public Matrix(Tone[] firstRow = null)
{
firstRow = firstRow ?? GetRandomFirstRow();
Validate(firstRow);
InitializeVariables(firstRow);
InitializeMatrix(firstRow);
}
public Tone[] Column(int i)
{
Tone[] column = new Tone[12];
for (int j = 0; j < 12; j++)
{
column[j] = notes[j][i];
}
return column;
}
private void InitializeMatrix(Tone[] firstRow)
{
for (int i = 1; i < 12; ++i)
{
int primeRowNumber = 12 - noteToOrdinal[notes[0][i]];
notes[i][0] = ordinalToNote[primeRowNumber];
for (int j = 1; j < 12; ++j)
{
int nextOrdinal = primeRowNumber + noteToOrdinal[notes[0][j]];
nextOrdinal = nextOrdinal >= 12 ? nextOrdinal - 12 : nextOrdinal;
notes[i][j] = ordinalToNote[nextOrdinal];
}
}
}
public static Tone[] GetRandomFirstRow(Random randomNumberGenerator = null)
{
randomNumberGenerator = randomNumberGenerator ?? new Random();
Tone[] firstRow = new Tone[12];
var firstFrequencies = Enumerable.Range(0, 12).Select(x => Tone.GetFrequency(x)).ToList();
for (int i = 0; i < 12; i++)
{
int nextIndex = randomNumberGenerator.Next(0, firstFrequencies.Count - 1);
firstRow[i] = new Tone(firstFrequencies[nextIndex]);
firstFrequencies.RemoveAt(nextIndex);
}
return firstRow;
}
public Note(Tone tone, int milliseconds)
{
Tone = tone;
Milliseconds = milliseconds;
}
private void InitializeVariables(Tone[] firstRow)
{
notes = new Tone[12][];
notes[0] = firstRow
.Select(x => Normalize(x, firstRow[0], firstRow[0] * 2))
.ToArray();
for (int i = 1; i < 12; i++)
{
notes[i] = new Tone[12];
}
noteToOrdinal = notes[0]
.OrderBy(x => (int)x)
.Select((note, ordinal) => new { note, ordinal })
.ToDictionary(obj => obj.note, obj => obj.ordinal);
ordinalToNote = noteToOrdinal
.ToDictionary(x => x.Value, x => x.Key);
}
private void Validate(Tone[] firstRow)
{
if (firstRow.Length != 12)
{
throw new ArgumentException("firstRow must have 12 tones");
}
if (firstRow.Select(x => (int)x).Distinct().Count() != firstRow.Length)
{
throw new ArgumentException("row must not have repeated values");
}
}
private Tone Normalize(Tone x, int lowend, int highend)
{
while (lowend > (int)x)
{
x = new Tone(2 * (int)x);
}
while (highend <= (int)x)
{
x = new Tone((int)x / 2);
}
return x;
}
