private void BuildDecodeRecs()
{
if (convTable4BitTo8Bit == null)
{
BuildConversionTables();
}
decodeRecs = new DecodeOpRec[256];
int x = 0;
for (x = 0; x < decodeRecs.Length; x++)
{
decodeRecs[x] = new DecodeOpRec((Byte)x, convTable4BitTo8Bit);
}
decodeRawBytes = new DecodeRawByte[256];
for (x = 0; x < decodeRawBytes.Length; x++)
{
decodeRawBytes[x] = new DecodeRawByte((byte)x, convTable4BitTo8Bit);
}
} /* BuildDecodeRecs */
} /* SkipNextScanLine */
override public void ReadNextScanLine(byte[] scanLine)
{
bool eol = false;
int idx = 0;
byte rec = GetNextByte();
while ((!eof) && (!eol))
{
DecodeOpRec dr = decodeRecs[rec];
switch (dr.opCode)
{
case 0:// End of Line
eol = true;
break;
case 1:// Text Block
{
ProcessTextBlock(dr);
}
break;
case 2:// Instrument Data
{
//
ProcessInstrumentData(dr);
}
break;
case 3:
break; // Unused.
case 4: // Run Length of 2
case 5: // Run Length of 3
case 6: // Run Length of 4
case 7: // Run Length of 5
case 8: // Run Length of 6
case 9: // Run Length of 7
{
int endIdx = idx + (int)dr.runLength - 1;
if (endIdx >= scanLine.Length)
{
endIdx = scanLine.Length - 1;
}
while (idx <= endIdx)
{
scanLine[idx] = dr.runLengthChar;
++idx;
}
}
break;
case 10:
{
// Will need to get next byte to determine runLength;
int runLen = GetNextByte() + 1;
int endIdx = idx + runLen - 1;
if (endIdx >= scanLine.Length)
{
endIdx = scanLine.Length - 1;
}
while (idx <= endIdx)
{
scanLine[idx] = dr.runLengthChar;
++idx;
}
}
break;
case 11:// Raw-String (1 Pixel Length).
{
scanLine[idx] = dr.rawPixel;
++idx;
}
break;
case 12:// Raw-String (Even length 2 thru 32).
{
byte[] buff = GetNextBuff((uint)dr.rawStringBytesToRead);
if (buff != null)
{
for (int x = 0; x < buff.Length; ++x)
{
decodeRawBytes[buff[x]].FillIntoScanLine(scanLine, ref idx);
}
}
}
break;
case 13:// Raw-String (Odd Length 1 thru 513).
{
byte nextByte = GetNextByte();
DecodeRawByte rb = decodeRawBytes[nextByte];
uint bytesToRead = (dr.bytesToReadHighOrder + rb.lower4Bits) + 1;
if (idx < scanLine.Length)
{
scanLine[idx] = rb.pixel1;
}
byte[] buff = GetNextBuff((uint)bytesToRead);
if (buff != null)
{
for (int x = 0; x < buff.Length; ++x)
{
decodeRawBytes[buff[x]].FillIntoScanLine(scanLine, ref idx);
}
}
}
break;
case 14:
break; // Unused.
case 15:
break; // Unused.
}
if (!eol)
{
rec = GetNextByte();
}
}
} /* ReadNextScanLine */