/*
 * @(#) bitstrea.cpp - I/O bit stream support functions library (source).
 * (c) 1998 Ivan Maidanski <ivmai@chat.ru> http://ivmai.chat.ru
 * Freeware function library source. All rights reserved.
 **
 * Language: ISO/ANSI C++
 * Tested with: Watcom C++ 16/32 v11.0
 * Last modified: 1998-06-21 21:10:00 GMT+04:00
 */

#include "bitstrea.h" // library header

// implementation section

ostream &BitPut(ostream &Stream, unsigned char &BufP, int Bit)
{
 if (!BufP)
  BufP=(unsigned char)~((unsigned char)~0>>1);
 if (BufP&1)
 {
  BufP>>=1;
  if (Bit)
   BufP|=~((unsigned char)~0>>1);
  Stream.put(BufP);
  BufP=0;
 }
  else
  {
   BufP>>=1;
   if (Bit)
    BufP|=~((unsigned char)~0>>1);
  }
 return Stream;
}

ostream &BitFlush(ostream &Stream, unsigned char &BufP)
{
 if (BufP)
 {
  while (!(BufP&1))
   BufP>>=1;
  Stream.put(BufP>>=1);
  BufP=0;
 }
 return Stream;
}

int BitGet(istream &Stream, unsigned char &BufG)
{
 unsigned char Prev=BufG;
 if (!(BufG>>=1))
  BufG=(unsigned char)(((Prev=(unsigned char)Stream.get())>>1)|
                       ~((unsigned char)~0>>1));
 return Prev&1;
}

ostream &BitValPut(ostream &Stream, unsigned char &BufP,
                   unsigned long Value, unsigned long MaxVal)
{
 for (;MaxVal;Value>>=1,MaxVal>>=1)
  BitPut(Stream,BufP,(int)(Value&1));
 return Stream;
}

unsigned long BitValGet(istream &Stream, unsigned char &BufG,
                        unsigned long MaxVal, int &Wrapped)
{
 unsigned long Value,Mask;
 for (Value=0,Mask=1;Mask && MaxVal>=Mask;Mask<<=1)
  if (BitGet(Stream,BufG))
   Value|=Mask;
 Wrapped=Value>MaxVal;
 if (Wrapped)
  Value-=MaxVal+1;
 return Value;
}