e14743d1 |
1 | /* |
2 | SDL - Simple DirectMedia Layer |
3 | Copyright (C) 1997-2009 Sam Lantinga |
4 | |
5 | This library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | This library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with this library; if not, write to the Free Software |
17 | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
18 | |
19 | Sam Lantinga |
20 | slouken@libsdl.org |
21 | */ |
22 | #include "SDL_config.h" |
23 | |
24 | /* |
25 | Code to load and save surfaces in Windows BMP format. |
26 | |
27 | Why support BMP format? Well, it's a native format for Windows, and |
28 | most image processing programs can read and write it. It would be nice |
29 | to be able to have at least one image format that we can natively load |
30 | and save, and since PNG is so complex that it would bloat the library, |
31 | BMP is a good alternative. |
32 | |
33 | This code currently supports Win32 DIBs in uncompressed 8 and 24 bpp. |
34 | */ |
35 | |
36 | #include "SDL_video.h" |
37 | #include "SDL_endian.h" |
38 | |
39 | /* Compression encodings for BMP files */ |
40 | #ifndef BI_RGB |
41 | #define BI_RGB 0 |
42 | #define BI_RLE8 1 |
43 | #define BI_RLE4 2 |
44 | #define BI_BITFIELDS 3 |
45 | #endif |
46 | |
47 | |
48 | SDL_Surface * SDL_LoadBMP_RW (SDL_RWops *src, int freesrc) |
49 | { |
50 | SDL_bool was_error; |
51 | long fp_offset; |
52 | int bmpPitch; |
53 | int i, pad; |
54 | SDL_Surface *surface; |
55 | Uint32 Rmask; |
56 | Uint32 Gmask; |
57 | Uint32 Bmask; |
58 | SDL_Palette *palette; |
59 | Uint8 *bits; |
60 | Uint8 *top, *end; |
61 | SDL_bool topDown; |
62 | int ExpandBMP; |
63 | |
64 | /* The Win32 BMP file header (14 bytes) */ |
65 | char magic[2]; |
66 | Uint32 bfSize; |
67 | Uint16 bfReserved1; |
68 | Uint16 bfReserved2; |
69 | Uint32 bfOffBits; |
70 | |
71 | /* The Win32 BITMAPINFOHEADER struct (40 bytes) */ |
72 | Uint32 biSize; |
73 | Sint32 biWidth; |
74 | Sint32 biHeight; |
75 | Uint16 biPlanes; |
76 | Uint16 biBitCount; |
77 | Uint32 biCompression; |
78 | Uint32 biSizeImage; |
79 | Sint32 biXPelsPerMeter; |
80 | Sint32 biYPelsPerMeter; |
81 | Uint32 biClrUsed; |
82 | Uint32 biClrImportant; |
83 | |
84 | /* Make sure we are passed a valid data source */ |
85 | surface = NULL; |
86 | was_error = SDL_FALSE; |
87 | if ( src == NULL ) { |
88 | was_error = SDL_TRUE; |
89 | goto done; |
90 | } |
91 | |
92 | /* Read in the BMP file header */ |
93 | fp_offset = SDL_RWtell(src); |
94 | SDL_ClearError(); |
95 | if ( SDL_RWread(src, magic, 1, 2) != 2 ) { |
96 | SDL_Error(SDL_EFREAD); |
97 | was_error = SDL_TRUE; |
98 | goto done; |
99 | } |
100 | if ( SDL_strncmp(magic, "BM", 2) != 0 ) { |
101 | SDL_SetError("File is not a Windows BMP file"); |
102 | was_error = SDL_TRUE; |
103 | goto done; |
104 | } |
105 | bfSize = SDL_ReadLE32(src); |
106 | bfReserved1 = SDL_ReadLE16(src); |
107 | bfReserved2 = SDL_ReadLE16(src); |
108 | bfOffBits = SDL_ReadLE32(src); |
109 | |
110 | /* Read the Win32 BITMAPINFOHEADER */ |
111 | biSize = SDL_ReadLE32(src); |
112 | if ( biSize == 12 ) { |
113 | biWidth = (Uint32)SDL_ReadLE16(src); |
114 | biHeight = (Uint32)SDL_ReadLE16(src); |
