src/video/SDL_bmp.c
author Sam Lantinga <slouken@libsdl.org>
Tue, 29 Nov 2011 02:11:39 -0500
changeset 6094 5dac1b1261c0
parent 6037 2feab4874268
child 6138 4c64952a58fb
permissions -rw-r--r--
Yes, let's save 32-bit BMP files, very useful for you know, making a game...
slouken@0
     1
/*
slouken@5535
     2
  Simple DirectMedia Layer
slouken@5535
     3
  Copyright (C) 1997-2011 Sam Lantinga <slouken@libsdl.org>
slouken@0
     4
slouken@5535
     5
  This software is provided 'as-is', without any express or implied
slouken@5535
     6
  warranty.  In no event will the authors be held liable for any damages
slouken@5535
     7
  arising from the use of this software.
slouken@0
     8
slouken@5535
     9
  Permission is granted to anyone to use this software for any purpose,
slouken@5535
    10
  including commercial applications, and to alter it and redistribute it
slouken@5535
    11
  freely, subject to the following restrictions:
slouken@0
    12
slouken@5535
    13
  1. The origin of this software must not be misrepresented; you must not
slouken@5535
    14
     claim that you wrote the original software. If you use this software
slouken@5535
    15
     in a product, an acknowledgment in the product documentation would be
slouken@5535
    16
     appreciated but is not required.
slouken@5535
    17
  2. Altered source versions must be plainly marked as such, and must not be
slouken@5535
    18
     misrepresented as being the original software.
slouken@5535
    19
  3. This notice may not be removed or altered from any source distribution.
slouken@0
    20
*/
slouken@1402
    21
#include "SDL_config.h"
slouken@0
    22
slouken@0
    23
/* 
slouken@0
    24
   Code to load and save surfaces in Windows BMP format.
slouken@0
    25
slouken@0
    26
   Why support BMP format?  Well, it's a native format for Windows, and
slouken@0
    27
   most image processing programs can read and write it.  It would be nice
slouken@0
    28
   to be able to have at least one image format that we can natively load
slouken@0
    29
   and save, and since PNG is so complex that it would bloat the library,
slouken@0
    30
   BMP is a good alternative. 
slouken@0
    31
slouken@0
    32
   This code currently supports Win32 DIBs in uncompressed 8 and 24 bpp.
slouken@0
    33
*/
slouken@0
    34
slouken@0
    35
#include "SDL_video.h"
slouken@0
    36
#include "SDL_endian.h"
slouken@2823
    37
#include "SDL_pixels_c.h"
slouken@0
    38
slouken@6094
    39
#define SAVE_32BIT_BMP
slouken@6094
    40
slouken@0
    41
/* Compression encodings for BMP files */
slouken@0
    42
#ifndef BI_RGB
slouken@0
    43
#define BI_RGB		0
slouken@0
    44
#define BI_RLE8		1
slouken@0
    45
#define BI_RLE4		2
slouken@0
    46
#define BI_BITFIELDS	3
slouken@0
    47
#endif
slouken@0
    48
slouken@0
    49
slouken@1895
    50
SDL_Surface *
slouken@1895
    51
SDL_LoadBMP_RW(SDL_RWops * src, int freesrc)
slouken@0
    52
{
slouken@3310
    53
    SDL_bool was_error;
aschiffler@6037
    54
    long fp_offset = 0;
slouken@1895
    55
    int bmpPitch;
slouken@1895
    56
    int i, pad;
slouken@1895
    57
    SDL_Surface *surface;
slouken@1895
    58
    Uint32 Rmask;
slouken@1895
    59
    Uint32 Gmask;
slouken@1895
    60
    Uint32 Bmask;
slouken@3497
    61
    Uint32 Amask;
slouken@1895
    62
    SDL_Palette *palette;
slouken@1895
    63
    Uint8 *bits;
slouken@3310
    64
    Uint8 *top, *end;
slouken@3310
    65
    SDL_bool topDown;
slouken@1895
    66
    int ExpandBMP;
slouken@0
    67
slouken@1895
    68
    /* The Win32 BMP file header (14 bytes) */
slouken@1895
    69
    char magic[2];
