Initial commit

backends/midi/webmidi.cpp

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+// Disable symbol overrides so that we can use system headers.
+#define FORBIDDEN_SYMBOL_EXCEPTION_FILE
+#define FORBIDDEN_SYMBOL_EXCEPTION_getenv
+
+#ifdef EMSCRIPTEN
+#include <emscripten.h>
+
+#include "audio/mpu401.h"
+#include "audio/musicplugin.h"
+#include "common/config-manager.h"
+#include "common/debug.h"
+#include "common/error.h"
+#include "common/scummsys.h"
+#include "common/textconsole.h"
+#include "common/util.h"
+
+/* WebMidi MIDI driver
+ */
+class MidiDriver_WebMIDI : public MidiDriver_MPU401 {
+public:
+	MidiDriver_WebMIDI(Common::String name, const char *id);
+	~MidiDriver_WebMIDI();
+	int open() override;
+	bool isOpen() const override;
+	void close() override;
+	void send(uint32 b) override;
+	void sysEx(const byte *msg, uint16 length) override;
+
+private:
+	Common::String _name;
+	const char *_id;
+};
+
+MidiDriver_WebMIDI::MidiDriver_WebMIDI(Common::String name, const char *id)
+	: _name(name), _id(id), MidiDriver_MPU401() {
+	debug(5, "WebMIDI: Creating device %s %s", _name.c_str(), _id);
+}
+
+MidiDriver_WebMIDI::~MidiDriver_WebMIDI() {
+}
+
+EM_ASYNC_JS(int, _midiOpen, (const char *id_c), {
+	var id = UTF8ToString(id_c);
+	result = await midiOutputMap.get(id).open().catch((error) => {
+		console.error(error);
+		return 1;
+	});
+	return 0;
+});
+
+int MidiDriver_WebMIDI::open() {
+	debug(5, "WebMIDI: Opening device %s", _name.c_str());
+	if (isOpen())
+		return MERR_ALREADY_OPEN;
+	return _midiOpen(_id);
+}
+
+EM_JS(bool, _midiIsOpen, (const char *id_c), {
+	var id = UTF8ToString(id_c);
+	return midiOutputMap.get(id) && midiOutputMap.get(id).connection == "open";
+});
+
+bool MidiDriver_WebMIDI::isOpen() const {
+	return _midiIsOpen(_id);
+}
+
+EM_ASYNC_JS(void, _midiClose, (const char *id_c), {
+	var id = UTF8ToString(id_c);
+	await midiOutputMap.get(id).close(); // TODO: Wait for promise to resolve (should be possible with Asyncify)
+});
+
+void MidiDriver_WebMIDI::close() {
+	debug(5, "WebMIDI: Closing device %s", _name.c_str());
+	MidiDriver_MPU401::close();
+	if(_midiIsOpen(_id))
+		_midiClose(_id);
+	else
+		warning("WebMIDI: Device %s is not open", _name.c_str());
+}
+
+EM_JS(void, _midiSendMessage, (const char *id_c, int status_byte, int first_byte, int second_byte), {
+	var id = UTF8ToString(id_c);
+	if (status_byte < 0xc0 || status_byte > 0xdf) {
+		midiOutputMap.get(id).send([status_byte, first_byte, second_byte]);
+	} else {
+		midiOutputMap.get(id).send([status_byte, first_byte]);		
+	}
+});
+
+void MidiDriver_WebMIDI::send(uint32 b) {
+	if(!isOpen()) {
+		warning("WebMIDI: Send called on closed device %s", _name.c_str());
+		return;
+	}
+	debug(5, "WebMIDI: Sending message for device %s %x", _name.c_str(), b);
+	midiDriverCommonSend(b);
+
+	const byte status_byte = b & 0xff;
+	const byte first_byte = (b >> 8) & 0xff;
+	const byte second_byte = (b >> 16) & 0xff;
+	_midiSendMessage(_id, status_byte, first_byte, second_byte);
+}
+
+void MidiDriver_WebMIDI::sysEx(const byte *msg, uint16 length) {
+	if(!isOpen()) {
+		warning("WebMIDI: SysEx called on closed device %s", _name.c_str());
+		return;
+	}
+	midiDriverCommonSysEx(msg, length);
+	warning("WebMIDI: SysEx not implemented yet, skipping %d bytes", length);
+}
+
+// Plugin interface
+
+class WebMIDIMusicPlugin : public MusicPluginObject {
+public:
+	const char *getName() const {
+		return "Web Midi";
+	}
+
+	const char *getId() const {
+		return "WebMidi";
+	}
+
+	MusicDevices getDevices() const;
+	Common::Error createInstance(MidiDriver **mididriver, MidiDriver::DeviceHandle = 0) const;
+};
+
+EM_JS(char **, _midiGetOutputNames, (), {
+	deviceNames = Array.from(midiOutputMap || []).map((elem) => elem[1].name);
+	deviceNames.push(""); // we need this to find the end of the array on the native side.
+
+	// convert the strings to C strings
+	var c_strings = deviceNames.map((s) => {
+		var size = lengthBytesUTF8(s) + 1;
+		var ret = Module._malloc(size);
+		stringToUTF8Array(s, HEAP8, ret, size);
+		return ret;
+	});
+
+	// populate return array
+	var ret_arr = Module._malloc(c_strings.length * 4); // 4-bytes per pointer
+	c_strings.forEach((ptr, i) => { Module.setValue(ret_arr + i * 4, ptr, "i32"); });
+
+	return ret_arr;
+});
+
+MusicDevices WebMIDIMusicPlugin::getDevices() const {
+	MusicDevices devices;
+	char **outputNames = _midiGetOutputNames();
+	char **iter = outputNames;
+	while (strcmp(*iter, "") != 0) {
+		char *c_name = *iter++;
+		Common::String name = Common::String(c_name);
+		devices.push_back(MusicDevice(this, name, MT_GM));
+		free(c_name);
+	}
+	free(outputNames);
+	return devices;
+}
+
+EM_JS(const char *, _midiGetOutputId, (const char *name_c), {
+	var name = UTF8ToString(name_c);
+	for (const [key, midiOutput] of midiOutputMap.entries()) {
+		if (midiOutput.name == name) {
+			return stringToNewUTF8(key)
+		}
+	}
+	return;
+});
+
+Common::Error WebMIDIMusicPlugin::createInstance(MidiDriver **mididriver, MidiDriver::DeviceHandle device) const {
+	MusicDevices deviceList = getDevices();
+	for (MusicDevices::iterator j = deviceList.begin(), jend = deviceList.end(); j != jend; ++j) {
+		if (j->getHandle() == device) {
+			*mididriver = new MidiDriver_WebMIDI(j->getName(), _midiGetOutputId(j->getName().c_str()));
+			return Common::kNoError;
+		}
+	}
+	return Common::kUnknownError;
+}
+
+//#if PLUGIN_ENABLED_DYNAMIC(WebMidi)
+	//REGISTER_PLUGIN_DYNAMIC(WebMidi, PLUGIN_TYPE_MUSIC, WebMIDIMusicPlugin);
+//#else
+	REGISTER_PLUGIN_STATIC(WEBMIDI, PLUGIN_TYPE_MUSIC, WebMIDIMusicPlugin);
+//#endif
+
+#endif // EMSCRIPTEN