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