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authorKari Salminen2008-06-10 22:37:55 +0000
committerKari Salminen2008-06-10 22:37:55 +0000
commitefc4fd7ae0f106f2cfe9d9109b3331604f97be9c (patch)
tree9c5d6d0185b7b659b2e8636c15a552dac973e3e0
parent235504e60000f3c74c262b9b54fcb4cc9ff6f126 (diff)
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A little Delphine unpacker documentation addition and variable renaming.
svn-id: r32660
-rw-r--r--engines/cine/unpack.cpp28
-rw-r--r--engines/cine/unpack.h10
2 files changed, 22 insertions, 16 deletions
diff --git a/engines/cine/unpack.cpp b/engines/cine/unpack.cpp
index 7afeeb1509..8e775c3632 100644
--- a/engines/cine/unpack.cpp
+++ b/engines/cine/unpack.cpp
@@ -36,23 +36,23 @@ uint32 CineUnpacker::readSource() {
return value;
}
-int CineUnpacker::rcr(int CF) {
- int rCF = (_chk & 1);
- _chk >>= 1;
- if (CF) {
- _chk |= 0x80000000;
+int CineUnpacker::rcr(int inputCarry) {
+ int outputCarry = (_chunk32b & 1);
+ _chunk32b >>= 1;
+ if (inputCarry) {
+ _chunk32b |= 0x80000000;
}
- return rCF;
+ return outputCarry;
}
int CineUnpacker::nextBit() {
- int CF = rcr(0);
- if (_chk == 0) {
- _chk = readSource();
- _crc ^= _chk;
- CF = rcr(1);
+ int carry = rcr(0);
+ if (_chunk32b == 0) {
+ _chunk32b = readSource();
+ _crc ^= _chunk32b;
+ carry = rcr(1);
}
- return CF;
+ return carry;
}
uint16 CineUnpacker::getBits(byte numBits) {
@@ -85,8 +85,8 @@ bool CineUnpacker::unpack(byte *dst, const byte *src, int srcLen) {
_datasize = readSource();
_dst = dst + _datasize - 1;
_crc = readSource();
- _chk = readSource();
- _crc ^= _chk;
+ _chunk32b = readSource();
+ _crc ^= _chunk32b;
do {
if (!nextBit()) {
if (!nextBit()) {
diff --git a/engines/cine/unpack.h b/engines/cine/unpack.h
index c401c8679b..894d59d0b4 100644
--- a/engines/cine/unpack.h
+++ b/engines/cine/unpack.h
@@ -38,7 +38,13 @@ public:
private:
/** Reads a single big endian 32-bit integer from the source and goes backwards 4 bytes. */
uint32 readSource();
- int rcr(int CF);
+
+ /**
+ * Shifts the current internal 32-bit chunk to the right by one.
+ * Puts input carry into internal chunk's topmost (i.e. leftmost) bit.
+ * Returns the least significant bit that was shifted out.
+ */
+ int rcr(int inputCarry);
int nextBit();
uint16 getBits(byte numBits);
void unpackBytes(uint16 numBytes);
@@ -46,7 +52,7 @@ private:
private:
int _datasize;
uint32 _crc;
- uint32 _chk;
+ uint32 _chunk32b; //!< The current internal 32-bit chunk
byte *_dst;
const byte *_src;
};