115 | biPlanes = SDL_ReadLE16(src); |
116 | biBitCount = SDL_ReadLE16(src); |
117 | biCompression = BI_RGB; |
118 | biSizeImage = 0; |
119 | biXPelsPerMeter = 0; |
120 | biYPelsPerMeter = 0; |
121 | biClrUsed = 0; |
122 | biClrImportant = 0; |
123 | } else { |
124 | biWidth = SDL_ReadLE32(src); |
125 | biHeight = SDL_ReadLE32(src); |
126 | biPlanes = SDL_ReadLE16(src); |
127 | biBitCount = SDL_ReadLE16(src); |
128 | biCompression = SDL_ReadLE32(src); |
129 | biSizeImage = SDL_ReadLE32(src); |
130 | biXPelsPerMeter = SDL_ReadLE32(src); |
131 | biYPelsPerMeter = SDL_ReadLE32(src); |
132 | biClrUsed = SDL_ReadLE32(src); |
133 | biClrImportant = SDL_ReadLE32(src); |
134 | } |
135 | if (biHeight < 0) { |
136 | topDown = SDL_TRUE; |
137 | biHeight = -biHeight; |
138 | } else { |
139 | topDown = SDL_FALSE; |
140 | } |
141 | |
142 | /* Check for read error */ |
143 | if ( SDL_strcmp(SDL_GetError(), "") != 0 ) { |
144 | was_error = SDL_TRUE; |
145 | goto done; |
146 | } |
147 | |
148 | /* Expand 1 and 4 bit bitmaps to 8 bits per pixel */ |
149 | switch (biBitCount) { |
150 | case 1: |
151 | case 4: |
152 | ExpandBMP = biBitCount; |
153 | biBitCount = 8; |
154 | break; |
155 | default: |
156 | ExpandBMP = 0; |
157 | break; |
158 | } |
159 | |
160 | /* We don't support any BMP compression right now */ |
161 | Rmask = Gmask = Bmask = 0; |
162 | switch (biCompression) { |
163 | case BI_RGB: |
164 | /* If there are no masks, use the defaults */ |
165 | if ( bfOffBits == (14+biSize) ) { |
166 | /* Default values for the BMP format */ |
167 | switch (biBitCount) { |
168 | case 15: |
169 | case 16: |
170 | Rmask = 0x7C00; |
171 | Gmask = 0x03E0; |
172 | Bmask = 0x001F; |
173 | break; |
174 | case 24: |
175 | #if SDL_BYTEORDER == SDL_BIG_ENDIAN |
176 | Rmask = 0x000000FF; |
177 | Gmask = 0x0000FF00; |
178 | Bmask = 0x00FF0000; |
179 | break; |
180 | #endif |
181 | case 32: |
182 | Rmask = 0x00FF0000; |
183 | Gmask = 0x0000FF00; |
184 | Bmask = 0x000000FF; |
185 | break; |
186 | default: |
187 | break; |
188 | } |
189 | break; |
190 | } |
191 | /* Fall through -- read the RGB masks */ |
192 | |
193 | case BI_BITFIELDS: |
194 | switch (biBitCount) { |
195 | case 15: |
196 | case 16: |
197 | case 32: |
198 | Rmask = SDL_ReadLE32(src); |
199 | Gmask = SDL_ReadLE32(src); |
200 | Bmask = SDL_ReadLE32(src); |
201 | break; |
202 | default: |
203 | break; |
204 | } |
205 | break; |
206 | default: |
207 | SDL_SetError("Compressed BMP files not supported"); |
208 | was_error = SDL_TRUE; |
209 | goto done; |
210 | } |
211 | |
212 | /* Create a compatible surface, note that the colors are RGB ordered */ |
213 | surface = SDL_CreateRGBSurface(SDL_SWSURFACE, |
214 | biWidth, biHeight, biBitCount, Rmask, Gmask, Bmask, 0); |
215 | if ( surface == NULL ) { |
216 | was_error = SDL_TRUE; |
217 | goto done; |
218 | } |
219 | |
220 | /* Load the palette, if any */ |
221 | palette = (surface->format)->palette; |
222 | if ( palette ) { |
223 | if ( biClrUsed == 0 ) { |
224 | biClrUsed = 1 << biBitCount; |
225 | } |
226 | if ( biSize == 12 ) { |
227 | for ( i = 0; i < (int)biClrUsed; ++i ) { |
