Update index.html

index.html

@@ -10,27 +10,33 @@ <h1>JumpFall Bytebeat</h1>
   </textarea>
   <button onclick="startByteBeat()">Start</button>
   <button onclick="stopByteBeat()">Stop</button>
+  <input type="range" id="volume" min="0" max="1" step="0.01" value="0.5">
 
   <script>
     let audioCtx = new (window.AudioContext || window.webkitAudioContext)();
+    let gainNode = audioCtx.createGain();
     let scriptNode = audioCtx.createScriptProcessor(4096, 1, 1);
     let t = 0;
 
+    gainNode.connect(audioCtx.destination);
+
     function startByteBeat() {
       let code = document.getElementById("code").value;
       scriptNode.onaudioprocess = function(audioProcessingEvent) {
         let outputBuffer = audioProcessingEvent.outputBuffer;
         let outputData = outputBuffer.getChannelData(0);
+        let volume = document.getElementById("volume").value;
+        gainNode.gain.value = volume;
         for (let sample = 0; sample < outputBuffer.length; sample++) {
           outputData[sample] = eval(code) / 128.0;
           t++;
         }
       }
-      scriptNode.connect(audioCtx.destination);
+      scriptNode.connect(gainNode);
     }
 
     function stopByteBeat() {
-      scriptNode.disconnect(audioCtx.destination);
+      scriptNode.disconnect(gainNode);
     }
   </script>
 </body>