Fix RAF re-entry

Author: vankeisb

core/src/TeaCup/Animation.ts

@@ -27,34 +27,51 @@ import { Sub } from './Sub';
 
 let subs: Array<RafSub<any>> = [];
 
+let ticking = false;
+
 function tick() {
-  if (subs.length > 0) {
+  console.log("tick()");
+  if (!ticking) {
+    ticking = true;
     requestAnimationFrame((t: number) => {
+      console.log("got RAF", t, "subs", subs.length);
       subs.forEach((s) => s.trigger(t));
+      ticking = false;
     });
   }
 }
 
+let rafSubId = 0;
+
 class RafSub<M> extends Sub<M> {
   readonly mapper: (t: number) => M;
 
+  private readonly uuid: string;
+
   constructor(mapper: (t: number) => M) {
     super();
     this.mapper = mapper;
+    this.uuid = "rafsub-" + rafSubId;
+    rafSubId++;
   }
 
   protected onInit() {
+    console.log("RafSub", this.uuid ,"onInit()");
     super.onInit();
     subs.push(this);
+    console.log("RafSub", this.uuid ,"onInit()", subs.length);
     tick();
   }
 
   protected onRelease() {
+    console.log("RafSub", this.uuid ,"onRelease()");
     super.onRelease();
     subs = subs.filter((s) => s !== this);
+    console.log("RafSub", this.uuid ,"onRelease()", subs.length);
   }
 
   trigger(t: number) {
+    console.log("RafSub", this.uuid ,"trigger(", t, ")");
     this.dispatch(this.mapper(t));
   }
 }