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#ifndef _RAR_GETBITS_
#define _RAR_GETBITS_
class BitInput
{
public:
enum BufferSize {MAX_SIZE=0x8000}; // Size of input buffer.
int InAddr; // Curent byte position in the buffer.
int InBit; // Current bit position in the current byte.
bool ExternalBuffer;
public:
BitInput(bool AllocBuffer);
~BitInput();
byte *InBuf; // Dynamically allocated input buffer.
void InitBitInput()
{
InAddr=InBit=0;
}
// Move forward by 'Bits' bits.
void addbits(uint Bits)
{
Bits+=InBit;
InAddr+=Bits>>3;
InBit=Bits&7;
}
// Return 16 bits from current position in the buffer.
// Bit at (InAddr,InBit) has the highest position in returning data.
uint getbits()
{
uint BitField=(uint)InBuf[InAddr] << 16;
BitField|=(uint)InBuf[InAddr+1] << 8;
BitField|=(uint)InBuf[InAddr+2];
BitField >>= (8-InBit);
return(BitField & 0xffff);
}
// Return 32 bits from current position in the buffer.
// Bit at (InAddr,InBit) has the highest position in returning data.
uint getbits32()
{
uint BitField=(uint)InBuf[InAddr] << 24;
BitField|=(uint)InBuf[InAddr+1] << 16;
BitField|=(uint)InBuf[InAddr+2] << 8;
BitField|=(uint)InBuf[InAddr+3];
BitField <<= InBit;
BitField|=(uint)InBuf[InAddr+4] >> (8-InBit);
return(BitField & 0xffffffff);
}
void faddbits(uint Bits);
uint fgetbits();
// Check if buffer has enough space for IncPtr bytes. Returns 'true'
// if buffer will be overflown.
bool Overflow(uint IncPtr)
{
return(InAddr+IncPtr>=MAX_SIZE);
}
void SetExternalBuffer(byte *Buf);
};
#endif
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