1 /* ScummVM - Graphic Adventure Engine
2 *
3 * ScummVM is the legal property of its developers, whose names
4 * are too numerous to list here. Please refer to the COPYRIGHT
5 * file distributed with this source distribution.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20 *
21 */
22
23 #include "image/pcx.h"
24
25 #include "common/stream.h"
26 #include "common/textconsole.h"
27 #include "graphics/pixelformat.h"
28 #include "graphics/surface.h"
29
30 /**
31 * Based on the PCX specs:
32 * http://www.fileformat.info/format/pcx/spec/a10e75307b3a4cc49c3bbe6db4c41fa2/view.htm
33 * and the PCX decoder of FFmpeg (libavcodec/pcx.c):
34 * http://git.videolan.org/?p=ffmpeg.git;a=blob;f=libavcodec/pcx.c
35 */
36
37 namespace Image {
38
PCXDecoder()39 PCXDecoder::PCXDecoder() {
40 _surface = 0;
41 _palette = 0;
42 _paletteColorCount = 0;
43 }
44
~PCXDecoder()45 PCXDecoder::~PCXDecoder() {
46 destroy();
47 }
48
destroy()49 void PCXDecoder::destroy() {
50 if (_surface) {
51 _surface->free();
52 delete _surface;
53 _surface = 0;
54 }
55
56 delete[] _palette;
57 _palette = 0;
58 _paletteColorCount = 0;
59 }
60
loadStream(Common::SeekableReadStream & stream)61 bool PCXDecoder::loadStream(Common::SeekableReadStream &stream) {
62 destroy();
63
64 if (stream.readByte() != 0x0a) // ZSoft PCX
65 return false;
66
67 byte version = stream.readByte(); // 0 - 5
68 if (version > 5)
69 return false;
70
71 bool compressed = stream.readByte(); // encoding, 1 = run length encoding
72 byte bitsPerPixel = stream.readByte(); // 1, 2, 4 or 8
73
74 // Window
75 uint16 xMin = stream.readUint16LE();
76 uint16 yMin = stream.readUint16LE();
77 uint16 xMax = stream.readUint16LE();
78 uint16 yMax = stream.readUint16LE();
79
80 uint16 width = xMax - xMin + 1;
81 uint16 height = yMax - yMin + 1;
82
83 if (xMax < xMin || yMax < yMin) {
84 warning("Invalid PCX image dimensions");
85 return false;
86 }
87
88 stream.skip(4); // HDpi, VDpi
89
90 // Read the EGA palette (colormap)
91 _palette = new byte[16 * 3];
92 for (uint16 i = 0; i < 16; i++) {
93 _palette[i * 3 + 0] = stream.readByte();
94 _palette[i * 3 + 1] = stream.readByte();
95 _palette[i * 3 + 2] = stream.readByte();
96 }
97
98 if (stream.readByte() != 0) // reserved, should be set to 0
99 return false;
100
101 byte nPlanes = stream.readByte();
102 uint16 bytesPerLine = stream.readUint16LE();
103 uint16 bytesPerscanLine = nPlanes * bytesPerLine;
104
105 if (bytesPerscanLine < width * bitsPerPixel * nPlanes / 8) {
106 warning("PCX data is corrupted");
107 return false;
108 }
109
110 stream.skip(60); // PaletteInfo, HscreenSize, VscreenSize, Filler
111
112 _surface = new Graphics::Surface();
113
114 byte *scanLine = new byte[bytesPerscanLine];
115 byte *dst;
116 int x, y;
117
118 if (nPlanes == 3 && bitsPerPixel == 8) { // 24bpp
119 Graphics::PixelFormat format = Graphics::PixelFormat(4, 8, 8, 8, 8, 24, 16, 8, 0);
120 _surface->create(width, height, format);
121 dst = (byte *)_surface->getPixels();
122 _paletteColorCount = 0;
123
124 for (y = 0; y < height; y++) {
125 decodeRLE(stream, scanLine, bytesPerscanLine, compressed);
126
127 for (x = 0; x < width; x++) {
128 byte b = scanLine[x];
129 byte g = scanLine[x + bytesPerLine];
130 byte r = scanLine[x + (bytesPerLine << 1)];
131 uint32 color = format.RGBToColor(r, g, b);
132
133 *((uint32 *)dst) = color;
134 dst += format.bytesPerPixel;
135 }
136 }
137 } else if (nPlanes == 1 && bitsPerPixel == 8) { // 8bpp indexed
138 _surface->create(width, height, Graphics::PixelFormat::createFormatCLUT8());
139 dst = (byte *)_surface->getPixels();
140 _paletteColorCount = 16;
141
142 for (y = 0; y < height; y++, dst += _surface->pitch) {
143 decodeRLE(stream, scanLine, bytesPerscanLine, compressed);
144 memcpy(dst, scanLine, width);
145 }
146
147 if (version == 5) {
148 if (stream.readByte() != 12) {
149 warning("Expected a palette after the PCX image data");
150 delete[] scanLine;
151 return false;
152 }
153
154 // Read the VGA palette
155 delete[] _palette;
156 _palette = new byte[256 * 3];
157 for (uint16 i = 0; i < 256; i++) {
158 _palette[i * 3 + 0] = stream.readByte();
159 _palette[i * 3 + 1] = stream.readByte();
160 _palette[i * 3 + 2] = stream.readByte();
161 }
162
163 _paletteColorCount = 256;
164 }
165 } else if ((nPlanes == 2 || nPlanes == 3 || nPlanes == 4) && bitsPerPixel == 1) { // planar, 4, 8 or 16 colors
166 _surface->create(width, height, Graphics::PixelFormat::createFormatCLUT8());
167 dst = (byte *)_surface->getPixels();
168 _paletteColorCount = 16;
169
170 for (y = 0; y < height; y++, dst += _surface->pitch) {
171 decodeRLE(stream, scanLine, bytesPerscanLine, compressed);
172
173 for (x = 0; x < width; x++) {
174 int m = 0x80 >> (x & 7), v = 0;
175 for (int i = nPlanes - 1; i >= 0; i--) {
176 v <<= 1;
177 v += (scanLine[i * bytesPerLine + (x >> 3)] & m) == 0 ? 0 : 1;
178 }
179 dst[x] = v;
180 }
181 }
182 } else {
183 // Known unsupported case: 1 plane and bpp < 8 (1, 2 or 4)
184 warning("Invalid PCX file (%d planes, %d bpp)", nPlanes, bitsPerPixel);
185 delete[] scanLine;
186 return false;
187 }
188
189 delete[] scanLine;
190
191 return true;
192 }
193
decodeRLE(Common::SeekableReadStream & stream,byte * dst,uint32 bytesPerscanLine,bool compressed)194 void PCXDecoder::decodeRLE(Common::SeekableReadStream &stream, byte *dst, uint32 bytesPerscanLine, bool compressed) {
195 uint32 i = 0;
196 byte run, value;
197
198 if (compressed) {
199 while (i < bytesPerscanLine) {
200 run = 1;
201 value = stream.readByte();
202 if (value >= 0xc0) {
203 run = value & 0x3f;
204 value = stream.readByte();
205 }
206 while (i < bytesPerscanLine && run--)
207 dst[i++] = value;
208 }
209 } else {
210 stream.read(dst, bytesPerscanLine);
211 }
212 }
213
214 } // End of namespace Image
215