midi.c

//midi for embedded chips,
//Copyright 2010 Alex Norman
//
//This file is part of avr-midi.
//
//avr-midi 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.
//
//avr-midi 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 avr-midi.  If not, see <http://www.gnu.org/licenses/>.

#include "midi.h"
#include <string.h> //for memcpy

#define MIN(x,y) (((x) < (y)) ? (x) : (y)) 

#ifndef NULL
#define NULL 0
#endif

bool midi_is_statusbyte(uint8_t theByte){
   return (bool)(theByte & MIDI_STATUSMASK);
}

bool midi_is_realtime(uint8_t theByte){
   return (theByte >= MIDI_CLOCK);
}

midi_packet_length_t midi_packet_length(uint8_t status){
   switch(status & 0xF0){
      case MIDI_CC:
      case MIDI_NOTEON:
      case MIDI_NOTEOFF:
      case MIDI_AFTERTOUCH:
      case MIDI_PITCHBEND:
         return THREE;
      case MIDI_PROGCHANGE:
      case MIDI_CHANPRESSURE:
      case MIDI_SONGSELECT:
         return TWO;
      case 0xF0:
         switch(status) {
            case MIDI_CLOCK:
            case MIDI_TICK:
            case MIDI_START:
            case MIDI_CONTINUE:
            case MIDI_STOP:
            case MIDI_ACTIVESENSE:
            case MIDI_RESET:
            case MIDI_TUNEREQUEST:
               return ONE;
            case MIDI_SONGPOSITION:
               return THREE;
            case MIDI_TC_QUARTERFRAME:
            case MIDI_SONGSELECT:
               return TWO;
            case SYSEX_END:
            case SYSEX_BEGIN:
            default:
               return UNDEFINED;
         }
      default:
         return UNDEFINED;
   }
}

void midi_send_cc(MidiDevice * device, uint8_t chan, uint8_t num, uint8_t val){
   //CC Status: 0xB0 to 0xBF where the low nibble is the MIDI channel.
   //CC Data: Controller Num, Controller Val
   device->send_func(device, 3,
         MIDI_CC | (chan & MIDI_CHANMASK),
         num & 0x7F,
         val & 0x7F);
}

void midi_send_noteon(MidiDevice * device, uint8_t chan, uint8_t num, uint8_t vel){
   //Note Data: Note Num, Note Velocity
   device->send_func(device, 3,
         MIDI_NOTEON | (chan & MIDI_CHANMASK),
         num & 0x7F,
         vel & 0x7F);
}

void midi_send_noteoff(MidiDevice * device, uint8_t chan, uint8_t num, uint8_t vel){
   //Note Data: Note Num, Note Velocity
   device->send_func(device, 3,
         MIDI_NOTEOFF | (chan & MIDI_CHANMASK),
         num & 0x7F,
         vel & 0x7F);
}

void midi_send_aftertouch(MidiDevice * device, uint8_t chan, uint8_t note_num, uint8_t amt){
   device->send_func(device, 3,
         MIDI_AFTERTOUCH | (chan & MIDI_CHANMASK),
         note_num & 0x7F,
         amt & 0x7F);
}

//XXX does this work right?
//amt in range -0x2000, 0x1fff
//uAmt should be in range..
//0x0000 to 0x3FFF
void midi_send_pitchbend(MidiDevice * device, uint8_t chan, int16_t amt){
   uint16_t uAmt;
   //check range
   if(amt > 0x1fff){
      uAmt = 0x3FFF;
   } else if(amt < -0x2000){
      uAmt = 0;
   } else {
      uAmt = amt + 0x2000;
   }
   device->send_func(device, 3,
         MIDI_PITCHBEND | (chan & MIDI_CHANMASK),
         uAmt & 0x7F,
         (uAmt >> 7) & 0x7F);
}

void midi_send_programchange(MidiDevice * device, uint8_t chan, uint8_t num){
   device->send_func(device, 2,
         MIDI_PROGCHANGE | (chan & MIDI_CHANMASK),
         num & 0x7F,
         0);
}

void midi_send_channelpressure(MidiDevice * device, uint8_t chan, uint8_t amt){
   device->send_func(device, 2,
         MIDI_CHANPRESSURE | (chan & MIDI_CHANMASK),
         amt & 0x7F,
         0);
}

void midi_send_clock(MidiDevice * device){
   device->send_func(device, 1, MIDI_CLOCK, 0, 0);
}

