diff --git a/external/bitbuf/bitbuf.cpp b/external/bitbuf/bitbuf.cpp new file mode 100644 index 0000000..52a25e4 --- /dev/null +++ b/external/bitbuf/bitbuf.cpp @@ -0,0 +1,1490 @@ +//========= Copyright Valve Corporation, All rights reserved. ============// +// +// Purpose: +// +// $NoKeywords: $ +// +//=============================================================================// + +#include "bitbuf.h" +#include "coordsize.h" +#include "mathlib/vector.h" +#include "mathlib/mathlib.h" +#include "tier1/strtools.h" +#include "bitvec.h" + +// FIXME: Can't use this until we get multithreaded allocations in tier0 working for tools +// This is used by VVIS and fails to link +// NOTE: This must be the last file included!!! +//#include "tier0/memdbgon.h" + +#ifdef _X360 +// mandatory ... wary of above comment and isolating, tier0 is built as MT though +#include "tier0/memdbgon.h" +#endif + +#if _WIN32 +#define FAST_BIT_SCAN 1 +#if _X360 +#define CountLeadingZeros(x) _CountLeadingZeros(x) +inline unsigned int CountTrailingZeros( unsigned int elem ) +{ + // this implements CountTrailingZeros() / BitScanForward() + unsigned int mask = elem-1; + unsigned int comp = ~elem; + elem = mask & comp; + return (32 - _CountLeadingZeros(elem)); +} +#else +#include +#pragma intrinsic(_BitScanReverse) +#pragma intrinsic(_BitScanForward) + +inline unsigned int CountLeadingZeros(unsigned int x) +{ + unsigned long firstBit; + if ( _BitScanReverse(&firstBit,x) ) + return 31 - firstBit; + return 32; +} +inline unsigned int CountTrailingZeros(unsigned int elem) +{ + unsigned long out; + if ( _BitScanForward(&out, elem) ) + return out; + return 32; +} + +#endif +#else +#define FAST_BIT_SCAN 0 +#endif + + +static BitBufErrorHandler g_BitBufErrorHandler = 0; + +inline int BitForBitnum(int bitnum) +{ + return GetBitForBitnum(bitnum); +} + +void InternalBitBufErrorHandler( BitBufErrorType errorType, const char *pDebugName ) +{ + if ( g_BitBufErrorHandler ) + g_BitBufErrorHandler( errorType, pDebugName ); +} + + +void SetBitBufErrorHandler( BitBufErrorHandler fn ) +{ + g_BitBufErrorHandler = fn; +} + + +// #define BB_PROFILING + +unsigned long g_LittleBits[32]; + +// Precalculated bit masks for WriteUBitLong. Using these tables instead of +// doing the calculations gives a 33% speedup in WriteUBitLong. +unsigned long g_BitWriteMasks[32][33]; + +// (1 << i) - 1 +unsigned long g_ExtraMasks[33]; + +class CBitWriteMasksInit +{ +public: + CBitWriteMasksInit() + { + for( unsigned int startbit=0; startbit < 32; startbit++ ) + { + for( unsigned int nBitsLeft=0; nBitsLeft < 33; nBitsLeft++ ) + { + unsigned int endbit = startbit + nBitsLeft; + g_BitWriteMasks[startbit][nBitsLeft] = BitForBitnum(startbit) - 1; + if(endbit < 32) + g_BitWriteMasks[startbit][nBitsLeft] |= ~(BitForBitnum(endbit) - 1); + } + } + + for ( unsigned int maskBit=0; maskBit < 32; maskBit++ ) + g_ExtraMasks[maskBit] = BitForBitnum(maskBit) - 1; + g_ExtraMasks[32] = ~0ul; + + for ( unsigned int littleBit=0; littleBit < 32; littleBit++ ) + StoreLittleDWord( &g_LittleBits[littleBit], 0, 1u<> ( 32 - numbits ) ); + int nSignExtension = ( nValue >> 31 ) & ~nPreserveBits; + nValue &= nPreserveBits; + nValue |= nSignExtension; + + AssertMsg2( nValue == data, "WriteSBitLong: 0x%08x does not fit in %d bits", data, numbits ); + + WriteUBitLong( nValue, numbits, false ); +} + +void bf_write::WriteVarInt32( uint32 data ) +{ + // Check if align and we have room, slow path if not + if ( (m_iCurBit & 7) == 0 && (m_iCurBit + bitbuf::kMaxVarint32Bytes * 8 ) <= m_nDataBits) + { + uint8 *target = ((uint8*)m_pData) + (m_iCurBit>>3); + + target[0] = static_cast(data | 0x80); + if ( data >= (1 << 7) ) + { + target[1] = static_cast((data >> 7) | 0x80); + if ( data >= (1 << 14) ) + { + target[2] = static_cast((data >> 14) | 0x80); + if ( data >= (1 << 21) ) + { + target[3] = static_cast((data >> 21) | 0x80); + if ( data >= (1 << 28) ) + { + target[4] = static_cast(data >> 28); + m_iCurBit += 5 * 8; + return; + } + else + { + target[3] &= 0x7F; + m_iCurBit += 4 * 8; + return; + } + } + else + { + target[2] &= 0x7F; + m_iCurBit += 3 * 8; + return; + } + } + else + { + target[1] &= 0x7F; + m_iCurBit += 2 * 8; + return; + } + } + else + { + target[0] &= 0x7F; + m_iCurBit += 1 * 8; + return; + } + } + else // Slow path + { + while ( data > 0x7F ) + { + WriteUBitLong( (data & 0x7F) | 0x80, 8 ); + data >>= 7; + } + WriteUBitLong( data & 0x7F, 8 ); + } +} + +void bf_write::WriteVarInt64( uint64 data ) +{ + // Check if align and we have room, slow path if not + if ( (m_iCurBit & 7) == 0 && (m_iCurBit + bitbuf::kMaxVarintBytes * 8 ) <= m_nDataBits ) + { + uint8 *target = ((uint8*)m_pData) + (m_iCurBit>>3); + + // Splitting into 32-bit pieces gives better performance on 32-bit + // processors. + uint32 part0 = static_cast(data ); + uint32 part1 = static_cast(data >> 28); + uint32 part2 = static_cast(data >> 56); + + int size; + + // Here we can't really optimize for small numbers, since the data is + // split into three parts. Cheking for numbers < 128, for instance, + // would require three comparisons, since you'd have to make sure part1 + // and part2 are zero. However, if the caller is using 64-bit integers, + // it is likely that they expect the numbers to often be very large, so + // we probably don't want to optimize for small numbers anyway. Thus, + // we end up with a hardcoded binary search tree... + if ( part2 == 0 ) + { + if ( part1 == 0 ) + { + if ( part0 < (1 << 14) ) + { + if ( part0 < (1 << 7) ) + { + size = 1; goto size1; + } + else + { + size = 2; goto size2; + } + } + else + { + if ( part0 < (1 << 21) ) + { + size = 3; goto size3; + } + else + { + size = 4; goto size4; + } + } + } + else + { + if ( part1 < (1 << 14) ) + { + if ( part1 < (1 << 7) ) + { + size = 5; goto size5; + } + else + { + size = 6; goto size6; + } + } + else + { + if ( part1 < (1 << 21) ) + { + size = 7; goto size7; + } + else + { + size = 8; goto