| 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 | } |