public static ChromaticPitchClass GetPitchClass(this DiatonicToneClass key)
{
switch (key)
{
case DiatonicToneClass.C:
return(ChromaticPitchClass.C);
case DiatonicToneClass.D:
return(ChromaticPitchClass.D);
case DiatonicToneClass.E:
return(ChromaticPitchClass.E);
case DiatonicToneClass.F:
return(ChromaticPitchClass.F);
case DiatonicToneClass.G:
return(ChromaticPitchClass.G);
case DiatonicToneClass.A:
return(ChromaticPitchClass.A);
case DiatonicToneClass.B:
return(ChromaticPitchClass.B);
default:
return((ChromaticPitchClass)key);
}
}
public DiatonicTone(
DiatonicToneClass keyclass,
int octave
)
{
KeyClass = keyclass;
Octave = octave;
}
public static DiatonicToneClass ToLeft(this DiatonicToneClass key) => (DiatonicToneClass)(((int)key - 1) % 7);
public static DiatonicToneClass ToRight(this DiatonicToneClass key) => (DiatonicToneClass)(((int)key + 1) % 7);
public static DiatonicTone ToKey(this DiatonicToneClass keyclass, int octave) =>
new DiatonicTone(
keyclass,
octave
);
public PitchTransform this[DiatonicToneClass key] {
get { return(keytransforms[key]); }
set { keytransforms[key] = value; }
}
public static KeySignature Create(
DiatonicToneClass key,
PitchTransform transform,
Mode mode
)
{
var modesteps = new PitchTransform[] {
PitchTransform.DoubleSharp,
PitchTransform.DoubleSharp,
PitchTransform.Sharp,
PitchTransform.DoubleSharp,
PitchTransform.DoubleSharp,
PitchTransform.DoubleSharp,
PitchTransform.Sharp
};
var keysteps = new PitchTransform[] {
PitchTransform.DoubleSharp,
PitchTransform.DoubleSharp,
PitchTransform.Sharp,
PitchTransform.DoubleSharp,
PitchTransform.DoubleSharp,
PitchTransform.DoubleSharp,
PitchTransform.Sharp
};
var mode_copy = mode;
while (mode_copy != Mode.Major)
{
// rotate L one step
var step0 = modesteps[0];
for (int i = 1; i < modesteps.Length; i++)
{
modesteps[i - 1] = modesteps[i];
}
modesteps[modesteps.Length - 1] = step0;
mode_copy = (Mode)((int)mode_copy - 1);
}
var key_copy = key;
while (key_copy != DiatonicToneClass.C)
{
// rotate L one step
var step0 = keysteps[0];
for (int i = 1; i < keysteps.Length; i++)
{
keysteps[i - 1] = keysteps[i];
}
keysteps[keysteps.Length - 1] = step0;
key_copy = (DiatonicToneClass)((int)key_copy - 1);
}
var signature =
new KeySignature();
var pitch = key.GetPitchClass();
for (int i = 0; i < 7; i++)
{
signature[key] = transform;
transform += modesteps[i];
transform -= keysteps[i];
//TODO: should modesteps[i] or transform be used here
pitch = modesteps[i].Transform(pitch);
key = key.ToRight();
}
return(signature);
}