228 | SDL_RWread(src, &palette->colors[i].b, 1, 1); |
229 | SDL_RWread(src, &palette->colors[i].g, 1, 1); |
230 | SDL_RWread(src, &palette->colors[i].r, 1, 1); |
231 | palette->colors[i].unused = 0; |
232 | } |
233 | } else { |
234 | for ( i = 0; i < (int)biClrUsed; ++i ) { |
235 | SDL_RWread(src, &palette->colors[i].b, 1, 1); |
236 | SDL_RWread(src, &palette->colors[i].g, 1, 1); |
237 | SDL_RWread(src, &palette->colors[i].r, 1, 1); |
238 | SDL_RWread(src, &palette->colors[i].unused, 1, 1); |
239 | } |
240 | } |
241 | palette->ncolors = biClrUsed; |
242 | } |
243 | |
244 | /* Read the surface pixels. Note that the bmp image is upside down */ |
245 | if ( SDL_RWseek(src, fp_offset+bfOffBits, RW_SEEK_SET) < 0 ) { |
246 | SDL_Error(SDL_EFSEEK); |
247 | was_error = SDL_TRUE; |
248 | goto done; |
249 | } |
250 | top = (Uint8 *)surface->pixels; |
251 | end = (Uint8 *)surface->pixels+(surface->h*surface->pitch); |
252 | switch (ExpandBMP) { |
253 | case 1: |
254 | bmpPitch = (biWidth + 7) >> 3; |
255 | pad = (((bmpPitch)%4) ? (4-((bmpPitch)%4)) : 0); |
256 | break; |
257 | case 4: |
258 | bmpPitch = (biWidth + 1) >> 1; |
259 | pad = (((bmpPitch)%4) ? (4-((bmpPitch)%4)) : 0); |
260 | break; |
261 | default: |
262 | pad = ((surface->pitch%4) ? |
263 | (4-(surface->pitch%4)) : 0); |
264 | break; |
265 | } |
266 | if ( topDown ) { |
267 | bits = top; |
268 | } else { |
269 | bits = end - surface->pitch; |
270 | } |
271 | while ( bits >= top && bits < end ) { |
272 | switch (ExpandBMP) { |
273 | case 1: |
274 | case 4: { |
275 | Uint8 pixel = 0; |
276 | int shift = (8-ExpandBMP); |
277 | for ( i=0; i<surface->w; ++i ) { |
278 | if ( i%(8/ExpandBMP) == 0 ) { |
279 | if ( !SDL_RWread(src, &pixel, 1, 1) ) { |
280 | SDL_SetError( |
281 | "Error reading from BMP"); |
282 | was_error = SDL_TRUE; |
283 | goto done; |
284 | } |
285 | } |
286 | *(bits+i) = (pixel>>shift); |
287 | pixel <<= ExpandBMP; |
288 | } } |
289 | break; |
290 | |
291 | default: |
292 | if ( SDL_RWread(src, bits, 1, surface->pitch) |
293 | != surface->pitch ) { |
294 | SDL_Error(SDL_EFREAD); |
295 | was_error = SDL_TRUE; |
296 | goto done; |
297 | } |
298 | #if SDL_BYTEORDER == SDL_BIG_ENDIAN |
299 | /* Byte-swap the pixels if needed. Note that the 24bpp |
300 | case has already been taken care of above. */ |
301 | switch(biBitCount) { |
302 | case 15: |
303 | case 16: { |
304 | Uint16 *pix = (Uint16 *)bits; |
305 | for(i = 0; i < surface->w; i++) |
306 | pix[i] = SDL_Swap16(pix[i]); |
307 | break; |
308 | } |
309 | |
310 | case 32: { |
311 | Uint32 *pix = (Uint32 *)bits; |
312 | for(i = 0; i < surface->w; i++) |
313 | pix[i] = SDL_Swap32(pix[i]); |
314 | break; |
315 | } |
316 | } |
317 | #endif |
318 | break; |
319 | } |
320 | /* Skip padding bytes, ugh */ |
321 | if ( pad ) { |
322 | Uint8 padbyte; |
323 | for ( i=0; i<pad; ++i ) { |
324 | SDL_RWread(src, &padbyte, 1, 1); |
325 | } |
326 | } |
327 | if ( topDown ) { |
328 | bits += surface->pitch; |
329 | } else { |
330 | bits -= surface->pitch; |
331 | } |
332 | } |
333 | done: |
334 | if ( was_error ) { |
335 | if ( src ) { |
336 | SDL_RWseek(src, fp_offset, RW_SEEK_SET); |