void midi_send_tick(MidiDevice * device){
   device->send_func(device, 1, MIDI_TICK, 0, 0);
}

void midi_send_start(MidiDevice * device){
   device->send_func(device, 1, MIDI_START, 0, 0);
}

void midi_send_continue(MidiDevice * device){
   device->send_func(device, 1, MIDI_CONTINUE, 0, 0);
}

void midi_send_stop(MidiDevice * device){
   device->send_func(device, 1, MIDI_STOP, 0, 0);
}

void midi_send_activesense(MidiDevice * device){
   device->send_func(device, 1, MIDI_ACTIVESENSE, 0, 0);
}

void midi_send_reset(MidiDevice * device){
   device->send_func(device, 1, MIDI_RESET, 0, 0);
}

void midi_send_tcquarterframe(MidiDevice * device, uint8_t time){
   device->send_func(device, 2,
         MIDI_TC_QUARTERFRAME,
         time & 0x7F,
         0);
}

//XXX is this right?
void midi_send_songposition(MidiDevice * device, uint16_t pos){
   device->send_func(device, 3,
         MIDI_SONGPOSITION,
         pos & 0x7F,
         (pos >> 7) & 0x7F);
}

void midi_send_songselect(MidiDevice * device, uint8_t song){
   device->send_func(device, 2,
         MIDI_SONGSELECT,
         song & 0x7F,
         0);
}

void midi_send_tunerequest(MidiDevice * device){
   device->send_func(device, 1, MIDI_TUNEREQUEST, 0, 0);
}

void midi_send_byte(MidiDevice * device, uint8_t b){
   device->send_func(device, 1, b, 0, 0);
}

void midi_send_data(MidiDevice * device, uint16_t count, uint8_t byte0, uint8_t byte1, uint8_t byte2){
   //ensure that the count passed along is always 3 or lower
   if (count > 3) {
      //TODO how to do this correctly?
   }
   device->send_func(device, count, byte0, byte1, byte2);
}

void midi_send_array(MidiDevice * device, uint16_t count, uint8_t * array) {
  uint16_t i;
  for (i = 0; i < count; i += 3) {
    uint8_t b[3] = { 0, 0, 0 };
    uint16_t to_send = count - i;
    to_send = (to_send > 3) ? 3 : to_send;
    memcpy(b, array + i, to_send);
    midi_send_data(device, to_send, b[0], b[1], b[2]);
  }
}


void midi_register_cc_callback(MidiDevice * device, midi_three_byte_func_t func){
   device->input_cc_callback = func;
}

void midi_register_noteon_callback(MidiDevice * device, midi_three_byte_func_t func){
   device->input_noteon_callback = func;
}

void midi_register_noteoff_callback(MidiDevice * device, midi_three_byte_func_t func){
   device->input_noteoff_callback = func;
}

void midi_register_aftertouch_callback(MidiDevice * device, midi_three_byte_func_t func){
   device->input_aftertouch_callback = func;
}

void midi_register_pitchbend_callback(MidiDevice * device, midi_three_byte_func_t func){
   device->input_pitchbend_callback = func;
}

void midi_register_songposition_callback(MidiDevice * device, midi_three_byte_func_t func){
   device->input_songposition_callback = func;
}

void midi_register_progchange_callback(MidiDevice * device, midi_two_byte_func_t func) {
   device->input_progchange_callback = func;
}

void midi_register_chanpressure_callback(MidiDevice * device, midi_two_byte_func_t func) {
   device->input_chanpressure_callback = func;
}

void midi_register_songselect_callback(MidiDevice * device, midi_two_byte_func_t func) {
   device->input_songselect_callback = func;
}

void midi_register_tc_quarterframe_callback(MidiDevice * device, midi_two_byte_func_t func) {
   device->input_tc_quarterframe_callback = func;
}

void midi_register_realtime_callback(MidiDevice * device, midi_one_byte_func_t func){
   device->input_realtime_callback = func;
}

void midi_register_tunerequest_callback(MidiDevice * device, midi_one_byte_func_t func){
   device->input_tunerequest_callback = func;
}

void midi_register_sysex_callback(MidiDevice * device, midi_sysex_func_t func) {
   device->input_sysex_callback = func;
}

void midi_register_fallthrough_callback(MidiDevice * device, midi_var_byte_func_t func){
   device->input_fallthrough_callback = func;
}

void midi_register_catchall_callback(MidiDevice * device, midi_var_byte_func_t func){
   device->input_catchall_callback = func;
}