From 39ed87570bdb2f86969d4be821c94b722dc71179 Mon Sep 17 00:00:00 2001
From: Joe Ludwig <joe@valvesoftware.com>
Date: Wed, 26 Jun 2013 15:22:04 -0700
Subject: First version of the SOurce SDK 2013

---
 mp/src/tier1/bitbuf.cpp | 1490 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 1490 insertions(+)
 create mode 100644 mp/src/tier1/bitbuf.cpp

(limited to 'mp/src/tier1/bitbuf.cpp')

diff --git a/mp/src/tier1/bitbuf.cpp b/mp/src/tier1/bitbuf.cpp
new file mode 100644
index 00000000..8294c93c
--- /dev/null
+++ b/mp/src/tier1/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 <intrin.h>
+#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<<littleBit );
+	}
+};
+static CBitWriteMasksInit g_BitWriteMasksInit;
+
+
+// ---------------------------------------------------------------------------------------- //
+// bf_write
+// ---------------------------------------------------------------------------------------- //
+
+bf_write::bf_write()
+{
+	m_pData = NULL;
+	m_nDataBytes = 0;
+	m_nDataBits = -1; // set to -1 so we generate overflow on any operation
+	m_iCurBit = 0;
+	m_bOverflow = false;
+	m_bAssertOnOverflow = true;
+	m_pDebugName = NULL;
+}
+
+bf_write::bf_write( const char *pDebugName, void *pData, int nBytes, int nBits )
+{
+	m_bAssertOnOverflow = true;
+	m_pDebugName = pDebugName;
+	StartWriting( pData, nBytes, 0, nBits );
+}
+
+bf_write::bf_write( void *pData, int nBytes, int nBits )
+{
+	m_bAssertOnOverflow = true;
+	m_pDebugName = NULL;
+	StartWriting( pData, nBytes, 0, nBits );
+}
+
+void bf_write::StartWriting( void *pData, int nBytes, int iStartBit, int nBits )
+{
+	// Make sure it's dword aligned and padded.
+	Assert( (nBytes % 4) == 0 );
+	Assert(((unsigned long)pData & 3) == 0);
+
+	// The writing code will overrun the end of the buffer if it isn't dword aligned, so truncate to force alignment
+	nBytes &= ~3;
+
+	m_pData = (unsigned long*)pData;
+	m_nDataBytes = nBytes;
+
+	if ( nBits == -1 )
+	{
+		m_nDataBits = nBytes << 3;
+	}
+	else
+	{
+		Assert( nBits <= nBytes*8 );
+		m_nDataBits = nBits;
+	}
+
+	m_iCurBit = iStartBit;
+	m_bOverflow = false;
+}
+
+void bf_write::Reset()
+{
+	m_iCurBit = 0;
+	m_bOverflow = false;
+}
+
+
+void bf_write::SetAssertOnOverflow( bool bAssert )
+{
+	m_bAssertOnOverflow = bAssert;
+}
+
+
+const char* bf_write::GetDebugName()
+{
+	return m_pDebugName;
+}
+
+
+void bf_write::SetDebugName( const char *pDebugName )
+{
+	m_pDebugName = pDebugName;
+}
+
+
+void bf_write::SeekToBit( int bitPos )
+{
+	m_iCurBit = bitPos;
+}
+
+
+// Sign bit comes first
+void bf_write::WriteSBitLong( int data, int numbits )
+{
+	// Force the sign-extension bit to be correct even in the case of overflow.
