path: root/controller/libs/midi.c

// This file is written to be read side-along with the MIDI 1.0 spec.
// Note the tables at its very end, with /absolutely no direct allusion in the text/.

#include <stdint.h>
#include <stdbool.h>

typedef struct {
  uint8_t len;
  uint8_t status;
  uint8_t data1;
  uint8_t data2;
} MIDIMessage;

typedef struct {
  uint8_t status;
  uint8_t sub_id;
  uint8_t* bytes;
  uint8_t size;
} SysExMessage;



// Channel voice messages.

#IFDEF KEY_ON_VELOCITY

MIDIMessage note_on(uint8_t channel, uint8_t note, uint8_t velocity) {
  if (channel > 0x0f || note > 127 || velocity > 127) {
    while(1);
  }

  return {.status = 0x90 & channel,
	  .data1 = note,
	  .data2 = velocity
	  .len = 3};
}

#ELSE

MIDIMessage note_on(uint8_t channel, uint8_t note) {
  if (channel > 0x0f || note > 127) {
    while(1);
  }

  return {.status = 0x90 & channel,
	  .data1 = note,
	  .data2 = 0x40
	  .len = 3};
}


#ENDIF

#IFDEF RELEASE_VELOCITY

MIDIMessage note_off(uint8_t channel, uint8_t note, uint8_t velocity) {
  if (channel > 0x0f || note > 127 || velocity > 127) {
    while(1);
  }

  return {.status = 0x80 & channel,
	  .data1 = note,
	  .data2 = velocity
	  .len = 3};
}

#ELSE

#IFDEF ACTUAL_OFF_MESSAGE

MIDIMessage note_off(uint8_t channel, uint8_t note) {
  if (channel > 0x0f || note > 127) {
    while(1);
  }

  return {.status = 0x80 & channel,
	  .data1 = note,
	  .data2 = 0x40
	  .len = 3};
}

#ELSE

MIDIMessage note_off(uint8_t channel, uint8_t note) {
  if (channel > 0x0f || note > 127) {
    while(1);
  }

  return {.status = 0x90 & channel,
	  .data1 = note,
	  .data2 = 0
	  .len = 3};
}

#ENDIF
#ENDIF

MIDIMessage control_change(uint8_t channel, uint8_t control_number, uint8_t control_value) {
  if (channel > 0x0f || control_number > 119 || control_value > 127) {
    while(1);
  }

  return {.status = 0xb0 & channel,
	  .data1 = control_number,
	  .data2 = control_value
	  .len = 3};
}

enum Controller {
  bank_select = 0,
  modulation_wheel = 1,
  breath_controller = 2,
  // undefined
  foot_controller = 4,
  portamento_time = 5,
  data_entry_msb = 6,
  channel_volume = 7,
  balance = 8,
  // undefined
  pan = 10,
  expression = 11,
  effect1 = 12,
  effect2 = 13,
  // undefined
  gp1 = 16,
  gp2 = 17,
  gp3 = 18,
  gp4 = 19,
  damper_pedal = 64,
  portamento_toggle = 65,
  sostenuto = 66,
  soft_pedal = 67,
  legato_footswitch = 68,
  hold2 = 69,
  sc1_sound_variation = 70,
  sc2_timbre = 71,
  sc3_release_time = 72,
  sc4_attack_time = 73,
  sc5_brightness = 74,
  sc6 = 75,
  sc7 = 76,
  sc8 = 77,
  sc9 = 78,
  sc10 = 79,
  gp5 = 80,
  gp6 = 81,
  gp7 = 82,
  gp8 = 83,
  portamento_control = 84,
  // undefined
  effects_depth1 = 91,
  effects_depth2 = 92,
  effects_depth3 = 93,
  effects_depth4 = 94,
  effects_depth5 = 95,
  data_increment = 96,
  data_decrement = 97,
  nonregistered_lsb = 98,
  nonregistered_msb = 99,
  registered_lsb = 100,
  regustered_msg = 101,
  // undefined 102-119
  // channel mode 120-127
};

enum RegisteredParams {
  pitch_bend_sensitivity = 0,
  fine_tuning = 1,
  coarse_tuning = 2,
  tuning_program_select = 3,
  tuning_bank_select = 4
};


