void OldUnpack(UBYTE *UnpAddr,int Solid);
void ShortLZ(void);
void LongLZ(void);
void HuffDecode(void);
void GetFlagsBuf(void);
void OldUnpInitData(int Solid);
void InitHuff(void);
void CorrHuff(unsigned int *CharSet,unsigned int *NumToPlace);
void OldCopyString(unsigned int Distance,unsigned int Length);
unsigned int DecodeNum(int Num,unsigned int StartPos,unsigned int *DecTab,
                       unsigned int *PosTab);


unsigned int FlagBuf;

int LCount;
int FlagsCnt;

unsigned int ChSet[256];
unsigned int Place[256];
unsigned int NToPl[256];

unsigned int ChSetA[256];
unsigned int PlaceA[256];

unsigned int ChSetB[256];
unsigned int PlaceB[256];
unsigned int NToPlB[256];

unsigned int ChSetC[256];
unsigned int PlaceC[256];
unsigned int NToPlC[256];

unsigned int AvrPlc;
unsigned int AvrPlcB;
unsigned int AvrLn1;
unsigned int AvrLn2;
unsigned int AvrLn3;

int NumHuf;
int StMode;

unsigned int Nhfb,Nlzb;

unsigned int MaxDist3;
int Buf60;


static unsigned int ShortLen1[]={1,3,4,4,5,6,7,8,8,4,4,5,6,6,4,0};
static unsigned int ShortXor1[]={0,0xa0,0xd0,0xe0,0xf0,0xf8,0xfc,0xfe,
                                 0xff,0xc0,0x80,0x90,0x98,0x9c,0xb0};
static unsigned int ShortLen2[]={2,3,3,3,4,4,5,6,6,4,4,5,6,6,4,0};
static unsigned int ShortXor2[]={0,0x40,0x60,0xa0,0xd0,0xe0,0xf0,0xf8,
                                 0xfc,0xc0,0x80,0x90,0x98,0x9c,0xb0};

#define STARTL1  2
static unsigned int DecL1[]={0x8000,0xa000,0xc000,0xd000,0xe000,0xea00,
                             0xee00,0xf000,0xf200,0xf200,0xffff};
static unsigned int PosL1[]={0,0,0,2,3,5,7,11,16,20,24,32,32};

#define STARTL2  3
static unsigned int DecL2[]={0xa000,0xc000,0xd000,0xe000,0xea00,0xee00,
                             0xf000,0xf200,0xf240,0xffff};
static unsigned int PosL2[]={0,0,0,0,5,7,9,13,18,22,26,34,36};

#define STARTHF0  4
static unsigned int DecHf0[]={0x8000,0xc000,0xe000,0xf200,0xf200,0xf200,
                              0xf200,0xf200,0xffff};
static unsigned int PosHf0[]={0,0,0,0,0,8,16,24,33,33,33,33,33};


#define STARTHF1  5
static unsigned int DecHf1[]={0x2000,0xc000,0xe000,0xf000,0xf200,0xf200,
                              0xf7e0,0xffff};
static unsigned int PosHf1[]={0,0,0,0,0,0,4,44,60,76,80,80,127};


#define STARTHF2  5
static unsigned int DecHf2[]={0x1000,0x2400,0x8000,0xc000,0xfa00,0xffff,
                              0xffff,0xffff};
static unsigned int PosHf2[]={0,0,0,0,0,0,2,7,53,117,233,0,0};


#define STARTHF3  6
static unsigned int DecHf3[]={0x800,0x2400,0xee00,0xfe80,0xffff,0xffff,
                              0xffff};
static unsigned int PosHf3[]={0,0,0,0,0,0,0,2,16,218,251,0,0};


