qpdf/libqpdf/BitStream.cc

46 lines
732 B
C++

#include <qpdf/BitStream.hh>
// See comments in bits.cc
#define BITS_READ 1
#include "bits.icc"
BitStream::BitStream(unsigned char const* p, int nbytes) :
start(p),
nbytes(nbytes)
{
reset();
}
void
BitStream::reset()
{
p = start;
bit_offset = 7;
bits_available = 8 * nbytes;
}
unsigned long
BitStream::getBits(int nbits)
{
return read_bits(this->p, this->bit_offset,
this->bits_available, nbits);
}
void
BitStream::skipToNextByte()
{
if (bit_offset != 7)
{
unsigned int bits_to_skip = bit_offset + 1;
if (bits_available < bits_to_skip)
{
throw QEXC::Internal("overflow skipping to next byte in bitstream");
}
bit_offset = 7;
++p;
bits_available -= bits_to_skip;
}
}