I would need explanation on why the following code doesn't do anything at all:

EXPORT init()
BEGIN
DIMGROB_P(G8,16,16);
LINE_P(G8,0,0,15,15,#FF0000);
INVERT_P(G8,3,3,8,8);
BLIT_P(G0,0,0,32,32,G8,0,0,16,16);
END;
I can't seem to figure out what I am doing wrong, considering I used line with the same syntax before and in this scenario, even INVERT_P does nothing. I am trying to draw something inside a 16x16 GROB placed in G8, then paste it over the screen.


EDIT: Nevermind, it works in this example. It's because I was using the code inside a sub-routine in my program, except that I had called the sub-routine from the wrong location >.<. My bad. I also had two LINE_P coordinates inverted it seems.