+	int nValue = data;
+	int nPreserveBits = ( 0x7FFFFFFF >> ( 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<uint8>(data | 0x80);
+		if ( data >= (1 << 7) )
+		{
+			target[1] = static_cast<uint8>((data >>  7) | 0x80);
+			if ( data >= (1 << 14) )
+			{
+				target[2] = static_cast<uint8>((data >> 14) | 0x80);
+				if ( data >= (1 << 21) )
+				{
+					target[3] = static_cast<uint8>((data >> 21) | 0x80);
+					if ( data >= (1 << 28) )
+					{
+						target[4] = static_cast<uint8>(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<uint32>(data      );
+		uint32 part1 = static_cast<uint32>(data >> 28);
+		uint32 part2 = static_cast<uint32>(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<uint8>((part2 >>  7) | 0x80);
+		size9 : target[8] = static_cast<uint8>((part2      ) | 0x80);
+		size8 : target[7] = static_cast<uint8>((part1 >> 21) | 0x80);
+		size7 : target[6] = static_cast<uint8>((part1 >> 14) | 0x80);
+		size6 : target[5] = static_cast<uint8>((part1 >>  7) | 0x80);
+		size5 : target[4] = static_cast<uint8>((part1      ) | 0x80);
+		size4 : target[3] = static_cast<uint8>((part0 >> 21) | 0x80);
+		size3 : target[2] = static_cast<uint8>((part0 >> 14) | 0x80);
+		size2 : target[1] = static_cast<uint8>((part0 >>  7) | 0x80);
+		size1 : target[0] = static_cast<uint8>((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_write::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<uint64>(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_write::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_write::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_FRACTIONAL_BITS),
+		-1.f/(1<<COORD_FRACTIONAL_BITS),
+		1.f/(1<<COORD_FRACTIONAL_BITS_MP_LOWPRECISION),
+		-1.f/(1<<COORD_FRACTIONAL_BITS_MP_LOWPRECISION)
+	};
+	//equivalent to: float multiply = mul_table[ ((flags & SIGN) ? 1 : 0) + bLowPrecision*2 ];
+	float multiply = *(float*)((uintptr_t)&mul_table[0] + (flags & 4) + bLowPrecision*8);
+
+	static const unsigned char numbits_table[8] =
+	{
+		COORD_FRACTIONAL_BITS,
+		COORD_FRACTIONAL_BITS,
+		COORD_FRACTIONAL_BITS + COORD_INTEGER_BITS,
+		COORD_FRACTIONAL_BITS + COORD_INTEGER_BITS_MP,
+		COORD_FRACTIONAL_BITS_MP_LOWPRECISION,
+		COORD_FRACTIONAL_BITS_MP_LOWPRECISION,
+		COORD_FRACTIONAL_BITS_MP_LOWPRECISION + COORD_INTEGER_BITS,
+		COORD_FRACTIONAL_BITS_MP_LOWPRECISION + COORD_INTEGER_BITS_MP
+	};
+	unsigned int bits = ReadUBitLong( numbits_table[ (flags & (INBOUNDS|INTVAL)) + bLowPrecision*4 ] );
+
+	if ( flags & INTVAL )
+	{
+		// Shuffle the bits to remap the integer portion from [0,N] to [1,N+1]
+		// and then paste in front of the fractional parts so we only need one
+		// int-to-float conversion.
