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
|
/* 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 3 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, see <http://www.gnu.org/licenses/>.
*
*/
#include "image/codecs/hlz.h"
#include "common/stream.h"
#include "common/textconsole.h"
#include "graphics/surface.h"
namespace Image {
HLZDecoder::HLZDecoder(int width, int height) : Codec(),
_width(width), _height(height), _surface(nullptr) {
}
HLZDecoder::~HLZDecoder() {
if (_surface) {
_surface->free();
delete _surface;
}
}
const Graphics::Surface *HLZDecoder::decodeFrame(Common::SeekableReadStream &stream) {
if (!_surface) {
_surface = new Graphics::Surface();
}
_surface->create(_width, _height, Graphics::PixelFormat::createFormatCLUT8());
byte *dst = (byte *)_surface->getPixels();
decodeFrameInPlace(stream, uint32(-1), dst);
return _surface;
}
Graphics::PixelFormat HLZDecoder::getPixelFormat() const {
return Graphics::PixelFormat::createFormatCLUT8();
}
static inline uint getReg(Common::SeekableReadStream &stream, uint32 *size, uint32 *reg,
int *regBits) {
if (*regBits == 0) {
if (*size < 4) {
error("Can't feed register: not enough data");
}
*reg = stream.readUint32LE();
*size -= 4;
*regBits = 32;
}
uint ret = (*reg >> 31) & 0x1;
*reg <<= 1;
(*regBits)--;
return ret;
}
void HLZDecoder::decodeFrameInPlace(Common::SeekableReadStream &stream, uint32 size, byte *dst) {
bool eof = false;
bool checkSize = (size != (uint32) - 1);
byte *orig = dst;
uint32 reg = 0;
int regBits = 0;
#define GETREG() getReg(stream, &size, ®, ®Bits)
while (!eof) {
if (GETREG()) {
if (size < 1) {
error("Can't read pixel byte");
}
byte c = stream.readByte();
*(dst++) = c;
size--;
} else {
int offset, repeat_count;
if (GETREG()) {
// Long repeat
if (size < 2) {
error("Can't read repeat count/offset");
}
uint16 tmp = stream.readUint16LE();
size -= 2;
repeat_count = tmp & 0x7;
offset = (tmp >> 3) - 0x2000;
if (repeat_count == 0) {
if (size < 1) {
error("Can't read long repeat count");
}
repeat_count = stream.readByte();
size--;
if (repeat_count == 0) {
eof = true;
continue;
}
}
} else {
// Short repeat
repeat_count = GETREG() << 1;
repeat_count |= GETREG();
if (size < 1) {
error("Can't read offset byte");
}
offset = stream.readByte() - 0x100;
size--;
}
repeat_count += 2;
if (dst + offset < orig) {
error("Invalid offset %d, dst is %d", offset, (int)(dst - orig));
}
for (; repeat_count > 0; repeat_count--) {
// offset is always < 0
*dst = *(dst + offset);
dst++;
}
}
}
if (checkSize && size != 0) {
stream.skip(size);
}
#undef GETREG
}
} // End of namespace Image
|
