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Diffstat (limited to 'indra/llcommon/llbitpack.h')
| -rwxr-xr-x | indra/llcommon/llbitpack.h | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/indra/llcommon/llbitpack.h b/indra/llcommon/llbitpack.h new file mode 100755 index 0000000000..f99a354cd4 --- /dev/null +++ b/indra/llcommon/llbitpack.h @@ -0,0 +1,208 @@ +/** + * @file llbitpack.h + * @brief Convert data to packed bit stream + * + * $LicenseInfo:firstyear=2000&license=viewerlgpl$ + * Second Life Viewer Source Code + * Copyright (C) 2010, Linden Research, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License only. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA + * $/LicenseInfo$ + */ + +#ifndef LL_BITPACK_H +#define LL_BITPACK_H + +#include "llerror.h" + +const U32 MAX_DATA_BITS = 8; + + +class LLBitPack +{ +public: + LLBitPack(U8 *buffer, U32 max_size) : mBuffer(buffer), mBufferSize(0), mLoad(0), mLoadSize(0), mTotalBits(0), mMaxSize(max_size) + { + } + + ~LLBitPack() + { + } + + void resetBitPacking() + { + mLoad = 0; + mLoadSize = 0; + mTotalBits = 0; + mBufferSize = 0; + } + + U32 bitPack(U8 *total_data, U32 total_dsize) + { + U32 dsize; + U8 data; + + while (total_dsize > 0) + { + if (total_dsize > MAX_DATA_BITS) + { + dsize = MAX_DATA_BITS; + total_dsize -= MAX_DATA_BITS; + } + else + { + dsize = total_dsize; + total_dsize = 0; + } + + data = *total_data++; + + data <<= (MAX_DATA_BITS - dsize); + while (dsize > 0) + { + if (mLoadSize == MAX_DATA_BITS) + { + *(mBuffer + mBufferSize++) = mLoad; + if (mBufferSize > mMaxSize) + { + LL_ERRS() << "mBufferSize exceeding mMaxSize!" << LL_ENDL; + } + mLoadSize = 0; + mLoad = 0x00; + } + mLoad <<= 1; + mLoad |= (data >> (MAX_DATA_BITS - 1)); + data <<= 1; + mLoadSize++; + mTotalBits++; + dsize--; + } + } + return mBufferSize; + } + + U32 bitCopy(U8 *total_data, U32 total_dsize) + { + U32 dsize; + U8 data; + + while (total_dsize > 0) + { + if (total_dsize > MAX_DATA_BITS) + { + dsize = MAX_DATA_BITS; + total_dsize -= MAX_DATA_BITS; + } + else + { + dsize = total_dsize; + total_dsize = 0; + } + + data = *total_data++; + + while (dsize > 0) + { + if (mLoadSize == MAX_DATA_BITS) + { + *(mBuffer + mBufferSize++) = mLoad; + if (mBufferSize > mMaxSize) + { + LL_ERRS() << "mBufferSize exceeding mMaxSize!" << LL_ENDL; + } + mLoadSize = 0; + mLoad = 0x00; + } + mLoad <<= 1; + mLoad |= (data >> (MAX_DATA_BITS - 1)); + data <<= 1; + mLoadSize++; + mTotalBits++; + dsize--; + } + } + return mBufferSize; + } + + U32 bitUnpack(U8 *total_retval, U32 total_dsize) + { + U32 dsize; + U8 *retval; + + while (total_dsize > 0) + { + if (total_dsize > MAX_DATA_BITS) + { + dsize = MAX_DATA_BITS; + total_dsize -= MAX_DATA_BITS; + } + else + { + dsize = total_dsize; + total_dsize = 0; + } + + retval = total_retval++; + *retval = 0x00; + while (dsize > 0) + { + if (mLoadSize == 0) + { +#ifdef _DEBUG + if (mBufferSize > mMaxSize) + { + LL_ERRS() << "mBufferSize exceeding mMaxSize" << LL_ENDL; + LL_ERRS() << mBufferSize << " > " << mMaxSize << LL_ENDL; + } +#endif + mLoad = *(mBuffer + mBufferSize++); + mLoadSize = MAX_DATA_BITS; + } + *retval <<= 1; + *retval |= (mLoad >> (MAX_DATA_BITS - 1)); + mLoadSize--; + mLoad <<= 1; + dsize--; + } + } + return mBufferSize; + } + + U32 flushBitPack() + { + if (mLoadSize) + { + mLoad <<= (MAX_DATA_BITS - mLoadSize); + *(mBuffer + mBufferSize++) = mLoad; + if (mBufferSize > mMaxSize) + { + LL_ERRS() << "mBufferSize exceeding mMaxSize!" << LL_ENDL; + } + mLoadSize = 0; + } + return mBufferSize; + } + + U8 *mBuffer; + U32 mBufferSize; + U8 mLoad; + U32 mLoadSize; + U32 mTotalBits; + U32 mMaxSize; +}; + +#endif |