Warning: when using truecolor images, you should always set the graphics mode before loading any bitmap data! Otherwise the pixel format (RGB or BGR) will not be known, so the file may be converted wrongly.
If the file contains a truecolor image, you must set the video mode or call set_color_conversion() before loading it. In this case, if the destination color depth is 8-bit, the palette will be generated by calling generate_optimized_palette() on the bitmap; otherwise, the returned palette will be generated by calling generate_332_palette().
The pal argument may be NULL. In this case, the palette data are simply not returned. Additionally, if the file is a truecolor image and the destination color depth is 8-bit, the color conversion process will use the current palette instead of generating an optimized one.
Example:
BITMAP *bmp; PALETTE palette; ... bmp = load_bitmap("image.pcx", palette); if (!bmp) abort_on_error("Couldn't load image.pcx!"); ... destroy_bitmap(bmp);
Return value: Returns a pointer to the bitmap or NULL on error. Remember that you are responsible for destroying the bitmap when you are finished with it to avoid memory leaks.
See also: load_bmp, load_lbm, load_pcx, load_tga, destroy_bitmap, save_bitmap, register_bitmap_file_type, set_color_depth, set_color_conversion, generate_optimized_palette, generate_332_palette.
Examples using this: Available Allegro examples.
Return value: Returns a pointer to the bitmap or NULL on error. Remember that you are responsible for destroying the bitmap when you are finished with it to avoid memory leaks.
See also: load_bitmap, load_bmp_pf.
PACKFILE *packfile; BITMAP *bmp; packfile = pack_fopen("mybitmap.bmp", F_READ); if (!packfile) abort_on_error("Couldn't open mybitmap.bmp"); bmp = load_bmp_pf(packfile, pal); if (!bmp) abort_on_error("Error loading mybitmap.bmp");
Return value: Returns a pointer to the bitmap or NULL on error. Remember that you are responsible for destroying the bitmap when you are finished with it to avoid memory leaks.
See also: load_bmp.
Examples using this: expackf.
Return value: Returns a pointer to the bitmap or NULL on error. Remember that you are responsible for destroying the bitmap when you are finished with it to avoid memory leaks.
See also: load_bitmap.
Return value: Returns a pointer to the bitmap or NULL on error. Remember that you are responsible for destroying the bitmap when you are finished with it to avoid memory leaks.
See also: load_bitmap.
Examples using this: expackf, exscale.
PACKFILE *packfile; BITMAP *bmp; packfile = pack_fopen("mybitmap.pcx", F_READ); if (!packfile) abort_on_error("Couldn't open mybitmap.pcx"); bmp = load_bmp_pf(packfile, pal); if (!bmp) abort_on_error("Error loading mybitmap.pcx");
Return value: Returns a pointer to the bitmap or NULL on error. Remember that you are responsible for destroying the bitmap when you are finished with it to avoid memory leaks.
See also: load_pcx.
Examples using this: expackf.
Return value: Returns a pointer to the bitmap or NULL on error. Remember that you are responsible for destroying the bitmap when you are finished with it to avoid memory leaks.
See also: load_bitmap.
PACKFILE *packfile; BITMAP *bmp; packfile = pack_fopen("mybitmap.tga", F_READ); if (!packfile) abort_on_error("Couldn't open mybitmap.tga"); bmp = load_bmp_pf(packfile, pal); if (!bmp) abort_on_error("Error loading mybitmap.tga");
Return value: Returns a pointer to the bitmap or NULL on error. Remember that you are responsible for destroying the bitmap when you are finished with it to avoid memory leaks.
See also: load_tga.
Examples using this: expackf.
Two things to watch out for: on some video cards it may be faster to copy the screen to a memory bitmap and save the latter, and if you use this to dump the screen into a file you may end up with an image much larger than you were expecting, because Allegro often creates virtual screens larger than the visible screen. You can get around this by using a sub-bitmap to specify which part of the screen to save, eg:
BITMAP *bmp; PALETTE pal; ... get_palette(pal); bmp = create_sub_bitmap(screen, 0, 0, SCREEN_W, SCREEN_H); save_bitmap("dump.pcx", bmp, pal); destroy_bitmap(bmp);
Return value: Returns non-zero on error.
See also: save_bmp, save_pcx, save_tga, load_bitmap, register_bitmap_file_type.
Return value: Returns non-zero on error.
See also: save_bitmap.
See also: save_bmp.
Examples using this: expackf.
Return value: Returns non-zero on error.