337 | } |
338 | if ( surface ) { |
339 | SDL_FreeSurface(surface); |
340 | } |
341 | surface = NULL; |
342 | } |
343 | if ( freesrc && src ) { |
344 | SDL_RWclose(src); |
345 | } |
346 | return(surface); |
347 | } |
348 | |
349 | int SDL_SaveBMP_RW (SDL_Surface *saveme, SDL_RWops *dst, int freedst) |
350 | { |
351 | long fp_offset; |
352 | int i, pad; |
353 | SDL_Surface *surface; |
354 | Uint8 *bits; |
355 | |
356 | /* The Win32 BMP file header (14 bytes) */ |
357 | char magic[2] = { 'B', 'M' }; |
358 | Uint32 bfSize; |
359 | Uint16 bfReserved1; |
360 | Uint16 bfReserved2; |
361 | Uint32 bfOffBits; |
362 | |
363 | /* The Win32 BITMAPINFOHEADER struct (40 bytes) */ |
364 | Uint32 biSize; |
365 | Sint32 biWidth; |
366 | Sint32 biHeight; |
367 | Uint16 biPlanes; |
368 | Uint16 biBitCount; |
369 | Uint32 biCompression; |
370 | Uint32 biSizeImage; |
371 | Sint32 biXPelsPerMeter; |
372 | Sint32 biYPelsPerMeter; |
373 | Uint32 biClrUsed; |
374 | Uint32 biClrImportant; |
375 | |
376 | /* Make sure we have somewhere to save */ |
377 | surface = NULL; |
378 | if ( dst ) { |
379 | if ( saveme->format->palette ) { |
380 | if ( saveme->format->BitsPerPixel == 8 ) { |
381 | surface = saveme; |
382 | } else { |
383 | SDL_SetError("%d bpp BMP files not supported", |
384 | saveme->format->BitsPerPixel); |
385 | } |
386 | } |
387 | else if ( (saveme->format->BitsPerPixel == 24) && |
388 | #if SDL_BYTEORDER == SDL_LIL_ENDIAN |
389 | (saveme->format->Rmask == 0x00FF0000) && |
390 | (saveme->format->Gmask == 0x0000FF00) && |
391 | (saveme->format->Bmask == 0x000000FF) |
392 | #else |
393 | (saveme->format->Rmask == 0x000000FF) && |
394 | (saveme->format->Gmask == 0x0000FF00) && |
395 | (saveme->format->Bmask == 0x00FF0000) |
396 | #endif |
397 | ) { |
398 | surface = saveme; |
399 | } else { |
400 | SDL_Rect bounds; |
401 | |
402 | /* Convert to 24 bits per pixel */ |
403 | surface = SDL_CreateRGBSurface(SDL_SWSURFACE, |
404 | saveme->w, saveme->h, 24, |
405 | #if SDL_BYTEORDER == SDL_LIL_ENDIAN |
406 | 0x00FF0000, 0x0000FF00, 0x000000FF, |
407 | #else |
408 | 0x000000FF, 0x0000FF00, 0x00FF0000, |
409 | #endif |
410 | 0); |
411 | if ( surface != NULL ) { |
412 | bounds.x = 0; |
413 | bounds.y = 0; |
414 | bounds.w = saveme->w; |
415 | bounds.h = saveme->h; |
416 | if ( SDL_LowerBlit(saveme, &bounds, surface, |
417 | &bounds) < 0 ) { |
418 | SDL_FreeSurface(surface); |
419 | SDL_SetError( |
420 | "Couldn't convert image to 24 bpp"); |
421 | surface = NULL; |
422 | } |
423 | } |
424 | } |
425 | } |
426 | |
427 | if ( surface && (SDL_LockSurface(surface) == 0) ) { |
428 | const int bw = surface->w*surface->format->BytesPerPixel; |
429 | |
430 | /* Set the BMP file header values */ |
431 | bfSize = 0; /* We'll write this when we're done */ |
432 | bfReserved1 = 0; |
433 | bfReserved2 = 0; |
434 | bfOffBits = 0; /* We'll write this when we're done */ |
435 | |
436 | /* Write the BMP file header values */ |
437 | fp_offset = SDL_RWtell(dst); |
438 | SDL_ClearError(); |
439 | SDL_RWwrite(dst, magic, 2, 1); |
440 | SDL_WriteLE32(dst, bfSize); |
441 | SDL_WriteLE16(dst, bfReserved1); |
