63 lines
1.5 KiB
C++
63 lines
1.5 KiB
C++
//+---------------------------------------------------------------------------
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//
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// Microsoft Windows
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// Copyright (C) Microsoft Corporation, 1999 - 1999.
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//
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// File: bitfield.hxx
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//
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// Contents: read/write access to a bitfield
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//
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// History: May-5-99 dlee Created
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//
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//----------------------------------------------------------------------------
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#pragma once
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//+---------------------------------------------------------------------------
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//
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// Class: CBitfield
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//
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// Purpose: Manages a bitfield allocated elsewhere
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//
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// History: May-5-99 dlee Created
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//
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//----------------------------------------------------------------------------
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const unsigned cBitsPerByte = 8;
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class CBitfield
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{
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public:
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CBitfield( BYTE * pbBitfield ) : _pbBitfield( pbBitfield)
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{
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}
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BOOL IsBitSet( unsigned iBit )
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{
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unsigned iByte = iBit / cBitsPerByte;
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unsigned cRemainder = ( iBit % cBitsPerByte );
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return ( 0 != ( _pbBitfield[ iByte ] & ( 1 << cRemainder ) ) );
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}
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void SetBit( unsigned iBit )
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{
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unsigned iByte = iBit / cBitsPerByte;
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unsigned cRemainder = ( iBit % cBitsPerByte );
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_pbBitfield[ iByte ] |= ( 1 << cRemainder );
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}
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void ClearBit( unsigned iBit )
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{
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unsigned iByte = iBit / cBitsPerByte;
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unsigned cRemainder = ( iBit % cBitsPerByte );
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_pbBitfield[ iByte ] &= ( ~ ( 1 << cRemainder ) );
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}
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private:
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BYTE * _pbBitfield;
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};
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