/
IMG_pcx.c
298 lines (272 loc) · 9 KB
1
/*
2
SDL_image: An example image loading library for use with SDL
3
Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
20
21
*/
22
23
24
25
26
27
28
/*
* PCX file reader:
* Supports:
* 1..4 bits/pixel in multiplanar format (1 bit/plane/pixel)
* 8 bits/pixel in single-planar format (8 bits/plane/pixel)
* 24 bits/pixel in 3-plane format (8 bits/plane/pixel)
*
29
30
* (The <8bpp formats are expanded to 8bpp surfaces)
*
31
32
33
34
* Doesn't support:
* single-planar packed-pixel formats other than 8bpp
* 4-plane 32bpp format with a fourth "intensity" plane
*/
35
36
37
38
39
40
41
42
#include "SDL_endian.h"
#include "SDL_image.h"
#ifdef LOAD_PCX
struct PCXheader {
43
44
45
46
47
48
49
50
51
52
53
54
55
56
Uint8 Manufacturer;
Uint8 Version;
Uint8 Encoding;
Uint8 BitsPerPixel;
Sint16 Xmin, Ymin, Xmax, Ymax;
Sint16 HDpi, VDpi;
Uint8 Colormap[48];
Uint8 Reserved;
Uint8 NPlanes;
Sint16 BytesPerLine;
Sint16 PaletteInfo;
Sint16 HscreenSize;
Sint16 VscreenSize;
Uint8 Filler[54];
57
58
59
60
61
};
/* See if an image is contained in a data source */
int IMG_isPCX(SDL_RWops *src)
{
62
63
64
65
66
67
68
Sint64 start;
int is_PCX;
const int ZSoft_Manufacturer = 10;
const int PC_Paintbrush_Version = 5;
const int PCX_Uncompressed_Encoding = 0;
const int PCX_RunLength_Encoding = 1;
struct PCXheader pcxh;
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
if ( !src )
return 0;
start = SDL_RWtell(src);
is_PCX = 0;
if ( SDL_RWread(src, &pcxh, sizeof(pcxh), 1) == 1 ) {
if ( (pcxh.Manufacturer == ZSoft_Manufacturer) &&
(pcxh.Version == PC_Paintbrush_Version) &&
(pcxh.Encoding == PCX_RunLength_Encoding ||
pcxh.Encoding == PCX_Uncompressed_Encoding) ) {
is_PCX = 1;
}
}
SDL_RWseek(src, start, RW_SEEK_SET);
return(is_PCX);
84
85
86
87
88
}
/* Load a PCX type image from an SDL datasource */
SDL_Surface *IMG_LoadPCX_RW(SDL_RWops *src)
{
89
90
91
92
93
94
95
96
97
98
99
100
Sint64 start;
struct PCXheader pcxh;
Uint32 Rmask;
Uint32 Gmask;
Uint32 Bmask;
Uint32 Amask;
SDL_Surface *surface = NULL;
int width, height;
int y, bpl;
Uint8 *row, *buf = NULL;
char *error = NULL;
int bits, src_bits;
101
102
int count = 0;
Uint8 ch;
103
104
105
106
107
108
if ( !src ) {
/* The error message has been set in SDL_RWFromFile */
return NULL;
}
start = SDL_RWtell(src);
109
110
if ( !SDL_RWread(src, &pcxh, sizeof(pcxh), 1) ) {
111
112
113
114
115
116
117
118
error = "file truncated";
goto done;
}
pcxh.Xmin = SDL_SwapLE16(pcxh.Xmin);
pcxh.Ymin = SDL_SwapLE16(pcxh.Ymin);
pcxh.Xmax = SDL_SwapLE16(pcxh.Xmax);
pcxh.Ymax = SDL_SwapLE16(pcxh.Ymax);
pcxh.BytesPerLine = SDL_SwapLE16(pcxh.BytesPerLine);
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
#if 0
printf("Manufacturer = %d\n", pcxh.Manufacturer);
printf("Version = %d\n", pcxh.Version);
printf("Encoding = %d\n", pcxh.Encoding);
printf("BitsPerPixel = %d\n", pcxh.BitsPerPixel);
printf("Xmin = %d, Ymin = %d, Xmax = %d, Ymax = %d\n", pcxh.Xmin, pcxh.Ymin, pcxh.Xmax, pcxh.Ymax);
printf("HDpi = %d, VDpi = %d\n", pcxh.HDpi, pcxh.VDpi);
printf("NPlanes = %d\n", pcxh.NPlanes);
printf("BytesPerLine = %d\n", pcxh.BytesPerLine);
printf("PaletteInfo = %d\n", pcxh.PaletteInfo);
printf("HscreenSize = %d\n", pcxh.HscreenSize);
printf("VscreenSize = %d\n", pcxh.VscreenSize);
#endif
134
135
136
137
138
139
140
141
142
143
/* Create the surface of the appropriate type */
width = (pcxh.Xmax - pcxh.Xmin) + 1;
height = (pcxh.Ymax - pcxh.Ymin) + 1;
Rmask = Gmask = Bmask = Amask = 0;
src_bits = pcxh.BitsPerPixel * pcxh.NPlanes;
if((pcxh.BitsPerPixel == 1 && pcxh.NPlanes >= 1 && pcxh.NPlanes <= 4)
|| (pcxh.BitsPerPixel == 8 && pcxh.NPlanes == 1)) {
bits = 8;