442 | SDL_WriteLE16(dst, bfReserved2); |
443 | SDL_WriteLE32(dst, bfOffBits); |
444 | |
445 | /* Set the BMP info values */ |
446 | biSize = 40; |
447 | biWidth = surface->w; |
448 | biHeight = surface->h; |
449 | biPlanes = 1; |
450 | biBitCount = surface->format->BitsPerPixel; |
451 | biCompression = BI_RGB; |
452 | biSizeImage = surface->h*surface->pitch; |
453 | biXPelsPerMeter = 0; |
454 | biYPelsPerMeter = 0; |
455 | if ( surface->format->palette ) { |
456 | biClrUsed = surface->format->palette->ncolors; |
457 | } else { |
458 | biClrUsed = 0; |
459 | } |
460 | biClrImportant = 0; |
461 | |
462 | /* Write the BMP info values */ |
463 | SDL_WriteLE32(dst, biSize); |
464 | SDL_WriteLE32(dst, biWidth); |
465 | SDL_WriteLE32(dst, biHeight); |
466 | SDL_WriteLE16(dst, biPlanes); |
467 | SDL_WriteLE16(dst, biBitCount); |
468 | SDL_WriteLE32(dst, biCompression); |
469 | SDL_WriteLE32(dst, biSizeImage); |
470 | SDL_WriteLE32(dst, biXPelsPerMeter); |
471 | SDL_WriteLE32(dst, biYPelsPerMeter); |
472 | SDL_WriteLE32(dst, biClrUsed); |
473 | SDL_WriteLE32(dst, biClrImportant); |
474 | |
475 | /* Write the palette (in BGR color order) */ |
476 | if ( surface->format->palette ) { |
477 | SDL_Color *colors; |
478 | int ncolors; |
479 | |
480 | colors = surface->format->palette->colors; |
481 | ncolors = surface->format->palette->ncolors; |
482 | for ( i=0; i<ncolors; ++i ) { |
483 | SDL_RWwrite(dst, &colors[i].b, 1, 1); |
484 | SDL_RWwrite(dst, &colors[i].g, 1, 1); |
485 | SDL_RWwrite(dst, &colors[i].r, 1, 1); |
486 | SDL_RWwrite(dst, &colors[i].unused, 1, 1); |
487 | } |
488 | } |
489 | |
490 | /* Write the bitmap offset */ |
491 | bfOffBits = SDL_RWtell(dst)-fp_offset; |
492 | if ( SDL_RWseek(dst, fp_offset+10, RW_SEEK_SET) < 0 ) { |
493 | SDL_Error(SDL_EFSEEK); |
494 | } |
495 | SDL_WriteLE32(dst, bfOffBits); |
496 | if ( SDL_RWseek(dst, fp_offset+bfOffBits, RW_SEEK_SET) < 0 ) { |
497 | SDL_Error(SDL_EFSEEK); |
498 | } |
499 | |
500 | /* Write the bitmap image upside down */ |
501 | bits = (Uint8 *)surface->pixels+(surface->h*surface->pitch); |
502 | pad = ((bw%4) ? (4-(bw%4)) : 0); |
503 | while ( bits > (Uint8 *)surface->pixels ) { |
504 | bits -= surface->pitch; |
505 | if ( SDL_RWwrite(dst, bits, 1, bw) != bw) { |
506 | SDL_Error(SDL_EFWRITE); |
507 | break; |
508 | } |
509 | if ( pad ) { |
510 | const Uint8 padbyte = 0; |
511 | for ( i=0; i<pad; ++i ) { |
512 | SDL_RWwrite(dst, &padbyte, 1, 1); |
513 | } |
514 | } |
515 | } |
516 | |
517 | /* Write the BMP file size */ |
518 | bfSize = SDL_RWtell(dst)-fp_offset; |
519 | if ( SDL_RWseek(dst, fp_offset+2, RW_SEEK_SET) < 0 ) { |
520 | SDL_Error(SDL_EFSEEK); |
521 | } |
522 | SDL_WriteLE32(dst, bfSize); |
523 | if ( SDL_RWseek(dst, fp_offset+bfSize, RW_SEEK_SET) < 0 ) { |
524 | SDL_Error(SDL_EFSEEK); |
525 | } |
526 | |
527 | /* Close it up.. */ |
528 | SDL_UnlockSurface(surface); |
529 | if ( surface != saveme ) { |
530 | SDL_FreeSurface(surface); |
531 | } |
532 | } |
533 | |
534 | if ( freedst && dst ) { |
535 | SDL_RWclose(dst); |
536 | } |
537 | return((SDL_strcmp(SDL_GetError(), "") == 0) ? 0 : -1); |
538 | } |