slouken@1895
    70
    Uint32 bfSize;
slouken@1895
    71
    Uint16 bfReserved1;
slouken@1895
    72
    Uint16 bfReserved2;
slouken@1895
    73
    Uint32 bfOffBits;
slouken@0
    74
slouken@1895
    75
    /* The Win32 BITMAPINFOHEADER struct (40 bytes) */
slouken@1895
    76
    Uint32 biSize;
slouken@1895
    77
    Sint32 biWidth;
slouken@1895
    78
    Sint32 biHeight;
slouken@1895
    79
    Uint16 biPlanes;
slouken@1895
    80
    Uint16 biBitCount;
slouken@1895
    81
    Uint32 biCompression;
slouken@1895
    82
    Uint32 biSizeImage;
slouken@1895
    83
    Sint32 biXPelsPerMeter;
slouken@1895
    84
    Sint32 biYPelsPerMeter;
slouken@1895
    85
    Uint32 biClrUsed;
slouken@1895
    86
    Uint32 biClrImportant;
slouken@0
    87
slouken@1895
    88
    /* Make sure we are passed a valid data source */
slouken@1895
    89
    surface = NULL;
slouken@3310
    90
    was_error = SDL_FALSE;
slouken@1895
    91
    if (src == NULL) {
slouken@3310
    92
        was_error = SDL_TRUE;
slouken@1895
    93
        goto done;
slouken@1895
    94
    }
slouken@0
    95
slouken@1895
    96
    /* Read in the BMP file header */
slouken@1895
    97
    fp_offset = SDL_RWtell(src);
slouken@1895
    98
    SDL_ClearError();
slouken@1895
    99
    if (SDL_RWread(src, magic, 1, 2) != 2) {
slouken@1895
   100
        SDL_Error(SDL_EFREAD);
slouken@3310
   101
        was_error = SDL_TRUE;
slouken@1895
   102
        goto done;
slouken@1895
   103
    }
slouken@1895
   104
    if (SDL_strncmp(magic, "BM", 2) != 0) {
slouken@1895
   105
        SDL_SetError("File is not a Windows BMP file");
slouken@3310
   106
        was_error = SDL_TRUE;
slouken@1895
   107
        goto done;
slouken@1895
   108
    }
slouken@1895
   109
    bfSize = SDL_ReadLE32(src);
slouken@1895
   110
    bfReserved1 = SDL_ReadLE16(src);
slouken@1895
   111
    bfReserved2 = SDL_ReadLE16(src);
slouken@1895
   112
    bfOffBits = SDL_ReadLE32(src);
slouken@0
   113
slouken@1895
   114
    /* Read the Win32 BITMAPINFOHEADER */
slouken@1895
   115
    biSize = SDL_ReadLE32(src);
slouken@1895
   116
    if (biSize == 12) {
slouken@1895
   117
        biWidth = (Uint32) SDL_ReadLE16(src);
slouken@1895
   118
        biHeight = (Uint32) SDL_ReadLE16(src);
slouken@1895
   119
        biPlanes = SDL_ReadLE16(src);
slouken@1895
   120
        biBitCount = SDL_ReadLE16(src);
slouken@1895
   121
        biCompression = BI_RGB;
slouken@1895
   122
        biSizeImage = 0;
slouken@1895
   123
        biXPelsPerMeter = 0;
slouken@1895
   124
        biYPelsPerMeter = 0;
slouken@1895
   125
        biClrUsed = 0;
slouken@1895
   126
        biClrImportant = 0;
slouken@1895
   127
    } else {
slouken@1895
   128
        biWidth = SDL_ReadLE32(src);
slouken@1895
   129
        biHeight = SDL_ReadLE32(src);
slouken@1895
   130
        biPlanes = SDL_ReadLE16(src);
slouken@1895
   131
        biBitCount = SDL_ReadLE16(src);
slouken@1895
   132
        biCompression = SDL_ReadLE32(src);
slouken@1895
   133
        biSizeImage = SDL_ReadLE32(src);
slouken@1895
   134
        biXPelsPerMeter = SDL_ReadLE32(src);
slouken@1895
   135
        biYPelsPerMeter = SDL_ReadLE32(src);
slouken@1895
   136
        biClrUsed = SDL_ReadLE32(src);
slouken@1895
   137
        biClrImportant = SDL_ReadLE32(src);
slouken@1895
   138
    }
slouken@3310
   139
    if (biHeight < 0) {
slouken@3310
   140
        topDown = SDL_TRUE;
slouken@3310
   141
        biHeight = -biHeight;
slouken@3310
   142
    } else {
slouken@3310
   143
        topDown = SDL_FALSE;
slouken@3310
   144
    }
slouken@0
   145
slouken@1895
   146
