NAME

       set_color_conversion - Tells Allegro how to convert images during loading time.

SYNOPSIS

       #include <allegro.h>

       void set_color_conversion(int mode);

DESCRIPTION

       Specifies  how  to  convert  images between the various color depths when reading graphics
       from external bitmap files or datafiles. The mode is a bitmask specifying which  types  of
       conversion  are  allowed.  If  the appropriate bit is set, data will be converted into the
       current pixel format (selected by calling the set_color_depth()  function),  otherwise  it
       will  be  left  in  the  same  format as the disk file, leaving you to convert it manually
       before the graphic can be displayed. The default mode is total  conversion,  so  that  all
       images  will  be  loaded  in  the appropriate format for the current video mode. Valid bit
       flags are:

          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

       For convenience, the following macros can be used to select common combinations  of  these
       flags:

          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  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.

       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(3alleg4),          load_bitmap(3alleg4),           load_datafile(3alleg4),
       fixup_datafile(3alleg4),     makecol15_dither(3alleg4),     get_color_conversion(3alleg4),
       exalpha(3alleg4), exblend(3alleg4), exdata(3alleg4), exexedat(3alleg4), exlights(3alleg4),
       exrotscl(3alleg4), exxfade(3alleg4)