vail/static/outputs.mjs

476 lines
10 KiB
JavaScript

const HIGH_FREQ = 555
const LOW_FREQ = 444
/**
* A duration.
*
* Because JavaScript has multiple confliction notions of duration,
* everything in vail uses this.
*
* @typedef {number} Duration
*/
/**
* An epoch time, as returned by Date.now().
*
* @typedef {number} Date
*/
const Millisecond = 1
const Second = 1000 * Millisecond
/** The amount of time it should take an oscillator to ramp to and from zero gain
*
* @constant {Duration}
*/
const OscillatorRampDuration = 5*Millisecond
console.warn("Chrome will now complain about an AudioContext not being allowed to start. This is normal, and there is no way to make Chrome stop complaining about this.")
const BuzzerAudioContext = new AudioContext({
latencyHint: 0,
})
/**
* Compute the special "Audio Context" time
*
* This is is a duration from now, in seconds.
*
* @param {Date} when Date to compute
* @returns audiocontext time
*/
function BuzzerAudioContextTime(when) {
if (!when) return 0
let acOffset = Date.now() - (BuzzerAudioContext.currentTime * Second)
return Math.max(when - acOffset, 0) / Second
}
class Oscillator {
/**
* Create a new oscillator, and encase it in a Gain for control.
*
* @param {number} frequency Oscillator frequency (Hz)
* @param {number} gain Gain (volume) of this oscillator (0.0 - 1.0)
* @param {string} type Oscillator type
* @returns {GainNode} A new GainNode object this oscillator is connected to
*/
constructor(frequency, gain = 0.5, type = "sine") {
this.targetGain = gain
this.gainNode = BuzzerAudioContext.createGain()
this.gainNode.connect(BuzzerAudioContext.destination)
this.gainNode.gain.value = 0
this.osc = BuzzerAudioContext.createOscillator()
this.osc.type = type
this.osc.connect(this.gainNode)
this.osc.frequency.value = frequency
this.osc.start()
return gain
}
/**
*
* @param {number} target Target gain
* @param {Date} when Time this should start
* @param {Duration} timeConstant Duration of ramp to target gain
*/
async setTargetAtTime(target, when, timeConstant=OscillatorRampDuration) {
await BuzzerAudioContext.resume()
this.gainNode.gain.setTargetAtTime(
target,
BuzzerAudioContextTime(when),
timeConstant/Second,
)
}
SoundAt(when=0, timeConstant=OscillatorRampDuration) {
return this.setTargetAtTime(this.targetGain, when, timeConstant)
}
HushAt(when=0, timeConstant=OscillatorRampDuration) {
return this.setTargetAtTime(0, when, timeConstant)
}
}
/**
* A digital sample, loaded from a URL.
*/
class Sample {
/**
*
* @param {string} url URL to resource
* @param {number} gain Gain (0.0 - 1.0)
*/
constructor(url, gain=0.5) {
this.resume = this.load(url)
this.gainNode = BuzzerAudioContext.createGain()
this.gainNode.connect(BuzzerAudioContext.destination)
this.gainNode.gain.value = gain
}
async load(url) {
let resp = await fetch(url)
let buf = await resp.arrayBuffer()
this.data = await BuzzerAudioContext.decodeAudioData(buf)
}
/**
* Play the sample
*
* @param {Date} when When to begin playback
*/
async PlayAt(when) {
await BuzzerAudioContext.resume()
await this.resume
let bs = BuzzerAudioContext.createBufferSource()
bs.buffer = this.data
bs.connect(this.gainNode)
bs.start(BuzzerAudioContextTime(when))
}
}
/**
* A (mostly) virtual class defining a buzzer.
*/
class Buzzer {
constructor() {
this.connected = true
}
/**
* Signal an error
*/
Error() {
console.log("Error")
}
/**
* Begin buzzing at time
*
* @param {boolean} tx Transmit or receive tone
* @param {number} when Time to begin, in ms (0=now)
*/
async Buzz(tx, when=0) {
console.log("Buzz", tx, when)
}
/**
* End buzzing at time
*
* @param {boolean} tx Transmit or receive tone
* @param {number} when Time to end, in ms (0=now)
*/
async Silence(tx, when=0) {
console.log("Silence", tx, when)
}
/**
* Buzz for a duration at time
*
* @param {boolean} tx Transmit or receive tone
* @param {number} when Time to begin, in ms (0=now)
* @param {number} duration Duration of buzz (ms)
*/
BuzzDuration(tx, when, duration) {
this.Buzz(tx, when)
this.Silence(tx, when + duration)
}
/**
* Set the "connectedness" indicator.
*
* @param {boolean} connected True if connected
*/
SetConnected(connected) {
this.connected = connected
}
}
class AudioBuzzer extends Buzzer {
constructor(errorFreq=30) {
super()
this.errorGain = new Oscillator(errorFreq, 0.1, "square")
}
Error() {
let now = Date.now()
this.errorGain.SoundAt(now)
this.errorGain.HushAt(now + 200*Millisecond)
}
}
class ToneBuzzer extends AudioBuzzer {
// Buzzers keep two oscillators: one high and one low.
// They generate a continuous waveform,
// and we change the gain to turn the pitches off and on.