size8; + } + } + } + } + else + { + if ( part2 < (1 << 7) ) + { + size = 9; goto size9; + } + else + { + size = 10; goto size10; + } + } + + AssertFatalMsg( false, "Can't get here." ); + + size10: target[9] = static_cast((part2 >> 7) | 0x80); + size9 : target[8] = static_cast((part2 ) | 0x80); + size8 : target[7] = static_cast((part1 >> 21) | 0x80); + size7 : target[6] = static_cast((part1 >> 14) | 0x80); + size6 : target[5] = static_cast((part1 >> 7) | 0x80); + size5 : target[4] = static_cast((part1 ) | 0x80); + size4 : target[3] = static_cast((part0 >> 21) | 0x80); + size3 : target[2] = static_cast((part0 >> 14) | 0x80); + size2 : target[1] = static_cast((part0 >> 7) | 0x80); + size1 : target[0] = static_cast((part0 ) | 0x80); + + target[size-1] &= 0x7F; + m_iCurBit += size * 8; + } + else // slow path + { + while ( data > 0x7F ) + { + WriteUBitLong( (data & 0x7F) | 0x80, 8 ); + data >>= 7; + } + WriteUBitLong( data & 0x7F, 8 ); + } +} + +void bf_write::WriteSignedVarInt32( int32 data ) +{ + WriteVarInt32( bitbuf::ZigZagEncode32( data ) ); +} + +void bf_write::WriteSignedVarInt64( int64 data ) +{ + WriteVarInt64( bitbuf::ZigZagEncode64( data ) ); +} + +int bf_write::ByteSizeVarInt32( uint32 data ) +{ + int size = 1; + while ( data > 0x7F ) { + size++; + data >>= 7; + } + return size; +} + +int bf_write::ByteSizeVarInt64( uint64 data ) +{ + int size = 1; + while ( data > 0x7F ) { + size++; + data >>= 7; + } + return size; +} + +int bf_write::ByteSizeSignedVarInt32( int32 data ) +{ + return ByteSizeVarInt32( bitbuf::ZigZagEncode32( data ) ); +} + +int bf_write::ByteSizeSignedVarInt64( int64 data ) +{ + return ByteSizeVarInt64( bitbuf::ZigZagEncode64( data ) ); +} + +void bf_write::WriteBitLong(unsigned int data, int numbits, bool bSigned) +{ + if(bSigned) + WriteSBitLong((int)data, numbits); + else + WriteUBitLong(data, numbits); +} + +bool bf_write::WriteBits(const void *pInData, int nBits) +{ +#if defined( BB_PROFILING ) + VPROF( "bf_write::WriteBits" ); +#endif + + unsigned char *pOut = (unsigned char*)pInData; + int nBitsLeft = nBits; + + // Bounds checking.. + if ( (m_iCurBit+nBits) > m_nDataBits ) + { + SetOverflowFlag(); + CallErrorHandler( BITBUFERROR_BUFFER_OVERRUN, GetDebugName() ); + return false; + } + + // Align output to dword boundary + while (((unsigned long)pOut & 3) != 0 && nBitsLeft >= 8) + { + + WriteUBitLong( *pOut, 8, false ); + ++pOut; + nBitsLeft -= 8; + } + + if ( IsPC() && (nBitsLeft >= 32) && (m_iCurBit & 7) == 0 ) + { + // current bit is byte aligned, do block copy + int numbytes = nBitsLeft >> 3; + int numbits = numbytes << 3; + + Q_memcpy( (char*)m_pData+(m_iCurBit>>3), pOut, numbytes ); + pOut += numbytes; + nBitsLeft -= numbits; + m_iCurBit += numbits; + } + + // X360TBD: Can't write dwords in WriteBits because they'll get swapped + if ( IsPC() && nBitsLeft >= 32 ) + { + unsigned long iBitsRight = (m_iCurBit & 31); + unsigned long iBitsLeft = 32 - iBitsRight; + unsigned long bitMaskLeft = g_BitWriteMasks[iBitsRight][32]; + unsigned long bitMaskRight = g_BitWriteMasks[0][iBitsRight]; + + unsigned long *pData = &m_pData[m_iCurBit>>5]; + + // Read dwords. + while(nBitsLeft >= 32) + { + unsigned long curData = *(unsigned long*)pOut; + pOut += sizeof(unsigned long); + + *pData &= bitMaskLeft; + *pData |= curData << iBitsRight; + + pData++; + + if ( iBitsLeft < 32 ) + { + curData >>= iBitsLeft; + *pData &= bitMaskRight; + *pData |= curData; + } + + nBitsLeft -= 32; + m_iCurBit += 32; + } + } + + + // write remaining bytes + while ( nBitsLeft >= 8 ) + { + WriteUBitLong( *pOut, 8, false ); + ++pOut; + nBitsLeft -= 8; + } + + // write remaining bits + if ( nBitsLeft ) + { + WriteUBitLong( *pOut, nBitsLeft, false ); + } + + return !IsOverflowed(); +} + + +bool bf_write::WriteBitsFromBuffer( bf_read *pIn, int nBits ) +{ + // This could be optimized a little by + while ( nBits > 32 ) + { + WriteUBitLong( pIn->ReadUBitLong( 32 ), 32 ); + nBits -= 32; + } + + WriteUBitLong( pIn->ReadUBitLong( nBits ), nBits ); + return !IsOverflowed() && !pIn->IsOverflowed(); +} + + +void bf_write::WriteBitAngle( float fAngle, int numbits ) +{ + int d; + unsigned int mask; + unsigned int shift; + + shift = BitForBitnum(numbits); + mask = shift - 1; + + d = (int)( (fAngle / 360.0) * shift ); + d &= mask; + + WriteUBitLong((unsigned int)d, numbits); +} + +void bf_write::WriteBitCoordMP( const float f, bool bIntegral, bool bLowPrecision ) +{ +#if defined( BB_PROFILING ) + VPROF( "bf_write::WriteBitCoordMP" ); +#endif + int signbit = (f <= -( bLowPrecision ? COORD_RESOLUTION_LOWPRECISION : COORD_RESOLUTION )); + int intval = (int)abs(f); + int fractval = bLowPrecision ? + ( abs((int)(f*COORD_DENOMINATOR_LOWPRECISION)) & (COORD_DENOMINATOR_LOWPRECISION-1) ) : + ( abs((int)(f*COORD_DENOMINATOR)) & (COORD_DENOMINATOR-1) ); + + bool bInBounds = intval < (1 << COORD_INTEGER_BITS_MP ); + + unsigned int bits, numbits; + + if ( bIntegral ) + { + // Integer encoding: in-bounds bit, nonzero bit, optional sign bit + integer value bits + if ( intval ) + { + // Adjust the integers from [1..MAX_COORD_VALUE] to [0..MAX_COORD_VALUE-1] + --intval; + bits = intval * 8 + signbit * 4 + 2 + bInBounds; + numbits = 3 + (bInBounds ? COORD_INTEGER_BITS_MP : COORD_INTEGER_BITS); + } + else + { + bits = bInBounds; + numbits = 2; + } + } + else + { + // Float encoding: in-bounds bit, integer bit, sign bit, fraction value bits, optional integer value bits + if ( intval ) + { + // Adjust the integers from [1..MAX_COORD_VALUE] to [0..MAX_COORD_VALUE-1] + --intval; + bits = intval * 8 + signbit * 4 + 2 + bInBounds; + bits += bInBounds ? (fractval << (3+COORD_INTEGER_BITS_MP)) : (fractval << (3+COORD_INTEGER_BITS)); + numbits = 3 + (bInBounds ? COORD_INTEGER_BITS_MP : COORD_INTEGER_BITS) + + (bLowPrecision ? COORD_FRACTIONAL_BITS_MP_LOWPRECISION : COORD_FRACTIONAL_BITS); + } + else + { + bits = fractval * 8 + signbit * 4 + 0 + bInBounds; + numbits = 3 + (bLowPrecision ? COORD_FRACTIONAL_BITS_MP_LOWPRECISION : COORD_FRACTIONAL_BITS); + } + } + + WriteUBitLong( bits, numbits ); +} + +void bf_write::WriteBitCoord (const float f) +{ +#if defined( BB_PROFILING ) + VPROF( "bf_write::WriteBitCoord" ); +#endif + int signbit = (f <= -COORD_RESOLUTION); + int intval = (int)abs(f); + int fractval = abs((int)(f*COORD_DENOMINATOR)) & (COORD_DENOMINATOR-1); + + + // Send the bit flags that indicate whether we have an integer part and/or a fraction part. + WriteOneBit( intval ); + WriteOneBit( fractval ); + + if ( intval || fractval ) + { + // Send the sign bit + WriteOneBit( signbit ); + + // Send the integer if we have one. + if ( intval ) + { + // Adjust the integers from [1..MAX_COORD_VALUE] to [0..MAX_COORD_VALUE-1] + intval--; + WriteUBitLong( (unsigned int)intval, COORD_INTEGER_BITS ); + } + + // Send the fraction if we have one + if ( fractval ) + { + WriteUBitLong( (unsigned int)fractval, COORD_FRACTIONAL_BITS ); + } + } +} + +void bf_write::WriteBitVec3Coord( const Vector& fa ) +{ + int xflag, yflag, zflag; + + xflag = (fa[0] >= COORD_RESOLUTION) || (fa[0] <= -COORD_RESOLUTION); + yflag = (fa[1] >= COORD_RESOLUTION) || (fa[1] <= -COORD_RESOLUTION); + zflag = (fa[2] >= COORD_RESOLUTION) || (fa[2] <= -COORD_RESOLUTION); + + WriteOneBit( xflag ); + WriteOneBit( yflag ); + WriteOneBit( zflag ); + + if ( xflag ) + WriteBitCoord( fa[0] ); + if ( yflag ) + WriteBitCoord( fa[1] ); + if ( zflag ) + WriteBitCoord( fa[2] ); +} + +void bf_write::WriteBitNormal( float f ) +{ + int signbit = (f <= -NORMAL_RESOLUTION); + + // NOTE: Since +/-1 are valid values for a normal, I'm going to encode that as all ones + unsigned int fractval = abs( (int)(f*NORMAL_DENOMINATOR) ); + + // clamp.. + if (fractval > NORMAL_DENOMINATOR) + fractval = NORMAL_DENOMINATOR; + + // Send the sign bit + WriteOneBit( signbit ); + + // Send the fractional component + WriteUBitLong( fractval, NORMAL_FRACTIONAL_BITS ); +} + +void bf_write::WriteBitVec3Normal( const Vector& fa ) +{ + int xflag, yflag; + + xflag = (fa[0] >= NORMAL_RESOLUTION) || (fa[0] <= -NORMAL_RESOLUTION); + yflag = (fa[1] >= NORMAL_RESOLUTION) || (fa[1] <= -NORMAL_RESOLUTION); + + WriteOneBit( xflag ); + WriteOneBit( yflag ); + + if ( xflag ) + WriteBitNormal( fa[0] ); + if ( yflag ) + WriteBitNormal( fa[1] ); + + // Write z sign bit + int signbit = (fa[2] <= -NORMAL_RESOLUTION); + WriteOneBit( signbit ); +} + +void bf_write::WriteBitAngles( const QAngle& fa ) +{ + // FIXME: + Vector tmp( fa.x, fa.y, fa.z ); + WriteBitVec3Coord( tmp ); +} + +void bf_write::WriteChar(int val) +{ + WriteSBitLong(val, sizeof(char) << 3); +} + +void bf_write::WriteByte(int val) +{ + WriteUBitLong(val, sizeof(unsigned char) << 3); +} + +void bf_write::WriteShort(int val) +{ + WriteSBitLong(val, sizeof(short) << 3); +} + +void bf_write::WriteWord(int val) +{ + WriteUBitLong(val, sizeof(unsigned short) << 3); +} + +void bf_write::WriteLong(long val) +{ + WriteSBitLong(val, sizeof(long) << 3); +} + +void bf_write::WriteLongLong(int64 val) +{ + uint *pLongs = (uint*)&val; + + // Insert the two DWORDS according to network endian + const short endianIndex = 0x0100; + byte *idx = (byte*)&endianIndex; + WriteUBitLong(pLongs[*idx++], sizeof(long) << 3); + WriteUBitLong(pLongs[*idx], sizeof(long) << 3); +} + +void bf_write::WriteFloat(float val) +{ + // Pre-swap the float, since WriteBits writes raw data + LittleFloat( &val, &val ); + + WriteBits(&val, sizeof(val) << 3); +} + +bool bf_write::WriteBytes( const void *pBuf, int nBytes ) +{ + return WriteBits(pBuf, nBytes << 3); +} + +bool bf_write::WriteString(const char *pStr) +{ + if(pStr) + { + do + { + WriteChar( *pStr ); + ++pStr; + } while( *(pStr-1) != 0 ); + } + else + { + WriteChar( 0 ); + } + + return !IsOverflowed(); +} + +// ---------------------------------------------------------------------------------------- // +// bf_read +// ---------------------------------------------------------------------------------------- // + +bf_read::bf_read() +{ + m_pData = NULL; + m_nDataBytes = 0; + m_nDataBits = -1; // set to -1 so we overflow on any operation + m_iCurBit = 0; + m_bOverflow = false; + m_bAssertOnOverflow = true; + m_pDebugName = NULL; +} + +bf_read::bf_read( const void *pData, int nBytes, int nBits ) +{ + m_bAssertOnOverflow = true; + StartReading( pData, nBytes, 0, nBits ); +} + +bf_read::bf_read( const char *pDebugName, const void *pData, int nBytes, int nBits ) +{ + m_bAssertOnOverflow = true; + m_pDebugName = pDebugName; + StartReading( pData, nBytes, 0, nBits ); +} + +void bf_read::StartReading( const void *pData, int nBytes, int iStartBit, int nBits ) +{ + // Make sure we're dword aligned. + Assert(((size_t)pData & 3) == 0); + + m_pData = (unsigned char*)pData; + m_nDataBytes = nBytes; + + if ( nBits == -1 ) + { + m_nDataBits = m_nDataBytes << 3; + } + else + { + Assert( nBits <= nBytes*8 ); + m_nDataBits = nBits; + } + + m_iCurBit = iStartBit; + m_bOverflow = false; +} + +void bf_read::Reset() +{ + m_iCurBit = 0; + m_bOverflow = false; +} + +void bf_read::SetAssertOnOverflow( bool bAssert ) +{ + m_bAssertOnOverflow = bAssert; +} + +void bf_read::SetDebugName( const char *pName ) +{ + m_pDebugName = pName; +} + +void bf_read::SetOverflowFlag() +{ + if ( m_bAssertOnOverflow ) + { + Assert( false ); + } + m_bOverflow = true; +} + +unsigned int bf_read::CheckReadUBitLong(int numbits) +{ + // Ok, just read bits out. + int i, nBitValue; + unsigned int r = 0; + + for(i=0; i < numbits; i++) + { + nBitValue = ReadOneBitNoCheck(); + r |= nBitValue << i; + } + m_iCurBit -= numbits; + + return r; +} + +void bf_read::ReadBits(void *pOutData, int nBits) +{ +#if defined( BB_PROFILING ) + VPROF( "bf_read::ReadBits" ); +#endif + + unsigned char *pOut = (unsigned char*)pOutData; + int nBitsLeft = nBits; + + + // align output to dword boundary + while( ((size_t)pOut & 3) != 0 && nBitsLeft >= 8 ) + { + *pOut = (unsigned