    /* Check for read error */
slouken@1895
   147
    if (SDL_strcmp(SDL_GetError(), "") != 0) {
slouken@3310
   148
        was_error = SDL_TRUE;
slouken@1895
   149
        goto done;
slouken@1895
   150
    }
slouken@0
   151
slouken@1895
   152
    /* Expand 1 and 4 bit bitmaps to 8 bits per pixel */
slouken@1895
   153
    switch (biBitCount) {
slouken@1895
   154
    case 1:
slouken@1895
   155
    case 4:
slouken@1895
   156
        ExpandBMP = biBitCount;
slouken@1895
   157
        biBitCount = 8;
slouken@1895
   158
        break;
slouken@1895
   159
    default:
slouken@1895
   160
        ExpandBMP = 0;
slouken@1895
   161
        break;
slouken@1895
   162
    }
slouken@0
   163
slouken@1895
   164
    /* We don't support any BMP compression right now */
slouken@3497
   165
    Rmask = Gmask = Bmask = Amask = 0;
slouken@1895
   166
    switch (biCompression) {
slouken@1895
   167
    case BI_RGB:
slouken@1895
   168
        /* If there are no masks, use the defaults */
slouken@1895
   169
        if (bfOffBits == (14 + biSize)) {
slouken@1895
   170
            /* Default values for the BMP format */
slouken@1895
   171
            switch (biBitCount) {
slouken@1895
   172
            case 15:
slouken@1895
   173
            case 16:
slouken@1895
   174
                Rmask = 0x7C00;
slouken@1895
   175
                Gmask = 0x03E0;
slouken@1895
   176
                Bmask = 0x001F;
slouken@1895
   177
                break;
slouken@1895
   178
            case 24:
slouken@0
   179
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
slouken@1895
   180
                Rmask = 0x000000FF;
slouken@1895
   181
                Gmask = 0x0000FF00;
slouken@1895
   182
                Bmask = 0x00FF0000;
slouken@3497
   183
#else
slouken@3497
   184
                Rmask = 0x00FF0000;
slouken@3497
   185
                Gmask = 0x0000FF00;
slouken@3497
   186
                Bmask = 0x000000FF;
slouken@3497
   187
#endif
slouken@1895
   188
                break;
slouken@1895
   189
            case 32:
slouken@3497
   190
                Amask = 0xFF000000;
slouken@1895
   191
                Rmask = 0x00FF0000;
slouken@1895
   192
                Gmask = 0x0000FF00;
slouken@1895
   193
                Bmask = 0x000000FF;
slouken@1895
   194
                break;
slouken@1895
   195
            default:
slouken@1895
   196
                break;
slouken@1895
   197
            }
slouken@1895
   198
            break;
slouken@1895
   199
        }
slouken@1895
   200
        /* Fall through -- read the RGB masks */
slouken@0
   201
slouken@1895
   202
    case BI_BITFIELDS:
slouken@1895
   203
        switch (biBitCount) {
slouken@1895
   204
        case 15:
slouken@1895
   205
        case 16:
slouken@3497
   206
            Rmask = SDL_ReadLE32(src);
slouken@3497
   207
            Gmask = SDL_ReadLE32(src);
slouken@3497
   208
            Bmask = SDL_ReadLE32(src);
slouken@3497
   209
            break;
slouken@1895
   210
        case 32:
slouken@1895
   211
            Rmask = SDL_ReadLE32(src);
slouken@1895
   212
            Gmask = SDL_ReadLE32(src);
slouken@1895
   213
            Bmask = SDL_ReadLE32(src);
slouken@3497
   214
            Amask = SDL_ReadLE32(src);
slouken@1895
   215
            break;
slouken@1895
   216
        default:
slouken@1895
   217
            break;
slouken@1895
   218
        }
slouken@1895
   219
        break;
slouken@1895
   220
    default:
slouken@1895
   221
        SDL_SetError("Compressed BMP files not supported");
slouken@3310
   222
        was_error = SDL_TRUE;
slouken@1895
   223
        goto done;
slouken@1895
   224
