From a7505ee0bcb6881b86aeade03b12ab12089aeca8 Mon Sep 17 00:00:00 2001
From: Ryan Braganza <ryan.braganza@gmail.com>
Date: Tue, 27 Aug 2024 20:22:09 +1000
Subject: [PATCH] Add Web MIDI support
Co-authored-by: Adam Scott <ascott.ca@gmail.com>
Co-authored-by: A Thousand Ships <96648715+AThousandShips@users.noreply.github.com>
---
doc/classes/InputEventMIDI.xml | 1 +
doc/classes/OS.xml | 10 +-
platform/web/SCsub | 2 +
platform/web/godot_midi.h | 51 ++++++++++
platform/web/js/libs/library_godot_webmidi.js | 94 ++++++++++++++++++
platform/web/os_web.h | 3 +
platform/web/webmidi_driver.cpp | 98 +++++++++++++++++++
platform/web/webmidi_driver.h | 61 ++++++++++++
8 files changed, 317 insertions(+), 3 deletions(-)
create mode 100644 platform/web/godot_midi.h
create mode 100644 platform/web/js/libs/library_godot_webmidi.js
create mode 100644 platform/web/webmidi_driver.cpp
create mode 100644 platform/web/webmidi_driver.h
diff --git a/doc/classes/InputEventMIDI.xml b/doc/classes/InputEventMIDI.xml
index 4dcaf987473e..c3b49408c20c 100644
--- a/doc/classes/InputEventMIDI.xml
+++ b/doc/classes/InputEventMIDI.xml
@@ -58,6 +58,7 @@
[/csharp]
[/codeblocks]
[b]Note:[/b] Godot does not support MIDI output, so there is no way to emit MIDI messages from Godot. Only MIDI input is supported.
+ [b]Note:[/b] On the Web platform, using MIDI input requires a browser permission to be granted first. This permission request is performed when calling [method OS.open_midi_inputs]. MIDI input will not work until the user accepts the permission request.
</description>
<tutorials>
<link title="MIDI Message Status Byte List">https://www.midi.org/specifications-old/item/table-2-expanded-messages-list-status-bytes</link>
diff --git a/doc/classes/OS.xml b/doc/classes/OS.xml
index 669c71778d2e..9ab37b1482f9 100644
--- a/doc/classes/OS.xml
+++ b/doc/classes/OS.xml
@@ -23,7 +23,7 @@
<return type="void" />
<description>
Shuts down the system MIDI driver. Godot will no longer receive [InputEventMIDI]. See also [method open_midi_inputs] and [method get_connected_midi_inputs].
- [b]Note:[/b] This method is implemented on Linux, macOS, and Windows.
+ [b]Note:[/b] This method is implemented on Linux, macOS, Windows, and Web.
</description>
</method>
<method name="crash">
@@ -244,7 +244,9 @@
<return type="PackedStringArray" />
<description>
Returns an array of connected MIDI device names, if they exist. Returns an empty array if the system MIDI driver has not previously been initialized with [method open_midi_inputs]. See also [method close_midi_inputs].
- [b]Note:[/b] This method is implemented on Linux, macOS, and Windows.
+ [b]Note:[/b] This method is implemented on Linux, macOS, Windows, and Web.
+ [b]Note:[/b] On the Web platform, Web MIDI needs to be supported by the browser. [url=https://caniuse.com/midi]For the time being[/url], it is currently supported by all major browsers, except Safari.
+ [b]Note:[/b] On the Web platform, using MIDI input requires a browser permission to be granted first. This permission request is performed when calling [method open_midi_inputs]. The browser will refrain from processing MIDI input until the user accepts the permission request.
</description>
</method>
<method name="get_data_dir" qualifiers="const">
@@ -704,7 +706,9 @@
<return type="void" />
<description>
Initializes the singleton for the system MIDI driver, allowing Godot to receive [InputEventMIDI]. See also [method get_connected_midi_inputs] and [method close_midi_inputs].
