of inactive nodes
for (i=0; i<self._audioNode.length; i++) {
if (self._audioNode[i].paused) {
inactive++;
}
}
// remove excess inactive nodes
for (i=self._audioNode.length-1; i>=0; i--) {
if (inactive <= 5) {
break;
}
if (self._audioNode[i].paused) {
// disconnect the audio source if using Web Audio
if (self._webAudio) {
self._audioNode[i].disconnect(0);
}
inactive--;
self._audioNode.splice(i, 1);
}
}
},
/**
* Clear 'onend' timeout before it ends.
* @param {String} soundId The play instance ID.
*/
_clearEndTimer: function(soundId) {
var self = this,
index = 0;
// loop through the timers to find the one associated with this sound
for (var i=0; i<self._onendTimer.length; i++) {
if (self._onendTimer[i].id === soundId) {
index = i;
break;
}
}
var timer = self._onendTimer[index];
if (timer) {
clearTimeout(timer.timer);
self._onendTimer.splice(index, 1);
}
},
/**
* Setup the gain node and panner for a Web Audio instance.
* @return {Object} The new audio node.
*/
_setupAudioNode: function() {
var self = this,
node = self._audioNode,
index = self._audioNode.length;
// create gain node
node[index] = (typeof ctx.createGain === 'undefined') ? ctx.createGainNode() : ctx.createGain();
node[index].gain.value = self._volume;
node[index].paused = true;
node[index]._pos = 0;
node[index].readyState = 4;
node[index].connect(masterGain);
// create the panner
node[index].panner = ctx.createPanner();
node[index].panner.panningModel = self._model || 'equalpower';
node[index].panner.setPosition(self._pos3d[0], self._pos3d[1], self._pos3d[2]);
node[index].panner.connect(node[index]);
return node[index];
},
/**
* Call/set custom events.
* @param {String} event Event type.
* @param {Function} fn Function to call.
* @return {Howl}
*/
on: function(event, fn) {
var self = this,
events = self['_on' + event];
if (typeof fn === 'function') {
events.push(fn);
} else {
for (var i=0; i<events.length; i++) {
if (fn) {
events[i].call(self, fn);
} else {
events[i].call(self);
}
}
}
return self;
},
/**
* Remove a custom event.
* @param {String} event Event type.
* @param {Function} fn Listener to remove.
* @return {Howl}
*/
off: function(event, fn) {
var self = this,
events = self['_on' + event],
fnString = fn ? fn.toString() : null;
if (fnString) {
// loop through functions in the event for comparison
for (var i=0; i<events.length; i++) {
if (fnString === events[i].toString()) {
events.splice(i, 1);
break;
}
}
} else {
self['_on' + event] = [];
}
return self;
},
/**
* Unload and destroy the current Howl object.
* This will immediately stop all play instances attached to this sound.
*/
unload: function() {
var self = this;
// stop playing any active nodes
var nodes = self._audioNode;
for (var i=0; i<self._audioNode.length; i++) {
// stop the sound if it is currently playing
if (!nodes[i].paused) {
self.stop(nodes[i].id);
self.on('end', nodes[i].id);
}
if (!self._webAudio) {
// remove the source if using HTML5 Audio
nodes[i].src = '';
} else {
// disconnect the output from the master gain
nodes[i].disconnect(0);
}
}
// make sure all timeouts are cleared
for (i=0; i<self._onendTimer.length; i++) {
clearTimeout(self._onendTimer[i].timer);
}
// remove the reference in the global Howler object
var index = Howler._howls.indexOf(self);
if (index !== null && index >= 0) {
Howler._howls.splice(index, 1);
}
// delete this sound from the cache
delete cache[self._src];
self = null;
}
};
// only define these functions when using WebAudio
if (usingWebAudio) {
/**
* Buffer a sound from URL (or from cache) and decode to audio source (Web Audio API).
* @param {Object} obj The Howl object for the sound to load.
* @param {String} url The path to the sound file.
*/
var loadBuffer = function(obj, url) {
// check if the buffer has already been cached
if (url in cache) {
// set the duration from the cache
obj._duration = cache[url].duration;
// load the sound into this object
loadSound(obj);
return;
}
if (/^data:[^;]+;base64,/.test(url)) {
// Decode base64 data-URIs because some browsers cannot load data-URIs with XMLHttpRequest.
var data = atob(url.split(',')[1]);
var dataView = new Uint8Array(data.length);
for (var i=0; i<data.length; ++i) {
dataView[i] = data.charCodeAt(i);
}
decodeAudioData(dataView.buffer, obj, url);
} else {
// load the buffer from the URL
var xhr = new XMLHttpRequest();
xhr.open('GET', url, true);
xhr.responseType = 'arraybuffer';
xhr.onload = function() {
decodeAudioData(xhr.response, obj, url);
};
xhr.onerror = function() {
// if there is an error, switch the sound to HTML Audio
if (obj._webAudio) {
obj._buffer = true;
obj._webAudio = false;
obj._audioNode = [];
delete obj._gainNode;
delete cache[url];
obj.load();
}
};
try {
xhr.send();
} catch (e) {
xhr.onerror();
}
}
};
/**
* Decode audio data from an array buffer.
* @param {ArrayBuffer} arraybuffer The audio data.
* @param {Object} obj The Howl object for the sound to load.
* @param {String} url The path to the sound file.
*/
var decodeAudioData = function(arraybuffer, obj, url) {
// decode the buffer into an audio source
ctx.decodeAudioData(
arraybuffer,
function(buffer) {
if (buffer) {
cache[url] = buffer;
loadSound(obj, buffer);
}
},
function(err) {
obj.on('loaderror');
}
);
};
/**
* Finishes loading the Web Audio API sound and fires the loaded event
* @param {Object} obj The Howl object for the sound to load.
* @param {Objecct} buffer The decoded buffer sound source.
*/
var loadSound = function(obj, buffer) {
// set the duration
obj._duration = (buffer) ? buffer.duration : obj._duration;
// setup a sprite if none is defined
if (Object.getOwnPropertyNames(obj._sprite).length === 0) {
obj._sprite = {_default: [0, obj._duration * 1000]};
}
// fire the loaded event
if (!obj._loaded) {
obj._loaded = true;
obj.on('load');
}
if (obj._autoplay) {
obj.play();
}
};
/**
* Load the sound back into the buffer source.
* @param {Object} obj The sound to load.
* @param {Array} loop Loop boolean, pos, and duration.
* @param {String} id (optional) The play instance ID.
*/
var refreshBuffer = function(obj, loop, id) {
// determine which node to connect to
var node = obj._nodeById(id);
// setup the buffer source for playback
node.bufferSource = ctx.createBufferSource();
node.bufferSource.buffer = cache[obj._src];
node.bufferSource.connect(node.panner);
node.bufferSource.loop = loop[0];
if (loop[0]) {
node.bufferSource.loopStart = loop[1];
node.bufferSource.loopEnd = loop[1] + loop[2];
}
node.bufferSource.playbackRate.value = obj._rate;
};
}
/**
* Add support for AMD (Asynchronous Module Definition) libraries such as require.js.
*/
if (typeof define === 'function' && define.amd) {
define(function() {
return {
Howler: Howler,
Howl: Howl
};
});
}
/**
* Add support for CommonJS libraries such as browserify.
*/
if (typeof exports !== 'undefined') {
exports.Howler = Howler;
exports.Howl = Howl;
}
// define globally in case AMD is not available or available but not used
if (typeof window !== 'undefined') {
window.Howler = Howler;
window.Howl = Howl;
}
})();