    }
slouken@0
   225
slouken@1895
   226
    /* Create a compatible surface, note that the colors are RGB ordered */
slouken@1895
   227
    surface =
slouken@1895
   228
        SDL_CreateRGBSurface(0, biWidth, biHeight, biBitCount, Rmask, Gmask,
slouken@3497
   229
                             Bmask, Amask);
slouken@1895
   230
    if (surface == NULL) {
slouken@3310
   231
        was_error = SDL_TRUE;
slouken@1895
   232
        goto done;
slouken@1895
   233
    }
slouken@0
   234
slouken@1895
   235
    /* Load the palette, if any */
slouken@1895
   236
    palette = (surface->format)->palette;
slouken@1895
   237
    if (palette) {
slouken@1895
   238
        if (biClrUsed == 0) {
slouken@1895
   239
            biClrUsed = 1 << biBitCount;
slouken@1895
   240
        }
slouken@2920
   241
        if ((int) biClrUsed > palette->ncolors) {
slouken@2851
   242
            palette->ncolors = biClrUsed;
slouken@2851
   243
            palette->colors =
slouken@2851
   244
                (SDL_Color *) SDL_realloc(palette->colors,
slouken@2851
   245
                                          palette->ncolors *
slouken@2851
   246
                                          sizeof(*palette->colors));
slouken@2851
   247
            if (!palette->colors) {
slouken@2851
   248
                SDL_OutOfMemory();
slouken@3310
   249
                was_error = SDL_TRUE;
slouken@2851
   250
                goto done;
slouken@2851
   251
            }
slouken@2920
   252
        } else if ((int) biClrUsed < palette->ncolors) {
slouken@2851
   253
            palette->ncolors = biClrUsed;
slouken@2851
   254
        }
slouken@1895
   255
        if (biSize == 12) {
slouken@1895
   256
            for (i = 0; i < (int) biClrUsed; ++i) {
slouken@1895
   257
                SDL_RWread(src, &palette->colors[i].b, 1, 1);
slouken@1895
   258
                SDL_RWread(src, &palette->colors[i].g, 1, 1);
slouken@1895
   259
                SDL_RWread(src, &palette->colors[i].r, 1, 1);
slouken@1895
   260
                palette->colors[i].unused = SDL_ALPHA_OPAQUE;
slouken@1895
   261
            }
slouken@1895
   262
        } else {
slouken@1895
   263
            for (i = 0; i < (int) biClrUsed; ++i) {
slouken@1895
   264
                SDL_RWread(src, &palette->colors[i].b, 1, 1);
slouken@1895
   265
                SDL_RWread(src, &palette->colors[i].g, 1, 1);
slouken@1895
   266
                SDL_RWread(src, &palette->colors[i].r, 1, 1);
slouken@1895
   267
                SDL_RWread(src, &palette->colors[i].unused, 1, 1);
slouken@1895
   268
            }
slouken@1895
   269
        }
slouken@1895
   270
    }
slouken@0
   271
slouken@1895
   272
    /* Read the surface pixels.  Note that the bmp image is upside down */
slouken@1895
   273
    if (SDL_RWseek(src, fp_offset + bfOffBits, RW_SEEK_SET) < 0) {
slouken@1895
   274
        SDL_Error(SDL_EFSEEK);
slouken@3310
   275
        was_error = SDL_TRUE;
slouken@1895
   276
        goto done;
slouken@1895
   277
    }
slouken@3310
   278
    top = (Uint8 *)surface->pixels;
slouken@3310
   279
    end = (Uint8 *)surface->pixels+(surface->h*surface->pitch);
slouken@1895
   280
    switch (ExpandBMP) {
slouken@1895
   281
    case 1:
slouken@1895
   282
        bmpPitch = (biWidth + 7) >> 3;
slouken@1895
   283
        pad = (((bmpPitch) % 4) ? (4 - ((bmpPitch) % 4)) : 0);
slouken@1895
   284
        break;
slouken@1895
   285
    case 4:
slouken@1895
   286
        bmpPitch = (biWidth + 1) >> 1;
slouken@1895
   287
        pad = (((bmpPitch) % 4) ? (4 - ((bmpPitch) % 4)) : 0);
slouken@1895
   288
        break;
slouken@1895