- [b]Note:[/b] This method is implemented on Linux, macOS, and Windows.
+ [b]Note:[/b] This method is implemented on Linux, macOS, Windows, and Web.
+ [b]Note:[/b] On the Web platform, Web MIDI needs to be supported by the browser. [url=https://caniuse.com/midi]For the time being[/url], it is currently supported by all major browsers, except Safari.
+ [b]Note:[/b] On the Web platform, using MIDI input requires a browser permission to be granted first. This permission request is performed when calling [method open_midi_inputs]. The browser will refrain from processing MIDI input until the user accepts the permission request.
</description>
</method>
<method name="read_buffer_from_stdin">
diff --git a/platform/web/SCsub b/platform/web/SCsub
index 9a2eea9e07b3..7ba12eecb96b 100644
--- a/platform/web/SCsub
+++ b/platform/web/SCsub
@@ -22,6 +22,7 @@ if "serve" in COMMAND_LINE_TARGETS or "run" in COMMAND_LINE_TARGETS:
web_files = [
"audio_driver_web.cpp",
+ "webmidi_driver.cpp",
"display_server_web.cpp",
"http_client_web.cpp",
"javascript_bridge_singleton.cpp",
@@ -38,6 +39,7 @@ sys_env.AddJSLibraries(
"js/libs/library_godot_audio.js",
"js/libs/library_godot_display.js",
"js/libs/library_godot_fetch.js",
+ "js/libs/library_godot_webmidi.js",
"js/libs/library_godot_os.js",
"js/libs/library_godot_runtime.js",
"js/libs/library_godot_input.js",
diff --git a/platform/web/godot_midi.h b/platform/web/godot_midi.h
new file mode 100644
index 000000000000..db8de3ec23c7
--- /dev/null
+++ b/platform/web/godot_midi.h
@@ -0,0 +1,51 @@
+/**************************************************************************/
+/* godot_midi.h */
+/**************************************************************************/
+/* This file is part of: */
+/* GODOT ENGINE */
+/* https://godotengine.org */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
+/* */
+/* 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. */
+/**************************************************************************/
+
+#ifndef GODOT_MIDI_H
+#define GODOT_MIDI_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+extern int godot_js_webmidi_open_midi_inputs(
+ void (*p_callback)(int p_size, const char **p_connected_input_names),
+ void (*p_on_midi_message)(int p_device_index, int p_status, const uint8_t *p_data, int p_data_len),
+ const uint8_t *p_data_buffer,
+ const int p_data_buffer_len);
+
+extern void godot_js_webmidi_close_midi_inputs();
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // GODOT_MIDI_H
diff --git a/platform/web/js/libs/library_godot_webmidi.js b/platform/web/js/libs/library_godot_webmidi.js
new file mode 100644
index 000000000000..1c94b1559fcd
--- /dev/null
+++ b/platform/web/js/libs/library_godot_webmidi.js
@@ -0,0 +1,94 @@
+/**************************************************************************/
+/* library_godot_webmidi.js */
+/**************************************************************************/
+/* This file is part of: */
+/* GODOT ENGINE */
+/* https://godotengine.org */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
+/* */
+/* 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. */
+/**************************************************************************/
+
+const GodotWebMidi = {
+
+ $GodotWebMidi__deps: ['$GodotRuntime'],
+ $GodotWebMidi: {
+ abortControllers: [],
+ isListening: false,
+ },
+
+ godot_js_webmidi_open_midi_inputs__deps: ['$GodotWebMidi'],
+ godot_js_webmidi_open_midi_inputs__proxy: 'sync',
