AGS: Removed lzwexpand_to_mem(), tidied load_lzw()

From upstream 2b9f130e119f9cfc81d0257a446edc4e31df19c0

engines/ags/globals.h

@@ -1054,7 +1054,7 @@ public:
 	char *_lzbuffer = nullptr;
 	int *_node = nullptr;
 	int _pos = 0;
-	long _outbytes = 0, _maxsize = 0, _putbytes = 0;
+	size_t _outbytes = 0, _maxsize = 0, _putbytes = 0;
 
 	/**@}*/
 

engines/ags/shared/util/compress.cpp

@@ -359,79 +359,42 @@ void save_lzw(Stream *out, const Bitmap *bmpp, const RGB(*pal)[256]) {
 }
 
 void load_lzw(Stream *in, Bitmap **dst_bmp, int dst_bpp, RGB(*pal)[256]) {
-	soff_t        uncompsiz;
-	int *loptr;
-	unsigned char *membuffer;
-	int           arin;
-
+	*dst_bmp = nullptr;
 	// NOTE: old format saves full RGB struct here (4 bytes, including the filler)
 	if (pal)
 		in->Read(*pal, sizeof(RGB) * 256);
 	else
 		in->Seek(sizeof(RGB) * 256);
-	_G(maxsize) = in->ReadInt32();
-	uncompsiz = in->ReadInt32();
+	const size_t uncomp_sz = in->ReadInt32();
+	const size_t comp_sz = in->ReadInt32();
+	const soff_t end_pos = in->GetPosition() + comp_sz;
 
-	uncompsiz += in->GetPosition();
-	_G(outbytes) = 0; _G(putbytes) = 0;
-
-	update_polled_stuff_if_runtime();
-	membuffer = lzwexpand_to_mem(in);
-	update_polled_stuff_if_runtime();
-
-	loptr = (int *)&membuffer[0];
-	membuffer += 8;
-#if AGS_PLATFORM_ENDIAN_BIG
-	loptr[0] = BBOp::SwapBytesInt32(loptr[0]);
-	loptr[1] = BBOp::SwapBytesInt32(loptr[1]);
-	int bitmapNumPixels = loptr[0] * loptr[1] / dst_bpp;
-	switch (dst_bpp) // bytes per pixel!
+	// First decompress data into the memory buffer
+	std::vector<uint8_t> membuf;
 	{
-	case 1:
-	{
-		// all done
-		break;
+		MemoryStream memws(membuf, kStream_Write);
+		lzwexpand(in, &memws, uncomp_sz);
 	}
-	case 2:
-	{
-		short *sp = (short *)membuffer;
-		for (int i = 0; i < bitmapNumPixels; ++i) {
-			sp[i] = BBOp::SwapBytesInt16(sp[i]);
-}
-		// all done
-		break;
-	}
-	case 4:
-	{
-		int *ip = (int *)membuffer;
-		for (int i = 0; i < bitmapNumPixels; ++i) {
-			ip[i] = BBOp::SwapBytesInt32(ip[i]);
-		}
-		// all done
-		break;
-	}
-  }
-#endif // AGS_PLATFORM_ENDIAN_BIG
 
-	update_polled_stuff_if_runtime();
-
-	Bitmap *bmm = BitmapHelper::CreateBitmap((loptr[0] / dst_bpp), loptr[1], dst_bpp * 8);
+	// Open same buffer for reading and get params and pixels
+	MemoryStream mem_in(membuf);
+	int stride = mem_in.ReadInt32(); // width * bpp
+	int height = mem_in.ReadInt32();
+	Bitmap *bmm = BitmapHelper::CreateBitmap((stride / dst_bpp), height, dst_bpp * 8);
 	if (bmm == nullptr)
-		quit("load_room: not enough memory to load room background");
+		return; // out of mem?
 
-	update_polled_stuff_if_runtime();
+	size_t num_pixels = stride * height / dst_bpp;
+	uint8_t *bmp_data = bmm->GetDataForWriting();
+	switch (dst_bpp) {
+	case 1: mem_in.Read(bmp_data, num_pixels); break;
+	case 2: mem_in.ReadArrayOfInt16(reinterpret_cast<int16_t *>(bmp_data), num_pixels); break;
+	case 4: mem_in.ReadArrayOfInt32(reinterpret_cast<int32_t *>(bmp_data), num_pixels); break;
+	default: assert(0); break;
+	}
 
-	for (arin = 0; arin < loptr[1]; arin++)
-		memcpy(&bmm->GetScanLineForWriting(arin)[0], &membuffer[arin * loptr[0]], loptr[0]);
-
-	update_polled_stuff_if_runtime();
-
-	free(membuffer - 8);
-
-	if (in->GetPosition() != uncompsiz)
-		in->Seek(uncompsiz, kSeekBegin);
-
-	update_polled_stuff_if_runtime();
+	if (in->GetPosition() != end_pos)
+		in->Seek(end_pos, kSeekBegin);
 