   289
    default:
slouken@1895
   290
        pad = ((surface->pitch % 4) ? (4 - (surface->pitch % 4)) : 0);
slouken@1895
   291
        break;
slouken@1895
   292
    }
slouken@3310
   293
    if (topDown) {
slouken@3310
   294
        bits = top;
slouken@3310
   295
    } else {
slouken@3310
   296
        bits = end - surface->pitch;
slouken@3310
   297
    }
slouken@3310
   298
    while (bits >= top && bits < end) {
slouken@1895
   299
        switch (ExpandBMP) {
slouken@1895
   300
        case 1:
slouken@3310
   301
        case 4:{
slouken@1895
   302
                Uint8 pixel = 0;
slouken@1895
   303
                int shift = (8 - ExpandBMP);
slouken@1895
   304
                for (i = 0; i < surface->w; ++i) {
slouken@1895
   305
                    if (i % (8 / ExpandBMP) == 0) {
slouken@1895
   306
                        if (!SDL_RWread(src, &pixel, 1, 1)) {
slouken@1895
   307
                            SDL_SetError("Error reading from BMP");
slouken@3310
   308
                            was_error = SDL_TRUE;
slouken@1895
   309
                            goto done;
slouken@1895
   310
                        }
slouken@1895
   311
                    }
slouken@1895
   312
                    *(bits + i) = (pixel >> shift);
slouken@1895
   313
                    pixel <<= ExpandBMP;
slouken@1895
   314
                }
slouken@1895
   315
            }
slouken@1895
   316
            break;
slouken@0
   317
slouken@1895
   318
        default:
slouken@1895
   319
            if (SDL_RWread(src, bits, 1, surface->pitch)
slouken@1895
   320
                != surface->pitch) {
slouken@1895
   321
                SDL_Error(SDL_EFREAD);
slouken@3310
   322
                was_error = SDL_TRUE;
slouken@1895
   323
                goto done;
slouken@1895
   324
            }
slouken@0
   325
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
slouken@1895
   326
            /* Byte-swap the pixels if needed. Note that the 24bpp
slouken@1895
   327
               case has already been taken care of above. */
slouken@1895
   328
            switch (biBitCount) {
slouken@1895
   329
            case 15:
slouken@3310
   330
            case 16:{
slouken@1895
   331
                    Uint16 *pix = (Uint16 *) bits;
slouken@1895
   332
                    for (i = 0; i < surface->w; i++)
slouken@1895
   333
                        pix[i] = SDL_Swap16(pix[i]);
slouken@1895
   334
                    break;
slouken@1895
   335
                }
slouken@0
   336
slouken@3310
   337
            case 32:{
slouken@1895
   338
                    Uint32 *pix = (Uint32 *) bits;
slouken@1895
   339
                    for (i = 0; i < surface->w; i++)
slouken@1895
   340
                        pix[i] = SDL_Swap32(pix[i]);
slouken@1895
   341
                    break;
slouken@1895
   342
                }
slouken@1895
   343
            }
slouken@0
   344
#endif
slouken@1895
   345
            break;
slouken@1895
   346
        }
slouken@1895
   347
        /* Skip padding bytes, ugh */
slouken@1895
   348
        if (pad) {
slouken@1895
   349
            Uint8 padbyte;
slouken@1895
   350
            for (i = 0; i < pad; ++i) {
slouken@1895
   351
                SDL_RWread(src, &padbyte, 1, 1);
slouken@1895
   352
            }
slouken@1895
   353
        }
slouken@3310
   354
        if (topDown) {
slouken@3310
   355
            bits += surface->pitch;
slouken@3310
   356
        } else {
slouken@3310
   357
            bits -= surface->pitch;
slouken@3310
   358
        }
slouken@1895
   359
    }
slouken@1895
   360
  done:
slouken@1895
   361
