public static async Task <ScaleFinderResultSet> FindScalesAsync(IScaleFinderOptions scaleFinderOptions, CancellationToken cancelToken)
{
if (null == scaleFinderOptions)
{
throw new ArgumentNullException(nameof(scaleFinderOptions));
}
InternalNote root = NoteUtils.ToInternalNote(scaleFinderOptions.RootNote);
IScale scale = scaleFinderOptions.Scale;
InternalNote[] notesInScale = NamedInterval.GetNotes(root, scale.Intervals);
ScaleFinderResultSet results = new ScaleFinderResultSet(scaleFinderOptions);
if (cancelToken.IsCancellationRequested)
{
return(results);
}
foreach (NoteNode startingNode in FindNodes(notesInScale[0], scaleFinderOptions))
{
await FindAllScalesAsync(results, startingNode, notesInScale, 1, startingNode.String, scaleFinderOptions, cancelToken);
}
return(results);
}
internal ScaleFinderResult(ScaleFinderResultSet parent, IEnumerable <MarkPosition> marks)
{
if (null == marks)
{
throw new ArgumentNullException(nameof(marks));
}
Parent = parent ?? throw new ArgumentNullException(nameof(parent));
_marks = new List <MarkPosition>(marks);
}
private static async Task FindAllScalesAsync(ScaleFinderResultSet results, NoteNode noteNode, InternalNote[] targetNotes, int nextNote, int str, IScaleFinderOptions scaleFinderOptions, CancellationToken cancelToken)
{
if (cancelToken.IsCancellationRequested)
{
return;
}
IInstrument instrument = scaleFinderOptions.Instrument;
if (nextNote == targetNotes.Length) // Build a scale result
{
List <MarkPosition> marks = new List <MarkPosition>();
NoteNode nn = noteNode;
// Walk back up the tree to set the marks on the result and flag each target note
while (null != nn)
{
if (nn.Fret >= 0)
{
marks.Add(new MarkPosition(nn.String + 1, nn.Fret));
}
nn = nn.Parent;
}
results.AddResult(marks);
}
else if (str < instrument.NumStrings) // Keep building the tree
{
// Look at all the notes on the string
int startingFret = scaleFinderOptions.AllowOpenStrings ? 0 : 1;
if (null != noteNode && noteNode.String == str)
{
startingFret = noteNode.Fret + 1;
}
for (int fret = startingFret; fret <= scaleFinderOptions.MaxFret; fret++)
{
InternalNote note = NoteUtils.Shift(scaleFinderOptions.Tuning.RootNotes[str].InternalNote, fret);
// See if the note is the next target note
if (note == targetNotes[nextNote])
{
NoteNode child = new NoteNode(str, fret, note, noteNode); // Add found note
await FindAllScalesAsync(results, child, targetNotes, nextNote + 1, str, scaleFinderOptions, cancelToken); // Look for the next note on the same string
}
}
await FindAllScalesAsync(results, noteNode, targetNotes, nextNote, str + 1, scaleFinderOptions, cancelToken); // Look for the next note on the next string
}
}