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author | Kari Salminen | 2008-06-10 19:08:53 +0000 |
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committer | Kari Salminen | 2008-06-10 19:08:53 +0000 |
commit | 3823a23b70ccb7346563e2d46ae3c12acb786712 (patch) | |
tree | bab6669238cf8aa6e37925f59e4b58ffdfb54b02 /engines | |
parent | c51b11e86269acddd77acf903cdc3fc60dc2205f (diff) | |
download | scummvm-rg350-3823a23b70ccb7346563e2d46ae3c12acb786712.tar.gz scummvm-rg350-3823a23b70ccb7346563e2d46ae3c12acb786712.tar.bz2 scummvm-rg350-3823a23b70ccb7346563e2d46ae3c12acb786712.zip |
Objectified the Delphine decompression routine (i.e. delphineUnpack).
svn-id: r32646
Diffstat (limited to 'engines')
-rw-r--r-- | engines/cine/part.cpp | 6 | ||||
-rw-r--r-- | engines/cine/unpack.cpp | 101 | ||||
-rw-r--r-- | engines/cine/unpack.h | 20 |
3 files changed, 72 insertions, 55 deletions
diff --git a/engines/cine/part.cpp b/engines/cine/part.cpp index 0ce8dfdb21..535bf841d5 100644 --- a/engines/cine/part.cpp +++ b/engines/cine/part.cpp @@ -127,7 +127,8 @@ void CineEngine::readVolCnf() { uint8 *buf = new uint8[unpackedSize]; f.read(buf, packedSize); if (packedSize != unpackedSize) { - if (!delphineUnpack(buf, buf, packedSize)) { + CineUnpacker cineUnpacker; + if (!cineUnpacker.unpack(buf, buf, packedSize)) { error("Error while unpacking 'vol.cnf' data"); } } @@ -224,7 +225,8 @@ byte *readBundleFile(int16 foundFileIdx) { if (partBuffer[foundFileIdx].unpackedSize != partBuffer[foundFileIdx].packedSize) { byte *unpackBuffer = (byte *)malloc(partBuffer[foundFileIdx].packedSize); readFromPart(foundFileIdx, unpackBuffer); - delphineUnpack(dataPtr, unpackBuffer, partBuffer[foundFileIdx].packedSize); + CineUnpacker cineUnpacker; + cineUnpacker.unpack(dataPtr, unpackBuffer, partBuffer[foundFileIdx].packedSize); free(unpackBuffer); } else { readFromPart(foundFileIdx, dataPtr); diff --git a/engines/cine/unpack.cpp b/engines/cine/unpack.cpp index 4409af4b07..ef761e87f1 100644 --- a/engines/cine/unpack.cpp +++ b/engines/cine/unpack.cpp @@ -30,94 +30,91 @@ namespace Cine { -struct UnpackCtx { - int size, datasize; - uint32 crc; - uint32 chk; - byte *dst; - const byte *src; -}; +uint32 CineUnpacker::readSource() { + uint32 value = READ_BE_UINT32(_src); + _src -= 4; + return value; +} -static int rcr(UnpackCtx *uc, int CF) { - int rCF = (uc->chk & 1); - uc->chk >>= 1; +int CineUnpacker::rcr(int CF) { + int rCF = (_chk & 1); + _chk >>= 1; if (CF) { - uc->chk |= 0x80000000; + _chk |= 0x80000000; } return rCF; } -static int nextChunk(UnpackCtx *uc) { - int CF = rcr(uc, 0); - if (uc->chk == 0) { - uc->chk = READ_BE_UINT32(uc->src); uc->src -= 4; - uc->crc ^= uc->chk; - CF = rcr(uc, 1); +int CineUnpacker::nextChunk() { + int CF = rcr(0); + if (_chk == 0) { + _chk = readSource(); + _crc ^= _chk; + CF = rcr(1); } return CF; } -static uint16 getCode(UnpackCtx *uc, byte numChunks) { +uint16 CineUnpacker::getCode(byte numChunks) { uint16 c = 0; while (numChunks--) { c <<= 1; - if (nextChunk(uc)) { + if (nextChunk()) { c |= 1; } } return c; } -static void unpackHelper1(UnpackCtx *uc, byte numChunks, byte addCount) { - uint16 count = getCode(uc, numChunks) + addCount + 1; - uc->datasize -= count; +void CineUnpacker::unpackHelper1(byte numChunks, byte addCount) { + uint16 count = getCode(numChunks) + addCount + 1; + _datasize -= count; while (count--) { - *uc->dst = (byte)getCode(uc, 8); - --uc->dst; + *_dst = (byte)getCode(8); + --_dst; } } -static void unpackHelper2(UnpackCtx *uc, byte numChunks) { - uint16 i = getCode(uc, numChunks); - uint16 count = uc->size + 1; - uc->datasize -= count; +void CineUnpacker::unpackHelper2(byte numChunks) { + uint16 i = getCode(numChunks); + uint16 count = _size + 1; + _datasize -= count; while (count--) { - *uc->dst = *(uc->dst + i); - --uc->dst; + *_dst = *(_dst + i); + --_dst; } } -bool delphineUnpack(byte *dst, const byte *src, int len) { - UnpackCtx uc; - uc.src = src + len - 4; - uc.datasize = READ_BE_UINT32(uc.src); uc.src -= 4; - uc.dst = dst + uc.datasize - 1; - uc.size = 0; - uc.crc = READ_BE_UINT32(uc.src); uc.src -= 4; - uc.chk = READ_BE_UINT32(uc.src); uc.src -= 4; - uc.crc ^= uc.chk; +bool CineUnpacker::unpack(byte *dst, const byte *src, int srcLen) { + _src = src + srcLen - 4; + _datasize = readSource(); + _dst = dst + _datasize - 1; + _size = 0; + _crc = readSource(); + _chk = readSource(); + _crc ^= _chk; do { - if (!nextChunk(&uc)) { - uc.size = 1; - if (!nextChunk(&uc)) { - unpackHelper1(&uc, 3, 0); + if (!nextChunk()) { + _size = 1; + if (!nextChunk()) { + unpackHelper1(3, 0); } else { - unpackHelper2(&uc, 8); + unpackHelper2(8); } } else { - uint16 c = getCode(&uc, 2); + uint16 c = getCode(2); if (c == 3) { - unpackHelper1(&uc, 8, 8); + unpackHelper1(8, 8); } else if (c < 2) { - uc.size = c + 2; - unpackHelper2(&uc, c + 9); + _size = c + 2; + unpackHelper2(c + 9); } else { - uc.size = getCode(&uc, 8); - unpackHelper2(&uc, 12); + _size = getCode(8); + unpackHelper2(12); } } - } while (uc.datasize > 0 && uc.src >= src - 4); - return uc.crc == 0; + } while (_datasize > 0 && _src >= src - 4); + return _crc == 0; } } // End of namespace Cine diff --git a/engines/cine/unpack.h b/engines/cine/unpack.h index 5f57a3531b..9433fafa58 100644 --- a/engines/cine/unpack.h +++ b/engines/cine/unpack.h @@ -31,7 +31,25 @@ namespace Cine { -bool delphineUnpack(byte *dst, const byte *src, int len); +class CineUnpacker { +public: + /** Returns true if unpacking was successful, otherwise false. */ + bool unpack(byte *dst, const byte *src, int srcLen); +private: + /** Reads a single big endian 32-bit integer from the source and goes backwards 4 bytes. */ + uint32 readSource(); + int rcr(int CF); + int nextChunk(); + uint16 getCode(byte numChunks); + void unpackHelper1(byte numChunks, byte addCount); + void unpackHelper2(byte numChunks); +private: + int _size, _datasize; + uint32 _crc; + uint32 _chk; + byte *_dst; + const byte *_src; +}; } // End of namespace Cine |