// 主調mainKeyと内属記号keyRelationのペアから調keyを決定する
public static MusicKey MainKeyAndKeyRelationToKey(MusicKey mainKey, KeyRelation keyRelation)
{
for (int internalKey = 0; internalKey < (int)MusicKey.NUM; ++internalKey)
{
if (keyRelation == mainKeyInternalKeyToKeyRelation[(int)mainKey * (int)MusicKey.NUM + internalKey])
{
return((MusicKey)internalKey);
}
}
System.Console.WriteLine("MainKeyAndKeyRelationToKey not found {0} {1}", mainKey, keyRelation);
return(MusicKey.Invalid);
}
public static KeyRelation MusicKeyAndChordDegreeToKeyRelation(MusicKey key, CD chordDegree)
{
MusicKeyInfo mki = new MusicKeyInfo(key, KeyRelation.I調);
KeyRelation kr = KeyRelation.Unknown;
switch (chordDegree)
{
case CD.I: kr = KeyRelation.I調; break;
case CD.II: /* 長調の時はII調、短調の時はない。 */
if (mki.IsMajor())
{
kr = KeyRelation.II調;
}
break;
case CD.III: kr = KeyRelation.III調; break;
case CD.IV: kr = KeyRelation.IV調; break;
case CD.V: kr = KeyRelation.V調; break;
case CD.VI: kr = KeyRelation.VI調; break;
case CD.VII: /* 短調の時はVII調、長調の時はない。*/
if (mki.IsMinor())
{
kr = KeyRelation.VII調;
}
break;
case CD.V_V:/* 長調のV調のV調は＋II調、短調のV調のV調は△II調 */
if (mki.IsMajor())
{
kr = KeyRelation.PII調;
}
else
{
kr = KeyRelation.TII調;
}
break;
default: System.Diagnostics.Debug.Assert(false); break;
}
return(kr);
}
/// <summary>
/// 和音の属する内部調と、和音の音度から、その和音がIの和音である調を得る。
/// </summary>
public static MusicKey MusicKeyAndChordDegreeToInternalKey(MusicKey key, CD chordDegree)
{
System.Diagnostics.Debug.Assert(key != MusicKey.Invalid);
KeyRelation desirableKR = MusicKeyAndChordDegreeToKeyRelation(key, chordDegree);
MusicKey result = MusicKey.Invalid;
for (int internalKey = 0; internalKey < (int)MusicKey.NUM; ++internalKey)
{
if (desirableKR == mainKeyInternalKeyToKeyRelation[(int)key * (int)MusicKey.NUM + internalKey])
{
result = (MusicKey)internalKey;
break;
}
}
return(result);
}
/// <summary>
/// こちらのctorはあまり用いない方が良い。
/// </summary>
public MusicKeyInfo(MusicKey mainKey, KeyRelation keyRelation)
{
this.mainKey = mainKey;
this.internalKey = MainKeyAndKeyRelationToKey(mainKey, keyRelation);
}
public KeyRelationInfo(KeyRelation chordKey)
{
this.keyRelation = chordKey;
}
