/// <summary>
/// Writes a variable-length quantity (VLQ) into this file's byte array, resizing the byte array if necessary.
/// </summary>
/// <param name="offset">Offset into the byte array at which the VLQ is written.</param>
/// <param name="vlq">The VLQ to write.</param>
/// <param name="length">Length of quantity that the VLQ is replacing (for resizing purposes).</param>
public void WriteVLQ(int offset, int vlq, int length)
{
/* Resize the byte array (if necessary). */
int i, n = Midi.SizeVLQ(vlq) - length;
if (n != 0)
{
this.Resize(n, offset + length, 0);
}
/* For the simple (and common) case of a single-byte VLQ, take a shortcut. */
if (vlq < 0x80)
{
this.Bytes[offset] = (byte)vlq; return;
}
/* The VLQ is stored as 7 bits per byte (most significant byte first). All bytes except the last have the
* Most Significant Bit (MSB) set, and the last byte has the MSB clear. The easiest way to accomplish this
* is to write the VLQ "backwards" (least significant byte first) to a temporary byte array, then reverse it.
*/
for (n = 0, i = vlq; i > 0; i >>= 7)
{
this.Bytes[offset + n] = (byte)((i % 0x100) & 0x7F);
if (n > 0)
{
this.Bytes[offset + n] |= 0x80;
}
++n;
}
Array.Reverse(this.Bytes, offset, n);
}
/***********
* Methods *
***********/
#region Public Methods
/// <summary>Returns the number of bytes required to store an item of this type.</summary>
public static int SizeItem(int deltaTime, bool runningStatus, MidiMessageType messageType)
{
return(Midi.SizeVLQ(deltaTime) + (runningStatus ? 0 : 1) + (MidiChannelEvent.HasData2(messageType) ? 2 : 1));
}
/***********
* Methods *
***********/
#region Public Methods
/// <summary>Returns the number of bytes required to store an item of this type.</summary>
public static int SizeItem(int deltaTime, int dataLength)
{
return(Midi.SizeVLQ(deltaTime) + 2 + Midi.SizeVLQ(dataLength) + dataLength);
}
