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unpackerHelper2(numBits) -> copyRelocatesBytes(offset, numBytes) and some revising of the unpacking routine.

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svn-id: r32653
This commit is contained in:
Kari Salminen 2008-06-10 21:34:26 +00:00
parent 7453cf8b0b
commit 420d29932b
2 changed files with 17 additions and 17 deletions
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30
engines/cine/unpack.cpp
View File

@ -73,12 +73,10 @@ void CineUnpacker::unpackHelper1(byte numBits, byte addCount) {
}
}
void CineUnpacker::unpackHelper2(byte numBits) {
uint16 i = getBits(numBits);
uint16 count = _size + 1;
_datasize -= count;
while (count--) {
*_dst = *(_dst + i);
void CineUnpacker::copyRelocatedBytes(uint16 offset, uint16 numBytes) {
_datasize -= numBytes;
while (numBytes--) {
*_dst = *(_dst + offset);
--_dst;
}
}
@ -87,28 +85,30 @@ 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 (!nextBit()) {
_size = 1;
if (!nextBit()) {
unpackHelper1(3, 0);
} else {
unpackHelper2(8);
uint16 numBytes = 2;
uint16 offset = getBits(8);
copyRelocatedBytes(offset, numBytes);
}
} else {
uint16 c = getBits(2);
if (c == 3) {
unpackHelper1(8, 8);
} else if (c < 2) {
_size = c + 2;
unpackHelper2(c + 9);
} else {
_size = getBits(8);
unpackHelper2(12);
} else if (c < 2) { // c == 0 || c == 1
uint16 numBytes = c + 3;
uint16 offset = getBits(c + 9);
copyRelocatedBytes(offset, numBytes);
} else { // c == 2
uint16 numBytes = getBits(8) + 1;
uint16 offset = getBits(12);
copyRelocatedBytes(offset, numBytes);
}
}
} while (_datasize > 0 && _src >= src - 4);

4
engines/cine/unpack.h
View File

@ -42,9 +42,9 @@ private:
int nextBit();
uint16 getBits(byte numBits);
void unpackHelper1(byte numBits, byte addCount);
void unpackHelper2(byte numBits);
void copyRelocatedBytes(uint16 offset, uint16 numBytes);
private:
int _size, _datasize;
int _datasize;
uint32 _crc;
uint32 _chk;
byte *_dst;