/*static*/ int DreamGrafix::UnpackLZW(const uint8_t* srcBuf, long srcLen,
uint8_t* dstBuf, long dstLen)
{
uint16_t finChar, oldCode, inCode, freeCode, maxCode, k;
uint16_t nBitMod1, nBitMask;
int bitOffset;
uint16_t hashNext[4096];
uint16_t hashChar[4096];
uint8_t* pOrigDst = dstBuf;
int iCode;
uint16_t stack[32768];
int stackIdx = 0;
/* initialize table and code reader */
INIT_TABLE();
bitOffset = 0;
while (true) {
if (dstBuf - pOrigDst > dstLen) {
LOGI("LZW overrun");
return -1;
}
int A;
int Y;
READ_CODE();
if (iCode == kEofCode) {
break;
}
if (iCode == kClearCode) {
// Got Clear
INIT_TABLE();
READ_CODE();
oldCode = iCode;
k = iCode;
finChar = iCode;
*dstBuf++ = (uint8_t) iCode;
continue;
}
A = inCode = iCode;
if (iCode < freeCode) {
goto inTable;
}
stack[stackIdx] = finChar;
stackIdx++;
A = oldCode;
inTable:
if (A < 256) {
goto gotChar;
}
while (A >= 256) {
Y = A;
A = hashChar[Y];
stack[stackIdx] = A;
stackIdx++;
A = hashNext[Y];
}
gotChar:
A &= 0xFF;
finChar = A;
k = A;
Y = 0;
dstBuf[Y++] = A;
while (stackIdx) {
stackIdx--;
A = stack[stackIdx];
dstBuf[Y++] = A;
}
dstBuf += Y;
ADD_CODE();
oldCode = inCode;
if (freeCode < maxCode) {
continue; // goto nextCode;
}
if (12 == nBitMod1) {
continue; // goto nextCode;
}
nBitMod1++;
nBitMask = bitMasks[nBitMod1];
//printf("nBitMod1 = %d, nBitMask = %04x\n",
// nBitMod1, nBitMask);
maxCode <<= 1;
}
return dstBuf - pOrigDst;
}
/* add the tail of while */
int fytheCodegenWhileTail(struct Buffer_char *buf)
{
int ret = buf->bufused;
ADD_CODE(*buf, start_While_Tail, end_While_Tail);
return ret;
}
/* add the mid of while */
int fytheCodegenWhileMid(struct Buffer_char *buf)
{
int ret = buf->bufused;
ADD_CODE(*buf, start_While_Mid, start_While_Body);
return ret;
}
/* add the head of while */
int fytheCodegenWhileHead(struct Buffer_char *buf)
{
int ret = buf->bufused;
ADD_CODE(*buf, start_While_Head, start_While_Cond);
return ret;
}
/* add the mid of if */
int fytheCodegenIfMid(struct Buffer_char *buf)
{
int ret = buf->bufused;
ADD_CODE(*buf, start_If_Mid, start_If_False);
return ret;
}
/* add the head of if */
int fytheCodegenIfHead(struct Buffer_char *buf)
{
int ret = buf->bufused;
ADD_CODE(*buf, start_If_Head, start_If_True);
return ret;
}