ciderpress/reformat/DreamGrafix.cpp
2007-03-27 17:47:10 +00:00

371 lines
8.7 KiB
C++

/*
* CiderPress
* Copyright (C) 2007 by faddenSoft, LLC. All Rights Reserved.
* See the file LICENSE for distribution terms.
*/
/*
* DreamGrafix super-hi-res conversions.
*
* Based on code provided by Jason Andersen.
*/
#include "StdAfx.h"
#include "SuperHiRes.h"
/*
* ==========================================================================
* ReformatDG256SHR
* ==========================================================================
*/
/*
* Decide whether or not we want to handle this file.
*/
void
ReformatDG256SHR::Examine(ReformatHolder* pHolder)
{
ReformatHolder::ReformatApplies applies = ReformatHolder::kApplicNot;
if (fDG.ScanDreamGrafix(pHolder) && fDG.fNumColors == 256)
applies = ReformatHolder::kApplicYes;
pHolder->SetApplic(ReformatHolder::kReformatSHR_DG256, applies,
ReformatHolder::kApplicNot, ReformatHolder::kApplicNot);
}
/*
* Convert a 256-color DreamGrafix Super Hi-Res Image.
*/
int
ReformatDG256SHR::Process(const ReformatHolder* pHolder,
ReformatHolder::ReformatID id, ReformatHolder::ReformatPart part,
ReformatOutput* pOutput)
{
const unsigned char* srcBuf = pHolder->GetSourceBuf(part);
long srcLen = pHolder->GetSourceLen(part);
int retval = -1;
if (fDG.UnpackDG(srcBuf, srcLen, &fScreen, NULL)) {
MyDIBitmap* pDib = SHRScreenToBitmap8(&fScreen);
if (pDib != nil) {
SetResultBuffer(pOutput, pDib);
retval = 0;
}
}
return retval;
}
/*
* ==========================================================================
* ReformatDG3200SHR
* ==========================================================================
*/
/*
* Decide whether or not we want to handle this file.
*/
void
ReformatDG3200SHR::Examine(ReformatHolder* pHolder)
{
ReformatHolder::ReformatApplies applies = ReformatHolder::kApplicNot;
if (fDG.ScanDreamGrafix(pHolder) && fDG.fNumColors == 3200)
applies = ReformatHolder::kApplicYes;
pHolder->SetApplic(ReformatHolder::kReformatSHR_DG3200, applies,
ReformatHolder::kApplicNot, ReformatHolder::kApplicNot);
}
/*
* Convert a 3200-color DreamGrafix Super Hi-Res Image.
*/
int
ReformatDG3200SHR::Process(const ReformatHolder* pHolder,
ReformatHolder::ReformatID id, ReformatHolder::ReformatPart part,
ReformatOutput* pOutput)
{
const unsigned char* srcBuf = pHolder->GetSourceBuf(part);
long srcLen = pHolder->GetSourceLen(part);
int retval = -1;
if (fDG.UnpackDG(srcBuf, srcLen, &fScreen, fExtColorTable)) {
MyDIBitmap* pDib = SHR3200ToBitmap24();
if (pDib != nil) {
SetResultBuffer(pOutput, pDib);
retval = 0;
}
}
return retval;
}
/*
* ==========================================================================
* ReformatDreamGrafix
* ==========================================================================
*/
/*
* Examine a DreamGrafix file. This figures out if its any of the
* DreamGrafix formats, i.e. 256-color, 3200-color, packed, or unpacked.
*/
bool
DreamGrafix::ScanDreamGrafix(ReformatHolder* pHolder)
{
long fileType = pHolder->GetFileType();
long auxType = pHolder->GetAuxType();
long fileLen = pHolder->GetSourceLen(ReformatHolder::kPartData);
bool relaxed, couldBe;
relaxed = pHolder->GetOption(ReformatHolder::kOptRelaxGfxTypeCheck) != 0;
couldBe = false;
if (fileType == Reformat::kTypePNT && auxType == 0x8005)
couldBe = true; // $c0/8005 DG packed
else if (fileType == Reformat::kTypePIC && auxType == 0x8003)
couldBe = false; // $c1/8003 DG unpacked -- not supported
else if (relaxed) {
if (fileType == Reformat::kTypeBIN && auxType == 0x8005)
couldBe = true;
}
if (fileLen < 256)
couldBe = false;
if (!couldBe)
return false;
const unsigned char* ptr;
ptr = pHolder->GetSourceBuf(ReformatHolder::kPartData)
+ fileLen - kHeaderOffset;
if (memcmp(ptr+6, "\x0a""DreamWorld", 11) != 0)
return false;
fNumColors = (*ptr == 0) ? 256 : 3200;
fHeight = Reformat::Get16LE(ptr + 2);
fWidth = Reformat::Get16LE(ptr + 4);
if (fWidth != 320 || fHeight != 200) {
WMSG2("ODD: strange height %dx%x in DG\n", fWidth, fHeight);
return false;
}
return true;
}
/*
* Unpack a DreamGrafix SHR image compressed with LZW.
