Provides access to a variable bitsize values stream. More...

#include <BitStream.h>

Inheritance diagram for WorldStone::BitStreamView:

Public Member Functions
	BitStreamView (const void *inputBuffer, size_t sizeInBits, size_t firstBitOffsetInBuffer=0)
	Creates a bitstream from raw memory.

BitStreamView	createSubView (size_t newbufferSizeInBits) const

size_t	tell () const
	Returns the current position in the stream in bits.

void	setPosition (size_t newPosition)
	Set the current position, in bits.

size_t	bitPositionInBuffer () const
	Returns the current position in the buffer (ignoring the first bit position) in bits.

void	skip (size_t nbBits)
	Skips the next nbBits bits.

void	alignToByte ()

size_t	bufferSizeInBytes () const

size_t	bufferSizeInBits () const
	Returns the total size of the current stream buffer in bits. More...

size_t	sizeInBits () const
	Returns the total size of the current stream buffer in bytes.

bool	readBool ()
	Reads a single bit from the stream.

uint32_t	readBit ()
	Reads a single bit from the stream (uint32_t version)

template<typename RetType = uint32_t>
RetType	readUnsigned (unsigned nbBits)
	Reads an unsigned value of variable bit size. More...

uint8_t	readUnsigned8OrLess (const int nbBits)

uint32_t	read0Bits ()
	Return 0u, used for member function tables as replacement for BitStream::readUnsigned<0>

template<unsigned NbBits, typename std::enable_if<(NbBits > 0>
int32_t	readSigned ()
	Reads an signed value of variable bit size. More...

template<unsigned NbBits, typename std::enable_if<(NbBits==0)>::type * = nullptr>
int32_t	readSigned ()
	Return 0 if reading less than 2 bits. More...

Public Member Functions inherited from WorldStone::IOBase
	operator bool () const

bool	operator! () const

bool	good () const

bool	eof () const

bool	fail () const

bool	bad () const

Additional Inherited Members
Public Types inherited from WorldStone::IOBase
using	Path = std::string

using	iostate = int

Protected Member Functions inherited from WorldStone::IOBase
void	setstate (iostate state)

Protected Attributes inherited from WorldStone::IOBase
iostate	_state = goodbit

Static Protected Attributes inherited from WorldStone::IOBase
static constexpr iostate	goodbit = 0x0

static constexpr iostate	eofbit = 0x1

static constexpr iostate	failbit = 0x2

static constexpr iostate	badbit = 0x4

Detailed Description

Provides access to a variable bitsize values stream.

The bitstream operates as a view on raw memory to get values of different sizes. This assumes that the data is ordered in a little endian fashion, and signed values are encoded using 2's complement.

Note: This is basicly the bitstream format used by the DCC format of Diablo 2; Does not inherit from IStream to avoid confusion since size is in bits and not bytes. Use MemoryStream instead.

Warning: As this class acts as a view, the buffer must outlive the usage of this class.

Todo:

Add some bounds checking and set io flags on error ?

Implement a MemoryStream class

Tests:: RO_bitstream

Definition at line 33 of file BitStream.h.

Member Function Documentation

size_t WorldStone::BitStreamView::bufferSizeInBits ( ) const

inline

Returns the total size of the current stream buffer in bits.

Note: This will always return a multiple of the size of a byte in bits.

Definition at line 91 of file BitStream.h.

template<unsigned NbBits, typename std::enable_if<(NbBits > 0>

int32_t WorldStone::BitStreamView::readSigned ( )

inline

Reads an signed value of variable bit size.

Values are using 2's complement.

Template Parameters

NbBits The number of bits to read from the stream

Note: The value is sign extended, hence for 1-bit values: 0b0 is 0 and 0b1 is -1.

Definition at line 161 of file BitStream.h.

template<unsigned NbBits, typename std::enable_if<(NbBits==0)>::type * = nullptr>

int32_t WorldStone::BitStreamView::readSigned ( )

inline

Return 0 if reading less than 2 bits.

Note: This specialization is only available because sometimes we want to read a number of bits choosen at runtime and use a method pointers table. But really, it'd be best to just not call it.

Definition at line 172 of file BitStream.h.

template<typename RetType = uint32_t>

RetType WorldStone::BitStreamView::readUnsigned ( unsigned nbBits )

inline

Reads an unsigned value of variable bit size.

Template Parameters

RetType The type of the value to return, must be at least NbBits bits big.

Parameters

nbBits The number of bits to read from the stream

Definition at line 112 of file BitStream.h.

The documentation for this class was generated from the following file:

source/system/include/BitStream.h

Public Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation