internal MidiContext()
{
Channels = _InitChannels();
RunningStatus = 0;
ChannelPrefix = 0xFF;
MicroTempo = 0;
TimeSignature = MidiTimeSignature.Default;
}
/// <summary>
/// Creates a new instance with the specified tempo
/// </summary>
/// <param name="timeSignature">The time signature</param>
public MidiMessageMetaTimeSignature(MidiTimeSignature timeSignature) : base(0x58, new byte[] {
timeSignature.Numerator,
unchecked ((byte)(Math.Log(timeSignature.Denominator) / Math.Log(2))),
timeSignature.MidiTicksPerMetronomeTick,
timeSignature.ThirtySecondNotesPerQuarterNote
})
{
}
/// <summary>
/// Process a message, adjusting the MIDI context
/// </summary>
/// <param name="message">The message to process</param>
public void ProcessMessage(MidiMessage message)
{
var hasStatus = true;
if (0 != message.Status)
{
RunningStatus = message.Status;
}
else
{
hasStatus = false;
}
int cn = (hasStatus ? message.Status & 0xF : (0XFF != ChannelPrefix ? ChannelPrefix : (RunningStatus & 0xF)));
switch (RunningStatus & 0xF0)
{
case 0xC0:
var mb = message as MidiMessageByte;
Channels[cn].Patch = mb.Data1;
break;
case 0xD0:
mb = message as MidiMessageByte;
Channels[cn].ChannelPressure = mb.Data1;
break;
case 0x80:
var mw = message as MidiMessageWord;
Channels[cn].Notes[mw.Data1] = 0;
break;
case 0x90:
mw = message as MidiMessageWord;
Channels[cn].Notes[mw.Data1] = mw.Data2;
break;
case 0xA0:
mw = message as MidiMessageWord;
Channels[cn].KeyPressure[mw.Data1] = mw.Data2;
break;
case 0xB0:
mw = message as MidiMessageWord;
// respect send all notes off as necessary
if (mw.Data1 >= 123 && mw.Data2 >= 127)
{
for (int i = 0; i < 128; ++i)
{
var b = Channels[cn].Notes[i];
if (0xFF != b)
{
Channels[cn].Notes[i] = 0;
}
}
}
Channels[cn].Controls[mw.Data1] = mw.Data2;
break;
case 0xE0:
mw = message as MidiMessageWord;
Channels[cn].PitchWheel = mw.Data;
break;
case 0xF0:
switch (RunningStatus & 0xF)
{
case 0xF:
var mbs = message as MidiMessageMeta;
switch (mbs.Data1)
{
case 0x20:
ChannelPrefix = mbs.Data[0];
break;
case 0x51:
if (BitConverter.IsLittleEndian)
{
MicroTempo = (mbs.Data[0] << 16) | (mbs.Data[1] << 8) | mbs.Data[2];
}
else
{
MicroTempo = (mbs.Data[2] << 16) | (mbs.Data[1] << 8) | mbs.Data[0];
}
break;
case 0x58:
TimeSignature = new MidiTimeSignature(mbs.Data[0], (byte)Math.Pow(mbs.Data[1], 2), mbs.Data[2], mbs.Data[3]);
break;
}
break;
}
break;
}
}