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semantics

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This commit is contained in:
Connor Olding 2016-11-27 21:55:09 -08:00
parent 449c021110
commit 4a1e704cc3
1 changed files with 10 additions and 18 deletions
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28
z64yaz0.c
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@ -15,7 +15,6 @@ typedef unsigned int u32;
static u32 simpleEnc(u8 *src, int size, int pos, u32 *pMatchPos) static u32 simpleEnc(u8 *src, int size, int pos, u32 *pMatchPos)
{ {
int startPos = pos - 0x1000; int startPos = pos - 0x1000;
int i, j;
u32 numBytes = 1; u32 numBytes = 1;
u32 matchPos = 0; u32 matchPos = 0;
@ -26,7 +25,8 @@ static u32 simpleEnc(u8 *src, int size, int pos, u32 *pMatchPos)
if (startPos < 0) if (startPos < 0)
startPos = 0; startPos = 0;
for (i = startPos; i < pos; i++) { for (int i = startPos; i < pos; i++) {
int j;
for (j = 0; j < end; j++) { for (j = 0; j < end; j++) {
if (src[i + j] != src[j + pos]) if (src[i + j] != src[j + pos])
break; break;
@ -89,7 +89,7 @@ static int encodeYaz0(u8 *src, u8 *dst, int srcSize)
u8 buf[24]; // 8 codes * 3 bytes maximum u8 buf[24]; // 8 codes * 3 bytes maximum
u32 validBitCount = 0; // number of valid bits left in "code" byte u32 validBitCount = 0; // number of valid bits left in "code" byte
u8 currCodeByte = 0; u8 currCodeByte = 0; // a bitfield, set bits meaning copy, unset meaning RLE
while (srcPos < srcSize) { while (srcPos < srcSize) {
u32 numBytes; u32 numBytes;
@ -164,39 +164,31 @@ void decompress(u8 *src, u8 *dst, int uncompressedSize)
while (dstPlace < uncompressedSize) { while (dstPlace < uncompressedSize) {
// read new "code" byte if the current one is used up // read new "code" byte if the current one is used up
if (validBitCount == 0) { if (validBitCount == 0) {
currCodeByte = src[srcPlace]; currCodeByte = src[srcPlace++];
++srcPlace;
validBitCount = 8; validBitCount = 8;
} }
if ((currCodeByte & 0x80) != 0) { if ((currCodeByte & 0x80) != 0) {
// straight copy // straight copy
dst[dstPlace] = src[srcPlace]; dst[dstPlace++] = src[srcPlace++];
dstPlace++;
srcPlace++;
} else { } else {
// RLE part // RLE part
u8 byte1 = src[srcPlace]; u8 byte1 = src[srcPlace++];
u8 byte2 = src[srcPlace + 1]; u8 byte2 = src[srcPlace++];
srcPlace += 2;
u32 dist = ((byte1 & 0xF) << 8) | byte2; u32 dist = ((byte1 & 0xF) << 8) | byte2;
u32 copySource = dstPlace - (dist + 1); u32 copySource = dstPlace - (dist + 1);
u32 numBytes = byte1 >> 4; u32 numBytes = byte1 >> 4;
if (numBytes == 0) { if (numBytes == 0) {
numBytes = src[srcPlace] + 0x12; numBytes = src[srcPlace++] + 0x12;
srcPlace++;
} else { } else {
numBytes += 2; numBytes += 2;
} }
// copy run // copy run
int i; for(int i = 0; i < numBytes; ++i) {
for(i = 0; i < numBytes; ++i) { dst[dstPlace++] = dst[copySource++];
dst[dstPlace] = dst[copySource];
copySource++;
dstPlace++;
} }
} }