initial commit, 4.5 stable

core/os/midi_driver.h

@@ -0,0 +1,111 @@
+/**************************************************************************/
+/*  midi_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.                 */
+/**************************************************************************/
+
+#pragma once
+
+#include "core/typedefs.h"
+#include "core/variant/variant.h"
+
+/**
+ * Multi-Platform abstraction for accessing to MIDI.
+ */
+
+class MIDIDriver {
+	static MIDIDriver *singleton;
+	static uint8_t last_received_message;
+
+protected:
+	// Categories of message for parser logic.
+	enum class MessageCategory {
+		Data,
+		Voice,
+		SysExBegin,
+		SystemCommon, // excluding System Exclusive Begin/End
+		SysExEnd,
+		RealTime,
+	};
+
+	// Convert midi data to InputEventMIDI and send it to Input.
+	// p_data_len is the length of the buffer passed at p_data, this must be
+	// at least equal to the data required by the passed message type, but
+	// may be larger. Only the required data will be read.
+	static void send_event(int p_device_index, uint8_t p_status,
+			const uint8_t *p_data = nullptr, size_t p_data_len = 0);
+
+	class Parser {
+	public:
+		Parser() = default;
+		Parser(int p_device_index) :
+				device_index{ p_device_index } {}
+		virtual ~Parser() = default;
+
+		// Push a byte of MIDI stream. Any completed messages will be
+		// forwarded to MIDIDriver::send_event.
+		void parse_fragment(uint8_t p_fragment);
+
+		static MessageCategory category(uint8_t p_midi_fragment);
+
+		// If the byte is a Voice Message status byte return the contained
+		// channel number, otherwise zero.
+		static uint8_t channel(uint8_t p_status_byte);
+
+		// If the byte is a status byte for a message with a fixed number of
+		// additional data bytes, return the number expected, otherwise zero.
+		static size_t expected_data(uint8_t p_status_byte);
+		static size_t expected_data(MIDIMessage p_msg_type);
+
+		// If the fragment is a status byte return the message type
+		// represented, otherwise MIDIMessage::NONE.
+		static MIDIMessage status_to_msg_enum(uint8_t p_status_byte);
+
+	private:
+		int device_index = 0;
+
+		static constexpr size_t DATA_BUFFER_SIZE = 2;
+
+		uint8_t status_byte = 0;
+		uint8_t data_buffer[DATA_BUFFER_SIZE] = { 0 };
+		size_t received_data_len = 0;
+		bool skipping_sys_ex = false;
+	};
+
+	PackedStringArray connected_input_names;
+
+public:
+	static MIDIDriver *get_singleton();
+
+	MIDIDriver();
+	virtual ~MIDIDriver() = default;
+
+	virtual Error open() = 0;
+	virtual void close() = 0;
+
+	PackedStringArray get_connected_inputs() const;
+};