geta (3) - Linux Manuals

geta: Extract a color component from the current pixel format. Allegro game programming library.

NAME

getr, getg, getb, geta - Extract a color component from the current pixel format. Allegro game programming library.

SYNOPSIS

#include <allegro.h>

int getr(int c);

int getg(int c);

int getb(int c);

int geta(int c);

DESCRIPTION

Given a color in the format being used by the current video mode, these functions extract one of the red, green, blue, or alpha components (ranging 0-255), calling the preceding 8, 15, 16, 24, or 32-bit get functions as appropriate. The alpha part is only meaningful for 32-bit pixels. Example:

   int r, g, b, color_value;
   
   color_value = getpixel(screen, 100, 100);
   r = getr(color_value);
   g = getg(color_value);
   b = getb(color_value);

SEE ALSO

getr8(3), getr_depth(3), makecol(3), set_color_depth(3), exalpha(3)