Background music support

src/sound.js

@@ -1,13 +1,30 @@
 // @ts-ignore
 export const audio = new (window.AudioContext || window.webkitAudioContext)();
-export const gain = audio.createGain(audio);
-gain.gain.setValueAtTime(0.05, audio.currentTime);
-gain.connect(audio.destination);
+
+export const music = audio.createGain(audio);
+music.gain.setValueAtTime(0.4, audio.currentTime);
+music.connect(audio.destination);
+
+export const sfx = audio.createGain(audio);
+sfx.gain.setValueAtTime(0.05, audio.currentTime);
+sfx.connect(audio.destination);
+
+export async function createAudioLoop(src) {
+  const file = await fetch(src);
+  const buffer = await file.arrayBuffer();
+  const source = audio.createBufferSource();
+  audio.decodeAudioData(buffer, (buffer) => {
+    source.buffer = buffer;
+    source.connect(music);
+    source.loop = true;
+    source.start(0);
+  })
+}
 
 export function createOsc() {
   const osc = audio.createOscillator();
   osc.type = 'triangle';
-  osc.connect(gain);
+  osc.connect(sfx);
   return osc;
 }