begin reimplementing draw logic for parallel use

packages/react/src/hooks/useFrame.mjs

@@ -0,0 +1,43 @@
+import { useEffect, useRef } from 'react';
+
+function useFrame(callback, autostart = false) {
+  const requestRef = useRef();
+  const previousTimeRef = useRef();
+
+  const animate = (time) => {
+    if (previousTimeRef.current !== undefined) {
+      const deltaTime = time - previousTimeRef.current;
+      callback(time, deltaTime);
+    }
+    previousTimeRef.current = time;
+    requestRef.current = requestAnimationFrame(animate);
+  };
+
+  const start = () => {
+    requestRef.current = requestAnimationFrame(animate);
+  };
+  const stop = () => {
+    requestRef.current && cancelAnimationFrame(requestRef.current);
+    delete requestRef.current;
+  };
+  useEffect(() => {
+    if (requestRef.current) {
+      stop();
+      start();
+    }
+  }, [callback]);
+
+  useEffect(() => {
+    if (autostart) {
+      start();
+    }
+    return stop;
+  }, []); // Make sure the effect only runs once
+
+  return {
+    start,
+    stop,
+  };
+}
+
+export default useFrame;

packages/react/src/hooks/usePatternFrame.mjs

@@ -0,0 +1,34 @@
+import { useCallback, useEffect, useRef } from 'react';
+import 'tailwindcss/tailwind.css';
+import useFrame from '../hooks/useFrame.mjs';
+
+function usePatternFrame({ pattern, started, getTime, onDraw }) {
+  let visibleHaps = useRef([]);
+  let lastFrame = useRef(null);
+  const { start: startFrame, stop: stopFrame } = useFrame(
+    useCallback(() => {
+      const phase = getTime();
+      if (lastFrame.current === null) {
+        lastFrame.current = phase;
+        return;
+      }
+      const haps = pattern.queryArc(Math.max(lastFrame.current, phase - 1 / 10), phase);
+      const cycles = 4;
+      lastFrame.current = phase;
+      visibleHaps.current = (visibleHaps.current || [])
+        .filter((h) => h.whole.end > phase - cycles) // in frame
+        .concat(haps.filter((h) => h.hasOnset()));
+      onDraw(phase, visibleHaps.current);
+    }, [pattern]),
+  );
+  useEffect(() => {
+    if (started) {
+      startFrame();
+    } else {
+      visibleHaps.current = [];
+      stopFrame();
+    }
+  }, [started]);
+}
+
+export default usePatternFrame;

packages/react/src/hooks/useStrudel.mjs

@@ -14,8 +14,10 @@ function useStrudel({
   afterEval,
   onEvalError,
   onToggle,
+  canvasId,
 }) {
   const id = useMemo(() => s4(), []);
+  canvasId = canvasId || `canvas-${id}`;
   // scheduler
   const [schedulerError, setSchedulerError] = useState();
   const [evalError, setEvalError] = useState();
@@ -97,6 +99,8 @@ function useStrudel({
   };
   const error = schedulerError || evalError;
   return {
+    id,
+    canvasId,
     code,
     setCode,
     error,