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implemented "selective initialization", meaning that gain and convolv…
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…er nodes aren't created until the initialize function is called, see #18
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@jbphet
jbphet committed Jul 16, 2018
1 parent 577b916 commit 91fe862
Showing 1 changed file with 86 additions and 84 deletions.
170 changes: 86 additions & 84 deletions js/soundManager.js
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Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,7 @@
* - master gain for sounds in general
* - enable/disable of sounds based on their assigned sonification level (e.g. "basic" or "enhanced")
* - gain control for sounds based on their assigned class, e.g. UI versus sim-specific sounds
* - a shared reverb unit to add some spatialization and make all sounds seem to originate with the same room
* - a shared reverb unit to add some spatialization and make all sounds seem to originate with the same space
*
* The singleton object must be initialized before sound generators can be added.
*/
Expand Down Expand Up @@ -52,91 +52,19 @@ define( function( require ) {
// array where the sound generators are stored along with information about how to manage them
var soundGeneratorInfoArray = [];

// master gain node for all sounds managed by this sonification manager
var masterGainNode = phetAudioContext.createGain();
masterGainNode.connect( phetAudioContext.destination );

// output level for the master gain node when sonification is enabled
var masterOutputLevel = 1;

// convolver node, which will be used to create the reverb effect
var convolver = phetAudioContext.createConvolver();

// gain node that will control the reverb level
var reverbGainNode = phetAudioContext.createGain();
reverbGainNode.connect( masterGainNode );
reverbGainNode.gain.setValueAtTime( DEFAULT_REVERB_LEVEL, phetAudioContext.currentTime );
convolver.connect( reverbGainNode );

// dry (non-reverbed) portion of the output
var dryGainNode = phetAudioContext.createGain();
dryGainNode.gain.setValueAtTime( 1 - DEFAULT_REVERB_LEVEL, phetAudioContext.currentTime );
dryGainNode.connect( masterGainNode );

// load the reverb impulse response into the convolver
soundInfoDecoder.decode(
reverbImpulseResponse,
phetAudioContext,
function( decodedAudioData ) {
convolver.buffer = decodedAudioData;
},
function() {

// we haven't seen this happen, so for now a message is logged to the console and that's it
console.log( 'Error: Unable to decode audio data.' );
}
);

// list of reset-in-progress properties, one should be supplied for each screen
var resetInProgressProperties = [];

// a local property that is true when no resets are happening (which would presumably be most of the time) and goes
// false when a reset is in progress
var noResetInProgressProperty = new BooleanProperty( true );

// create the gain nodes for each of the defined "classes" and hook them up, will be defined during init
// gain nodes for each of the defined "classes", will be defined during init
var gainNodesForClasses = {};

// Below is some platform-specific code for handling some issues related to audio. It may be possible to remove some
// or all of this as Web Audio becomes more consistently implemented.
if ( phetAudioContext ) {

if ( !platform.mobileSafari ) {

// In some browsers the audio context is not allowed to run before the user interacts with the simulation. The
// motivation for this is to prevent auto-play of sound (mostly videos) when users land on websites, but it ends
// up preventing PhET sims from being able to play sound. To deal with this, we add a listener that can check the
// state of the audio context and "resume" it if necessary when the user starts interacting with the sim. See
// https://github.com/phetsims/vibe/issues/32 and https://github.com/phetsims/tambo/issues/9 for more information.
if ( phetAudioContext.state !== 'running' ) {

Display.userGestureEmitter.addListener( function resumeAudioContext() {
if ( phetAudioContext.state !== 'running' ) {

// the audio context isn't running, so tell it to resume
phetAudioContext.resume().catch( function( err ) {
assert && assert( false, 'error when trying to resume audio context, err = ' + err );
} );
}
Display.userGestureEmitter.removeListener( resumeAudioContext ); // only do this once
} );
}
}
else {

// There is a different issue for audio on iOS+Safari: On this platform, we must play an audio file from a thread
// initiated by a user event such as touchstart before any sounds will play. This requires the user to touch the
// screen before audio can be played. See
// http://stackoverflow.com/questions/12517000/no-sound-on-ios-6-web-audio-api
var silence = new OneShotSoundClip( empty, { connectImmediately: true } );
var playSilence = function() {
silence.play();
window.removeEventListener( 'touchstart', playSilence, false );
};
window.addEventListener( 'touchstart', playSilence, false );
}
}

// flag that tracks whether the sonification manager has been initialized
var initialized = false;

Expand All @@ -146,13 +74,14 @@ define( function( require ) {
var soundManager = {

/**
* initialize the sonification manager - this function must be invoked before the sonification manager is used
* initialize the sonification manager - this function must be invoked before any sound generators can be added
* @param {BooleanProperty} simVisibleProperty
* @param {Object} [options]
*/
initialize: function( simVisibleProperty, options ) {

assert && assert( !initialized, 'can\'t initialize the sound manager more than once' );
var self = this;

options = _.extend( {

Expand All @@ -170,11 +99,43 @@ define( function( require ) {
'unexpected type for options.classes'
);

// create the master gain node for all sounds managed by this sonification manager
this.masterGainNode = phetAudioContext.createGain();
this.masterGainNode.connect( phetAudioContext.destination );

// convolver node, which will be used to create the reverb effect
this.convolver = phetAudioContext.createConvolver();