char)ReadUBitLong(8); + ++pOut; + nBitsLeft -= 8; + } + + // X360TBD: Can't read dwords in ReadBits because they'll get swapped + if ( IsPC() ) + { + // read dwords + while ( nBitsLeft >= 32 ) + { + *((unsigned long*)pOut) = ReadUBitLong(32); + pOut += sizeof(unsigned long); + nBitsLeft -= 32; + } + } + + // read remaining bytes + while ( nBitsLeft >= 8 ) + { + *pOut = ReadUBitLong(8); + ++pOut; + nBitsLeft -= 8; + } + + // read remaining bits + if ( nBitsLeft ) + { + *pOut = ReadUBitLong(nBitsLeft); + } + +} + +int bf_read::ReadBitsClamped_ptr(void *pOutData, size_t outSizeBytes, size_t nBits) +{ + size_t outSizeBits = outSizeBytes * 8; + size_t readSizeBits = nBits; + int skippedBits = 0; + if ( readSizeBits > outSizeBits ) + { + // Should we print a message when we clamp the data being read? Only + // in debug builds I think. + AssertMsg( 0, "Oversized network packet received, and clamped." ); + readSizeBits = outSizeBits; + skippedBits = (int)( nBits - outSizeBits ); + // What should we do in this case, which should only happen if nBits + // is negative for some reason? + //if ( skippedBits < 0 ) + // return 0; + } + + ReadBits( pOutData, readSizeBits ); + SeekRelative( skippedBits ); + + // Return the number of bits actually read. + return (int)readSizeBits; +} + +float bf_read::ReadBitAngle( int numbits ) +{ + float fReturn; + int i; + float shift; + + shift = (float)( BitForBitnum(numbits) ); + + i = ReadUBitLong( numbits ); + fReturn = (float)i * (360.0 / shift); + + return fReturn; +} + +unsigned int bf_read::PeekUBitLong( int numbits ) +{ + unsigned int r; + int i, nBitValue; +#ifdef BIT_VERBOSE + int nShifts = numbits; +#endif + + bf_read savebf; + + savebf = *this; // Save current state info + + r = 0; + for(i=0; i < numbits; i++) + { + nBitValue = ReadOneBit(); + + // Append to current stream + if ( nBitValue ) + { + r |= BitForBitnum(i); + } + } + + *this = savebf; + +#ifdef BIT_VERBOSE + Con_Printf( "PeekBitLong: %i %i\n", nShifts, (unsigned int)r ); +#endif + + return r; +} + +unsigned int bf_read::ReadUBitLongNoInline( int numbits ) +{ + return ReadUBitLong( numbits ); +} + +unsigned int bf_read::ReadUBitVarInternal( int encodingType ) +{ + m_iCurBit -= 4; + // int bits = { 4, 8, 12, 32 }[ encodingType ]; + int bits = 4 + encodingType*4 + (((2 - encodingType) >> 31) & 16); + return ReadUBitLong( bits ); +} + +// Append numbits least significant bits from data to the current bit stream +int bf_read::ReadSBitLong( int numbits ) +{ + unsigned int r = ReadUBitLong(numbits); + unsigned int s = 1 << (numbits-1); + if (r >= s) + { + // sign-extend by removing sign bit and then subtracting sign bit again + r = r - s - s; + } + return r; +} + +uint32 bf_read::ReadVarInt32() +{ + uint32 result = 0; + int count = 0; + uint32 b; + + do + { + if ( count == bitbuf::kMaxVarint32Bytes ) + { + return result; + } + b = ReadUBitLong( 8 ); + result |= (b & 0x7F) << (7 * count); + ++count; + } while (b & 0x80); + + return result; +} + +uint64 bf_read::ReadVarInt64() +{ + uint64 result = 0; + int count = 0; + uint64 b; + + do + { + if ( count == bitbuf::kMaxVarintBytes ) + { + return result; + } + b = ReadUBitLong( 8 ); + result |= static_cast(b & 0x7F) << (7 * count); + ++count; + } while (b & 0x80); + + return result; +} + +int32 bf_read::ReadSignedVarInt32() +{ + uint32 value = ReadVarInt32(); + return bitbuf::ZigZagDecode32( value ); +} + +int64 bf_read::ReadSignedVarInt64() +{ + uint32 value = ReadVarInt64(); + return bitbuf::ZigZagDecode64( value ); +} + +unsigned int bf_read::ReadBitLong(int numbits, bool bSigned) +{ + if(bSigned) + return (unsigned int)ReadSBitLong(numbits); + else + return ReadUBitLong(numbits); +} + + +// Basic Coordinate Routines (these contain bit-field size AND fixed point scaling constants) +float bf_read::ReadBitCoord (void) +{ +#if defined( BB_PROFILING ) + VPROF( "bf_read::ReadBitCoord" ); +#endif + int intval=0,fractval=0,signbit=0; + float value = 0.0; + + + // Read the required integer and fraction flags + intval = ReadOneBit(); + fractval = ReadOneBit(); + + // If we got either parse them, otherwise it's a zero. + if ( intval || fractval ) + { + // Read the sign bit + signbit = ReadOneBit(); + + // If there's an integer, read it in + if ( intval ) + { + // Adjust the integers from [0..MAX_COORD_VALUE-1] to [1..MAX_COORD_VALUE] + intval = ReadUBitLong( COORD_INTEGER_BITS ) + 1; + } + + // If there's a fraction, read it in + if ( fractval ) + { + fractval = ReadUBitLong( COORD_FRACTIONAL_BITS ); + } + + // Calculate the correct floating point value + value = intval + ((float)fractval * COORD_RESOLUTION); + + // Fixup the sign if negative. + if ( signbit ) + value = -value; + } + + return value; +} + +float bf_read::ReadBitCoordMP( bool bIntegral, bool bLowPrecision ) +{ +#if defined( BB_PROFILING ) + VPROF( "bf_read::ReadBitCoordMP" ); +#endif + // BitCoordMP float encoding: inbounds bit, integer bit, sign bit, optional int bits, float bits + // BitCoordMP integer encoding: inbounds bit, integer bit, optional sign bit, optional int bits. + // int bits are always encoded as (value - 1) since zero is handled by the integer bit + + // With integer-only encoding, the presence of the third bit depends on the second + int flags = ReadUBitLong(3 - bIntegral); + enum { INBOUNDS=1, INTVAL=2, SIGN=4 }; + + if ( bIntegral ) + { + if ( flags & INTVAL ) + { + // Read the third bit and the integer portion together at once + unsigned int bits = ReadUBitLong( (flags & INBOUNDS) ? COORD_INTEGER_BITS_MP+1 : COORD_INTEGER_BITS+1 ); + // Remap from [0,N] to [1,N+1] + int intval = (bits >> 1) + 1; + return (bits & 1) ? -intval : intval; + } + return 0.f; + } + + static const float mul_table[4] = + { + 1.f/(1<> COORD_INTEGER_BITS_MP; + uint fracbits = bits >> COORD_INTEGER_BITS; + + uint intmaskMP = ((1<> 3; +} + +int bf_read::CompareBitsAt( int offset, bf_read * RESTRICT other, int otherOffset, int numbits ) RESTRICT +{ + extern