/// <summary>
/// Throws an exception if family is not valid.
/// </summary>
/// <param name="family">The family to validate.</param>
/// <exception cref="ArgumentOutOfRangeException">The family is out-of-range.</exception>
public static void Validate(this NoteFamily family)
{
if (!family.IsValid())
{
throw new ArgumentOutOfRangeException("NoteFamily out of range");
}
}
/// <summary>
/// Returns the number of semitones that note is above tonic.
/// </summary>
/// <param name="note">The note.</param>
/// <param name="tonic">The tonic.</param>
/// <returns>The number of semitones, always in [0..11].</returns>
public static int SemitonesAbove(this Note note, NoteFamily tonic)
{
int result = ((int)note % 12 - (int)tonic);
if (result < 0)
{
result += 12;
}
return(result);
}
/// <summary>
/// Returns a copy of family which is made valid by wrapping if necessary.
/// </summary>
/// <param name="family">The family to wrap.</param>
/// <returns>The wrapped copy of family.</returns>
public static NoteFamily Wrapped(this NoteFamily family)
{
if ((int)family < 0)
{
return((NoteFamily)(11 - ((-(int)family - 1) % 12)));
}
else
{
return((NoteFamily)((int)family % 12));
}
}
/// <summary>
/// Constructs a chord from its root note, pattern, and inversion.
/// </summary>
/// <param name="root">The root note of the chord.</param>
/// <param name="pattern">The chord pattern.</param>
/// <param name="inversion">The inversion, in [0..N-1] where N is the number of notes
/// in pattern.</param>
/// <exception cref="ArgumentOutOfRangeException">root is invalid or inversion is out of
/// range.</exception>
public Chord(NoteFamily root, Pattern pattern, int inversion)
{
root.Validate();
if (inversion < 0 || inversion >= pattern.SemitoneSequence.Length)
{
throw new ArgumentOutOfRangeException("inversion out of range.");
}
this.root = root;
this.pattern = pattern;
this.inversion = inversion;
this.invertedSequence = InvertSequence(pattern.SemitoneSequence, inversion);
}
/// <summary>
/// Constructs a scale from its tonic and its pattern.
/// </summary>
/// <param name="tonic"></param>
/// <param name="pattern"></param>
public Scale(NoteFamily tonic, Pattern pattern)
{
this.tonic = tonic;
this.pattern = pattern;
this.ascendingMask =
new bool[13] {
true, false, false, false, false, false, false, false, false, false,
false, false, true
};
this.descendingMask =
new bool[13] {
true, false, false, false, false, false, false, false, false, false,
false, false, true
};
if (!ComputeMasks())
{
throw new ArgumentException("Invalid pattern.");
}
}
/// <summary>
/// Returns the number of semitones that note is above tonic.
/// </summary>
/// <param name="note">The note.</param>
/// <param name="tonic">The tonic.</param>
/// <returns>The number of semitones, always in [0..11].</returns>
public static int SemitonesAbove(this Note note, NoteFamily tonic)
{
int result = ((int)note % 12 - (int)tonic);
if (result < 0)
{
result += 12;
}
return result;
}
/// <summary>
/// Constructs a chord from its root note, pattern, and inversion.
/// </summary>
/// <param name="root">The root note of the chord.</param>
/// <param name="pattern">The chord pattern.</param>
/// <param name="inversion">The inversion, in [0..N-1] where N is the number of notes
/// in pattern.</param>
/// <exception cref="ArgumentOutOfRangeException">root is invalid or inversion is out of
/// range.</exception>
public Chord(NoteFamily root, Pattern pattern, int inversion)
{
root.Validate();
if (inversion < 0 || inversion >= pattern.SemitoneSequence.Length)
{
throw new ArgumentOutOfRangeException("inversion out of range.");
}
this.root = root;
this.pattern = pattern;
this.inversion = inversion;
this.invertedSequence = InvertSequence(pattern.SemitoneSequence, inversion);
}
/// <summary>
/// Returns the human-readable name of a note family.
/// </summary>
/// <param name="family">The family.</param>
/// <exception cref="ArgumentOutOfRangeException">The family is out-of-range.</exception>
public static string Name(this NoteFamily family)
{
family.Validate();
return(NoteFamilyNames[(int)family]);
}
/// <summary>
/// Returns true if the specified note family is valid.
/// </summary>
/// <param name="family">The family to test.</param>
public static bool IsValid(this NoteFamily family)
{
return((int)family >= 0 && (int)family < 12);
}
/// <summary>
/// Fills ascendingMask and descendingMask based on ascendingDescendingPattern.
