man COLOR_MAP (3): Stores a color map to accelerate drawing. Allegro game programming library.

COLOR_MAP(3) Stores a color map to accelerate drawing. Allegro game programming library.

SYNOPSIS

#include <allegro.h>

typedef struct COLOR_MAP

   unsigned char data[PAL_SIZE][PAL_SIZE];

Read chapter "Transparency and patterned drawing", section "256-color transparency" for a description on how to obtain/use this structure.