private static MelodyElement TransposeElement(MelodyElement element, int tonesToTransponse)
{
var noteElement = element as NoteElement;
if (noteElement == null)
{
return(element);
}
// Every octave consists of 12 notes numberd from 1 to 12. Each octave numbered from 1 to 8.
// To transpose over octaves we will get absolute index of note like (octave index - 1) * 12 + (note index - 1).
// As far as octave and note numbered starting from 1 we decrease it's values by 1 for farher calculation.
var absoluteNoteNumber = ((int)noteElement.Octave - 1) * 12 + ((int)noteElement.Note - 1);
// Then we transpose absolute number. In case gotten value exceeds maximum value of 96 (12 notes * 8 octave)
// we calculate remainder of dividing by 96. In case gotten value is below 0 we add 96.
absoluteNoteNumber = (absoluteNoteNumber + tonesToTransponse) % 96;
absoluteNoteNumber = absoluteNoteNumber >= 0 ? absoluteNoteNumber : absoluteNoteNumber + 96;
// Then to get transposed octave index we divide transposed absolute index
// value by 12 and increase it by 1 due to we decreased it by 1 before.
// To get transposed note index we will get remainder of dividing by 12
// and increase it by 1 due to we decreased it by 1 before.
noteElement.Octave = (Octave)(absoluteNoteNumber / 12 + 1);
noteElement.Note = (Note)(absoluteNoteNumber % 12 + 1);
return(noteElement);
}
private void PlayElement(MelodyElement element)
{
var durationInMilliseconds = _wholeNoteDurationInMilliseconds / (int)element.Duration;
var noteElement = element as NoteElement;
if (noteElement == null)
{
// In case it's a pause element we have only just wait desired time.
Thread.Sleep(durationInMilliseconds);
}
else
{
// In case it's a note element we play it.
var frequency = GetFrequency(noteElement.Note, noteElement.Octave);
_buzzer.PlayTone(frequency, (int)(durationInMilliseconds * 0.7));
Thread.Sleep((int)(durationInMilliseconds * 0.3));
}
}