    if (was_error) {
slouken@1895
   362
        if (src) {
slouken@1895
   363
            SDL_RWseek(src, fp_offset, RW_SEEK_SET);
slouken@1895
   364
        }
slouken@1895
   365
        if (surface) {
slouken@1895
   366
            SDL_FreeSurface(surface);
slouken@1895
   367
        }
slouken@1895
   368
        surface = NULL;
slouken@1895
   369
    }
slouken@1895
   370
    if (freesrc && src) {
slouken@1895
   371
        SDL_RWclose(src);
slouken@1895
   372
    }
slouken@1895
   373
    return (surface);
slouken@0
   374
}
slouken@0
   375
slouken@1895
   376
int
slouken@1895
   377
SDL_SaveBMP_RW(SDL_Surface * saveme, SDL_RWops * dst, int freedst)
slouken@0
   378
{
slouken@1895
   379
    long fp_offset;
slouken@1895
   380
    int i, pad;
slouken@1895
   381
    SDL_Surface *surface;
slouken@1895
   382
    Uint8 *bits;
slouken@0
   383
slouken@1895
   384
    /* The Win32 BMP file header (14 bytes) */
slouken@1895
   385
    char magic[2] = { 'B', 'M' };
slouken@1895
   386
    Uint32 bfSize;
slouken@1895
   387
    Uint16 bfReserved1;
slouken@1895
   388
    Uint16 bfReserved2;
slouken@1895
   389
    Uint32 bfOffBits;
slouken@0
   390
slouken@1895
   391
    /* The Win32 BITMAPINFOHEADER struct (40 bytes) */
slouken@1895
   392
    Uint32 biSize;
slouken@1895
   393
    Sint32 biWidth;
slouken@1895
   394
    Sint32 biHeight;
slouken@1895
   395
    Uint16 biPlanes;
slouken@1895
   396
    Uint16 biBitCount;
slouken@1895
   397
    Uint32 biCompression;
slouken@1895
   398
    Uint32 biSizeImage;
slouken@1895
   399
    Sint32 biXPelsPerMeter;
slouken@1895
   400
    Sint32 biYPelsPerMeter;
slouken@1895
   401
    Uint32 biClrUsed;
slouken@1895
   402
    Uint32 biClrImportant;
slouken@0
   403
slouken@1895
   404
    /* Make sure we have somewhere to save */
slouken@1895
   405
    surface = NULL;
slouken@1895
   406
    if (dst) {
slouken@2969
   407
        SDL_bool save32bit = SDL_FALSE;
slouken@2969
   408
#ifdef SAVE_32BIT_BMP
slouken@2969
   409
        /* We can save alpha information in a 32-bit BMP */
slouken@2969
   410
        if (saveme->map->info.flags & SDL_COPY_COLORKEY ||
slouken@2969
   411
            saveme->format->Amask) {
slouken@2969
   412
            save32bit = SDL_TRUE;
slouken@2969
   413
        }
slouken@2969
   414
#endif /* SAVE_32BIT_BMP */
slouken@2969
   415
slouken@2969
   416
        if (saveme->format->palette && !save32bit) {
slouken@1895
   417
            if (saveme->format->BitsPerPixel == 8) {
slouken@1895
   418
                surface = saveme;
slouken@1895
   419
            } else {
slouken@1895
   420
                SDL_SetError("%d bpp BMP files not supported",
slouken@1895
   421
                             saveme->format->BitsPerPixel);
slouken@1895
   422
            }
slouken@1895
   423
        } else if ((saveme->format->BitsPerPixel == 24) &&
slouken@0
   424
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
slouken@1895
   425
                   (saveme->format->Rmask == 0x00FF0000) &&
slouken@1895
   426
                   (saveme->format->Gmask == 0x0000FF00) &&
slouken@1895
   427
                   (saveme->format->Bmask == 0x000000FF)
slouken@0
   428
#else
slouken@1895
   429
                   (saveme->format->Rmask == 0x000000FF) &&
slouken@1895
   430
                   (saveme->format->Gmask == 0x0000FF00) &&
slouken@1895
   431
                   (saveme->format->Bmask == 0x00FF0000)
slouken@0
   432
#endif
slouken@1895
   433
            ) {
slouken@1895
   434
            surface = saveme;
slouken@1895
   435
        } else {
slouken@2967
   436
            SDL_PixelFormat format;
