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scheduler error correction via getTime

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This commit is contained in:
Felix Roos 2022-08-21 11:20:15 +02:00
parent e72c47869a
commit 2172d1a767
2 changed files with 12 additions and 3 deletions
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2
packages/core/clockworker.mjs
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@ -12,7 +12,7 @@ const createWorker = (func) => new Worker(urlifyFunction(func));
// this is just a setInterval with a counter, running in a worker // this is just a setInterval with a counter, running in a worker
export class ClockWorker { export class ClockWorker {
worker; worker;
interval = 0.1; // query span interval = 1 / 32; // query span, use powers of 2 to get better float accuracy
tick = 0; tick = 0;
constructor(callback, interval = this.interval) { constructor(callback, interval = this.interval) {
this.interval = interval; this.interval = interval;

13
packages/core/scheduler.mjs
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@ -12,9 +12,18 @@ export class Scheduler {
started = false; started = false;
phase = 0; phase = 0;
cps = 1; cps = 1;
constructor({ interval = 0.1, onTrigger, onError, latency = 0.1 }) { lastTime;
constructor({ interval, onTrigger, onError, latency = 0.1, getTime }) {
this.worker = new ClockWorker((_, interval) => { this.worker = new ClockWorker((_, interval) => {
try { 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 begin = this.phase;
const end = this.phase + interval * this.cps; const end = this.phase + interval * this.cps;
this.phase = end; this.phase = end;
@ -26,7 +35,7 @@ export class Scheduler {
if (!hap.part.begin.equals(hap.whole.begin)) { if (!hap.part.begin.equals(hap.whole.begin)) {
return; return;
} }
const deadline = (hap.whole.begin - begin) / this.cps + latency; const deadline = (hap.whole.begin - begin) / this.cps + latency - error;
// TODO: use legato / duration of objectified value // TODO: use legato / duration of objectified value
const duration = hap.duration / this.cps; const duration = hap.duration / this.cps;
onTrigger?.(hap, deadline, duration); onTrigger?.(hap, deadline, duration);