+		
+		uint fracbitsMP = bits >> COORD_INTEGER_BITS_MP;
+		uint fracbits = bits >> COORD_INTEGER_BITS;
+
+		uint intmaskMP = ((1<<COORD_INTEGER_BITS_MP)-1);
+		uint intmask = ((1<<COORD_INTEGER_BITS)-1);
+
+		uint selectNotMP = (flags & INBOUNDS) - 1;
+
+		fracbits -= fracbitsMP;
+		fracbits &= selectNotMP;
+		fracbits += fracbitsMP;
+
+		intmask -= intmaskMP;
+		intmask &= selectNotMP;
+		intmask += intmaskMP;
+
+		uint intpart = (bits & intmask) + 1;
+		uint intbitsLow = intpart << COORD_FRACTIONAL_BITS_MP_LOWPRECISION;
+		uint intbits = intpart << COORD_FRACTIONAL_BITS;
+		uint selectNotLow = (uint)bLowPrecision - 1;
+		
+		intbits -= intbitsLow;
+		intbits &= selectNotLow;
+		intbits += intbitsLow;
+
+		bits = fracbits | intbits;
+	}
+
+	return (int)bits * multiply;
+}
+
+unsigned int bf_read::ReadBitCoordBits (void)
+{
+#if defined( BB_PROFILING )
+	VPROF( "bf_write::ReadBitCoordBits" );
+#endif
+
+	unsigned int flags = ReadUBitLong(2);
+	if ( flags == 0 )
+		return 0;
+
+	static const int numbits_table[3] =
+	{
+		COORD_INTEGER_BITS + 1,
+		COORD_FRACTIONAL_BITS + 1,
+		COORD_INTEGER_BITS + COORD_FRACTIONAL_BITS + 1
+	};
+	return ReadUBitLong( numbits_table[ flags-1 ] ) * 4 + flags;
+}
+
+unsigned int bf_read::ReadBitCoordMPBits( bool bIntegral, bool bLowPrecision )
+{
+#if defined( BB_PROFILING )
+	VPROF( "bf_write::ReadBitCoordMPBits" );
+#endif
+
+	unsigned int flags = ReadUBitLong(2);
+	enum { INBOUNDS=1, INTVAL=2 };
+	int numbits = 0;
+
+	if ( bIntegral )
+	{
+		if ( flags & INTVAL )
+		{
+			numbits = (flags & INBOUNDS) ? (1 + COORD_INTEGER_BITS_MP) : (1 + COORD_INTEGER_BITS);
+		}
+		else
+		{
+			return flags; // no extra bits
+		}
+	}
+	else
+	{
+		static const unsigned char numbits_table[8] =
+		{
+			1 + COORD_FRACTIONAL_BITS,
+			1 + COORD_FRACTIONAL_BITS,
+			1 + COORD_FRACTIONAL_BITS + COORD_INTEGER_BITS,
+			1 + COORD_FRACTIONAL_BITS + COORD_INTEGER_BITS_MP,
+			1 + COORD_FRACTIONAL_BITS_MP_LOWPRECISION,
+			1 + COORD_FRACTIONAL_BITS_MP_LOWPRECISION,
+			1 + COORD_FRACTIONAL_BITS_MP_LOWPRECISION + COORD_INTEGER_BITS,
+			1 + COORD_FRACTIONAL_BITS_MP_LOWPRECISION + COORD_INTEGER_BITS_MP
+		};
+		numbits = numbits_table[ flags + bLowPrecision*4 ];
+	}
+
+	return flags + ReadUBitLong(numbits)*4;
+}
+
+void bf_read::ReadBitVec3Coord( Vector& fa )
+{
+	int		xflag, yflag, zflag;
+
+	// This vector must be initialized! Otherwise, If any of the flags aren't set, 
+	// the corresponding component will not be read and will be stack garbage.
+	fa.Init( 0, 0, 0 );
+
+	xflag = ReadOneBit();
+	yflag = ReadOneBit(); 
+	zflag = ReadOneBit();
+
+	if ( xflag )
+		fa[0] = ReadBitCoord();
+	if ( yflag )
+		fa[1] = ReadBitCoord();
+	if ( zflag )
+		fa[2] = ReadBitCoord();
+}
+
+float bf_read::ReadBitNormal (void)
+{
+	// Read the sign bit
+	int	signbit = ReadOneBit();
+
+	// Read the fractional part
+	unsigned int fractval = ReadUBitLong( NORMAL_FRACTIONAL_BITS );
+
+	// Calculate the correct floating point value
+	float value = (float)fractval * NORMAL_RESOLUTION;
+
+	// Fixup the sign if negative.