*
* Returns true on success, false if the uncompress step failed to produce
* exactly 32768+32*200 bytes.
*/
bool
DreamGrafix::UnpackDG(const unsigned char* srcBuf, long srcLen,
ReformatSHR::SHRScreen* pScreen, unsigned char* extColorTable)
{
int expectedLen;
unsigned char* tmpBuf;
int actual;
if (extColorTable == NULL) {
/*
* 32000 for pixels (320*200*0.5 bytes)
* 256 for SCB (200 + 56 unused)
* 512 for basic palette (16 sets * 16 colors * 2 bytes)\
* 512 optional/unused?
*/
expectedLen = 33280;
} else {
/*
* 32000 for pixels (320*200*0.5 bytes)
* 6400 for palette (200 lines * 16 entries * 2 bytes)
* 512 optional/unused?
*/
expectedLen = 38912;
}
/* over-alloc -- our LZW decoder doesn't check often */
tmpBuf = new unsigned char[expectedLen + 1024];
if (tmpBuf == NULL)
return false;
actual = UnpackLZW(srcBuf, srcLen, tmpBuf, expectedLen);
if (actual != expectedLen && actual != (expectedLen-512)) {
WMSG2("UnpackLZW expected %d, got %d\n", expectedLen, actual);
free(tmpBuf);
return false;
}
memcpy(pScreen->pixels, tmpBuf, 32000);
if (extColorTable == NULL) {
memcpy(pScreen->scb, tmpBuf + 32000, 256);
memcpy(pScreen->colorTable, tmpBuf + 32256, 512);
} else {
const unsigned short* pSrcTable;
unsigned short* pDstTable;
pSrcTable = (const unsigned short*) (tmpBuf + 32000);
pDstTable = (unsigned short*) extColorTable;
int table;
for (table = 0; table < ReformatSHR::kNumLines; table++) {
int entry;
for (entry = 0; entry < ReformatSHR::kNumEntriesPerColorTable; entry++) {
pDstTable[(ReformatSHR::kNumEntriesPerColorTable-1) - entry] =
*pSrcTable++;
}
pDstTable += ReformatSHR::kNumEntriesPerColorTable;
}
}
free(tmpBuf);
return true;
}
/*
* Constants for LZW.
*/
static const int kClearCode = 256;
static const int kEofCode = 257;
static const int kFirstFreeCode = 258;
static const unsigned int bitMasks[] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0x1ff, 0x3ff, 0x7ff, 0xfff
};
/* initialize the table */
#define INIT_TABLE() { \
nBitMod1 = 9; \
nBitMask = bitMasks[nBitMod1]; \
maxCode = 1 << nBitMod1; \
freeCode = kFirstFreeCode; \
};
/* add a new code to our data structure */
#define ADD_CODE() { \
hashChar[freeCode] = k; \
hashNext[freeCode] = oldCode; \
freeCode++; \
};
/* read the next code and put the value into iCode */
#define READ_CODE() { \
int bit_idx = bitOffset & 0x7; \
int byte_idx = bitOffset >> 3; \
\
iCode = srcBuf[ byte_idx ]; \
iCode &= 0xFF; \
iCode |= (srcBuf[ byte_idx+1 ]<<8); \
iCode &= 0xFFFF; \
iCode |= (srcBuf[ byte_idx+2 ]<<16); \
iCode >>= bit_idx; \
iCode &= nBitMask; \
bitOffset += nBitMod1; \
};
/*static*/ int
DreamGrafix::UnpackLZW(const unsigned char* srcBuf, long srcLen,
unsigned char* dstBuf, long dstLen)
{
unsigned short finChar, oldCode, inCode, freeCode, maxCode, k;
unsigned short nBitMod1, nBitMask;
int bitOffset;
unsigned short hashNext[4096];
unsigned short hashChar[4096];
unsigned char* pOrigDst = dstBuf;
int iCode;
short stack[32768];
int stackIdx = 0;
/* initialize table and code reader */
INIT_TABLE();
bitOffset = 0;
while (true) {
if (dstBuf - pOrigDst > dstLen) {
WMSG0("LZW overrun\n");
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++ = (unsigned char)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;
}