+ godot_js_webmidi_open_midi_inputs__sig: 'iiii',
+ godot_js_webmidi_open_midi_inputs: function (pSetInputNamesCb, pOnMidiMessageCb, pDataBuffer, dataBufferLen) {
+ if (GodotWebMidi.is_listening) {
+ return 0; // OK
+ }
+ if (!navigator.requestMIDIAccess) {
+ return 2; // ERR_UNAVAILABLE
+ }
+ const setInputNamesCb = GodotRuntime.get_func(pSetInputNamesCb);
+ const onMidiMessageCb = GodotRuntime.get_func(pOnMidiMessageCb);
+
+ GodotWebMidi.isListening = true;
+ navigator.requestMIDIAccess().then((midi) => {
+ const inputs = [...midi.inputs.values()];
+ const inputNames = inputs.map((input) => input.name);
+
+ const c_ptr = GodotRuntime.allocStringArray(inputNames);
+ setInputNamesCb(inputNames.length, c_ptr);
+ GodotRuntime.freeStringArray(c_ptr, inputNames.length);
+
+ inputs.forEach((input, i) => {
+ const abortController = new AbortController();
+ GodotWebMidi.abortControllers.push(abortController);
+ input.addEventListener('midimessage', (event) => {
+ const status = event.data[0];
+ const data = event.data.slice(1);
+ const size = data.length;
+
+ if (size > dataBufferLen) {
+ throw new Error(`data too big ${size} > ${dataBufferLen}`);
+ }
+ HEAPU8.set(data, pDataBuffer);
+
+ onMidiMessageCb(i, status, pDataBuffer, data.length);
+ }, { signal: abortController.signal });
+ });
+ });
+
+ return 0; // OK
+ },
+
+ godot_js_webmidi_close_midi_inputs__deps: ['$GodotWebMidi'],
+ godot_js_webmidi_close_midi_inputs__proxy: 'sync',
+ godot_js_webmidi_close_midi_inputs__sig: 'v',
+ godot_js_webmidi_close_midi_inputs: function () {
+ for (const abortController of GodotWebMidi.abortControllers) {
+ abortController.abort();
+ }
+ GodotWebMidi.abortControllers = [];
+ GodotWebMidi.isListening = false;
+ },
+};
+
+mergeInto(LibraryManager.library, GodotWebMidi);
diff --git a/platform/web/os_web.h b/platform/web/os_web.h
index 1ddb745965ac..e9040f04d4d3 100644
--- a/platform/web/os_web.h
+++ b/platform/web/os_web.h
@@ -32,6 +32,7 @@
#define OS_WEB_H
#include "audio_driver_web.h"
+#include "webmidi_driver.h"
#include "godot_js.h"
@@ -45,6 +46,8 @@ class OS_Web : public OS_Unix {
MainLoop *main_loop = nullptr;
List<AudioDriverWeb *> audio_drivers;
+ MIDIDriverWebMidi midi_driver;
+
bool idb_is_syncing = false;
bool idb_available = false;
bool idb_needs_sync = false;
diff --git a/platform/web/webmidi_driver.cpp b/platform/web/webmidi_driver.cpp
new file mode 100644
index 000000000000..51c58344419d
--- /dev/null
+++ b/platform/web/webmidi_driver.cpp
@@ -0,0 +1,98 @@
+/**************************************************************************/
+/* webmidi_driver.cpp */
+/**************************************************************************/
+/* This file is part of: */
+/* GODOT ENGINE */
+/* https://godotengine.org */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
+/* */
+/* 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. */
+/**************************************************************************/
+
+#include "webmidi_driver.h"
+
+#ifdef PROXY_TO_PTHREAD_ENABLED
+#include "core/object/callable_method_pointer.h"
+#endif
+
+MIDIDriverWebMidi *MIDIDriverWebMidi::get_singleton() {
+ return static_cast<MIDIDriverWebMidi *>(MIDIDriver::get_singleton());
+}
+
+Error MIDIDriverWebMidi::open() {
+ Error error = (Error)godot_js_webmidi_open_midi_inputs(&MIDIDriverWebMidi::set_input_names_callback, &MIDIDriverWebMidi::on_midi_message, _event_buffer, MIDIDriverWebMidi::MAX_EVENT_BUFFER_LENGTH);
