/**
* Within the given set of notes find the one that is the leftmost one and that is nearest to the
* given pitch, but exclude notes that have the same pitch.
*
* @param pitch
* @param notes
* @return
*/
private static Note nearestNote(int pitch, List<Note> notes) {
Note result = null;
int smallestPitchdiff = Integer.MAX_VALUE;
long nearestPos = Long.MAX_VALUE;
for (Note n : notes) {
int thisPitchDiff = Math.abs(pitch - n.getPitch());
long thisPos = n.getTickPos();
if (thisPos < nearestPos) {
result = n;
nearestPos = thisPos;
smallestPitchdiff = thisPitchDiff;
} else {
if (nearestPos == thisPos) {
if (thisPitchDiff < smallestPitchdiff) {
result = n;
smallestPitchdiff = thisPitchDiff;
}
}
}
}
if (smallestPitchdiff != 0) {
return result;
} else {
return null;
}
}
private static void handleTrack(
Track outputTrack, Track inputTrack, long startTick, long endTick) {
// handle all other events
for (int eventI = 0; eventI < inputTrack.size(); eventI++) {
MidiEvent midEvent = inputTrack.get(eventI);
if (!Note.isNoteOnEvent(midEvent)) {
if (!Note.isNoteOffEvent(midEvent)) {
outputTrack.add(midEvent);
}
}
}
// handle all note events
NoteTrack noteTrack = new NoteTrack(inputTrack);
for (int i = 0; i < noteTrack.size(); i++) {
Note thisNote = noteTrack.get(i);
List<Note> followingNotes = findFollowingNotes(noteTrack, i);
Note newNote = handleNote(thisNote, followingNotes, startTick, endTick);
outputTrack.add(newNote.getNoteOnEvent());
outputTrack.add(newNote.getNoteOffEvent());
}
}
/**
* Collect all the notes that follow the given note, within a range correspondin to the minimum
* rest.
*
* @param noteTrack
* @param index
* @return
*/
private static List<Note> findFollowingNotes(NoteTrack noteTrack, int index) {
ArrayList<Note> result = new ArrayList<>();
long posStart = noteTrack.get(index).getTickPos();
long noteDur = noteTrack.get(index).getDuration();
long posEnd = posStart + noteDur;
long maxSearch = posEnd + minimumRest;
for (int i = index + 1; i < noteTrack.size(); i++) {
Note note = noteTrack.get(i);
if (note.getTickPos() > maxSearch) {
// the note is outside our search area, as the note are sorted in ascending order, we have
// finished.
break;
}
// all notes that follow the end of the given note are added to the list
// remarque: we allow for an overlap of five ticks because of the impression of some Midi
// editors.
if (note.getTickPos() >= (posEnd - 5)) {
result.add(note);
}
}
return result;
}
/**
* Within the set set of following notes find one that we can link with.
*
* @param note
* @param follwoingNotes
* @return
*/
private static Note noteToLinkWith(Note note, List<Note> follwoingNotes) {
if (follwoingNotes.isEmpty()) {
return null;
}
Note candidate = nearestNote(note.getPitch(), follwoingNotes);
if (candidate == null) {
return null;
}
// avoid collision with a following note
long newNoteEnd = note.getTickPos() + prolongatedDuration(note, candidate);
for (Note fNote : follwoingNotes) {
if (fNote.getPitch() == note.getPitch()) {
if (fNote.getTickPos() <= newNoteEnd) {
return null;
}
}
}
return candidate;
}
private static Note handleNote(
Note note, List<Note> follwoingNotes, long startTick, long endTick) {
if (note.getTickPos() < startTick) {
return note;
}
if (note.getTickPos() + note.getDuration() > endTick) {
return note;
}
Note noteToLinkWith = noteToLinkWith(note, follwoingNotes);
if (noteToLinkWith != null) {
long newDuration = prolongatedDuration(note, noteToLinkWith);
Note newNote =
new Note(
note.getChannel(),
note.getPitch(),
note.getVelocity(),
note.getTickPos(),
newDuration);
slurEndNotes.add(noteToLinkWith);
slurEndNotes.remove(note);
return newNote;
}
if (slurEndNotes.contains(note)) {
Note newNote =
new Note(
note.getChannel(),
note.getPitch(),
(note.getVelocity() * 80) / 100,
note.getTickPos(),
(note.getDuration() * 80) / 100);
slurEndNotes.remove(note);
return newNote;
}
return note;
}
private static long prolongatedDuration(Note note, Note noteToLinkWith) {
return (noteToLinkWith.getTickPos() - note.getTickPos()) + noteOverlap;
}