#define STARTHF4  8
static unsigned int DecHf4[]={0xff00,0xffff,0xffff,0xffff,0xffff,0xffff};
static unsigned int PosHf4[]={0,0,0,0,0,0,0,0,0,255,0,0,0};


void OldUnpack(UBYTE *UnpAddr,int Solid)
{
  int SetStMode;
  UnpBuf=UnpAddr;
  if (Solid==0x1000)
  {
    Solid=0;
    SetStMode=1;
  }
  else
    SetStMode=0;
  if (Suspend)
    UnpPtr=WrPtr;
  else
  {
    UnpInitData(Solid);
    OldUnpInitData(Solid);
    UnpReadBuf(1);
    if (!Solid)
    {
      InitHuff();
      UnpPtr=0;
    }
    else
      UnpPtr=WrPtr;
    DestUnpSize--;
  }
  if (SetStMode)
    StMode=1;
  else
    if (DestUnpSize>=0)
    {
      GetFlagsBuf();
      FlagsCnt=8;
    }

  while (DestUnpSize>=0)
  {
    UnpPtr&=MAXWINMASK;

    if (InAddr>sizeof(InBuf)-30)
      UnpReadBuf(0);
    if (((WrPtr-UnpPtr) & MAXWINMASK)<270 && WrPtr!=UnpPtr)
    {
      UnpWriteBuf();
      if (Suspend)
        return;
    }
    if (StMode)
    {
      HuffDecode();
      continue;
    }

    if (--FlagsCnt < 0)
    {
      GetFlagsBuf();
      FlagsCnt=7;
    }

    if (FlagBuf & 0x80)
    {
      FlagBuf<<=1;
      if (Nlzb > Nhfb)
        LongLZ();
      else
        HuffDecode();
    }
    else
    {
      FlagBuf<<=1;
      if (--FlagsCnt < 0)
      {
        GetFlagsBuf();
        FlagsCnt=7;
      }
      if (FlagBuf & 0x80)
      {
        FlagBuf<<=1;
        if (Nlzb > Nhfb)
          HuffDecode();
        else
          LongLZ();
      }
      else
      {
        FlagBuf<<=1;
        ShortLZ();
      }
    }
  }
  UnpWriteBuf();
}


void ShortLZ(void)
{
  unsigned int Length,SaveLength;
  unsigned int LastDistance;
  unsigned int Distance;
  int DistancePlace;
  NumHuf=0;
  GetBits();
  if (LCount==2)
  {
    AddBits(1);
    if (BitField >= 0x8000)
    {
      OldCopyString((unsigned int)LastDist,LastLength);
      return;
    }
    BitField <<= 1;
    LCount=0;
  }

  BitField>>=8;

  ShortLen1[1]=ShortLen2[3]=Buf60+3;

  if (AvrLn1<37)
  {
    for (Length=0;;Length++)
      if (((BitField^ShortXor1[Length]) & (~(0xff>>ShortLen1[Length])))==0)
        break;
    AddBits(ShortLen1[Length]);
  }
  else
  {
    for (Length=0;;Length++)
      if (((BitField^ShortXor2[Length]) & (~(0xff>>ShortLen2[Length])))==0)
        break;
    AddBits(ShortLen2[Length]);
  }

  if (Length >= 9)
  {
    if (Length == 9)
    {
      LCount++;
      OldCopyString((unsigned int)LastDist,LastLength);
      return;
    }
    if (Length == 14)
    {
      LCount=0;
      GetBits();
      Length=DecodeNum(BitField,STARTL2,DecL2,PosL2)+5;
      GetBits();
      Distance=(BitField>>1) | 0x8000;
      AddBits(15);
      LastLength=Length;
      LastDist=Distance;
      OldCopyString(Distance,Length);
      return;
    }

    LCount=0;
    SaveLength=Length;
    Distance=OldDist[(OldDistPtr-(Length-9)) & 3];
    GetBits();
    Length=DecodeNum(BitField,STARTL1,DecL1,PosL1)+2;
    if (Length==0x101 && SaveLength==10)
    {
      Buf60 ^= 1;
      return;
    }
    if (Distance > 256)
      Length++;
    if (Distance >= MaxDist3)
      Length++;

    OldDist[OldDistPtr++]=Distance;
    OldDistPtr = OldDistPtr & 3;
    LastLength=Length;
    LastDist=Distance;
    OldCopyString(Distance,Length);
    return;
  }

  LCount=0;
  AvrLn1 += Length;
  AvrLn1 -= AvrLn1 >> 4;

