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I'll work on Yaz0 more

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This commit is contained in:
Denis
2022-01-28 23:13:35 +01:00
parent b4f2ce301d
commit af09d30b3b
1 changed files with 3 additions and 64 deletions
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67
BMGEditor/FS/Yaz0Stream.cs
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@@ -25,76 +25,15 @@ namespace BMGEditor
private Stream m_Backend;
}
public static class Yaz0 // TODO: Finish rewriting this
public static class Yaz0 // TODO: Write it
{
public static void Decompress(ref byte[] data)
unsafe public static void Decompress(ref byte[] data)
{
if (data[0] != 'Y' || data[1] != 'a' || data[2] != 'z' || data[3] != '0')
return;
Int32 decompSize = (data[4] << 24 | data[5] << 16 | data[6] << 8 | data[7]);
uint sourcePos = 16; //start at 0x10
uint writePos = 0; //destination to write data to
byte[] decodedData = new byte[decompSize + 1];
byte groupHead = 0;
byte lastGroupHead = 0;
uint validBitCount = 0;
while (writePos < decompSize)
{
//System.Windows.Forms.MessageBox.Show(groupHead.ToString("X") + "|" + validBitCount);
if (validBitCount == 0) //new group header
{
groupHead = data[sourcePos];
lastGroupHead = groupHead;
++sourcePos;
validBitCount = 8; //reset count
}
if ((groupHead & 0x80) != 0) //straight copy as long as groupheader maintains left most bit as 1 (1000 0000)
{
decodedData[writePos] = data[sourcePos];
writePos++;
sourcePos++;
}
else
{
byte b1 = data[sourcePos]; //byte 1
byte b2 = data[sourcePos + 1]; //byte 2
sourcePos += 2; //move past those two bytes
uint dist = (uint)((b1 & 0xF) << 8) | b2; //distance
if (Tests.isBE)
dist = (UInt32)((dist >> 24) | ((dist & 0xFF0000) >> 8) | ((dist & 0xFF00) << 8) | (dist << 24));
uint copySource = writePos - (dist + 1); //copy
uint numBytes = (uint)b1 >> 4; //how many bytes to copy
//if (sourcePos-2 > 0x13C0) //debug decode
//System.Windows.Forms.MessageBox.Show("lastGroupHead: 0x" + lastGroupHead.ToString("X") + "\n" + "b1: 0x" + b1.ToString("X") + "\n" + "b2: 0x" + b2.ToString("X") + "\n" + "sourcePos: 0x" + sourcePos.ToString("X") + "\n" + "dist: " + dist + "\n" + "copySource: 0x" + copySource.ToString("X") + "\n" + "writePos: 0x" + writePos.ToString("X") + "\n" + "numBytes: " + numBytes);
if (numBytes == 0) //If the first 4 bits of the first byte is 0...
{
numBytes = data[sourcePos] + (uint)0x12;
sourcePos++;
}
else
{
numBytes += 2;
}
for (int i = 0; i < numBytes; ++i)
{
decodedData[writePos] = decodedData[copySource];
copySource++;
writePos++;
}
}
groupHead <<= 1; //left shift!!!
validBitCount -= 1; //group header validation count of the binary position
}
Array.Resize(ref data, decompSize + 1);
decodedData.CopyTo(data, 0);
FileStream test = File.OpenWrite("./test.bin");
test.Write(data);
return;
}
}