sfx.js

class Sfx {
	constructor() {
		this.timestamp = +new Date()
		window.play = this.tradeToSong.bind(this)
		this.connect()
	}

	connect() {
		this.context = new(window.AudioContext || window.webkitAudioContext)()
		this.queued = 0

		var tuna = new Tuna(this.context)

		this.output = new tuna.PingPongDelay({
			wetLevel: 0.5, //0 to 1
			feedback: 0.01, //0 to 1
			delayTimeLeft: 175, //1 to 10000 (milliseconds)
			delayTimeRight: 100, //1 to 10000 (milliseconds)
		})

		var filter = new tuna.Filter({
			frequency: 700, //20 to 22050
			Q: 10, //0.001 to 100
			gain: -10, //-40 to 40 (in decibels)
			filterType: 'highpass', //lowpass, highpass, bandpass, lowshelf, highshelf, peaking, notch, allpass
			bypass: 0,
		})

		this.output.connect(filter)
		filter.connect(this.context.destination)
	}

	tradeToSong(factor, side) {
		const now = +new Date()

		this.queued++

		setTimeout(() => {
			this.queued--

			if (side) {
				if (factor >= 10) {
					;
					[659.26, 830.6, 987.76, 1318.52].forEach((f, i, a) =>
						setTimeout(
							() =>
							this.play(f, 0.05 + Math.sqrt(factor) / 15, 0.1 + factor * 0.1),
							i * 80
						)
					)
				} else if (factor >= 1) {
					;
					[659.26, 830.6].forEach((f, i) =>
						setTimeout(
							() =>
							this.play(f, 0.05 + Math.sqrt(factor) / 10, 0.1 + factor * 0.1),
							i * 80
						)
					)
				} else {
					this.play(
						659.26,
						Math.sqrt(factor) / 10,
						0.1 + Math.sqrt(factor) / 10
					)
				}
			} else {
				if (factor >= 10) {
					;
					[493.88, 369.99, 293.66, 246.94].forEach((f, i, a) =>
						setTimeout(
							() =>
							this.play(
								f,
								0.05 + Math.sqrt(factor) / 10,
								i > 2 ? 0.1 + factor * 0.1 : 0.2
							),
							i > 2 ? 80 * 3 : i * 80
						)
					)
				} else if (factor >= 1) {
					;
					[493.88, 392].forEach((f, i) =>
						setTimeout(
							() =>
							this.play(f, 0.05 + Math.sqrt(factor) / 10, 0.1 + factor * 0.1),
							i * 80
						)
					)
				} else {
					this.play(
						493.88,
						Math.sqrt(factor) / 10,
						0.1 + Math.sqrt(factor) / 10
					)
				}
			}
		}, this.timestamp - now)

		this.timestamp = Math.max(this.timestamp, now) + (this.queued > 20 ? 40 : 80)
	}

	play(frequency, value = 0.5, length = 0.1, type = 'triangle', volume = 0.8) {
		if (this.context.state !== 'running') {
			return
		}

		const time = this.context.currentTime
		const oscillator = this.context.createOscillator()
		const gain = this.context.createGain()

		oscillator.frequency.value = frequency
		oscillator.type = type

		oscillator.onended = () => {
			oscillator.disconnect()
		}

		gain.connect(this.output)
		oscillator.connect(gain)
		length *= 1.1

		gain.gain.value = volume

		gain.gain.setValueAtTime(gain.gain.value, time)
		gain.gain.exponentialRampToValueAtTime(0.001, time + length)

		oscillator.start(time)
		oscillator.stop(time + length)
	}

	liquidation() {
		;
		[329.63, 329.63].forEach((f, i, a) =>
			setTimeout(() => this.play(f, 0.5, 0.25, 'sine'), i * 80)
		)
	}

	disconnect() {
		this.context && this.context.state === 'running' && this.context.close()
	}
}