fix: reconcile lightweight interaction frames

Issue: #451
User-Visible: no

src/pointer-move-queue.ts

@@ -1,8 +1,15 @@
-interface QueuedMove { raf: number; run: () => void }
+interface QueuedMove { run: () => void }
 
 const moveQueues = new WeakMap<object, Map<string, QueuedMove>>();
 
-/** Keep only the latest raw move of each active gesture between two frames. */
+/**
+ * Keep only the latest raw move from one browser event turn.
+ *
+ * Gesture state must be current before a following pointerup/cancel is handled:
+ * postponing the input itself until requestAnimationFrame lets the terminal
+ * event clear that state first.  The live renderer still coalesces the paint
+ * to one animation frame; this queue only coalesces the state calculation.
+ */
 export function queueHouseplanPointerMove(host: object, key: string, run: () => void): void {
   let queues = moveQueues.get(host);
   if (!queues) {
@@ -14,14 +21,10 @@ export function queueHouseplanPointerMove(host: object, key: string, run: () =>
     queued.run = run;
     return;
   }
-  const entry: QueuedMove = { raf: 0, run };
+  const entry: QueuedMove = { run };
   queues.set(key, entry);
-  if (typeof requestAnimationFrame !== 'function') {
-    queues.delete(key);
-    run();
-    return;
-  }
-  entry.raf = requestAnimationFrame(() => {
+  queueMicrotask(() => {
+    if (queues!.get(key) !== entry) return;
     queues!.delete(key);
     entry.run();
   });
@@ -31,7 +34,6 @@ export function flushHouseplanPointerMove(host: object, key: string): void {
   const queues = moveQueues.get(host);
   const queued = queues?.get(key);
   if (!queued) return;
-  if (queued.raf && typeof cancelAnimationFrame === 'function') cancelAnimationFrame(queued.raf);
   queues!.delete(key);
   queued.run();
 }
@@ -40,9 +42,6 @@ export function cancelHouseplanPointerMove(host: object, key?: string): void {
   const queues = moveQueues.get(host);
   if (!queues) return;
   const entries = key ? [...queues].filter(([name]) => name === key) : [...queues];
-  for (const [name, queued] of entries) {
-    if (queued.raf && typeof cancelAnimationFrame === 'function') cancelAnimationFrame(queued.raf);
-    queues.delete(name);
-  }
+  for (const [name] of entries) queues.delete(name);
   if (!queues.size) moveQueues.delete(host);
 }