  GetBits();
  DistancePlace=DecodeNum(BitField,STARTHF2,DecHf2,PosHf2) & 0xff;
  Distance=ChSetA[DistancePlace];
  if (--DistancePlace != -1)
  {
    PlaceA[Distance]--;
    LastDistance=ChSetA[DistancePlace];
    PlaceA[LastDistance]++;
    ChSetA[DistancePlace+1]=LastDistance;
    ChSetA[DistancePlace]=Distance;
  }
  Length+=2;
  OldDist[OldDistPtr++] = ++Distance;
  OldDistPtr = OldDistPtr & 3;
  LastLength=Length;
  LastDist=Distance;
  OldCopyString(Distance,Length);
  return;
}


void LongLZ(void)
{
  unsigned int Length;
  unsigned int Distance;
  unsigned int DistancePlace,NewDistancePlace;
  unsigned int OldAvr2,OldAvr3;

  NumHuf=0;
  Nlzb+=16;
  if (Nlzb > 0xff)
  {
    Nlzb=0x90;
    Nhfb >>= 1;
  }
  OldAvr2=AvrLn2;

  GetBits();
  if (AvrLn2 >= 122)
    Length=DecodeNum(BitField,STARTL2,DecL2,PosL2);
  else
    if (AvrLn2 >= 64)
      Length=DecodeNum(BitField,STARTL1,DecL1,PosL1);
    else
      if (BitField < 0x100)
      {
        Length=BitField;
        AddBits(16);
      }
      else
      {
        for (Length=0;((BitField<<Length)&0x8000)==0;Length++)
          ;
        AddBits(Length+1);
      }

  AvrLn2 += Length;
  AvrLn2 -= AvrLn2 >> 5;

  GetBits();
  if (AvrPlcB > 0x28ff)
    DistancePlace=DecodeNum(BitField,STARTHF2,DecHf2,PosHf2);
  else
    if (AvrPlcB > 0x6ff)
      DistancePlace=DecodeNum(BitField,STARTHF1,DecHf1,PosHf1);
    else
      DistancePlace=DecodeNum(BitField,STARTHF0,DecHf0,PosHf0);

  AvrPlcB += DistancePlace;
  AvrPlcB -= AvrPlcB >> 8;
  while (1)
  {
    Distance = ChSetB[DistancePlace];
    NewDistancePlace = NToPlB[Distance++ & 0xff]++;
    if (!(Distance & 0xff))
      CorrHuff(ChSetB,NToPlB);
    else
      break;
  }

  ChSetB[DistancePlace]=ChSetB[NewDistancePlace];
  ChSetB[NewDistancePlace]=Distance;

  GetBits();
  Distance=((UWORD)((Distance & 0xff00) | (BitField >> 8))) >> 1;
  AddBits(7);

  OldAvr3=AvrLn3;
  if (Length!=1 && Length!=4)
    if (Length==0 && Distance <= MaxDist3)
    {
      AvrLn3++;
      AvrLn3 -= AvrLn3 >> 8;
    }
    else
      if (AvrLn3 > 0)
        AvrLn3--;
  Length+=3;
  if (Distance >= MaxDist3)
    Length++;
  if (Distance <= 256)
    Length+=8;
  if (OldAvr3 > 0xb0 || AvrPlc >= 0x2a00 && OldAvr2 < 0x40)
    MaxDist3=0x7f00;
  else
    MaxDist3=0x2001;
  OldDist[OldDistPtr++]=Distance;
  OldDistPtr = OldDistPtr & 3;
  LastLength=Length;
  LastDist=Distance;
  OldCopyString(Distance,Length);
}


void HuffDecode(void)
{
  unsigned int CurByte,NewBytePlace;
  unsigned int Length;
  unsigned int Distance;
  int BytePlace;

  GetBits();

