create_color_table(3alleg4)      Allegro manual      create_color_table(3alleg4)

       create_color_table - Fills a color mapping table for customised effects.
       Allegro game programming library.

       #include <allegro.h>

       void create_color_table(COLOR_MAP *table, const PALETTE pal, void
       (*blend)(PALETTE pal, int x, int y, RGB *rgb), void (*callback)(int

       Fills the specified color mapping table with lookup data for doing
       customised effects with the specified palette, calling the blend function
       to determine the results of each color combination.

       Your blend routine will be passed a pointer to the palette and the two
       indices of the colors which are to be combined, and should fill in the
       RGB structure with the desired result in 0-63 format. Allegro will then
       search the palette for the closest match to the RGB color that you
       requested, so it doesn't matter if the palette has no exact match for
       this color.

       If the callback function is not NULL, it will be called 256 times during
       the calculation, allowing you to display a progress indicator. Example:

          COLOR_MAP greyscale_table;
          void return_grey_color(const PALETTE pal,
                                 int x, int y, RGB *rgb)
             /* Build a color lookup table for greyscale effect. */
             create_color_table(&greyscale_table, pal,
                                return_grey_color, NULL);

       color_map(3alleg4), create_light_table(3alleg4),
       create_trans_table(3alleg4), create_blender_table(3alleg4),
       draw_trans_sprite(3alleg4), draw_lit_sprite(3alleg4),
       draw_gouraud_sprite(3alleg4), rgb_map(3alleg4), excolmap(3alleg4)

Allegro                           version 4.4.3      create_color_table(3alleg4)