MIDIMessage program_change(uint8_t channel, uint8_t program_number) {
  if (channel > 0x0f || program_number > 119) {
    while(1);
  }

  return {.status = 0xc0 & channel,
	  .data1 = program_number,
	  .len = 2};
}

MIDIMessage aftertouch(uint8_t channel, uint8_t pressure_value) {
  if (channel > 0x0f || pressure_value > 127) {
    while(1);
  }

  return {.status = 0xd0 & channel,
	  .data1 = pressure_value,
	  .len = 2};
}

MIDIMessage pitch_bend_change(uint8_t channel, uint16_t change) {
  if (channel > 0x0f || pressure_value < 0x40 || pressure_value > 0x7f7f) {
    while(1);
  }

  return {.status = 0xe0 & channel,
	  .data1 = pressure_value,
	  .len = 2};
}

// Channel mode messages.


MIDIMessage all_sound_off(uint8_t channel) {
  if (channel > 0x0f) {
    while(1);
  }

  return {.status = 0xb0 & channel,
	  .data1 = 120,
	  .data2 = 0};
}

MIDIMessage reset_all_controllers(uint8_t channel) {
  if (channel > 0x0f) {
    while(1);
  }

  return {.status = 0xb0 & channel,
	  .data1 = 121,
	  .data2 = 0};
}

MIDIMessage local_control(uint8_t channel, bool status) {
  if (channel > 0x0f) {
    while(1);
  }

  if (status) {
    return {.status = 0xb0 & channel,
	    .data1 = 122,
	    .data2 = 127};
  } else {
     return {.status = 0xb0 & channel,
	    .data1 = 122,
	    .data2 = 0};
  }
}

MIDIMessage all_notes_off(uint8_t channel) {
  if (channel > 0x0f) {
    while(1);
  }

  return {.status = 0xb0 & channel,
	  .data1 = 123,
	  .data2 = 0};
}

MIDIMessage omni_toggle(uint8_t channel, bool status) {
  if (channel > 0x0f) {
    while(1);
  }

  if (status) {
    return {.status = 0xb0 & channel,
	    .data1 = 125,
	    .data2 = 0};
  } else {
     return {.status = 0xb0 & channel,
	    .data1 = 124,
	    .data2 = 0};
  }
}

#define RECEIVER_CHANNEL_COUNT 0
MIDIMessage mono_on(uint8_t channel, uint8_t channel_count) {
  if (channel > 0x0f || channel_count > 127) {
    while(1);
  }

  return {.status = 0xb0 & channel,
	  .data1 = 126,
	  .data2 = channel_count};
}

MIDIMessage poly_on(uint8_t channel) {
  if (channel > 0x0f) {
    while(1);
  }

  return {.status = 0xb0 & channel,
	  .data1 = 127,
	  .data2 = 0};
}


// System common messages.
// Not implemented:
//   - MTC Quarter Frame,
//   - Song Position Pointer,
//   - Song Select,
//   - Tune Request.

const MIDIMessage eox = {.status = 0xf7, .len = 1};


// System real time messages.
// Not implemented:
//   - Timing Clock,
//   - Start,
//   - Continue,
//   - Stop,
//   - Active Sensing,

MIDIMessage rst = {.status = 0xff, .len = 1};


// System exclusive messages.

SysExMessage sysex(uint8_t sub_id, uint8_t* contents, size_t size) {
  if (sub_id > 127) {
    while(1);
  }

  return {.status = 0xf0,
	  .sub_id = sub_id,
	  .data = contents,
	  .size = size};
}

// Only implement MIDI Tuning Standard universals
// and general information.

SysExMessage universal_sysex(uint8_t sub_id1, uint8_t sub_id2, uint8_t* contents, size_t size, bool real_time) {
  if (sub_id1 > 127 || sub_id2 > 127) {
    while(1);
  }

  uint8_t* new = malloc(contents, size + 2); // Might forget to free this...
  new[0] = sub_id1;
  new[1] = subid2;
  memcpy(new + 2, contents, size);


  if (real_time) {
    return sysex(0x7e, new, size + 2);
  } else {
    return sysex(0x7e, new, size + 2);
  }
}

SysExMessage bulk_tuning_dump(uint8_t)