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Work-around to make sound for iOS devices a little more robust without having to do anything iOS-specific

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This commit is contained in:
Jeff Parsons 2017-08-12 15:08:30 -07:00 • committed by Jeff Parsons
commit 1226392d9f
8 changed files with 500 additions and 484 deletions
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38
modules/pcx86/lib/chipset.js
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@ -153,7 +153,7 @@ class ChipSet extends Component {
* To start, we create an audio context, unless the 'sound' parameter has been explicitly set to false
* or 0; the boolean value true (along with any illegal number) now defaults to 0.5 instead of 1.0.
*/
this.fSpeaker = false;
this.fSpeaker = this.fUserSound = false;
this.volumeInit = 0;
var sound = parmsChipSet['sound'];
if (sound) {
@ -4631,6 +4631,12 @@ class ChipSet extends Component {
/**
* startAudio(event)
*
* NOTE: We currently use named properties rather than "dot" properties to access all the AudioContext
* properties and methods, because we don't have any built-in declarations or externs for them, so neither
* WebStorm nor the Closure Compiler recognize them. We could live with the WebStorm inspection warnings,
* but we definitely can't have the Closure Compiler renaming any of the properties -- and since it
* automatically converts them all to "dot" properties, there's no incentive for us to do anything more.
*
* @this {ChipSet}
* @param {Event} [event] object from a 'touch' event, if any
* @return {boolean}
@ -4644,27 +4650,29 @@ class ChipSet extends Component {
* devices are concerned, because those devices require the oscillator's start() method to be
* called in the context of a user-initiated event.
*
* One possible corrective solution would be to simply recreate the oscillator and gain objects
* every time we're called with an event object, but I'm not prepared to go that far yet....
* So, for the benefit of iOS devices, when we finally receive a user-generated call, we will
* simply recreate the oscillator. This is a one-time work-around for the life of the machine.
*
* TODO: Consider adding a "Sound On/Off" button to all machines (probably in the top right corner,
* where "Full Screen" and "Lock Pointer" buttons typically appear), at least on iOS devices.
*/
if (event) {
if (this.fUserSound) return true;
this.oscillatorAudio = null;
this.fUserSound = true;
}
if (this.oscillatorAudio) return true;
try {
this.oscillatorAudio = this.contextAudio['createOscillator']();
this.volumeAudio = this.contextAudio['createGain']();
this.oscillatorAudio['connect'](this.volumeAudio);
this.volumeAudio['connect'](this.contextAudio['destination']);
this.volumeAudio['gain']['value'] = 0;
if (typeof this.oscillatorAudio['type'] == "number") {
this.oscillatorAudio['type'] = 1; // deprecated (0: "sine", 1: "square", 2: "sawtooth", 3: "triangle")
} else {
if ('start' in this.oscillatorAudio) { // early versions of Web Audio used noteOn() instead of start()
this.volumeAudio = this.contextAudio['createGain']();
this.oscillatorAudio['connect'](this.volumeAudio);
this.volumeAudio['connect'](this.contextAudio['destination']);
this.volumeAudio['gain']['value'] = 0;
this.oscillatorAudio['type'] = "square";
}
if ('start' in this.oscillatorAudio) {
this.oscillatorAudio['start'](0);
} else {
this.oscillatorAudio['noteOn'](0); // deprecated
return true;
}
return true;
} catch(e) {
this.notice("AudioContext exception: " + e.message);
this.contextAudio = null;