} else if(pcxh.BitsPerPixel == 8 && pcxh.NPlanes == 3) {
bits = 24;
144
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
145
146
147
Rmask = 0x000000FF;
Gmask = 0x0000FF00;
Bmask = 0x00FF0000;
148
#else
149
150
151
Rmask = 0xFF0000;
Gmask = 0x00FF00;
Bmask = 0x0000FF;
152
#endif
153
154
155
156
157
158
159
160
} else {
error = "unsupported PCX format";
goto done;
}
surface = SDL_CreateRGBSurface(SDL_SWSURFACE, width, height,
bits, Rmask, Gmask, Bmask, Amask);
if ( surface == NULL )
goto done;
161
162
bpl = pcxh.NPlanes * pcxh.BytesPerLine;
163
if ( bpl < 0 || bpl > surface->pitch ) {
164
error = "bytes per line is too large (corrupt?)";
165
goto done;
166
}
167
buf = (Uint8 *)SDL_calloc(surface->pitch, 1);
168
169
170
row = (Uint8 *)surface->pixels;
for ( y=0; y<surface->h; ++y ) {
/* decode a scan line to a temporary buffer first */
171
172
int i;
Uint8 *dst = buf;
173
if ( pcxh.Encoding == 0 ) {
174
if ( !SDL_RWread(src, dst, bpl, 1) ) {
175
176
177
178
error = "file truncated";
goto done;
}
} else {
179
180
181
for ( i = 0; i < bpl; i++ ) {
if ( !count ) {
if ( !SDL_RWread(src, &ch, 1, 1) ) {
182
183
184
error = "file truncated";
goto done;
}
185
186
187
188
189
if ( ch < 0xc0 ) {
count = 1;
} else {
count = ch - 0xc0;
if( !SDL_RWread(src, &ch, 1, 1) ) {
190
191
192
error = "file truncated";
goto done;
}
193
}
194
195
196
197
198
}
dst[i] = ch;
count--;
}
}
199
200
if ( src_bits <= 4 ) {
201
202
203
/* expand planes to 1 byte/pixel */
Uint8 *innerSrc = buf;
int plane;
204
for ( plane = 0; plane < pcxh.NPlanes; plane++ ) {
205
int j, k, x = 0;
206
for( j = 0; j < pcxh.BytesPerLine; j++ ) {
207
Uint8 byte = *innerSrc++;
208
for( k = 7; k >= 0; k-- ) {
209
210
211
212
213
214
215
216
unsigned bit = (byte >> k) & 1;
/* skip padding bits */
if (j * 8 + k >= width)
continue;
row[x++] |= bit << plane;
}
}
}
217
} else if ( src_bits == 24 ) {
218
219
220
/* de-interlace planes */
Uint8 *innerSrc = buf;
int plane;
221
for ( plane = 0; plane < pcxh.NPlanes; plane++ ) {
222
223
int x;
dst = row + plane;
224
225
226
227
228
for ( x = 0; x < width; x++ ) {
if ( dst >= row+surface->pitch ) {
error = "decoding out of bounds (corrupt?)";
goto done;
}
229
230
231
232
*dst = *innerSrc++;
dst += pcxh.NPlanes;
}
}
233
234
} else {
SDL_memcpy(row, buf, bpl);
235
}
236
237
238
row += surface->pitch;
}
239
240
if ( bits == 8 ) {
241
242
243
SDL_Color *colors = surface->format->palette->colors;
int nc = 1 << src_bits;
int i;
244
245
surface->format->palette->ncolors = nc;
246
if ( src_bits == 8 ) {
247
248
249
Uint8 ch;
/* look for a 256-colour palette */
do {
250
251
252
253
if ( !SDL_RWread(src, &ch, 1, 1) ) {
/* Couldn't find the palette, try the end of the file */
SDL_RWseek(src, -768, RW_SEEK_END);
break;
254
255
}
} while ( ch != 12 );
256
257
for ( i = 0; i < 256; i++ ) {
258
259
260
261
262
SDL_RWread(src, &colors[i].r, 1, 1);
SDL_RWread(src, &colors[i].g, 1, 1);
SDL_RWread(src, &colors[i].b, 1, 1);
}
} else {
263
for ( i = 0; i < nc; i++ ) {
264
265
266
267
268
269
colors[i].r = pcxh.Colormap[i * 3];
colors[i].g = pcxh.Colormap[i * 3 + 1];
colors[i].b = pcxh.Colormap[i * 3 + 2];
}
}
}
270
271
done:
272
273
274
275
276
277
278
SDL_free(buf);
if ( error ) {
SDL_RWseek(src, start, RW_SEEK_SET);
if ( surface ) {
SDL_FreeSurface(surface);
surface = NULL;
}
279
IMG_SetError("%s", error);
280
281
}
return(surface);
282
283
284
285
286
287
288
}
#else
/* See if an image is contained in a data source */
int IMG_isPCX(SDL_RWops *src)
{
289
return(0);
290
291
292
293
294
}
/* Load a PCX type image from an SDL datasource */
SDL_Surface *IMG_LoadPCX_RW(SDL_RWops *src)
{
295
return(NULL);
296
297
298
}
#endif /* LOAD_PCX */