unsigned long g_ExtraMasks[33]; + + if ( numbits == 0 ) + return 0; + + int overflow1 = offset + numbits > m_nDataBits; + int overflow2 = otherOffset + numbits > other->m_nDataBits; + + int x = overflow1 | overflow2; + if ( x != 0 ) + return x; + + unsigned int iStartBit1 = offset & 31u; + unsigned int iStartBit2 = otherOffset & 31u; + unsigned long *pData1 = (unsigned long*)m_pData + (offset >> 5); + unsigned long *pData2 = (unsigned long*)other->m_pData + (otherOffset >> 5); + unsigned long *pData1End = pData1 + ((offset + numbits - 1) >> 5); + unsigned long *pData2End = pData2 + ((otherOffset + numbits - 1) >> 5); + + while ( numbits > 32 ) + { + x = LoadLittleDWord( (unsigned long*)pData1, 0 ) >> iStartBit1; + x ^= LoadLittleDWord( (unsigned long*)pData1, 1 ) << (32 - iStartBit1); + x ^= LoadLittleDWord( (unsigned long*)pData2, 0 ) >> iStartBit2; + x ^= LoadLittleDWord( (unsigned long*)pData2, 1 ) << (32 - iStartBit2); + if ( x != 0 ) + { + return x; + } + ++pData1; + ++pData2; + numbits -= 32; + } + + x = LoadLittleDWord( (unsigned long*)pData1, 0 ) >> iStartBit1; + x ^= LoadLittleDWord( (unsigned long*)pData1End, 0 ) << (32 - iStartBit1); + x ^= LoadLittleDWord( (unsigned long*)pData2, 0 ) >> iStartBit2; + x ^= LoadLittleDWord( (unsigned long*)pData2End, 0 ) << (32 - iStartBit2); + return x & g_ExtraMasks[ numbits ]; +} diff --git a/external/bitbuf/bitbuf.h b/external/bitbuf/bitbuf.h new file mode 100644 index 0000000..b92e010 --- /dev/null +++ b/external/bitbuf/bitbuf.h @@ -0,0 +1,809 @@ +//========= Copyright Valve Corporation, All rights reserved. ============// +// +// Purpose: +// +// $NoKeywords: $ +// +//=============================================================================// + +// NOTE: bf_read is guaranteed to return zeros if it overflows. + +#ifndef BITBUF_H +#define BITBUF_H + +#ifdef _WIN32 +#pragma once +#endif + + +#include "mathlib/mathlib.h" +#include "mathlib/vector.h" +#include "basetypes.h" +#include "tier0/dbg.h" + + +#if _DEBUG +#define BITBUF_INLINE inline +#else +#define BITBUF_INLINE FORCEINLINE +#endif + +//----------------------------------------------------------------------------- +// Forward declarations. +//----------------------------------------------------------------------------- + +class Vector; +class QAngle; + +//----------------------------------------------------------------------------- +// You can define a handler function that will be called in case of +// out-of-range values and overruns here. +// +// NOTE: the handler is only called in debug mode. +// +// Call SetBitBufErrorHandler to install a handler. +//----------------------------------------------------------------------------- + +typedef enum +{ + BITBUFERROR_VALUE_OUT_OF_RANGE=0, // Tried to write a value with too few bits. + BITBUFERROR_BUFFER_OVERRUN, // Was about to overrun a buffer. + + BITBUFERROR_NUM_ERRORS +} BitBufErrorType; + + +typedef void (*BitBufErrorHandler)( BitBufErrorType errorType, const char *pDebugName ); + + +#if defined( _DEBUG ) + extern void InternalBitBufErrorHandler( BitBufErrorType errorType, const char *pDebugName ); + #define CallErrorHandler( errorType, pDebugName ) InternalBitBufErrorHandler( errorType, pDebugName ); +#else + #define CallErrorHandler( errorType, pDebugName ) +#endif + + +// Use this to install the error handler. Call with NULL to uninstall your error handler. +void SetBitBufErrorHandler( BitBufErrorHandler fn ); + + +//----------------------------------------------------------------------------- +// Helpers. +//----------------------------------------------------------------------------- + +inline int BitByte( int bits ) +{ + // return PAD_NUMBER( bits, 8 ) >> 3; + return (bits + 7) >> 3; +} + +//----------------------------------------------------------------------------- +// namespaced helpers +//----------------------------------------------------------------------------- +namespace bitbuf +{ + // ZigZag Transform: Encodes signed integers so that they can be + // effectively used with varint encoding. + // + // varint operates on unsigned integers, encoding smaller numbers into + // fewer bytes. If you try to use it on a signed integer, it will treat + // this number as a very large unsigned integer, which means that even + // small signed numbers like -1 will take the maximum number of bytes + // (10) to encode. ZigZagEncode() maps signed integers to unsigned + // in such a way that those with a small absolute value will have smaller + // encoded values, making them appropriate for encoding using varint. + // + // int32 -> uint32 + // ------------------------- + // 0 -> 0 + // -1 -> 1 + // 1 -> 2 + // -2 -> 3 + // ... -> ... + // 2147483647 -> 4294967294 + // -2147483648 -> 4294967295 + // + // >> encode >> + // << decode << + + inline uint32 ZigZagEncode32(int32 n) + { + // Note: the right-shift must be arithmetic + return(n << 1) ^ (n >> 31); + } + + inline int32 ZigZagDecode32(uint32 n) + { + return(n >> 1) ^ -static_cast(n & 1); + } + + inline uint64 ZigZagEncode64(int64 n) + { + // Note: the right-shift must be arithmetic + return(n << 1) ^ (n >> 63); + } + + inline int64 ZigZagDecode64(uint64 n) + { + return(n >> 1) ^ -static_cast(n & 1); + } + + const int kMaxVarintBytes = 10; + const int kMaxVarint32Bytes = 5; +} + +//----------------------------------------------------------------------------- +// Used for serialization +//----------------------------------------------------------------------------- + +class bf_write +{ +public: + bf_write(); + + // nMaxBits can be used as the number of bits in the buffer. + // It must be <= nBytes*8. If you leave it at -1, then it's set to nBytes * 8. + bf_write( void *pData, int nBytes, int nMaxBits = -1 ); + bf_write( const char *pDebugName, void *pData, int nBytes, int nMaxBits = -1 ); + + // Start writing to the specified buffer. + // nMaxBits can be used as the number of bits in the buffer. + // It must be <= nBytes*8. If you leave it at -1, then it's set to nBytes * 8. + void StartWriting( void *pData, int nBytes, int iStartBit = 0, int nMaxBits = -1 ); + + // Restart buffer writing. + void Reset(); + + // Get the base pointer. + unsigned char* GetBasePointer() { return (unsigned char*) m_pData; } + + // Enable or disable assertion on overflow. 