freebsd man page for rgb_map

rgb_map(3alleg4)						  Allegro manual						  rgb_map(3alleg4)

NAME

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

SYNOPSIS

       #include <allegro.h>

       extern RGB_MAP *rgb_map;

DESCRIPTION

       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  cre-
       ate_*_table() functions. RGB tables can be precalculated with the rgbmap utility, or generated at runtime with create_rgb_table().

SEE ALSO

       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 4.4.2						  rgb_map(3alleg4)