slouken@0
   437
slouken@2969
   438
            /* If the surface has a colorkey or alpha channel we'll save a
slouken@2969
   439
               32-bit BMP with alpha channel, otherwise save a 24-bit BMP. */
slouken@2969
   440
            if (save32bit) {
slouken@5288
   441
                SDL_InitFormat(&format, 
slouken@5288
   442
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
slouken@5288
   443
                               SDL_PIXELFORMAT_ARGB8888
slouken@5288
   444
#else
slouken@5288
   445
                               SDL_PIXELFORMAT_BGRA8888
slouken@5288
   446
#endif
slouken@5288
   447
                               );
slouken@2969
   448
            } else {
slouken@5288
   449
                SDL_InitFormat(&format, SDL_PIXELFORMAT_BGR24);
slouken@2969
   450
            }
slouken@2967
   451
            surface = SDL_ConvertSurface(saveme, &format, 0);
slouken@2967
   452
            if (!surface) {
slouken@2990
   453
                SDL_SetError("Couldn't convert image to %d bpp",
slouken@2990
   454
                             format.BitsPerPixel);
slouken@1895
   455
            }
slouken@1895
   456
        }
slouken@1895
   457
    }
slouken@0
   458
slouken@1895
   459
    if (surface && (SDL_LockSurface(surface) == 0)) {
slouken@1895
   460
        const int bw = surface->w * surface->format->BytesPerPixel;
slouken@1012
   461
slouken@1895
   462
        /* Set the BMP file header values */
slouken@1895
   463
        bfSize = 0;             /* We'll write this when we're done */
slouken@1895
   464
        bfReserved1 = 0;
slouken@1895
   465
        bfReserved2 = 0;
slouken@1895
   466
        bfOffBits = 0;          /* We'll write this when we're done */
slouken@0
   467
slouken@1895
   468
        /* Write the BMP file header values */
slouken@1895
   469
        fp_offset = SDL_RWtell(dst);
slouken@1895
   470
        SDL_ClearError();
slouken@1895
   471
        SDL_RWwrite(dst, magic, 2, 1);
slouken@1895
   472
        SDL_WriteLE32(dst, bfSize);
slouken@1895
   473
        SDL_WriteLE16(dst, bfReserved1);
slouken@1895
   474
        SDL_WriteLE16(dst, bfReserved2);
slouken@1895
   475
        SDL_WriteLE32(dst, bfOffBits);
slouken@0
   476
slouken@1895
   477
        /* Set the BMP info values */
slouken@1895
   478
        biSize = 40;
slouken@1895
   479
        biWidth = surface->w;
slouken@1895
   480
        biHeight = surface->h;
slouken@1895
   481
        biPlanes = 1;
slouken@1895
   482
        biBitCount = surface->format->BitsPerPixel;
slouken@1895
   483
        biCompression = BI_RGB;
slouken@1895
   484
        biSizeImage = surface->h * surface->pitch;
slouken@1895
   485
        biXPelsPerMeter = 0;
slouken@1895
   486
        biYPelsPerMeter = 0;
slouken@1895
   487
        if (surface->format->palette) {
slouken@1895
   488
            biClrUsed = surface->format->palette->ncolors;
slouken@1895
   489
        } else {
slouken@1895
   490
            biClrUsed = 0;
slouken@1895
   491
        }
slouken@1895
   492
        biClrImportant = 0;
slouken@0
   493
slouken@1895
   494
        /* Write the BMP info values */
slouken@1895
   495
        SDL_WriteLE32(dst, biSize);
slouken@1895
   496
        SDL_WriteLE32(dst, biWidth);
slouken@1895
   497
        SDL_WriteLE32(dst, biHeight);
slouken@1895
   498
        SDL_WriteLE16(dst, biPlanes);
slouken@1895
   499
        SDL_WriteLE16(dst, biBitCount);
slouken@1895
   500
        SDL_WriteLE32(dst, biCompression);
slouken@1895
   501
        SDL_WriteLE32(dst, biSizeImage);
slouken@1895
   502
        SDL_WriteLE32(dst, biXPelsPerMeter);
slouken@1895