+ if (error == ERR_UNAVAILABLE) {
+ ERR_PRINT("Web MIDI is not supported on this browser.");
+ }
+ return error;
+}
+
+void MIDIDriverWebMidi::close() {
+ get_singleton()->connected_input_names.clear();
+ godot_js_webmidi_close_midi_inputs();
+}
+
+MIDIDriverWebMidi::~MIDIDriverWebMidi() {
+ close();
+}
+
+void MIDIDriverWebMidi::set_input_names_callback(int p_size, const char **p_input_names) {
+ Vector<String> input_names;
+ for (int i = 0; i < p_size; i++) {
+ input_names.append(String::utf8(p_input_names[i]));
+ }
+#ifdef PROXY_TO_PTHREAD_ENABLED
+ if (!Thread::is_main_thread()) {
+ callable_mp_static(MIDIDriverWebMidi::_set_input_names_callback).call_deferred(input_names);
+ return;
+ }
+#endif
+
+ _set_input_names_callback(input_names);
+}
+
+void MIDIDriverWebMidi::_set_input_names_callback(const Vector<String> &p_input_names) {
+ get_singleton()->connected_input_names.clear();
+ for (const String &input_name : p_input_names) {
+ get_singleton()->connected_input_names.push_back(input_name);
+ }
+}
+
+void MIDIDriverWebMidi::on_midi_message(int p_device_index, int p_status, const uint8_t *p_data, int p_data_len) {
+ PackedByteArray data;
+ data.resize(p_data_len);
+ uint8_t *data_ptr = data.ptrw();
+ for (int i = 0; i < p_data_len; i++) {
+ data_ptr[i] = p_data[i];
+ }
+#ifdef PROXY_TO_PTHREAD_ENABLED
+ if (!Thread::is_main_thread()) {
+ callable_mp_static(MIDIDriverWebMidi::_on_midi_message).call_deferred(p_device_index, p_status, data, p_data_len);
+ return;
+ }
+#endif
+ _on_midi_message(p_device_index, p_status, data, p_data_len);
+}
+
+void MIDIDriverWebMidi::_on_midi_message(int p_device_index, int p_status, const PackedByteArray &p_data, int p_data_len) {
+ MIDIDriver::send_event(p_device_index, p_status, p_data.ptr(), p_data_len);
+}
diff --git a/platform/web/webmidi_driver.h b/platform/web/webmidi_driver.h
new file mode 100644
index 000000000000..00c7df1ae776
--- /dev/null
+++ b/platform/web/webmidi_driver.h
@@ -0,0 +1,61 @@
+/**************************************************************************/
+/* webmidi_driver.h */
+/**************************************************************************/
+/* This file is part of: */
+/* GODOT ENGINE */
+/* https://godotengine.org */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
+/* */
+/* 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. */
+/**************************************************************************/
+
+#ifndef WEBMIDI_DRIVER_H
+#define WEBMIDI_DRIVER_H
+
+#include "core/os/midi_driver.h"
+
+#include "godot_js.h"
+#include "godot_midi.h"
+
+class MIDIDriverWebMidi : public MIDIDriver {
+private:
+ static const int MAX_EVENT_BUFFER_LENGTH = 2;
+ uint8_t _event_buffer[MAX_EVENT_BUFFER_LENGTH];
+
+public:
+ // Override return type to make writing static callbacks less tedious.
+ static MIDIDriverWebMidi *get_singleton();
+
+ virtual Error open() override;
+ virtual void close() override final;
+
+ MIDIDriverWebMidi() = default;
+ virtual ~MIDIDriverWebMidi();
+
+ WASM_EXPORT static void set_input_names_callback(int p_size, const char **p_input_names);
+ static void _set_input_names_callback(const Vector<String> &p_input_names);
+
+ WASM_EXPORT static void on_midi_message(int p_device_index, int p_status, const uint8_t *p_data, int p_data_len);
+ static void _on_midi_message(int p_device_index, int p_status, const PackedByteArray &p_data, int p_data_len);
+};
+
+#endif // WEBMIDI_DRIVER_H