99% of the time, it's a bug that we need to catch, + // but there may be the occasional buffer that is allowed to overflow gracefully. + void SetAssertOnOverflow( bool bAssert ); + + // This can be set to assign a name that gets output if the buffer overflows. + const char* GetDebugName(); + void SetDebugName( const char *pDebugName ); + + +// Seek to a specific position. +public: + + void SeekToBit( int bitPos ); + + +// Bit functions. +public: + + void WriteOneBit(int nValue); + void WriteOneBitNoCheck(int nValue); + void WriteOneBitAt( int iBit, int nValue ); + + // Write signed or unsigned. Range is only checked in debug. + void WriteUBitLong( unsigned int data, int numbits, bool bCheckRange=true ); + void WriteSBitLong( int data, int numbits ); + + // Tell it whether or not the data is unsigned. If it's signed, + // cast to unsigned before passing in (it will cast back inside). + void WriteBitLong(unsigned int data, int numbits, bool bSigned); + + // Write a list of bits in. + bool WriteBits(const void *pIn, int nBits); + + // writes an unsigned integer with variable bit length + void WriteUBitVar( unsigned int data ); + + // writes a varint encoded integer + void WriteVarInt32( uint32 data ); + void WriteVarInt64( uint64 data ); + void WriteSignedVarInt32( int32 data ); + void WriteSignedVarInt64( int64 data ); + int ByteSizeVarInt32( uint32 data ); + int ByteSizeVarInt64( uint64 data ); + int ByteSizeSignedVarInt32( int32 data ); + int ByteSizeSignedVarInt64( int64 data ); + + // Copy the bits straight out of pIn. This seeks pIn forward by nBits. + // Returns an error if this buffer or the read buffer overflows. + bool WriteBitsFromBuffer( class bf_read *pIn, int nBits ); + + void WriteBitAngle( float fAngle, int numbits ); + void WriteBitCoord (const float f); + void WriteBitCoordMP( const float f, bool bIntegral, bool bLowPrecision ); + void WriteBitFloat(float val); + void WriteBitVec3Coord( const Vector& fa ); + void WriteBitNormal( float f ); + void WriteBitVec3Normal( const Vector& fa ); + void WriteBitAngles( const QAngle& fa ); + + +// Byte functions. +public: + + void WriteChar(int val); + void WriteByte(int val); + void WriteShort(int val); + void WriteWord(int val); + void WriteLong(long val); + void WriteLongLong(int64 val); + void WriteFloat(float val); + bool WriteBytes( const void *pBuf, int nBytes ); + + // Returns false if it overflows the buffer. + bool WriteString(const char *pStr); + + +// Status. +public: + + // How many bytes are filled in? + int GetNumBytesWritten() const; + int GetNumBitsWritten() const; + int GetMaxNumBits(); + int GetNumBitsLeft(); + int GetNumBytesLeft(); + unsigned char* GetData(); + const unsigned char* GetData() const; + + // Has the buffer overflowed? + bool CheckForOverflow(int nBits); + inline bool IsOverflowed() const {return m_bOverflow;} + + void SetOverflowFlag(); + + +public: + // The current buffer. + unsigned long* RESTRICT m_pData; + int m_nDataBytes; + int m_nDataBits; + + // Where we are in the buffer. + int m_iCurBit; + +private: + + // Errors? + bool m_bOverflow; + + bool m_bAssertOnOverflow; + const char *m_pDebugName; +}; + + +//----------------------------------------------------------------------------- +// Inlined methods +//----------------------------------------------------------------------------- + +// How many bytes are filled in? +inline int bf_write::GetNumBytesWritten() const +{ + return BitByte(m_iCurBit); +} + +inline int bf_write::GetNumBitsWritten() const +{ + return m_iCurBit; +} + +inline int bf_write::GetMaxNumBits() +{ + return m_nDataBits; +} + +inline int bf_write::GetNumBitsLeft() +{ + return m_nDataBits - m_iCurBit; +} + +inline int bf_write::GetNumBytesLeft() +{ + return GetNumBitsLeft() >> 3; +} + +inline unsigned char* bf_write::GetData() +{ + return (unsigned char*) m_pData; +} + +inline const unsigned char* bf_write::GetData() const +{ + return (unsigned char*) m_pData; +} + +BITBUF_INLINE bool bf_write::CheckForOverflow(int nBits) +{ + if ( m_iCurBit + nBits > m_nDataBits ) + { + SetOverflowFlag(); + CallErrorHandler( BITBUFERROR_BUFFER_OVERRUN, GetDebugName() ); + } + + return m_bOverflow; +} + +BITBUF_INLINE void bf_write::SetOverflowFlag() +{ +#ifdef DBGFLAG_ASSERT + if ( m_bAssertOnOverflow ) + { + Assert( false ); + } +#endif + m_bOverflow = true; +} + +BITBUF_INLINE void bf_write::WriteOneBitNoCheck(int nValue) +{ +#if __i386__ + if(nValue) + m_pData[m_iCurBit >> 5] |= 1u << (m_iCurBit & 31); + else + m_pData[m_iCurBit >> 5] &= ~(1u << (m_iCurBit & 31)); +#else + extern unsigned long g_LittleBits[32]; + if(nValue) + m_pData[m_iCurBit >> 5] |= g_LittleBits[m_iCurBit & 31]; + else + m_pData[m_iCurBit >> 5] &= ~g_LittleBits[m_iCurBit & 31]; +#endif + + ++m_iCurBit; +} + +inline void bf_write::WriteOneBit(int nValue) +{ + if( m_iCurBit >= m_nDataBits ) + { + SetOverflowFlag(); + CallErrorHandler( BITBUFERROR_BUFFER_OVERRUN, GetDebugName() ); + return; + } + WriteOneBitNoCheck( nValue ); +} + + +inline void bf_write::WriteOneBitAt( int iBit, int nValue ) +{ + if( iBit >= m_nDataBits ) + { + SetOverflowFlag(); + CallErrorHandler( BITBUFERROR_BUFFER_OVERRUN, GetDebugName() ); + return; + } + +#if __i386__ + if(nValue) + m_pData[iBit >> 5] |= 1u << (iBit & 31); + else + m_pData[iBit >> 5] &= ~(1u << (iBit & 31)); +#else + extern unsigned long g_LittleBits[32]; + if(nValue) + m_pData[iBit >> 5] |= g_LittleBits[iBit & 31]; + else + m_pData[iBit >> 5] &= ~g_LittleBits[iBit & 31]; +#endif +} + +BITBUF_INLINE void bf_write::WriteUBitLong( unsigned int curData, int numbits, bool bCheckRange ) RESTRICT +{ +#ifdef _DEBUG + // Make sure it doesn't overflow. + if ( bCheckRange && numbits < 32 ) + { + if ( curData >= (unsigned long)(1 << numbits) ) + { + CallErrorHandler( BITBUFERROR_VALUE_OUT_OF_RANGE, GetDebugName() ); + } + } + Assert( numbits >= 0 && numbits <= 32 ); +#endif + + if ( GetNumBitsLeft() < numbits ) + { + m_iCurBit = m_nDataBits; + SetOverflowFlag(); + CallErrorHandler( BITBUFERROR_BUFFER_OVERRUN, GetDebugName() ); + return; + } + + int iCurBitMasked = m_iCurBit & 31; + int iDWord = m_iCurBit >> 5; + m_iCurBit += numbits; + + // Mask in a dword. + Assert( (iDWord*4 + sizeof(long)) <= (unsigned int)m_nDataBytes ); + unsigned long * RESTRICT pOut = &m_pData[iDWord]; + + // Rotate data into dword alignment + curData = (curData << iCurBitMasked) | (curData >> (32 - iCurBitMasked)); + + // Calculate bitmasks for first and second word + unsigned int temp = 1 << (numbits-1); + unsigned int mask1 = (temp*2-1) << iCurBitMasked; + unsigned int mask2 = (temp-1) >> (31 - iCurBitMasked); + + // Only look beyond current word if necessary (avoid access violation) + int i = mask2 & 1; + unsigned long dword1 = LoadLittleDWord( pOut, 0 ); + unsigned long dword2 = LoadLittleDWord( pOut, i ); + + // Drop bits into place + dword1 ^= ( mask1 & ( curData ^ dword1 ) ); + dword2 ^= ( mask2 & ( curData ^ dword2 ) ); + + // Note reversed order of writes so that dword1 wins if mask2 == 0 && i == 0 + StoreLittleDWord( pOut, i, dword2 ); + StoreLittleDWord( pOut, 0, dword1 ); +} + +// writes an unsigned integer with variable bit length +BITBUF_INLINE void bf_write::WriteUBitVar( unsigned int data ) +{ + /* Reference: + if ( data < 0x10u ) + WriteUBitLong( 0, 2 ), WriteUBitLong( data, 4 ); + else if ( data < 0x100u ) + WriteUBitLong( 1, 2 ), WriteUBitLong( data, 8 ); + else if ( data < 0x1000u ) + WriteUBitLong( 2, 2 ), WriteUBitLong( data, 12 ); + else + WriteUBitLong( 3, 2 ), WriteUBitLong( data, 32 ); + */ + // a < b ? -1 : 0 translates into a CMP, SBB instruction pair + // with no flow control. should also be branchless on consoles. + int n = (data < 0x10u ? -1 : 0) + (data < 0x100u ? -1 : 0) + (data < 0x1000u ? -1 : 0); + WriteUBitLong( data*4 + n + 3, 6 + n*4 + 12 ); + if ( data >= 0x1000u ) + { + WriteUBitLong( data >> 16, 16 ); + } +} + +// write raw IEEE float bits in little endian form +BITBUF_INLINE void bf_write::WriteBitFloat(float val) +{ + long intVal; + + Assert(sizeof(long) == sizeof(float)); + Assert(sizeof(float) == 4); + + intVal = *((long*)&val); + WriteUBitLong( intVal, 32 ); +} + +//----------------------------------------------------------------------------- +// This is useful if you just want a buffer to write into on the stack. +//----------------------------------------------------------------------------- + +template +class old_bf_write_static : public bf_write +{ +public: + inline old_bf_write_static() : bf_write(m_StaticData, SIZE) {} + + char m_StaticData[SIZE]; +}; + + + +//----------------------------------------------------------------------------- +// Used for unserialization +//----------------------------------------------------------------------------- + +class bf_read +{ +public: + bf_read(); + + // nMaxBits can be used as the number of bits in the buffer. + // It must be <= nBytes*8. If you leave it at -1, then it's set to nBytes * 8. + bf_read( const void *pData, int nBytes, int nBits = -1 ); + bf_read( const char *pDebugName, const void *pData, int nBytes, int nBits = -1 ); + + // Start reading from the specified buffer. + // pData's start address must be dword-aligned. + // nMaxBits can be used as the number of bits in the buffer. + // It must be <= nBytes*8. If you leave it at -1, then it's set to nBytes * 8. + void StartReading( const void *pData, int nBytes, int iStartBit = 0, int nBits = -1 ); + + // Restart buffer reading. + void Reset(); + + // Enable or disable assertion on overflow. 99% of the time, it's a bug that we need to catch, + // but there may be the occasional buffer that is allowed to overflow gracefully. + void SetAssertOnOverflow( bool bAssert ); + + // This can be set to assign a name that gets output if the buffer overflows. + const char* GetDebugName() const { return m_pDebugName; } + void SetDebugName( const char *pName ); + + void ExciseBits( int startbit, int bitstoremove ); + + +// Bit functions. +public: + + // Returns 0 or 1. + int ReadOneBit(); + + +protected: + + unsigned int CheckReadUBitLong(int numbits); // For debugging. + int ReadOneBitNoCheck(); // Faster version, doesn't check bounds and is inlined. + bool CheckForOverflow(int nBits); + + +public: + + // Get the base pointer. + const unsigned char* GetBasePointer() { return m_pData; } + + BITBUF_INLINE int TotalBytesAvailable( void ) const + { + return m_nDataBytes; + } + + // Read a list of bits in. + void ReadBits(void *pOut, int nBits); + // Read a list of bits in, but don't overrun the destination buffer. + // Returns the number of bits read into the buffer. The remaining + // bits are skipped over. + int ReadBitsClamped_ptr(void *pOut, size_t outSizeBytes, size_t nBits); + // Helper 'safe' template function that infers the size of the destination + // array. This version of the function should be preferred. + // Usage: char databuffer[100]; + // ReadBitsClamped( dataBuffer, msg->m_nLength ); + template + int ReadBitsClamped( T (&pOut)[N], size_t nBits ) + { + return ReadBitsClamped_ptr( pOut, N * sizeof(T), nBits ); + } + + float ReadBitAngle( int numbits ); + + unsigned int ReadUBitLong( int numbits ) RESTRICT; + unsigned int ReadUBitLongNoInline( int numbits ) RESTRICT; + unsigned int PeekUBitLong( int numbits ); + int ReadSBitLong( int numbits ); + + // reads an unsigned integer with variable bit length + unsigned int ReadUBitVar(); + unsigned int ReadUBitVarInternal( int encodingType ); + + // reads a varint encoded integer + uint32 ReadVarInt32(); + uint64 ReadVarInt64(); + int32 