   503
        SDL_WriteLE32(dst, biYPelsPerMeter);
slouken@1895
   504
        SDL_WriteLE32(dst, biClrUsed);
slouken@1895
   505
        SDL_WriteLE32(dst, biClrImportant);
slouken@0
   506
slouken@1895
   507
        /* Write the palette (in BGR color order) */
slouken@1895
   508
        if (surface->format->palette) {
slouken@1895
   509
            SDL_Color *colors;
slouken@1895
   510
            int ncolors;
slouken@0
   511
slouken@1895
   512
            colors = surface->format->palette->colors;
slouken@1895
   513
            ncolors = surface->format->palette->ncolors;
slouken@1895
   514
            for (i = 0; i < ncolors; ++i) {
slouken@1895
   515
                SDL_RWwrite(dst, &colors[i].b, 1, 1);
slouken@1895
   516
                SDL_RWwrite(dst, &colors[i].g, 1, 1);
slouken@1895
   517
                SDL_RWwrite(dst, &colors[i].r, 1, 1);
slouken@1895
   518
                SDL_RWwrite(dst, &colors[i].unused, 1, 1);
slouken@1895
   519
            }
slouken@1895
   520
        }
slouken@0
   521
slouken@1895
   522
        /* Write the bitmap offset */
slouken@1895
   523
        bfOffBits = SDL_RWtell(dst) - fp_offset;
slouken@1895
   524
        if (SDL_RWseek(dst, fp_offset + 10, RW_SEEK_SET) < 0) {
slouken@1895
   525
            SDL_Error(SDL_EFSEEK);
slouken@1895
   526
        }
slouken@1895
   527
        SDL_WriteLE32(dst, bfOffBits);
slouken@1895
   528
        if (SDL_RWseek(dst, fp_offset + bfOffBits, RW_SEEK_SET) < 0) {
slouken@1895
   529
            SDL_Error(SDL_EFSEEK);
slouken@1895
   530
        }
slouken@0
   531
slouken@1895
   532
        /* Write the bitmap image upside down */
slouken@1895
   533
        bits = (Uint8 *) surface->pixels + (surface->h * surface->pitch);
slouken@1895
   534
        pad = ((bw % 4) ? (4 - (bw % 4)) : 0);
slouken@1895
   535
        while (bits > (Uint8 *) surface->pixels) {
slouken@1895
   536
            bits -= surface->pitch;
slouken@1895
   537
            if (SDL_RWwrite(dst, bits, 1, bw) != bw) {
slouken@1895
   538
                SDL_Error(SDL_EFWRITE);
slouken@1895
   539
                break;
slouken@1895
   540
            }
slouken@1895
   541
            if (pad) {
slouken@1895
   542
                const Uint8 padbyte = 0;
slouken@1895
   543
                for (i = 0; i < pad; ++i) {
slouken@1895
   544
                    SDL_RWwrite(dst, &padbyte, 1, 1);
slouken@1895
   545
                }
slouken@1895
   546
            }
slouken@1895
   547
        }
slouken@0
   548
slouken@1895
   549
        /* Write the BMP file size */
slouken@1895
   550
        bfSize = SDL_RWtell(dst) - fp_offset;
slouken@1895
   551
        if (SDL_RWseek(dst, fp_offset + 2, RW_SEEK_SET) < 0) {
slouken@1895
   552
            SDL_Error(SDL_EFSEEK);
slouken@1895
   553
        }
slouken@1895
   554
        SDL_WriteLE32(dst, bfSize);
slouken@1895
   555
        if (SDL_RWseek(dst, fp_offset + bfSize, RW_SEEK_SET) < 0) {
slouken@1895
   556
            SDL_Error(SDL_EFSEEK);
slouken@1895
   557
        }
slouken@0
   558
slouken@1895
   559
        /* Close it up.. */
slouken@1895
   560
        SDL_UnlockSurface(surface);
slouken@1895
   561
        if (surface != saveme) {
slouken@1895
   562
            SDL_FreeSurface(surface);
slouken@1895
   563
        }
slouken@1895
   564
    }
slouken@0
   565
slouken@1895
   566
    if (freedst && dst) {
slouken@1895
   567
        SDL_RWclose(dst);
slouken@1895
   568
    }
slouken@1895
   569
    return ((SDL_strcmp(SDL_GetError(), "") == 0) ? 0 : -1);
slouken@0
   570
}
slouken@1895
   571
slouken@1895
   572
/* vi: set ts=4 sw=4 expandtab: */