static void NormalizeRangeDecoder(WiltRangeDecoder self)
{
while (self.Range < 0x1000000)
{
self.Code = (UInt32)((self.Code << 8) | (uint)self.Strm.ReadByte());
self.Range <<= 8;
}
}
static void NormalizeRangeDecoder(WiltRangeDecoder self)
{
while (self.Range < 0x1000000)
{
self.Code = (UInt32)((self.Code << 8) | (uint)self.Strm.ReadByte());
self.Range <<= 8;
}
}
static void InitRangeDecoder(WiltRangeDecoder self, Stream fh)
{
self.Range = 0xffffffff;
self.Code = 0;
self.Strm = fh;
for (int i = 0; i < 4; i++)
self.Code = (UInt32)((self.Code << 8) | (uint)fh.ReadByte());
}
static void InitRangeDecoder(WiltRangeDecoder self, Stream fh)
{
self.Range = 0xffffffff;
self.Code = 0;
self.Strm = fh;
for (int i = 0; i < 4; i++)
{
self.Code = (UInt32)((self.Code << 8) | (uint)fh.ReadByte());
}
}
void DecompressData(Stream fh, byte[] buf, uint size, int typeshift, int literalshift, uint lengthshift1, uint lengthshift2, uint offsetshift1, uint offsetshift2)
{
WiltRangeDecoder dec = new WiltRangeDecoder();
InitRangeDecoder(dec, fh);
ushort typeweight = 0x800;
ushort[] lengthweights1 = new ushort[32];
ushort[] lengthweights2 = new ushort[32];
ushort[] offsetweights1 = new ushort[32];
ushort[] offsetweights2 = new ushort[32];
for (int i = 0; i < 32; i++)
{
lengthweights1[i] = lengthweights2[i] = offsetweights1[i] = offsetweights2[i] = 0x800;
}
ushort[] literalbitweights = new ushort[256];
for (int i = 0; i < 256; i++)
{
literalbitweights[i] = 0x800;
}
int pos = 0;
while (pos < size)
{
if (ReadBitAndUpdateWeight(dec, typeweight, (uint)typeshift) == 1)
{
int length = (int)(ReadUniversalCode(dec, lengthweights1, lengthshift1, lengthweights2, lengthshift2) + 3);
int offs = (int)(ReadUniversalCode(dec, offsetweights1, offsetshift1, offsetweights2, offsetshift2) + 1);
CopyMemory(buf, pos, buf, pos - offs, length);
pos += length;
}
else
{
int val = 1;
for (int i = 0; i < 8; i++)
{
int bit = (int)ReadBitAndUpdateWeight(dec, literalbitweights[val], (uint)literalshift);
val = (val << 1) | bit;
}
buf[pos++] = (byte)val;
}
}
}
void DecompressData(Stream fh, byte[] buf, uint size, int typeshift, int literalshift, uint lengthshift1, uint lengthshift2, uint offsetshift1, uint offsetshift2)
{
WiltRangeDecoder dec = new WiltRangeDecoder();
InitRangeDecoder(dec, fh);
ushort typeweight = 0x800;
ushort[] lengthweights1 = new ushort[32];
ushort[] lengthweights2 = new ushort[32];
ushort[] offsetweights1 = new ushort[32];
ushort[] offsetweights2 = new ushort[32];
for (int i = 0; i < 32; i++)
{
lengthweights1[i] = lengthweights2[i] = offsetweights1[i] = offsetweights2[i] = 0x800;
}
ushort[] literalbitweights = new ushort[256];
for (int i = 0; i < 256; i++)
{
literalbitweights[i] = 0x800;
}
int pos = 0;
while (pos < size)
{
if (ReadBitAndUpdateWeight(dec, typeweight, (uint)typeshift) == 1)
{
int length = (int)(ReadUniversalCode(dec, lengthweights1, lengthshift1, lengthweights2, lengthshift2) + 3);
int offs = (int)(ReadUniversalCode(dec, offsetweights1, offsetshift1, offsetweights2, offsetshift2) + 1);
CopyMemory(buf, pos, buf, pos - offs, length);
pos += length;
}
else
{
int val = 1;
for (int i = 0; i < 8; i++)
{
int bit = (int)ReadBitAndUpdateWeight(dec, literalbitweights[val], (uint)literalshift);
val = (val << 1) | bit;
}
buf[pos++] = (byte)val;
}
}
}
static uint ReadUniversalCode(WiltRangeDecoder self, ushort[] weights1, uint shift1, ushort[] weights2, uint shift2)
{
int numbits = 0;
while (ReadBitAndUpdateWeight(self, weights1[numbits], shift1) == 1)
{
numbits++;
}
if (numbits == 0)
{
return 0;
}
uint val = 1;
for (int i = 0; i < numbits - 1; i++)
{
val = (val << 1) | ReadBitAndUpdateWeight(self, weights2[numbits - 1 - i], shift2);
}
return val;
}
static uint ReadBitAndUpdateWeight(WiltRangeDecoder self, UInt16 weight, uint shift)
{
NormalizeRangeDecoder(self);
uint threshold = (self.Range >> 12) * weight;
if (self.Code < threshold)
{
self.Range = threshold;
weight += (ushort)((0x1000 - weight) >> (int)shift);
return 0;
}
else
{
self.Range -= threshold;
self.Code -= threshold;
weight -= (ushort)(weight >> (int)shift);
return 1;
}
}
static uint ReadBitAndUpdateWeight(WiltRangeDecoder self, UInt16 weight, uint shift)
{
NormalizeRangeDecoder(self);
uint threshold = (self.Range >> 12) * weight;
if (self.Code < threshold)
{
self.Range = threshold;
weight += (ushort)((0x1000 - weight) >> (int)shift);
return(0);
}
else
{
self.Range -= threshold;
self.Code -= threshold;
weight -= (ushort)(weight >> (int)shift);
return(1);
}
}
static uint ReadUniversalCode(WiltRangeDecoder self, ushort[] weights1, uint shift1, ushort[] weights2, uint shift2)
{
int numbits = 0;
while (ReadBitAndUpdateWeight(self, weights1[numbits], shift1) == 1)
{
numbits++;
}
if (numbits == 0)
{
return(0);
}
uint val = 1;
for (int i = 0; i < numbits - 1; i++)
{
val = (val << 1) | ReadBitAndUpdateWeight(self, weights2[numbits - 1 - i], shift2);
}
return(val);
}