public ChordResultSet FindChords(Note root, ChordQuality chordQuality, ChordFinderOptions chordFinderOptions)
{
if (null == chordQuality)
{
throw new ArgumentNullException("chordQuality");
}
if (null == chordFinderOptions)
{
throw new ArgumentNullException("chordFinderOptions");
}
InternalNote[] notesInChord = chordQuality.GetNotes(NoteUtils.ToInternalNote(root));
ChordResultSet results = new ChordResultSet(root, chordQuality, chordFinderOptions);
FindAllChords(results, null, notesInChord, 0, chordFinderOptions);
return(results);
}
private void FindAllChords(ChordResultSet results, NoteNode noteNode, InternalNote[] targetNotes, int str, ChordFinderOptions chordFinderOptions)
{
if (str == Instrument.NumStrings) // Build a chord result
{
int[] marks = new int[Instrument.NumStrings];
NoteNode nn = noteNode;
str--;
bool[] hasNotes = new bool[targetNotes.Length];
// Walk back up the tree to set the marks on the result and flag each target note
while (nn != null)
{
marks[str] = nn.Fret;
for (int i = 0; i < targetNotes.Length; i++)
{
if (nn.Note == targetNotes[i])
{
hasNotes[i] = true;
break;
}
}
nn = nn.Parent;
str--;
}
// The first target note is always the root, so ignore if we want
// to allow rootless chords
int firstTargetNote = chordFinderOptions.AllowRootlessChords ? 1 : 0;
// Add result if it had all the target notes
bool valid = true;
for (int i = firstTargetNote; i < hasNotes.Length; i++)
{
valid = valid && hasNotes[i];
}
if (valid)
{
results.AddResult(marks);
}
}
else // Keep building the tree
{
// Look at the muted string
if (chordFinderOptions.AllowMutedStrings)
{
NoteNode muted = new NoteNode();
muted.Parent = noteNode;
FindAllChords(results, muted, targetNotes, str + 1, chordFinderOptions);
}
// Look at all the notes on the string
int startingFret = chordFinderOptions.AllowOpenStrings ? 0 : 1;
for (int fret = startingFret; fret <= chordFinderOptions.MaxFret; fret++)
{
InternalNote note = Tuning.NoteAt(str, fret);
// See if the note is a target note
for (int i = 0; i < targetNotes.Length; i++)
{
// If it's a target note add it and search on the next string
if (note == targetNotes[i])
{
NoteNode child = new NoteNode(fret, note, noteNode);
FindAllChords(results, child, targetNotes, str + 1, chordFinderOptions);
break;
}
}
}
}
}