static int gate_intersect( ent_gate *gate, v3f pos, v3f last );
static u32 world_intersect_gates( world_instance *world, v3f pos, v3f last );
static int gate_intersect( ent_gate *gate, v3f pos, v3f last );
static u32 world_intersect_gates( world_instance *world, v3f pos, v3f last );