Add unpacktool

unpacktool/LZSSDecompressor.cpp

@@ -0,0 +1,83 @@
+#include "LZSSDecompressor.h"
+
+#include <string.h>
+
+bool LZSSDecompressor::ReadBytes(void *dest, size_t numBytes)
+{
+	for (size_t i = 0; i < numBytes; i++)
+	{
+		if (!ReadOneByte(static_cast<uint8_t*>(dest)[i]))
+			return false;
+	}
+
+	return true;
+}
+
+bool LZSSDecompressor::Reset(CSInputBuffer *input, size_t compressedSize, size_t decompressedSize)
+{
+	this->input = input;
+
+	windowbuffer = new uint8_t[windowsize];
+	windowmask = windowsize - 1; // Assumes windows are always power-of-two sized!
+
+	matchlength = 0;
+	matchoffset = 0;
+	memset(windowbuffer, 0, windowmask + 1);
+
+	return this->resetLZSSHandle();
+}
+
+LZSSDecompressor::LZSSDecompressor(int windowsize)
+	: windowbuffer(nullptr)
+	, windowmask(0)
+	, matchlength(0)
+	, matchoffset(0)
+	, input(nullptr)
+	, pos(0)
+	, windowsize(windowsize)
+{
+}
+
+LZSSDecompressor::~LZSSDecompressor()
+{
+	delete[] windowbuffer;
+}
+
+
+bool LZSSDecompressor::ReadOneByte(uint8_t &b)
+{
+	if (!matchlength)
+	{
+		int offset, length;
+		int val;
+		if (!this->nextLiteralOrOffset(&offset, &length, val))
+			return false;
+
+		if (val >= 0)
+		{
+			windowbuffer[pos&windowmask] = val;
+			b = val;
+			pos++;
+			return true;
+		}
+		else if (val == XADLZSSEnd)
+		{
+			return false;
+		}
+		else
+		{
+			matchlength = length;
+			matchoffset = (int)(pos - offset);
+		}
+	}
+
+	matchlength--;
+
+	uint8_t byte = windowbuffer[matchoffset++&windowmask];
+
+	windowbuffer[pos&windowmask] = byte;
+	pos++;
+
+	b = byte;
+	return true;
+}