message.h

/*
 * Copyright © 2024 Synthstrom Audible Limited
 *
 * This file is part of The Synthstrom Audible Deluge Firmware.
 *
 * The Synthstrom Audible Deluge Firmware 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 <https://www.gnu.org/licenses/>.
 */
 
#pragma once
 
#include <cinttypes>
#include <cstdlib>

size_t bytesPerStatusMessage(uint8_t status);

struct MIDIMessage {
    uint8_t statusType;
    uint8_t channel;
    uint8_t data1;
    uint8_t data2;
 
    [[gnu::always_inline]] [[nodiscard]] bool isSystemMessage() const { return statusType == 0x0f; }

 
    static MIDIMessage noteOff(uint8_t channel, uint8_t note, uint8_t velocity) {
        return MIDIMessage{.statusType = 0b1000, .channel = channel, .data1 = note, .data2 = velocity};
    }
 
    static MIDIMessage noteOn(uint8_t channel, uint8_t note, uint8_t velocity) {
        return MIDIMessage{.statusType = 0b1001, .channel = channel, .data1 = note, .data2 = velocity};
    }
 
    static MIDIMessage polyphonicAftertouch(uint8_t channel, uint8_t note, uint8_t aftertouch) {
        return MIDIMessage{.statusType = 0b1010, .channel = channel, .data1 = note, .data2 = aftertouch};
    }
 
    static MIDIMessage cc(uint8_t channel, uint8_t cc, uint8_t value) {
        return MIDIMessage{.statusType = 0b1011, .channel = channel, .data1 = cc, .data2 = value};
    }
 
    static MIDIMessage programChange(uint8_t channel, uint8_t program) {
        return MIDIMessage{.statusType = 0b1100, .channel = channel, .data1 = program, .data2 = 0};
    }
 
    static MIDIMessage channelAftertouch(uint8_t channel, uint8_t aftertouch) {
        return MIDIMessage{.statusType = 0b1101, .channel = channel, .data1 = aftertouch, .data2 = 0};
    }

    static MIDIMessage pitchBend(uint8_t channel, uint16_t bend) {
        return MIDIMessage{
            .statusType = 0b1110,
            .channel = channel,
            .data1 = static_cast<uint8_t>(bend & 0x7f),
            .data2 = static_cast<uint8_t>((bend >> 7) & 0x7f),
        };
    }
 
    static MIDIMessage realtimeClock() {
        return MIDIMessage{.statusType = 0x0F, .channel = 0x08, .data1 = 0, .data2 = 0};
    }
 
    static MIDIMessage realtimeStart() {
        return MIDIMessage{.statusType = 0x0F, .channel = 0x0A, .data1 = 0, .data2 = 0};
    }
 
    static MIDIMessage realtimeContinue() {
        return MIDIMessage{.statusType = 0x0F, .channel = 0x0B, .data1 = 0, .data2 = 0};
    }
 
    static MIDIMessage realtimeStop() {
        return MIDIMessage{.statusType = 0x0F, .channel = 0x0C, .data1 = 0, .data2 = 0};
    }
 
    static MIDIMessage systemPositionPointer(uint16_t position) {
        uint8_t positionPointerLSB = position & (uint32_t)0x7F;
        uint8_t positionPointerMSB = (position >> 7) & (uint32_t)0x7F;
        return MIDIMessage{
            .statusType = 0x0F, .channel = 0x02, .data1 = positionPointerLSB, .data2 = positionPointerMSB};
    }

};
 
static_assert(sizeof(MIDIMessage) == 4);