bg_gr            4139 ext/gd/gd.c    	int rd, gr, bl, fg_rd, fg_gr, fg_bl, bg_rd, bg_gr, bg_bl;
bg_gr            4181 ext/gd/gd.c    	bg_gr = gdImageGreen(bg_img, _bg);
bg_gr            4187 ext/gd/gd.c    		gr = bg_gr + (double) (fg_gr - bg_gr) / aa_steps * (i + 1);