ReadSignedVarInt32(); + int64 ReadSignedVarInt64(); + + // You can read signed or unsigned data with this, just cast to + // a signed int if necessary. + unsigned int ReadBitLong(int numbits, bool bSigned); + + float ReadBitCoord(); + float ReadBitCoordMP( bool bIntegral, bool bLowPrecision ); + float ReadBitFloat(); + float ReadBitNormal(); + void ReadBitVec3Coord( Vector& fa ); + void ReadBitVec3Normal( Vector& fa ); + void ReadBitAngles( QAngle& fa ); + + // Faster for comparisons but do not fully decode float values + unsigned int ReadBitCoordBits(); + unsigned int ReadBitCoordMPBits( bool bIntegral, bool bLowPrecision ); + +// Byte functions (these still read data in bit-by-bit). +public: + + BITBUF_INLINE int ReadChar() { return (char)ReadUBitLong(8); } + BITBUF_INLINE int ReadByte() { return ReadUBitLong(8); } + BITBUF_INLINE int ReadShort() { return (short)ReadUBitLong(16); } + BITBUF_INLINE int ReadWord() { return ReadUBitLong(16); } + BITBUF_INLINE long ReadLong() { return ReadUBitLong(32); } + int64 ReadLongLong(); + float ReadFloat(); + bool ReadBytes(void *pOut, int nBytes); + + // Returns false if bufLen isn't large enough to hold the + // string in the buffer. + // + // Always reads to the end of the string (so you can read the + // next piece of data waiting). + // + // If bLine is true, it stops when it reaches a '\n' or a null-terminator. + // + // pStr is always null-terminated (unless bufLen is 0). + // + // pOutNumChars is set to the number of characters left in pStr when the routine is + // complete (this will never exceed bufLen-1). + // + bool ReadString( char *pStr, int bufLen, bool bLine=false, int *pOutNumChars=NULL ); + + // Reads a string and allocates memory for it. If the string in the buffer + // is > 2048 bytes, then pOverflow is set to true (if it's not NULL). + char* ReadAndAllocateString( bool *pOverflow = 0 ); + + // Returns nonzero if any bits differ + int CompareBits( bf_read * RESTRICT other, int bits ) RESTRICT; + int CompareBitsAt( int offset, bf_read * RESTRICT other, int otherOffset, int bits ) RESTRICT; + +// Status. +public: + int GetNumBytesLeft(); + int GetNumBytesRead(); + int GetNumBitsLeft(); + int GetNumBitsRead() const; + + // Has the buffer overflowed? + inline bool IsOverflowed() const {return m_bOverflow;} + + inline bool Seek(int iBit); // Seek to a specific bit. + inline bool SeekRelative(int iBitDelta); // Seek to an offset from the current position. + + // Called when the buffer is overflowed. + void SetOverflowFlag(); + + +public: + + // The current buffer. + const unsigned char* RESTRICT m_pData; + int m_nDataBytes; + int m_nDataBits; + + // Where we are in the buffer. + int m_iCurBit; + + +private: + // Errors? + bool m_bOverflow; + + // For debugging.. + bool m_bAssertOnOverflow; + + const char *m_pDebugName; +}; + +//----------------------------------------------------------------------------- +// Inlines. +//----------------------------------------------------------------------------- + +inline int bf_read::GetNumBytesRead() +{ + return BitByte(m_iCurBit); +} + +inline int bf_read::GetNumBitsLeft() +{ + return m_nDataBits - m_iCurBit; +} + +inline int bf_read::GetNumBytesLeft() +{ + return GetNumBitsLeft() >> 3; +} + +inline int bf_read::GetNumBitsRead() const +{ + return m_iCurBit; +} + +inline bool bf_read::Seek(int iBit) +{ + if(iBit < 0 || iBit > m_nDataBits) + { + SetOverflowFlag(); + m_iCurBit = m_nDataBits; + return false; + } + else + { + m_iCurBit = iBit; + return true; + } +} + +// Seek to an offset from the current position. +inline bool bf_read::SeekRelative(int iBitDelta) +{ + return Seek(m_iCurBit+iBitDelta); +} + +inline bool bf_read::CheckForOverflow(int nBits) +{ + if( m_iCurBit + nBits > m_nDataBits ) + { + SetOverflowFlag(); + CallErrorHandler( BITBUFERROR_BUFFER_OVERRUN, GetDebugName() ); + } + + return m_bOverflow; +} + +inline int bf_read::ReadOneBitNoCheck() +{ +#if VALVE_LITTLE_ENDIAN + unsigned int value = ((unsigned long * RESTRICT)m_pData)[m_iCurBit >> 5] >> (m_iCurBit & 31); +#else + unsigned char value = m_pData[m_iCurBit >> 3] >> (m_iCurBit & 7); +#endif + ++m_iCurBit; + return value & 1; +} + +inline int bf_read::ReadOneBit() +{ + if( GetNumBitsLeft() <= 0 ) + { + SetOverflowFlag(); + CallErrorHandler( BITBUFERROR_BUFFER_OVERRUN, GetDebugName() ); + return 0; + } + return ReadOneBitNoCheck(); +} + +inline float bf_read::ReadBitFloat() +{ + union { uint32 u; float f; } c = { ReadUBitLong(32) }; + return c.f; +} + +BITBUF_INLINE unsigned int bf_read::ReadUBitVar() +{ + // six bits: low 2 bits for encoding + first 4 bits of value + unsigned int sixbits = ReadUBitLong(6); + unsigned int encoding = sixbits & 3; + if ( encoding ) + { + // this function will seek back four bits and read the full value + return ReadUBitVarInternal( encoding ); + } + return sixbits >> 2; +} + +BITBUF_INLINE unsigned int bf_read::ReadUBitLong( int numbits ) RESTRICT +{ + Assert( numbits > 0 && numbits <= 32 ); + + if ( GetNumBitsLeft() < numbits ) + { + m_iCurBit = m_nDataBits; + SetOverflowFlag(); + CallErrorHandler( BITBUFERROR_BUFFER_OVERRUN, GetDebugName() ); + return 0; + } + + unsigned int iStartBit = m_iCurBit & 31u; + int iLastBit = m_iCurBit + numbits - 1; + unsigned int iWordOffset1 = m_iCurBit >> 5; + unsigned int iWordOffset2 = iLastBit >> 5; + m_iCurBit += numbits; + +#if __i386__ + unsigned int bitmask = (2 << (numbits-1)) - 1; +#else + extern unsigned long g_ExtraMasks[33]; + unsigned int bitmask = g_ExtraMasks[numbits]; +#endif + + unsigned int dw1 = LoadLittleDWord( (unsigned long* RESTRICT)m_pData, iWordOffset1 ) >> iStartBit; + unsigned int dw2 = LoadLittleDWord( (unsigned long* RESTRICT)m_pData, iWordOffset2 ) << (32 - iStartBit); + + return (dw1 | dw2) & bitmask; +} + +BITBUF_INLINE int bf_read::CompareBits( bf_read * RESTRICT other, int numbits ) RESTRICT +{ + return (ReadUBitLong(numbits) != other->ReadUBitLong(numbits)); +} + + +#endif + + +