  if (AvrPlc > 0x75ff)
    BytePlace=DecodeNum(BitField,STARTHF4,DecHf4,PosHf4);
  else
    if (AvrPlc > 0x5dff)
      BytePlace=DecodeNum(BitField,STARTHF3,DecHf3,PosHf3);
    else
      if (AvrPlc > 0x35ff)
        BytePlace=DecodeNum(BitField,STARTHF2,DecHf2,PosHf2);
      else
        if (AvrPlc > 0x0dff)
          BytePlace=DecodeNum(BitField,STARTHF1,DecHf1,PosHf1);
        else
          BytePlace=DecodeNum(BitField,STARTHF0,DecHf0,PosHf0);
  BytePlace&=0xff;
  if (StMode)
  {
    if (BytePlace==0 && BitField > 0xfff)
      BytePlace=0x100;
    if (--BytePlace==-1)
    {
      GetBits();
      AddBits(1);
      if (BitField & 0x8000)
      {
        NumHuf=StMode=0;
        return;
      }
      else
      {
        Length = (BitField & 0x4000) ? 4 : 3;
        AddBits(1);
        GetBits();
        Distance=DecodeNum(BitField,STARTHF2,DecHf2,PosHf2);
        GetBits();
        Distance = (Distance << 5) | (BitField >> 11);
        AddBits(5);
        OldCopyString(Distance,Length);
        return;
      }
    }
  }
  else
    if (NumHuf++ >= 16 && FlagsCnt==0)
      StMode=1;
  AvrPlc += BytePlace;
  AvrPlc -= AvrPlc >> 8;
  Nhfb+=16;
  if (Nhfb > 0xff)
  {
    Nhfb=0x90;
    Nlzb >>= 1;
  }

  UnpBuf[UnpPtr++]=(UBYTE)(ChSet[BytePlace]>>8);
  DestUnpSize--;

  while (1)
  {
    CurByte=ChSet[BytePlace];
    NewBytePlace=NToPl[CurByte++ & 0xff]++;
    if ((CurByte & 0xff) > 0xa1)
      CorrHuff(ChSet,NToPl);
    else
      break;
  }

  ChSet[BytePlace]=ChSet[NewBytePlace];
  ChSet[NewBytePlace]=CurByte;
}


void GetFlagsBuf(void)
{
  unsigned int Flags,FlagsPlace,NewFlagsPlace;

  GetBits();
  FlagsPlace=DecodeNum(BitField,STARTHF2,DecHf2,PosHf2);

  while (1)
  {
    Flags=ChSetC[FlagsPlace];
    FlagBuf=Flags>>8;
    NewFlagsPlace=NToPlC[Flags++ & 0xff]++;
    if ((Flags & 0xff) == 0)
      CorrHuff(ChSetC,NToPlC);
    else
      break;
  }

  ChSetC[FlagsPlace]=ChSetC[NewFlagsPlace];
  ChSetC[NewFlagsPlace]=Flags;
}


void OldUnpInitData(int Solid)
{
  if (!Solid)
  {
    AvrPlcB=AvrLn1=AvrLn2=AvrLn3=NumHuf=Buf60=0;
    AvrPlc=0x3500;
    MaxDist3=0x2001;
    Nhfb=Nlzb=0x80;
  }
  FlagsCnt=0;
  FlagBuf=0;
  StMode=0;
  LCount=0;
}


void InitHuff(void)
{
  unsigned int I;
  for (I=0;I<256;I++)
  {
    Place[I]=PlaceA[I]=PlaceB[I]=I;
    PlaceC[I]=(~I+1) & 0xff;
    ChSet[I]=ChSetB[I]=I<<8;
    ChSetA[I]=I;
    ChSetC[I]=((~I+1) & 0xff)<<8;
  }
  memset(NToPl,0,sizeof(NToPl));
  memset(NToPlB,0,sizeof(NToPlB));
  memset(NToPlC,0,sizeof(NToPlC));
  CorrHuff(ChSetB,NToPlB);
}


void CorrHuff(unsigned int *CharSet,unsigned int *NumToPlace)
{
  int I,J;
  for (I=7;I>=0;I--)
    for (J=0;J<32;J++,CharSet++)
      *CharSet=(*CharSet & ~0xff) | I;
  memset(NumToPlace,0,sizeof(NToPl));
  for (I=6;I>=0;I--)
    NumToPlace[I]=(7-I)*32;
}


void OldCopyString(unsigned int Distance,unsigned int Length)
{
  DestUnpSize-=Length;
  while (Length--)
  {
    UnpBuf[UnpPtr]=UnpBuf[(UnpPtr-Distance) & MAXWINMASK];
    UnpPtr=(UnpPtr+1) & MAXWINMASK;
  }
}


unsigned int DecodeNum(int Num,unsigned int StartPos,unsigned int *DecTab,
                       unsigned int *PosTab)
{
  int I;
  for (Num&=0xfff0,I=0;DecTab[I]<=Num;I++)
    StartPos++;
  AddBits(StartPos);
  return(((Num-(I ? DecTab[I-1]:0))>>(16-StartPos))+PosTab[StartPos]);
}
