restructure

public/src/js/bufferedloop.js

@@ -0,0 +1,90 @@
+// thx to @LoveEevee for this - https://github.com/LoveEevee
+
+class BufferedLoop{
+	constructor(bgm1,bgm2){
+		this.context=new AudioContext()
+		this.buffers=[]
+		this.sources=new Set()
+		this.loadCallback=[]
+		this.bufferedTime=0
+		this.bgm1=bgm1
+		this.bgm2=bgm2
+		this.loadSound(bgm1.url,0)
+		this.loadSound(bgm2.url,1)
+	}
+	loadSound(url,number){
+		var self=this
+		var request=new XMLHttpRequest()
+		request.open("GET",url)
+		request.responseType="arraybuffer"
+		request.onload=function(){
+			self.context.decodeAudioData(request.response,function(buffer){
+				self.buffers[number]=buffer
+				self.setLoaded()
+			})
+		}
+		request.send()
+	}
+	setLoaded(){
+		if(this.buffers[0]&&this.buffers[1]){
+			this.loaded=true
+			for(var i in this.loadCallback){
+				this.loadCallback[i]()
+			}
+		}
+	}
+	onLoad(callback){
+		this.loadCallback.push(callback)
+	}
+	playSound(buffer,time,duration){
+		var self=this
+		var source=this.context.createBufferSource()
+		source.buffer=buffer
+		source.connect(this.context.destination)
+		source.start(time)
+		this.bufferedTime=time+duration
+		var sourceObject={
+			source:source,
+			timeout:setTimeout(function(){
+				self.sources.delete(sourceObject)
+			},duration*1000)
+		}
+		this.sources.add(sourceObject)
+	}
+	addLoop(){
+		if(this.context.currentTime>this.bufferedTime-1){
+			this.playSound(
+				this.buffers[1],
+				this.start+this.bgm1.duration+this.bgm2.duration*this.iteration,
+				this.bgm2.duration
+			)
+			this.iteration++
+		}
+	}
+	play(){
+		var self=this
+		if(!this.loaded){
+			return this.onLoad(function(){
+				self.play()
+			})
+		}
+		this.start=this.context.currentTime+0.1
+		this.iteration=0
+		this.playSound(
+			this.buffers[0],
+			this.start,
+			this.bgm1.duration
+		)
+		self.addLoop()
+		self.interval=setInterval(function(){
+			self.addLoop()
+		},100)
+	}
+	pause(){
+		clearInterval(this.interval)
+		this.sources.forEach(function(sourceObject){
+			sourceObject.source.stop(0)
+			clearTimeout(sourceObject.timeout)
+		})
+	}
+}