//
// This also implements a very quick ramp-up and ramp-down in gain,
// in order to avoid "pops" (square wave overtones)
// that happen with instant changes in gain.
constructor({txGain=0.5, highFreq=HIGH_FREQ, lowFreq=LOW_FREQ} = {}) {
super()
this.rxOsc = new Oscillator(lowFreq, txGain)
this.txOsc = new Oscillator(highFreq, txGain)
// Keep the speaker going always. This keeps the browser from "swapping out" our audio context.
this.bgOsc = new Oscillator(1, 0.001)
this.bgOsc.SoundAt()
}
/**
* Begin buzzing at time
*
* @param {boolean} tx Transmit or receive tone
* @param {number} when Time to begin, in ms (0=now)
*/
async Buzz(tx, when = null) {
let osc = tx?this.txOsc:this.rxOsc
osc.SoundAt(when)
}
/**
* End buzzing at time
*
* @param {boolean} tx Transmit or receive tone
* @param {number} when Time to end, in ms (0=now)
*/
async Silence(tx, when = null) {
let osc = tx?this.txOsc:this.rxOsc
osc.HushAt(when)
}
}
class TelegraphBuzzer extends AudioBuzzer{
constructor(gain=0.6) {
super()
this.gainNode = BuzzerAudioContext.createGain()
this.gainNode.connect(BuzzerAudioContext.destination)
this.gainNode.gain.value = gain
this.hum = new Oscillator(140, 0.005, "sawtooth")
this.closeSample = new Sample("telegraph-a.mp3")
this.openSample = new Sample("telegraph-b.mp3")
}
async Buzz(tx, when=0) {
if (tx) {
this.hum.SoundAt(when)
} else {
this.closeSample.PlayAt(when)
}
}
async Silence(tx ,when=0) {
if (tx) {
this.hum.HushAt(when)
} else {
this.openSample.PlayAt(when)
}
}
}
class LampBuzzer extends Buzzer {
constructor() {
super()
this.elements = document.querySelectorAll(".recv-lamp")
}
async Buzz(tx, when=0) {
if (tx) return
let ms = when?when - Date.now():0
setTimeout(
() =>{
for (let e of this.elements) {
e.classList.add("rx")
}
},
ms,
)
}
async Silence(tx, when=0) {
if (tx) return
let ms = when?when - Date.now():0
setTimeout(
() => {
for (let e of this.elements) {
e.classList.remove("rx")
}
},
ms,
)
}
SetConnected(connected) {
console.log(connected)
for (let e of this.elements) {
if (connected) {
e.classList.add("connected")
} else {
e.classList.remove("connected")
}
}
}
}
class MIDIBuzzer extends Buzzer {
constructor() {
super()
this.SetNote(69) // A4; 440Hz
this.midiAccess = {outputs: []} // stub while we wait for async stuff
if (navigator.requestMIDIAccess) {
this.midiInit()
}
}
async midiInit(access) {
this.outputs = new Set()
this.midiAccess = await navigator.requestMIDIAccess()
this.midiAccess.addEventListener("statechange", e => this.midiStateChange(e))
this.midiStateChange()
}
midiStateChange(event) {
let newOutputs = new Set()
for (let output of this.midiAccess.outputs.values()) {
console.log(output.state)
if ((output.state != "connected") || (output.name.includes("Through"))) {
continue
}
newOutputs.add(output)
}
this.outputs = newOutputs
}
sendAt(when, message) {
let ms = when?when - Date.now():0
setTimeout(
() => {
for (let output of this.outputs) {
output.send(message)
}
},
ms,
)
}
async Buzz(tx, when=0) {
if (tx) {
return
}
this.sendAt(when, [0x90, this.note, 0x7f])
}
async Silence(tx, when=0) {
if (tx) {
return
}
this.sendAt(when, [0x80, this.note, 0x7f])
}
/*
* Set note to transmit
*/
SetNote(tx, note) {
if (tx) {
return
}
this.note = note
}
}
/**
* Block until the audio system is able to start making noise.
*/
async function AudioReady() {
await BuzzerAudioContext.resume()
}
class Collection {
constructor() {
this.tone = new ToneBuzzer()
this.telegraph = new TelegraphBuzzer()
this.lamp = new LampBuzzer()
this.midi = new MIDIBuzzer()
this.collection = new Set([this.tone, this.lamp, this.midi])
}
/**
* Set the audio output type.
*
* @param {string} audioType "telegraph" for telegraph mode, otherwise tone mode
*/
SetAudioType(audioType) {
this.collection.delete(this.telegraph)
this.collection.delete(this.tone)
if (audioType == "telegraph") {
this.collection.add(this.telegraph)
} else {
this.collection.add(this.tone)
}
}
/**
* Buzz all outputs.
*
* @param tx True if transmitting
*/
Buzz(tx=False) {
for (let b of this.collection) {
b.Buzz(tx)
}
}
/**
* Silence all outputs.
*
* @param tx True if transmitting
*/
Silence(tx=false) {
for (let b of this.collection) {
b.Silence(tx)
}
}
/**
* Buzz for a certain duration at a certain time
*
* @param tx True if transmitting
* @param when Time to begin
* @param duration How long to buzz
*/
BuzzDuration(tx, when, duration) {
for (let b of this.collection) {
b.BuzzDuration(tx, when, duration)
}
}
/**
* Update the "connected" status display.
*
* For example, turn the receive light to black if the repeater is not connected.
*
* @param {boolean} connected True if we are "connected"
*/
SetConnected(connected) {
for (let b of this.collection) {
b.SetConnected(connected)
}
}
}
export {AudioReady, Collection}