/// <summary>
/// Called when one of the properties change value.
/// </summary>
/// <param name="newTimeDivision">Non-null when changed.</param>
/// <param name="newPpqn">Non-null when changed.</param>
/// <param name="newSmpte">Non-null when changed.</param>
protected virtual void OnValueChanged(int?newTimeDivision, int?newPpqn, SmpteTimeBase newSmpte)
{
if (newTimeDivision.HasValue)
{
_timeDivision = newTimeDivision.Value;
// test for smpte time
if (((short)_timeDivision) < 0)
{
var fps = SmpteTime.ToFrameRate(Math.Abs((sbyte)((_timeDivision & 0xFF00) >> 8)));
var subsPerFrame = _timeDivision & 0x00FF;
_smpte = new SmpteTimeBase(fps, subsPerFrame);
_ppqn = 0;
}
else
{
ThrowIfNotAMultipleOf24(newTimeDivision.Value, "TimeDivision");
_ppqn = _timeDivision;
_smpte = null;
}
}
if (newPpqn.HasValue)
{
Check.IfArgumentOutOfRange(newPpqn.Value, 0, ushort.MaxValue, "PulsesPerQuarterNote");
ThrowIfNotAMultipleOf24(newPpqn.Value, "PulsesPerQuarterNote");
_ppqn = newPpqn.Value;
_timeDivision = _ppqn;
_smpte = null;
}
if (newSmpte != null)
{
_timeDivision = (-(SmpteTime.FromFrameRate(newSmpte.FramesPerSecond) << 8)) | (newSmpte.SubFramesPerFrame & 0xFF);
_ppqn = 0;
_smpte = newSmpte;
}
}
/// <summary>
/// Factory method for Midi file compatible values.
/// </summary>
/// <param name="timeDivision">Must not be zero.</param>
/// <param name="tempo">Can be zero.</param>
/// <returns>Never returns null.</returns>
public static MidiTimeBase Create(int timeDivision, int tempo)
{
Check.IfArgumentOutOfRange(timeDivision, short.MinValue, ushort.MaxValue, "timeDivision");
if (timeDivision == 0)
{
throw new ArgumentException("The timeDivision value can not be zero.", "timeDivision");
}
var midiTimeBase = new MidiTimeBase();
if (((short)timeDivision) < 0)
{
var fps = SmpteTime.ToFrameRate(Math.Abs((sbyte)((timeDivision & 0xFF00) >> 8)));
var frames = timeDivision & 0x00FF;
midiTimeBase.SmpteTime = new SmpteTime(0, 0, 0, frames, fps);
}
else
{
midiTimeBase.MillisecondResolution = tempo / timeDivision;
}
return(midiTimeBase);
}