1 files changed, 211 insertions, 0 deletions
diff --git a/platform/web/js/libs/audio.worklet.js b/platform/web/js/libs/audio.worklet.js
new file mode 100644
index 0000000000..ea4d8cb221
--- /dev/null
+++ b/platform/web/js/libs/audio.worklet.js
@@ -0,0 +1,211 @@
+/*************************************************************************/
+/*  audio.worklet.js                                                     */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+class RingBuffer {
+	constructor(p_buffer, p_state, p_threads) {
+		this.buffer = p_buffer;
+		this.avail = p_state;
+		this.threads = p_threads;
+		this.rpos = 0;
+		this.wpos = 0;
+	}
+
+	data_left() {
+		return this.threads ? Atomics.load(this.avail, 0) : this.avail;
+	}
+
+	space_left() {
+		return this.buffer.length - this.data_left();
+	}
+
+	read(output) {
+		const size = this.buffer.length;
+		let from = 0;
+		let to_write = output.length;
+		if (this.rpos + to_write > size) {
+			const high = size - this.rpos;
+			output.set(this.buffer.subarray(this.rpos, size));
+			from = high;
+			to_write -= high;
+			this.rpos = 0;
+		}
+		if (to_write) {
+			output.set(this.buffer.subarray(this.rpos, this.rpos + to_write), from);
+		}
+		this.rpos += to_write;
+		if (this.threads) {
+			Atomics.add(this.avail, 0, -output.length);
+			Atomics.notify(this.avail, 0);
+		} else {
+			this.avail -= output.length;
+		}
+	}
+
+	write(p_buffer) {
+		const to_write = p_buffer.length;
+		const mw = this.buffer.length - this.wpos;
+		if (mw >= to_write) {
+			this.buffer.set(p_buffer, this.wpos);
+			this.wpos += to_write;
+			if (mw === to_write) {
+				this.wpos = 0;
+			}
+		} else {
+			const high = p_buffer.subarray(0, mw);
+			const low = p_buffer.subarray(mw);
+			this.buffer.set(high, this.wpos);
+			this.buffer.set(low);
+			this.wpos = low.length;
+		}
+		if (this.threads) {
+			Atomics.add(this.avail, 0, to_write);
+			Atomics.notify(this.avail, 0);
+		} else {
+			this.avail += to_write;
+		}
+	}
+}
+
+class GodotProcessor extends AudioWorkletProcessor {
+	constructor() {
+		super();
+		this.threads = false;
+		this.running = true;
+		this.lock = null;
+		this.notifier = null;
+		this.output = null;
+		this.output_buffer = new Float32Array();
+		this.input = null;
+		this.input_buffer = new Float32Array();
+		this.port.onmessage = (event) => {
+			const cmd = event.data['cmd'];
+			const data = event.data['data'];
+			this.parse_message(cmd, data);
+		};
+	}
+
+	process_notify() {
+		if (this.notifier) {
+			Atomics.add(this.notifier, 0, 1);
+			Atomics.notify(this.notifier, 0);
+		}
+	}
+
+	parse_message(p_cmd, p_data) {
+		if (p_cmd === 'start' && p_data) {
+			const state = p_data[0];
+			let idx = 0;
+			this.threads = true;
+			this.lock = state.subarray(idx, ++idx);
+			this.notifier = state.subarray(idx, ++idx);
+			const avail_in = state.subarray(idx, ++idx);
+			const avail_out = state.subarray(idx, ++idx);
+			this.input = new RingBuffer(p_data[1], avail_in, true);
+			this.output = new RingBuffer(p_data[2], avail_out, true);
+		} else if (p_cmd === 'stop') {
+			this.running = false;
+			this.output = null;
+			this.input = null;
+		} else if (p_cmd === 'start_nothreads') {
+			this.output = new RingBuffer(p_data[0], p_data[0].length, false);
+		} else if (p_cmd === 'chunk') {
+			this.output.write(p_data);
+		}
+	}
+
+	static array_has_data(arr) {
+		return arr.length && arr[0].length && arr[0][0].length;
+	}
+
+	process(inputs, outputs, parameters) {
+		if (!this.running) {
+			return false; // Stop processing.
+		}
+		if (this.output === null) {
+			return true; // Not ready yet, keep processing.
+		}
+		const process_input = GodotProcessor.array_has_data(inputs);
+		if (process_input) {
+			const input = inputs[0];
+			const chunk = input[0].length * input.length;
+			if (this.input_buffer.length !== chunk) {
+				this.input_buffer = new Float32Array(chunk);
+			}
+			if (!this.threads) {
+				GodotProcessor.write_input(this.input_buffer, input);
+				this.port.postMessage({ 'cmd': 'input', 'data': this.input_buffer });
+			} else if (this.input.space_left() >= chunk) {
+				GodotProcessor.write_input(this.input_buffer, input);
+				this.input.write(this.input_buffer);
+			} else {
+				this.port.postMessage('Input buffer is full! Skipping input frame.');
+			}
+		}
+		const process_output = GodotProcessor.array_has_data(outputs);
+		if (process_output) {
+			const output = outputs[0];
+			const chunk = output[0].length * output.length;
+			if (this.output_buffer.length !== chunk) {
+				this.output_buffer = new Float32Array(chunk);
+			}
+			if (this.output.data_left() >= chunk) {
+				this.output.read(this.output_buffer);
+				GodotProcessor.write_output(output, this.output_buffer);
+				if (!this.threads) {
+					this.port.postMessage({ 'cmd': 'read', 'data': chunk });
+				}
+			} else {
+				this.port.postMessage('Output buffer has not enough frames! Skipping output frame.');
+			}
+		}
+		this.process_notify();
+		return true;
+	}
+
+	static write_output(dest, source) {
+		const channels = dest.length;
+		for (let ch = 0; ch < channels; ch++) {
+			for (let sample = 0; sample < dest[ch].length; sample++) {
+				dest[ch][sample] = source[sample * channels + ch];
+			}
+		}
+	}
+
+	static write_input(dest, source) {
+		const channels = source.length;
+		for (let ch = 0; ch < channels; ch++) {
+			for (let sample = 0; sample < source[ch].length; sample++) {
+				dest[sample * channels + ch] = source[ch][sample];
+			}
+		}
+	}
+}
+
+registerProcessor('godot-processor', GodotProcessor);