rgb_map - Look up table to speed up reducing RGB values to palette colors. Allegro game programming

       To speed up reducing RGB values to 8-bit paletted colors, Allegro uses a 32k lookup  table  (5  bits  for
       each  color  component).  You  must  set  up this table before using the gouraud shading routines, and if
       present the table will also vastly accelerate the makecol8() and  some  create_*_table()  functions.  RGB
       tables can be precalculated with the rgbmap utility, or generated at runtime with create_rgb_table().

       rgb_map  -  Look  up  table  to  speed up reducing RGB values to palette colors. Allegro game programming
       library.

create_rgb_table(3alleg4),  makecol8(3alleg4),  create_trans_table(3alleg4), create_light_table(3alleg4),
       create_color_table(3alleg4),  ex3d(3alleg4),  excolmap(3alleg4),   exrgbhsv(3alleg4),   exshade(3alleg4),
       extrans(3alleg4)

Allegro                                           version 4.4.3                                 rgb_map(3alleg4)

#include<allegro.h>externRGB_MAP*rgb_map;