freebsd man page for getb_depth

getr_depth(3alleg4)						  Allegro manual					       getr_depth(3alleg4)

NAME

       getr_depth,  getg_depth, getb_depth, geta_depth - Extract a color component from a color in a specified pixel format. Allegro game program-
       ming 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  compo-
       nents (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);

SEE ALSO

       getr(3alleg4), getr8(3alleg4), geta32(3alleg4), makecol(3alleg4), set_color_depth(3alleg4), exlights(3alleg4)

Allegro 							   version 4.4.2					       getr_depth(3alleg4)