forked from 0ad/0ad
65 lines
1.8 KiB
C
65 lines
1.8 KiB
C
/* Copyright (c) 2011 Wildfire Games
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be included
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* in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
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* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
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* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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/*
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* FIFO bit queue
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*/
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#ifndef INCLUDED_ADTS_BIT_BUF
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#define INCLUDED_ADTS_BIT_BUF
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#include "lib/bits.h"
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struct BitBuf
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{
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uintptr_t buf;
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uintptr_t cur; // bit to be appended (toggled by add())
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size_t len; // |buf| [bits]
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void reset()
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{
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buf = 0;
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cur = 0;
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len = 0;
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}
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// toggle current bit if desired, and add to buffer (new bit is LSB)
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void add(uintptr_t toggle)
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{
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cur ^= toggle;
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buf <<= 1;
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buf |= cur;
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len++;
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}
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// extract LS n bits
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size_t extract(uintptr_t n)
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{
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const uintptr_t bits = buf & bit_mask<uintptr_t>(n);
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buf >>= n;
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return bits;
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}
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};
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#endif // #ifndef INCLUDED_ADTS_BIT_BUF
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