begin webaudio package

packages/webaudio/scheduler.mjs

@@ -0,0 +1,28 @@
+class Scheduler {
+  metro;
+  constructor(interval = 0.2, lookahead = 0.2) {
+    this.metro = new Metro(
+      audioContext,
+      (begin, end, lookahead) => {
+        pattern.query(new State(new TimeSpan(begin - lookahead, end - lookahead))).forEach((e) => {
+          if (!e.part.begin.equals(e.whole.begin)) {
+            return;
+          }
+          if (e.context.createAudioNode) {
+            e.context.createAudioNode(e);
+          } else {
+            console.warn('unplayable event: no audio node');
+          }
+        });
+      },
+      interval,
+      lookahead,
+    );
+  }
+  start() {
+    this.metro.start();
+  }
+  stop() {
+    this.metro.stop();
+  }
+}