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Robustify AudioContext code (thanks for the surprise, Chrome!)

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This commit is contained in:
Jeff Parsons 2015-03-07 10:53:15 -08:00 • committed by jeffpar
commit 568c4e031e
6 changed files with 1628 additions and 1597 deletions
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85
modules/pcjs/lib/chipset.js
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@ -233,10 +233,14 @@ function ChipSet(parmsChipSet)
*/
this.fSpeaker = false;
if (parmsChipSet['sound']) {
if (window && 'webkitAudioContext' in window) {
this.contextAudio = new window['webkitAudioContext']();
this.classAudio = this.contextAudio = null;
if (window) {
this.classAudio = window['AudioContext'] || window['webkitAudioContext'];
}
if (this.classAudio) {
this.contextAudio = new this.classAudio();
} else {
if (DEBUG) this.log("webkitAudioContext not available");
if (DEBUG) this.log("AudioContext not available");
}
}
@ -4771,37 +4775,56 @@ ChipSet.prototype.parseSwitches = function(s, def)
ChipSet.prototype.setSpeaker = function(fOn)
{
if (this.contextAudio) {
if (fOn !== undefined) {
this.fSpeaker = fOn;
} else {
fOn = this.fSpeaker && this.cpu && this.cpu.isRunning();
}
var freq = Math.round(ChipSet.TIMER_TICKS_PER_SEC / this.getTimerInit(ChipSet.TIMER2.INDEX));
/*
* Treat frequencies outside the normal hearing range (below 20hz or above 20Khz) as a clever attempt
* to turn sound off; we have to explicitly turn the sound off in those cases, to prevent the Audio API
* from "easing" the audio to the target frequency and creating odd sound effects.
*/
if (freq < 20 || freq > 20000) fOn = false;
if (fOn) {
if (this.sourceAudio) {
this.sourceAudio['frequency']['value'] = freq;
if (this.messageEnabled(Messages.SPEAKER)) this.printMessage("speaker set to " + freq + "hz", true);
try {
if (fOn !== undefined) {
this.fSpeaker = fOn;
} else {
this.sourceAudio = this.contextAudio['createOscillator']();
this.sourceAudio['type'] = "square"; // any of: "sine", "square", "sawtooth", "triangle", "custom"
this.sourceAudio['connect'](this.contextAudio['destination']);
this.sourceAudio['frequency']['value'] = freq;
if (this.messageEnabled(Messages.SPEAKER)) this.printMessage("speaker on at " + freq + "hz", true);
this.sourceAudio['start'](0);
fOn = this.fSpeaker && this.cpu && this.cpu.isRunning();
}
} else {
if (this.sourceAudio) {
this.sourceAudio['stop'](0);
this.sourceAudio['disconnect'](); // QUESTION: is this automatic following a stop(), since this particular source cannot be started again?
delete this.sourceAudio; // QUESTION: ditto?
if (this.messageEnabled(Messages.SPEAKER)) this.printMessage("speaker off at " + freq + "hz", true);
var freq = Math.round(ChipSet.TIMER_TICKS_PER_SEC / this.getTimerInit(ChipSet.TIMER2.INDEX));
/*
* Treat frequencies outside the normal hearing range (below 20hz or above 20Khz) as a clever attempt
* to turn sound off; we have to explicitly turn the sound off in those cases, to prevent the Audio API
* from "easing" the audio to the target frequency and creating odd sound effects.
*/
if (freq < 20 || freq > 20000) fOn = false;
if (fOn) {
if (this.sourceAudio) {
this.sourceAudio['frequency']['value'] = freq;
if (this.messageEnabled(Messages.SPEAKER)) this.printMessage("speaker set to " + freq + "hz", true);
} else {
this.sourceAudio = this.contextAudio['createOscillator']();
if (this.sourceAudio) {
if (typeof this.sourceAudio['type'] == "number") {
this.sourceAudio['type'] = 1; // deprecated: 0: "sine", 1: "square", 2: "sawtooth", 3: "triangle"
} else {
this.sourceAudio['type'] = "square";
}
this.sourceAudio['connect'](this.contextAudio['destination']);
this.sourceAudio['frequency']['value'] = freq;
if ('start' in this.sourceAudio) {
this.sourceAudio['start'](0);
} else {
this.sourceAudio['noteOn'](0); // deprecated: this.sourceAudio['noteOn'](0)
}
if (this.messageEnabled(Messages.SPEAKER)) this.printMessage("speaker on at " + freq + "hz", true);
}
}
} else {
if (this.sourceAudio) {
if ('stop' in this.sourceAudio) {
this.sourceAudio['stop'](0);
} else {
this.sourceAudio['noteOff'](0); // deprecated: this.sourceAudio['noteOff'](0)
}
this.sourceAudio['disconnect'](); // QUESTION: is this automatic following a stop(), since this particular source cannot be started again?
delete this.sourceAudio; // QUESTION: ditto?
if (this.messageEnabled(Messages.SPEAKER)) this.printMessage("speaker off at " + freq + "hz", true);
}
}
} catch(e) {
this.notice("AudioContext exception: " + e.message);
this.contextAudio = null;
}
} else if (fOn) {
this.printMessage("BEEP", Messages.SPEAKER);