+	if ( signbit )
+		value = -value;
+
+	return value;
+}
+
+void bf_read::ReadBitVec3Normal( Vector& fa )
+{
+	int xflag = ReadOneBit();
+	int yflag = ReadOneBit(); 
+
+	if (xflag)
+		fa[0] = ReadBitNormal();
+	else
+		fa[0] = 0.0f;
+
+	if (yflag)
+		fa[1] = ReadBitNormal();
+	else
+		fa[1] = 0.0f;
+
+	// The first two imply the third (but not its sign)
+	int znegative = ReadOneBit();
+
+	float fafafbfb = fa[0] * fa[0] + fa[1] * fa[1];
+	if (fafafbfb < 1.0f)
+		fa[2] = sqrt( 1.0f - fafafbfb );
+	else
+		fa[2] = 0.0f;
+
+	if (znegative)
+		fa[2] = -fa[2];
+}
+
+void bf_read::ReadBitAngles( QAngle& fa )
+{
+	Vector tmp;
+	ReadBitVec3Coord( tmp );
+	fa.Init( tmp.x, tmp.y, tmp.z );
+}
+
+int64 bf_read::ReadLongLong()
+{
+	int64 retval;
+	uint *pLongs = (uint*)&retval;
+
+	// Read the two DWORDs according to network endian
+	const short endianIndex = 0x0100;
+	byte *idx = (byte*)&endianIndex;
+	pLongs[*idx++] = ReadUBitLong(sizeof(long) << 3);
+	pLongs[*idx] = ReadUBitLong(sizeof(long) << 3);
+
+	return retval;
+}
+
+float bf_read::ReadFloat()
+{
+	float ret;
+	Assert( sizeof(ret) == 4 );
+	ReadBits(&ret, 32);
+
+	// Swap the float, since ReadBits reads raw data
+	LittleFloat( &ret, &ret );
+	return ret;
+}
+
+bool bf_read::ReadBytes(void *pOut, int nBytes)
+{
+	ReadBits(pOut, nBytes << 3);
+	return !IsOverflowed();
+}
+
+bool bf_read::ReadString( char *pStr, int maxLen, bool bLine, int *pOutNumChars )
+{
+	Assert( maxLen != 0 );
+
+	bool bTooSmall = false;
+	int iChar = 0;
+	while(1)
+	{
+		char val = ReadChar();
+		if ( val == 0 )
+			break;
+		else if ( bLine && val == '\n' )
+			break;
+
+		if ( iChar < (maxLen-1) )
+		{
+			pStr[iChar] = val;
+			++iChar;
+		}
+		else
+		{
+			bTooSmall = true;
+		}
+	}
+
+	// Make sure it's null-terminated.
+	Assert( iChar < maxLen );
+	pStr[iChar] = 0;
+
+	if ( pOutNumChars )
+		*pOutNumChars = iChar;
+
+	return !IsOverflowed() && !bTooSmall;
+}
+
+
+char* bf_read::ReadAndAllocateString( bool *pOverflow )
+{
+	char str[2048];
+	
+	int nChars;
+	bool bOverflow = !ReadString( str, sizeof( str ), false, &nChars );
+	if ( pOverflow )
+		*pOverflow = bOverflow;
+
+	// Now copy into the output and return it;
+	char *pRet = new char[ nChars + 1 ];
+	for ( int i=0; i <= nChars; i++ )
+		pRet[i] = str[i];
+
+	return pRet;
+}
+
+void bf_read::ExciseBits( int startbit, int bitstoremove )
+{
+	int endbit = startbit + bitstoremove;
+	int remaining_to_end = m_nDataBits - endbit;
+
+	bf_write temp;
+	temp.StartWriting( (void *)m_pData, m_nDataBits << 3, startbit );
+
+	Seek( endbit );
+
+	for ( int i = 0; i < remaining_to_end; i++ )
+	{
+		temp.WriteOneBit( ReadOneBit() );
+	}
+
+	Seek( startbit );
+	
+	m_nDataBits -= bitstoremove;
+	m_nDataBytes = m_nDataBits >> 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 ];
+}
-- 
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