// gain node that will control the reverb level
this.reverbGainNode = phetAudioContext.createGain();
this.reverbGainNode.connect( this.masterGainNode );
this.reverbGainNode.gain.setValueAtTime( DEFAULT_REVERB_LEVEL, phetAudioContext.currentTime );
this.convolver.connect( this.reverbGainNode );

// dry (non-reverbed) portion of the output
this.dryGainNode = phetAudioContext.createGain();
this.dryGainNode.gain.setValueAtTime( 1 - DEFAULT_REVERB_LEVEL, phetAudioContext.currentTime );
this.dryGainNode.connect( this.masterGainNode );

// load the reverb impulse response into the convolver
soundInfoDecoder.decode(
reverbImpulseResponse,
phetAudioContext,
function( decodedAudioData ) {
self.convolver.buffer = decodedAudioData;
},
function() {

// we haven't seen this happen, so for now a message is logged to the console and that's it
console.log( 'Error: Unable to decode audio data.' );
}
);

// create and hook up gain nodes for each of the defined classes
options.classes.forEach( function( className ) {
var gainNode = phetAudioContext.createGain();
gainNode.connect( convolver );
gainNode.connect( dryGainNode );
gainNode.connect( self.convolver );
gainNode.connect( self.dryGainNode );
gainNodesForClasses[ className ] = gainNode;
} );

Expand All @@ -183,10 +144,51 @@ define( function( require ) {
[ this.enabledProperty, simVisibleProperty ],
function( enabled, simVisible ) {
var gain = enabled && simVisible ? masterOutputLevel : 0;
masterGainNode.gain.setTargetAtTime( gain, phetAudioContext.currentTime, TC_FOR_PARAM_CHANGES );
self.masterGainNode.gain.setTargetAtTime( gain, phetAudioContext.currentTime, TC_FOR_PARAM_CHANGES );
}
);

// Below is some platform-specific code for handling some issues related to audio. It may be possible to remove
// some or all of this as Web Audio becomes more consistently implemented.
if ( phetAudioContext ) {

if ( !platform.mobileSafari ) {

// In some browsers the audio context is not allowed to run before the user interacts with the simulation.
// The motivation for this is to prevent auto-play of sound (mostly videos) when users land on websites, but
// it ends up preventing PhET sims from being able to play sound. To deal with this, we add a listener that
// can check the state of the audio context and "resume" it if necessary when the user starts interacting with
// the sim. See https://github.com/phetsims/vibe/issues/32 and https://github.com/phetsims/tambo/issues/9 for
// more information.
if ( phetAudioContext.state !== 'running' ) {

Display.userGestureEmitter.addListener( function resumeAudioContext() {
if ( phetAudioContext.state !== 'running' ) {

// the audio context isn't running, so tell it to resume
phetAudioContext.resume().catch( function( err ) {
assert && assert( false, 'error when trying to resume audio context, err = ' + err );
} );
}
Display.userGestureEmitter.removeListener( resumeAudioContext ); // only do this once
} );
}
}
else {

// There is a different issue for audio on iOS+Safari: On this platform, we must play an audio file from a
// thread initiated by a user event such as touchstart before any sounds will play. This requires the user to
// touch the screen before audio can be played. See
// http://stackoverflow.com/questions/12517000/no-sound-on-ios-6-web-audio-api
var silence = new OneShotSoundClip( empty, { connectImmediately: true } );
var playSilence = function() {
silence.play();
window.removeEventListener( 'touchstart', playSilence, false );
};
window.addEventListener( 'touchstart', playSilence, false );
}
}

initialized = true;
},

Expand Down Expand Up @@ -241,8 +243,8 @@ define( function( require ) {
// connect the sound generator to an output path unless the options indicate otherwise
if ( options.connect ) {
if ( options.className === null ) {
soundGenerator.connect( convolver );
soundGenerator.connect( dryGainNode );
soundGenerator.connect( this.convolver );
soundGenerator.connect( this.dryGainNode );
}
else {
soundGenerator.connect( gainNodesForClasses[ options.className ] );
Expand Down Expand Up @@ -323,7 +325,7 @@ define( function( require ) {

masterOutputLevel = outputLevel;
if ( enabledProperty.get() ) {
masterGainNode.gain.setTargetAtTime( outputLevel, phetAudioContext.currentTime, TC_FOR_PARAM_CHANGES );
this.masterGainNode.gain.setTargetAtTime( outputLevel, phetAudioContext.currentTime, TC_FOR_PARAM_CHANGES );
}
},

Expand Down Expand Up @@ -376,13 +378,13 @@ define( function( require ) {
setReverbLevel: function( reverbLevel ) {
assert && assert( reverbLevel >= 0 && reverbLevel <= 1 );
var now = phetAudioContext.currentTime;
reverbGainNode.gain.setTargetAtTime( reverbLevel, now, TC_FOR_PARAM_CHANGES );
dryGainNode.gain.setTargetAtTime( 1 - reverbLevel, now, TC_FOR_PARAM_CHANGES );
this.reverbGainNode.gain.setTargetAtTime( reverbLevel, now, TC_FOR_PARAM_CHANGES );
this.dryGainNode.gain.setTargetAtTime( 1 - reverbLevel, now, TC_FOR_PARAM_CHANGES );
},

getReverbLevel: function() {
// TODO: Test if this works in all browser, add a var to track if not.
return reverbGainNode.gain.value;
return this.reverbGainNode.gain.value;
},

/**
Expand Down

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