Buffer every sound asset

public/src/js/soundbuffer.js

@@ -0,0 +1,193 @@
+class SoundBuffer{
+	constructor(){
+		this.context = new AudioContext()
+		var resume = () => {
+			if(this.context.state == "suspended"){
+				this.context.resume()
+			}
+			removeEventListener("click", resume)
+		}
+		addEventListener("click", resume)
+	}
+	load(url, gain){
+		return new Promise((resolve, reject) => {
+			var request = new XMLHttpRequest()
+			request.open("GET", url)
+			request.responseType = "arraybuffer"
+			request.addEventListener("load", () => {
+				this.context.decodeAudioData(request.response, buffer => {
+					resolve(new Sound(gain || {soundBuffer: this}, buffer))
+				}, reject)
+			})
+			request.addEventListener("error", reject)
+			request.addEventListener("abort", reject)
+			request.send()
+		})
+	}
+	createGain(){
+		return new SoundGain(this)
+	}
+	setCrossfade(gain1, gain2, median){
+		gain1.setCrossfade(1 - median)
+		gain2.setCrossfade(median)
+	}
+	getTime(){
+		return this.context.currentTime
+	}
+	convertTime(time, absolute){
+		time = (time || 0)
+		if(time < 0){
+			time = 0
+		}
+		return time + (absolute ? 0 : this.getTime())
+	}
+	createSource(sound){
+		var source = this.context.createBufferSource()
+		source.buffer = sound.buffer
+		source.connect(sound.gain.gainNode || this.context.destination)
+		return source
+	}
+}
+class SoundGain{
+	constructor(soundBuffer){
+		this.soundBuffer = soundBuffer
+		this.gainNode = soundBuffer.context.createGain()
+		this.gainNode.connect(soundBuffer.context.destination)
+		this.setVolume(1)
+	}
+	load(url){
+		return this.soundBuffer.load(url, this)
+	}
+	convertTime(time, absolute){
+		return this.soundBuffer.convertTime(time, absolute)
+	}
+	setVolume(amount){
+		this.gainNode.gain.value = amount * amount
+		this.volume = amount
+	}
+	setCrossfade(amount){
+		this.setVolume(Math.pow(Math.sin(Math.PI / 2 * amount), 1 / 4))
+	}
+	fadeIn(duration, time, absolute){
+		this.fadeVolume(0, this.volume * this.volume, duration, time, absolute)
+	}
+	fadeOut(duration, time, absolute){
+		this.fadeVolume(this.volume * this.volume, 0, duration, time, absolute)
+	}
+	fadeVolume(vol1, vol2, duration, time, absolute){
+		time = this.convertTime(time, absolute)
+		this.gainNode.gain.linearRampToValueAtTime(vol1, time)
+		this.gainNode.gain.linearRampToValueAtTime(vol2, time + (duration || 0))
+	}
+	mute(){
+		this.gainNode.gain.value = 0
+	}
+	unmute(){
+		this.setVolume(this.volume)
+	}
+}
+class Sound{
+	constructor(gain, buffer){
+		this.gain = gain
+		this.buffer = buffer
+		this.soundBuffer = gain.soundBuffer
+		this.duration = buffer.duration
+		this.timeouts = new Set()
+		this.sources = new Set()
+	}
+	getTime(){
+		return this.soundBuffer.getTime()
+	}
+	convertTime(time, absolute){
+		return this.soundBuffer.convertTime(time, absolute)
+	}
+	setTimeouts(time){
+		return new Promise(resolve => {
+			var relTime = time - this.getTime()
+			if(relTime > 0){
+				var timeout = setTimeout(() => {
+					this.timeouts.delete(timeout)
+					resolve()
+				}, relTime * 1000)
+				this.timeouts.add(timeout)
+			}else{
+				resolve()
+			}
+		})
+	}
+	clearTimeouts(){
+		this.timeouts.forEach(timeout => {
+			clearTimeout(timeout)
+			this.timeouts.delete(timeout)
+		})
+	}
+	playLoop(time, absolute, seek1, seek2, until){
+		time = this.convertTime(time, absolute)
+		seek1 = seek1 || 0
+		seek2 = seek2 || seek1
+		until = until || this.duration
+		this.loop = {
+			started: time + until - seek1,
+			seek: seek2,
+			until: until
+		}
+		this.play(time, true, seek1, until)
+		this.addLoop()
+		this.loop.interval = setInterval(() => {
+			this.addLoop()
+		}, 100)
+	}
+	addLoop(){
+		if(this.getTime() > this.loop.started - 1){
+			this.play(this.loop.started, true, this.loop.seek, this.loop.until)
+			this.loop.started += this.loop.until - this.loop.seek
+		}
+	}
+	play(time, absolute, seek, until){
+		time = this.convertTime(time, absolute)
+		var source = this.soundBuffer.createSource(this)
+		seek = seek || 0
+		until = until || this.duration
+		this.setTimeouts(time).then(() => {
+			this.cfg = {
+				started: time,
+				seek: seek,
+				until: until
+			}
+		})
+		source.start(time, Math.max(0, seek || 0), Math.max(0, until - seek))
+		source.startTime = time
+		this.sources.add(source)
+		source.onended = () => {
+			this.sources.delete(source)
+		}
+	}
+	stop(time, absolute){
+		time = this.convertTime(time, absolute)
+		this.sources.forEach(source => {
+			source.stop(Math.max(source.startTime, time))
+		})
+		this.setTimeouts(time).then(() => {
+			if(this.loop){
+				clearInterval(this.loop.interval)
+			}
+			this.clearTimeouts()
+		})
+	}
+	pause(time, absolute){
+		if(this.cfg){
+			time = this.convertTime(time, absolute)
+			this.stop(time, true)
+			this.cfg.pauseSeek = time - this.cfg.started + this.cfg.seek
+		}
+	}
+	resume(time, absolute){
+		if(this.cfg){
+			if(this.loop){
+				this.playLoop(time, absolute, this.cfg.pauseSeek, this.loop.seek, this.loop.until)
+			}else{
+				this.play(time, absolute, this.cfg.pauseSeek, this.cfg.until)
+			}
+		}
+	}
+}