102 lines
2.6 KiB
JavaScript
102 lines
2.6 KiB
JavaScript
|
"use strict";
|
||
|
|
|
||
|
|
//////////////////////////////////// Audio ////////////////////////////////////
|
||
|
|
|
||
|
|
// Dedicated audio output processor
|
||
|
|
class Audio extends AudioWorkletProcessor {
|
||
|
|
|
||
|
|
// Instance fields
|
||
|
|
buffers; // Input sample buffer queue
|
||
|
|
core; // Communications with core thread
|
||
|
|
dom; // Communications with DOM thread
|
||
|
|
offset; // Offset into oldest buffer
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
///////////////////////// Initialization Methods //////////////////////////
|
||
|
|
|
||
|
|
constructor() {
|
||
|
|
super();
|
||
|
|
this.port.onmessage = async e=>{
|
||
|
|
await this.#construct(e.data.core);
|
||
|
|
this.port.postMessage(0);
|
||
|
|
};
|
||
|
|
}
|
||
|
|
|
||
|
|
// Asynchronous constructor
|
||
|
|
async #construct(core) {
|
||
|
|
|
||
|
|
// Configure instance fields
|
||
|
|
this.buffers = [];
|
||
|
|
this.core = core;
|
||
|
|
this.dom = this.port;
|
||
|
|
this.offset = 0;
|
||
|
|
|
||
|
|
// Configure communications
|
||
|
|
this.core.onmessage = e=>this.#onCore(e.data);
|
||
|
|
this.dom .onmessage = e=>this.#onDOM (e.data);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
///////////////////////////// Public Methods //////////////////////////////
|
||
|
|
|
||
|
|
// Produce output samples (called by the user agent)
|
||
|
|
process(inputs, outputs, parameters) {
|
||
|
|
let output = outputs[0];
|
||
|
|
let length = output [0].length;
|
||
|
|
let empty = null;
|
||
|
|
|
||
|
|
// Process all samples
|
||
|
|
for (let x = 0; x < length;) {
|
||
|
|
|
||
|
|
// No bufferfed samples are available
|
||
|
|
if (this.buffers.length == 0) {
|
||
|
|
for (; x < length; x++)
|
||
|
|
output[0][x] = output[1][x] = 0;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Transfer samples from the oldest buffer
|
||
|
|
let buffer = this.buffers[0];
|
||
|
|
let y = this.offset;
|
||
|
|
for (; x < length && y < buffer.length; x++, y+=2) {
|
||
|
|
output[0][x] = buffer[y ];
|
||
|
|
output[1][x] = buffer[y + 1];
|
||
|
|
}
|
||
|
|
|
||
|
|
// Advance to the next buffer
|
||
|
|
if (y == buffer.length) {
|
||
|
|
if (empty == null)
|
||
|
|
empty = [];
|
||
|
|
empty.push(this.buffers.shift().buffer);
|
||
|
|
this.offset = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Buffer is not empty
|
||
|
|
else this.offset = y;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Return emptied sample buffers to the core thread
|
||
|
|
if (empty != null)
|
||
|
|
this.core.postMessage(empty, empty);
|
||
|
|
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
///////////////////////////// Event Handlers //////////////////////////////
|
||
|
|
|
||
|
|
// Message received from core thread
|
||
|
|
#onCore(e) {
|
||
|
|
this.buffers.push(new Float32Array(e));
|
||
|
|
}
|
||
|
|
|
||
|
|
// Message received from DOM thread
|
||
|
|
#onDOM(e) {
|
||
|
|
}
|
||
|
|
|
||
|
|
}
|
||
|
|
registerProcessor("shrooms-vb", Audio);
|