midibuddy.h

#include <MIDI.h>
#include <arduino.h>

class MidiChannel{
  private:
  byte curPitch;
  boolean curState;
  unsigned long startTime;

  public:
  MidiChannel();
  byte getCurPitch() const;
  boolean getCurState() const;
  unsigned long getStartTime() const;
  void setCurPitch(const byte inCurPitch);
  void setCurState(const byte inState);
  void setStartTime();

};


MidiChannel::MidiChannel(){
   curPitch = 0x00;
   curState = false;
   startTime = millis();
}

byte MidiChannel::getCurPitch() const{
  return curPitch;
}

boolean MidiChannel::getCurState() const{
  return curState;
 }

unsigned long MidiChannel::getStartTime() const{
  return startTime;
}

void MidiChannel::setCurPitch(const byte inCurPitch){
  curPitch = inCurPitch;
}

void MidiChannel::setCurState(const boolean inState){
  curState = inState;
}

void MidiChannel::setStartTime(){
  startTime = millis();
}

class MCArray{
  private:
  MidiChannel Array[4];

  public:
  MCArray();
  byte noteOffMatch(const byte inPitch) const;
  void updateStatus(const kMIDIType curMessage, byte pitch, byte messageChannel);
  byte nextNotePlayPitch(byte& killPitch, byte numberOfChannels) const;
  byte nextNotePlayTime(byte& killPitch, byte numberOfChannels) const;


};

MCArray::MCArray(){
}

// check the channels with current status on and match pitch to determine note send off.
byte MCArray::noteOffMatch(const byte inPitch) const{
  for(int i = 0x00; i < 4; i++){
    if(Array[i].getCurState() == true && Array[i].getCurPitch() == inPitch){
      return i;
    }
  }
  // incase the note has already been turned off
  return 0xFF;

}
void MCArray::updateStatus(const kMIDIType curMessage, byte pitch, byte messageChannel){
  if(curMessage == NoteOn){
    Array[messageChannel].setCurPitch(pitch);
    Array[messageChannel].setCurState(true);
    Array[messageChannel].setStartTime();
  }

  if(curMessage == NoteOff){
    Array[messageChannel].setCurPitch(0x00);
    Array[messageChannel].setCurState(false);
  }
}


// use an algorithm to find which note should be played next
// killnote is in case all channels are in use.
byte MCArray::nextNotePlayPitch(byte& killPitch, byte numberOfChannels) const{

  // check if all notes are being played
  for(int i = 0x00; i < numberOfChannels; i++){
    if (Array[i].getCurState() == false){
      return i;
    }
  }

  // check play times
  byte dropChannel = 0x00;
  byte maxPitch = Array[0x00].getCurPitch();
  for(int i = 0x01; i < numberOfChannels; i++){
    if(maxPitch < Array[i].getCurPitch()){
      dropChannel = i;
      maxPitch = Array[i].getCurPitch();
    }
  }
  killPitch = maxPitch;
  return dropChannel;
}

// use an algorithm to find which note should be played next
// killnote is in case all channels are in use.
byte MCArray::nextNotePlayTime(byte& killPitch, byte numberOfChannels) const{

  // check if all notes are being played
  for(int i = 0x00; i < numberOfChannels; i++){
    if (Array[i].getCurState() == false){
      return i;
    }
  }

  // check play times
  byte dropChannel = 0x00;
  killPitch = Array[0x00].getCurPitch();
  unsigned long lowTime = Array[0x00].getStartTime();
  for(int i = 0x01; i < numberOfChannels; i++){
    if(lowTime > Array[i].getStartTime()){
      dropChannel = i;
      lowTime = Array[i].getCurPitch();
      killPitch = Array[i].getCurPitch();
    }
  }
  return dropChannel;
}