makecol_depth (3) Linux Manual Page
makecol_depth – Converts an RGB value into the specified pixel format. Allegro game programming library.
Synopsis
#include <allegro.h> int makecol_depth(int color_depth, int r, int g, int b);
Description
Converts colors from a hardware independent format (red, green, and blue values ranging 0-255) to the pixel format required by the specified color depth. Example:
/* Compose the green color for 15 bit color depth. */
int green_15bit = makecol_depth(15, 0, 255, 0);