//screen_set_brightness(arg) -1 darker 0 normal 1 brighter
depth=-1000000000000
if argument0<0 {
draw_set_alpha(-argument0);
draw_set_color(c_black)
draw_rectangle(0,0,room_width,room_height,0);
draw_set_color(c_black)
draw_set_alpha(1);}
if argument0==0 {}
if argument0>0
{draw_set_alpha(argument0);
draw_set_blend_mode(bm_add);
draw_set_color(c_white)
draw_rectangle(0,0,room_width,room_height,0);
draw_set_color(c_black)
draw_set_blend_mode(bm_normal);
draw_set_alpha(1);}