aboutsummaryrefslogtreecommitdiff
path: root/engines/sci/decompressor.h
blob: b49452ebc360c570e9d69d7709be0653b37a8525 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */

#ifndef SCI_DECOMPRESSOR_H
#define SCI_DECOMPRESSOR_H

#include "common/file.h"

namespace Sci {

enum ResourceCompression {
	kCompUnknown = -1,
	kCompNone = 0,
	kCompLZW,
	kCompHuffman,
	kCompLZW1,			// LZW-like compression used in SCI01 and SCI1
	kCompLZW1View,		// Comp3 + view Post-processing
	kCompLZW1Pic,		// Comp3 + pic Post-processing
#ifdef ENABLE_SCI32
	kCompSTACpack,	// ? Used in SCI32
#endif
	kCompDCL
};

/**
 * Base class for decompressors.
 * Simply copies nPacked bytes from src to dest.
 */
class Decompressor {
public:
	Decompressor() {}
	virtual ~Decompressor() {}


	virtual int unpack(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);

protected:
	/**
	 * Initialize decompressor.
	 * @param src		source stream to read from
	 * @param dest		destination stream to write to
	 * @param nPacked	size of packed data
	 * @param nUnpacket	size of unpacked data
	 * @return 0 on success, non-zero on error
	 */
	virtual void init(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);

	/**
	 * Get a number of bits from _src stream, starting with the most
	 * significant unread bit of the current four byte block.
	 * @param n		number of bits to get
	 * @return n-bits number
	 */
	uint32 getBitsMSB(int n);

	/**
	 * Get a number of bits from _src stream, starting with the least
	 * significant unread bit of the current four byte block.
	 * @param n		number of bits to get
	 * @return n-bits number
	 */
	uint32 getBitsLSB(int n);

	/**
	 * Get one byte from _src stream.
	 * @return byte
	 */
	byte getByteMSB();
	byte getByteLSB();

	void fetchBitsMSB();
	void fetchBitsLSB();

	/**
	 * Write one byte into _dest stream
	 * @param b byte to put
	 */

	virtual void putByte(byte b);

	/**
	 * Returns true if all expected data has been unpacked to _dest
	 * and there is no more data in _src.
	 */
	bool isFinished() {
		return (_dwWrote == _szUnpacked) && (_dwRead >= _szPacked);
	}

	uint32 _dwBits;		///< bits buffer
	byte _nBits;		///< number of unread bits in _dwBits
	uint32 _szPacked;	///< size of the compressed data
	uint32 _szUnpacked;	///< size of the decompressed data
	uint32 _dwRead;		///< number of bytes read from _src
	uint32 _dwWrote;	///< number of bytes written to _dest
	Common::ReadStream *_src;
	byte *_dest;
};

/**
 * Huffman decompressor
 */
class DecompressorHuffman : public Decompressor {
public:
	int unpack(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);

protected:
	int16 getc2();

	byte *_nodes;
};

/**
 * LZW-like decompressor for SCI01/SCI1.
 * TODO: Needs clean-up of post-processing fncs
 */
class DecompressorLZW : public Decompressor {
public:
	DecompressorLZW(int nCompression) {
		_compression = nCompression;
	}
	void init(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);
	int unpack(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);

protected:
	enum {
		PIC_OPX_EMBEDDED_VIEW = 1,
		PIC_OPX_SET_PALETTE = 2,
		PIC_OP_OPX = 0xfe
	};
	// unpacking procedures
	// TODO: unpackLZW and unpackLZW1 are similar and should be merged
	int unpackLZW1(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);
	int unpackLZW(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);

	// functions to post-process view and pic resources
	void reorderPic(byte *src, byte *dest, int dsize);
	void reorderView(byte *src, byte *dest);
	void decodeRLE(byte **rledata, byte **pixeldata, byte *outbuffer, int size);
	int getRLEsize(byte *rledata, int dsize);
	void buildCelHeaders(byte **seeker, byte **writer, int celindex, int *cc_lengths, int max);

	// decompressor data
	struct Tokenlist {
		byte data;
		uint16 next;
	};
	uint16 _numbits;
	uint16 _curtoken, _endtoken;
	int _compression;
};

/**
 * DCL decompressor for SCI1.1
 */
class DecompressorDCL : public Decompressor {
public:
	int unpack(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);

protected:
	int unpackDCL(byte *dest);
	int huffman_lookup(const int *tree);
};

#ifdef ENABLE_SCI32
/**
 * STACpack decompressor for SCI32
 */
class DecompressorLZS : public Decompressor {
public:
	int unpack(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);
protected:
	int unpackLZS();
	uint16 getCompLen();
	void copyComp(int offs, int clen);
};
#endif

} // End of namespace Sci

#endif // SCI_SCICORE_DECOMPRESSOR_H