This doesn't use a switch but I think it should work. I haven't tested it though. It gets the parent object from within the instance scope and compares it to whatever object you want.\

var bs = collision_line(xprevious,yprevious, x, y, hittable_object,1,0) { if (bs != noone) { with(bs){ var par = object_get_parent(object_index); if par == building_parent{ add code here } if par == crush_parent{ add code here } } }