Files
topos/src/TransportNode.js
2023-07-28 11:40:17 +02:00

49 lines
1.8 KiB
JavaScript

import { evaluate, tryEvaluate, evaluateCommand } from "./Evaluator";
export class TransportNode extends AudioWorkletNode {
constructor(context, options, application) {
super(context, "transport", options);
this.app = application
this.port.addEventListener("message", this.handleMessage);
this.port.start();
/** @type {HTMLSpanElement} */
this.$clock = document.getElementById("clockviewer");
this.offset_time = 0;
}
/** @type {(this: MessagePort, ev: MessageEvent<any>) => any} */
handleMessage = (message) => {
if (message.data === "bang") {
let info = this.convertTimeToBarsBeats(this.context.currentTime);
this.app.clock.time_position = { bar: info.bar, beat: info.beat, pulse: info.ppqn }
// this.$clock.innerHTML = `${info.bar} / ${info.beat} / ${info.ppqn}`
tryEvaluate( this.app, this.app.global_buffer );
}
};
start() {
this.port.postMessage("start");
}
pause() {
this.port.postMessage("pause");
}
convertTimeToBarsBeats(currentTime) {
// Calculate the duration of one beat in seconds
const beatDuration = 60 / this.app.clock.bpm;
// Calculate the beat number
const beatNumber = (currentTime - this.offset_time) / beatDuration;
// Calculate the bar and beat numbers
const beatsPerBar = this.app.clock.time_signature[0];
const barNumber = Math.floor(beatNumber / beatsPerBar) + 1; // Adding 1 to make it 1-indexed
const beatWithinBar = Math.floor(beatNumber % beatsPerBar) + 1; // Adding 1 to make it 1-indexed
// Calculate the PPQN position
const ppqnPosition = Math.floor((beatNumber % 1) * this.app.clock.ppqn);
return { bar: barNumber, beat: beatWithinBar, ppqn: ppqnPosition };
}
}