Just a quick question, does this interfere with any other drawing commands? I'm trying to get a fog of war functioning in the game and it simply won't draw it. In the create event of my fog of war object I've got:
res = 10;
sFog = surface_create(room_width/res,room_height/res);
And then in the draw event:
This should make the entire screen black, but it literally doesn't do anything? Just trying to figure out if it's a problem with my code somewhere or if the extension itself is interfering with it (maybe the gms_draw() function?)
I don't see why that would interfere, but you could try setting the depth of the GMS object to something lower than the depth of the fog-object, so the fog-object is drawn before gms_draw is called. That way gms_draw can't interfere with the drawing.
Not sure about this - but does draw_clear set the alpha as well? It might be worthwhile to try using draw_rectangle / draw_clear_ext.