See also: save_bitmap.
See also: save_pcx.
Return value: Returns non-zero on error.
See also: save_bitmap.
See also: save_tga.
Examples using this: expackf.
BITMAP *load_dump(const char *filename, RGB *pal) { ... } int save_dump(const char *filename, BITMAP *bmp, const RGB *pal) { ... } register_bitmap_file_type("dump", load_dump, save_dump);
See also: load_bitmap, save_bitmap.
For convenience, the following macros can be used to select common combinations of these flags:COLORCONV_NONE // disable all format // conversions COLORCONV_8_TO_15 // expand 8-bit to 15-bit COLORCONV_8_TO_16 // expand 8-bit to 16-bit COLORCONV_8_TO_24 // expand 8-bit to 24-bit COLORCONV_8_TO_32 // expand 8-bit to 32-bit COLORCONV_15_TO_8 // reduce 15-bit to 8-bit COLORCONV_15_TO_16 // expand 15-bit to 16-bit COLORCONV_15_TO_24 // expand 15-bit to 24-bit COLORCONV_15_TO_32 // expand 15-bit to 32-bit COLORCONV_16_TO_8 // reduce 16-bit to 8-bit COLORCONV_16_TO_15 // reduce 16-bit to 15-bit COLORCONV_16_TO_24 // expand 16-bit to 24-bit COLORCONV_16_TO_32 // expand 16-bit to 32-bit COLORCONV_24_TO_8 // reduce 24-bit to 8-bit COLORCONV_24_TO_15 // reduce 24-bit to 15-bit COLORCONV_24_TO_16 // reduce 24-bit to 16-bit COLORCONV_24_TO_32 // expand 24-bit to 32-bit COLORCONV_32_TO_8 // reduce 32-bit RGB to 8-bit COLORCONV_32_TO_15 // reduce 32-bit RGB to 15-bit COLORCONV_32_TO_16 // reduce 32-bit RGB to 16-bit COLORCONV_32_TO_24 // reduce 32-bit RGB to 24-bit COLORCONV_32A_TO_8 // reduce 32-bit RGBA to 8-bit COLORCONV_32A_TO_15 // reduce 32-bit RGBA to 15-bit COLORCONV_32A_TO_16 // reduce 32-bit RGBA to 16-bit COLORCONV_32A_TO_24 // reduce 32-bit RGBA to 24-bit COLORCONV_DITHER_PAL // dither when reducing to 8-bit COLORCONV_DITHER_HI // dither when reducing to // hicolor COLORCONV_KEEP_TRANS // keep original transparency
If you enable the COLORCONV_DITHER flag, dithering will be performed whenever truecolor graphics are converted into a hicolor or paletted format, including by the blit() function, and any automatic conversions that take place while reading graphics from disk. This can produce much better looking results, but is obviously slower than a direct conversion.COLORCONV_EXPAND_256 // expand 256-color to hi/truecolor COLORCONV_REDUCE_TO_256 // reduce hi/truecolor to 256-color COLORCONV_EXPAND_15_TO_16 // expand 15-bit hicolor to 16-bit COLORCONV_REDUCE_16_TO_15 // reduce 16-bit hicolor to 15-bit COLORCONV_EXPAND_HI_TO_TRUE // expand 15/16-bit to 24/32-bit COLORCONV_REDUCE_TRUE_TO_HI // reduce 24/32-bit to 15/16-bit COLORCONV_24_EQUALS_32 // convert between 24- and 32-bit COLORCONV_TOTAL // everything to current format COLORCONV_PARTIAL // convert 15 <-> 16-bit and // 24 <-> 32-bit COLORCONV_MOST // all but hi/truecolor <-> 256 COLORCONV_DITHER // dither during all color reductions COLORCONV_KEEP_ALPHA // convert everything to current format // unless it would lose alpha information
If you intend using converted bitmaps with functions like masked_blit() or draw_sprite(), you should specify the COLORCONV_KEEP_TRANS flag. It will ensure that the masked areas in the bitmap before and after the conversion stay exactly the same, by mapping transparent colors to each other and adjusting colors which would be converted to the transparent color otherwise. It affects every blit() operation between distinct pixel formats and every automatic conversion.
See also: set_color_depth, load_bitmap, load_datafile, fixup_datafile, makecol15_dither, get_color_conversion.
Examples using this: exalpha, exblend, exdata, exexedat, exlights, exrotscl, exxfade.
See also: set_color_conversion.