/// </summary>
/// <returns>True if the operation succeeded, false if the pattern was invalid.</returns>
private bool ComputeMasks()
{
int[] semitoneSequence = pattern.SemitoneSequence;
int numAscendingNotes = 2;
int numDescendingNotes = 2;
// First make sure it's non-empty and starts at zero.
if (semitoneSequence == null || semitoneSequence.Length == 0 ||
semitoneSequence[0] != 0)
{
return false;
}
// Now run through the rest of the pattern and make sure it ascends and then descends,
// and populate the masks as we go.
bool ascending = true;
for (int i = 1; i < semitoneSequence.Length; ++i)
{
if (ascending)
{
// Make sure we've just gone up.
if (semitoneSequence[i] <= semitoneSequence[i - 1])
{
return false;
}
// Make sure we haven't gone up too far.
if (semitoneSequence[i] > 12)
{
return false;
}
// If we've reached 12, start descending, otherwise add this to the ascending
// mask.
if (semitoneSequence[i] == 12)
{
ascending = false;
}
else
{
// Add this to the ascending mask.
ascendingMask[semitoneSequence[i]] = true;
numAscendingNotes++;
}
}
else
{
// Make sure we've just gone down.
if (semitoneSequence[i] >= semitoneSequence[i - 1])
{
return false;
}
// Make sure we haven't gone down too far.
if (semitoneSequence[i] < 0)
{
return false;
}
// If we've reached 0, make sure we're the last element, otherwise add this
// to the mask.
if (semitoneSequence[i] == 0)
{
if (i != semitoneSequence.Length - 1)
{
return false;
}
}
else
{
// Add this to the descending mask.
descendingMask[semitoneSequence[i]] = true;
numDescendingNotes++;
}
}
}
ascendingNotes = new NoteFamily[numAscendingNotes];
descendingNotes = new NoteFamily[numDescendingNotes];
int numAdded = 0;
for (int i = 0; i <= 12; ++i)
{
if (ascendingMask[i])
{
ascendingNotes[numAdded++] = (NoteFamily)(tonic + i).Wrapped();
}
}
numAdded = 0;
for (int i = 12; i >= 0; --i)
{
if (descendingMask[i])
{
descendingNotes[numAdded++] = (NoteFamily)(tonic + i).Wrapped();
}
}
return true;
}
/// <summary>
/// Constructs a scale from its tonic and its pattern.
/// </summary>
/// <param name="tonic"></param>
/// <param name="pattern"></param>
public Scale(NoteFamily tonic, Pattern pattern)
{
this.tonic = tonic;
this.pattern = pattern;
this.ascendingMask =
new bool[13] { true, false, false, false, false, false, false, false, false, false,
false, false, true };
this.descendingMask =
new bool[13] { true, false, false, false, false, false, false, false, false, false,
false, false, true };
if (!ComputeMasks())
{
throw new ArgumentException("Invalid pattern.");
}
}
/// <summary>
/// Fills ascendingMask and descendingMask based on ascendingDescendingPattern.
/// </summary>
/// <returns>True if the operation succeeded, false if the pattern was invalid.</returns>
private bool ComputeMasks()
{
int[] semitoneSequence = pattern.SemitoneSequence;
int numAscendingNotes = 2;
int numDescendingNotes = 2;
// First make sure it's non-empty and starts at zero.
if (semitoneSequence == null || semitoneSequence.Length == 0 ||
semitoneSequence[0] != 0)
{
return(false);
}
// Now run through the rest of the pattern and make sure it ascends and then descends,
// and populate the masks as we go.
bool ascending = true;
for (int i = 1; i < semitoneSequence.Length; ++i)
{
if (ascending)
{
// Make sure we've just gone up.
if (semitoneSequence[i] <= semitoneSequence[i - 1])
{
return(false);
}
// Make sure we haven't gone up too far.
if (semitoneSequence[i] > 12)
{
return(false);
}
// If we've reached 12, start descending, otherwise add this to the ascending
// mask.
if (semitoneSequence[i] == 12)
{
ascending = false;
}
else
{
// Add this to the ascending mask.
ascendingMask[semitoneSequence[i]] = true;
numAscendingNotes++;
}
}
else
{
// Make sure we've just gone down.
if (semitoneSequence[i] >= semitoneSequence[i - 1])
{
return(false);
}
// Make sure we haven't gone down too far.
if (semitoneSequence[i] < 0)
{
return(false);
}
// If we've reached 0, make sure we're the last element, otherwise add this
// to the mask.
if (semitoneSequence[i] == 0)
{
if (i != semitoneSequence.Length - 1)
{
return(false);
}
}
else
{
// Add this to the descending mask.
descendingMask[semitoneSequence[i]] = true;
numDescendingNotes++;
}
}
}
ascendingNotes = new NoteFamily[numAscendingNotes];
descendingNotes = new NoteFamily[numDescendingNotes];
int numAdded = 0;
for (int i = 0; i <= 12; ++i)
{
if (ascendingMask[i])
{
ascendingNotes[numAdded++] = (NoteFamily)(tonic + i).Wrapped();
}
}
numAdded = 0;
for (int i = 12; i >= 0; --i)
{
if (descendingMask[i])
{
descendingNotes[numAdded++] = (NoteFamily)(tonic + i).Wrapped();
}
}
return(true);
}