 	*dst_bmp = bmm;
 }

engines/ags/shared/util/lzw.cpp

@@ -195,8 +195,6 @@ void lzwcompress(Stream *lzw_in, Stream *out) {
 	free(_G(lzbuffer));
 }
 
-int expand_to_mem = 0;
-unsigned char *membfptr = nullptr;
 void myputc(int ccc, Stream *out) {
 	if (_G(maxsize) > 0) {
 		_G(putbytes)++;
@@ -205,21 +203,17 @@ void myputc(int ccc, Stream *out) {
 	}
 
 	_G(outbytes)++;
-	if (expand_to_mem) {
-		membfptr[0] = ccc;
-		membfptr++;
-	} else
-		out->WriteInt8(ccc);
+	out->WriteInt8(ccc);
 }
 
-void lzwexpand(Stream *lzw_in, Stream *out) {
+void lzwexpand(Stream *lzw_in, Stream *out, size_t out_size) {
 	int bits, ch, i, j, len, mask;
-	char *buf;
-	//  printf(" UnShrinking: %s ",filena);
-	_G(putbytes) = 0;
+	char *lzbuffer;
+	_G(outbytes) = 0; _G(putbytes) = 0;
+	_G(maxsize) = out_size;
 
-	buf = (char *)malloc(N);
-	if (buf == nullptr) {
+	lzbuffer = (char *)malloc(N);
+	if (lzbuffer == nullptr) {
 		quit("compress.cpp: unable to decompress: insufficient memory");
 	}
 	i = N - F;
@@ -237,13 +231,13 @@ void lzwexpand(Stream *lzw_in, Stream *out) {
 				j = (i - j - 1) & (N - 1);
 
 				while (len--) {
-					myputc(buf[i] = buf[j], out);
+					myputc(lzbuffer[i] = lzbuffer[j], out);
 					j = (j + 1) & (N - 1);
 					i = (i + 1) & (N - 1);
 				}
 			} else {
 				ch = lzw_in->ReadByte();
-				myputc(buf[i] = ch, out);
+				myputc(lzbuffer[i] = ch, out);
 				i = (i + 1) & (N - 1);
 			}
 
@@ -258,16 +252,7 @@ void lzwexpand(Stream *lzw_in, Stream *out) {
 			break;
 	}
 
-	free(buf);
-	expand_to_mem = 0;
-}
-
-unsigned char *lzwexpand_to_mem(Stream *in) {
-	unsigned char *membuff = (unsigned char *)malloc(_G(maxsize) + 10);
-	expand_to_mem = 1;
-	membfptr = membuff;
-	lzwexpand(in, nullptr);
-	return membuff;
+	free(lzbuffer);
 }
 
 } // namespace AGS3

engines/ags/shared/util/lzw.h

@@ -33,7 +33,7 @@ class Stream;
 using namespace AGS; // FIXME later
 
 void lzwcompress(Shared::Stream *lzw_in, Shared::Stream *out);
-unsigned char *lzwexpand_to_mem(Shared::Stream *in);
+void lzwexpand(Shared::Stream *lzw_in, Shared::Stream *out, size_t out_size);
 
 } // namespace AGS3
 

engines/ags/shared/util/memory_stream.cpp

@@ -35,6 +35,15 @@ MemoryStream::MemoryStream(const std::vector<uint8_t> &cbuf, DataEndianess strea
 	, _pos(0) {
 }
 
+MemoryStream::MemoryStream(const uint8_t *cbuf, size_t buf_sz, DataEndianess stream_endianess)
+	: DataStream(stream_endianess)
+	, _cbuf(cbuf)
+	, _len(buf_sz)
+	, _buf(nullptr)
+	, _mode(kStream_Read)
+	, _pos(0) {
+}
+
 MemoryStream::MemoryStream(const String &cbuf, DataEndianess stream_endianess)
 	: DataStream(stream_endianess)
 	, _cbuf(reinterpret_cast<const uint8_t *>(cbuf.GetCStr()))

engines/ags/shared/util/memory_stream.h

@@ -47,6 +47,9 @@ public:
 	// Construct memory stream in the read-only mode over a const std::vector;
 	// vector must persist in memory until the stream is closed.
 	MemoryStream(const std::vector<uint8_t> &cbuf, DataEndianess stream_endianess = kLittleEndian);
+	// Construct memory stream in the read-only mode over a const C-buffer;
+	// buffer must persist in memory until the stream is closed.
+	MemoryStream(const uint8_t *cbuf, size_t buf_sz, DataEndianess stream_endianess = kLittleEndian);
 	// Construct memory stream in the read-only mode over a const String;
 	// String object must persist in memory until the stream is closed.
 	MemoryStream(const String &cbuf, DataEndianess stream_endianess = kLittleEndian);