* The TrackChunk is basically a {@link java.util.Vector} for bytes.
* It's got a buffer, which will grow automatically as things are
* added to it.
* @param initialSize Initial bufffersize.
*/
public TrackChunk(int initialSize) {
chunklen = 0;
arySize = initialSize;
bytes = new byte[arySize];
}
/** Creates a new TrackChunk
*
* The intial buffer size will be 32 * @see TrackChunk(int) */ public TrackChunk() { this(32); } /** * Gets the bytes in a form suitable for passing to * {@link CMidi#writeChunk(String,byte[])} * @return an array of bytes */ public byte [] getBytes() { byte [] ret = new byte[chunklen]; System.arraycopy(bytes, 0, ret, 0, chunklen); return ret; } /** * Adds bytes to the chunk * @param bytes the bytes to add */ public void addBytes(byte[] data) { if (chunklen + data.length> arySize) { int newSize = Math.max(chunklen + data.length, arySize * 2); byte [] newAry = new byte[newSize]; System.arraycopy(bytes, 0, newAry, 0, chunklen); arySize = newSize; bytes = newAry; } System.arraycopy(data, 0, bytes, chunklen, data.length); chunklen += data.length; } /** * Adds a single byte to the buffer. * @param data the byte */ public void addByte(byte data) { if (chunklen + 1> arySize) { int newSize = arySize * 2; byte [] newAry = new byte[newSize]; System.arraycopy(bytes, 0, newAry, 0, chunklen); arySize = newSize; bytes = newAry; } bytes[chunklen++] = data; } /** * Adds a funky varlen. *
* This is a datatype used by MIDI files which
* can hold values from 0-0x0FFFFFFF and takes between 1 and 4 bytes.
* @param value The varlen to add.
*/
public void addVarLen(int value) {
int buffer = (value & 0x7F);
while((value>>= 7) != 0) {
buffer <<= 8; buffer |= ((value & 0x7F) | 0x80); } while(true) { addByte((byte)(buffer & 0xFF)); if ((buffer & 0x80) != 0) buffer>>= 8;
else
break;
}
}
/**
* Adds a text tag.
* @param text The text to add.
*/
public void addText(String text) {
addByte((byte)(0xFF));
addByte((byte)(0x03));
addVarLen(text.length());
addBytes(text.getBytes());
}
/**
* Ends the track.
*/
public void endTrack() {
final byte[] data = {(byte)(0x00), (byte)(0xFF),
(byte)(0x2f), (byte)(0x00)};
addBytes(data);
}
private void realWriteData(byte b) {
addVarLen(0);
addByte((byte)0x90); // note on
addByte(b);
addByte((byte)(127));
int timing;
if (haveNL)
timing = 48;
else if (haveSpace)
timing = 24;
else
timing = 12;
addVarLen(timing);
addByte((byte)0x80); // note off
addByte(b);
addByte((byte)(127));
haveSpace = haveNL = false;
}
/**
* Adds a note representing a byte from the input file.
* @param b The character to add.
* @trows IllegalArgumentException if b> 127
*/
public void writeDataByte(byte b) {
if (b> 127)
throw new IllegalArgumentException("Notes must be between 0 and 127");
switch(b) {
case ' ':
case '\t':
haveSpace = true;
break;
case '\n':
case '\r':
haveNL = true;
break;
default:
realWriteData(b);
break;
}
}
}