From 275931969e62f19f5edec01cbd63b9e940a37281 Mon Sep 17 00:00:00 2001
From: Felix Roos <roos@entrecode.de>
Date: Mon, 22 Aug 2022 22:15:32 +0200
Subject: [PATCH] scheduler error correction failed attempt

---
 packages/core/clockworker.mjs                 |  2 +-
 packages/core/scheduler.mjs                   | 32 +++++++++++++------
 packages/react/examples/nano-repl/src/App.jsx |  4 +--
 3 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/packages/core/clockworker.mjs b/packages/core/clockworker.mjs
index c56f38a4..97940d3e 100644
--- a/packages/core/clockworker.mjs
+++ b/packages/core/clockworker.mjs
@@ -12,7 +12,7 @@ const createWorker = (func) => new Worker(urlifyFunction(func));
 // this is just a setInterval with a counter, running in a worker
 export class ClockWorker {
   worker;
-  interval = 1 / 32; // query span, use powers of 2 to get better float accuracy
+  interval = 1 / 10; // query span, use powers of 2 to get better float accuracy
   tick = 0;
   constructor(callback, interval = this.interval) {
     this.interval = interval;
diff --git a/packages/core/scheduler.mjs b/packages/core/scheduler.mjs
index 8bcef060..c2c7448a 100644
--- a/packages/core/scheduler.mjs
+++ b/packages/core/scheduler.mjs
@@ -13,21 +13,22 @@ export class Scheduler {
   phase = 0;
   cps = 1;
   lastTime;
+  error = 0;
   constructor({ interval, onTrigger, onError, latency = 0.1, getTime }) {
     this.worker = new ClockWorker((_, interval) => {
       try {
-        let error = 0;
-        // measure time between last and current callback and calculate deviation from extected interval
-        const time = getTime?.();
-        if (time && this.lastTime) {
-          error = time - this.lastTime - interval; // how off is the callback? positive = too late
-          // console.log('ms error', error * 1000);
-        }
-        this.lastTime = time;
         const begin = this.phase;
         const end = this.phase + interval * this.cps;
         this.phase = end;
         const haps = this.pattern.queryArc(begin, end);
+        // this.log(begin, end, haps);
+        // measure time between last and current callback and calculate deviation from extected interval
+        const time = getTime?.();
+        if (time && this.lastTime) {
+          const diff = time - this.lastTime;
+          this.error = diff - interval;
+        }
+        this.lastTime = time;
         haps.forEach((hap) => {
           if (typeof hap.value?.cps === 'number') {
             this.setCps(hap.value?.cps);
@@ -35,7 +36,16 @@ export class Scheduler {
           if (!hap.part.begin.equals(hap.whole.begin)) {
             return;
           }
-          const deadline = (hap.whole.begin - begin) / this.cps + latency - error;
+          // console.log('error', this.error);
+          const deadline = (hap.whole.begin - begin) / this.cps + latency - this.error;
+          // const deadline = hap.whole.begin - begin + latency; // - error;
+          if (deadline < 0) {
+            console.warn(
+              `deadline ${deadline.toFixed(
+                2,
+              )} is below zero! latency ${latency}s, interval ${interval}s, error ${this.error.toFixed(2)}s`,
+            );
+          }
           // TODO: use legato / duration of objectified value
           const duration = hap.duration / this.cps;
           onTrigger?.(hap, deadline, duration);
@@ -68,4 +78,8 @@ export class Scheduler {
   setCps(cps = 1) {
     this.cps = cps;
   }
+  log(begin, end, haps) {
+    const onsets = haps.filter((h) => h.hasOnset());
+    console.log(`${begin.toFixed(4)} - ${end.toFixed(4)} ${Array(onsets.length).fill('I').join('')}`);
+  }
 }
diff --git a/packages/react/examples/nano-repl/src/App.jsx b/packages/react/examples/nano-repl/src/App.jsx
index e1ca3e42..f0756d74 100644
--- a/packages/react/examples/nano-repl/src/App.jsx
+++ b/packages/react/examples/nano-repl/src/App.jsx
@@ -47,7 +47,7 @@ stack(
   .superimpose(x=>x.add(.04)) // add second, slightly detuned voice
   .add(perlin.range(0,.5)) // random pitch variation
   .n() // wrap in "n"
-  .s('sawtooth') // waveform
+  .s('square') // waveform
   .gain(.16) // turn down
   .cutoff(500) // fixed cutoff
   .attack(1) // slowly fade in
@@ -67,9 +67,9 @@ stack(
 // await prebake();
 
 const ctx = getAudioContext();
-
 function App() {
   const [code, setCode] = useState(defaultTune);
+  // const [code, setCode] = useState(`"c3".note().slow(2)`);
   const { scheduler, evaluate, schedulerError, evalError, isDirty } = useStrudel({
     code,
     defaultOutput: webaudioOutput,