geta_depth (3) - Linux Manuals

geta_depth: Extract a color component from a color in a specified pixel format. Allegro game programming library.

NAME

getr_depth, getg_depth, getb_depth, geta_depth - Extract a color component from a color in a specified pixel format. Allegro game programming library.

SYNOPSIS

#include <allegro.h>

int getr_depth(int color_depth, int c);

int getg_depth(int color_depth, int c);

int getb_depth(int color_depth, int c);

int geta_depth(int color_depth, int c);

DESCRIPTION

Given a color in the format being used by the specified color depth, these functions extract one of the red, green, blue, or alpha components (ranging 0-255). The alpha part is only meaningful for 32-bit pixels. Example:

   int r, g, b, color_value, bpp;
   
   bpp = bitmap_color_depth(bitmap);
   color_value = getpixel(bitmap, 100, 100);
   r = getr_depth(bpp, color_value);
   g = getg_depth(bpp, color_value);
   b = getb_depth(bpp, color_value);