improving copilot and instruction mode

lib_planes/entities.lua

@@ -784,10 +784,14 @@ function airutils.on_rightclick(self, clicker)
                 if clicker:get_player_control().sneak == true then
                     -- flight instructor mode
                     self._instruction_mode = true
-                    airutils.attach(self, clicker, true)
+                    self.co_pilot_seat_base = self._passengers_base[1]
+                    self.pilot_seat_base = self._passengers_base[2]
+                    airutils.attach(self, clicker)
                 else
                     -- no driver => clicker is new driver
                     self._instruction_mode = false
+                    self.co_pilot_seat_base = self._passengers_base[2]
+                    self.pilot_seat_base = self._passengers_base[1]
                     airutils.attach(self, clicker)
                 end
                 self._command_is_given = false

lib_planes/forms.lua

@@ -126,7 +126,12 @@ function airutils.manage_copilot_formspec(name)
 	}, "")
 
     basic_form = basic_form.."label[1,1.0;Bring a copilot:]"
-    basic_form = basic_form.."dropdown[1,1.5;4,0.6;copilot;"..pass_list..";0;false]"
+
+    local max_seats = table.getn(ent._seats)
+    if ent._have_copilot and max_seats > 2 then --no need to select if there are only 2 occupants
+        basic_form = basic_form.."dropdown[1,1.5;4,0.6;copilot;"..pass_list..";0;false]"
+    end
+
     basic_form = basic_form.."button[1,2.5;4,1;pass_control;Pass the Control]"
 
     minetest.show_formspec(name, "lib_planes:manage_copilot", basic_form)

lib_planes/utilities.lua

@@ -140,7 +140,26 @@ function airutils.attach_pax(self, player, is_copilot)
         --randomize the seat
         local max_seats = table.getn(self._seats)
         local crew = 1
-        if self._have_copilot and max_seats > 2 then crew = crew + 1 end
+        if self._have_copilot and max_seats > 2 then
+            crew = crew + 1
+        else
+            self.co_pilot = name
+            player:set_attach(self.co_pilot_seat_base, "", {x = 0, y = 0, z = 0}, {x = 0, y = 0, z = 0})
+            player:set_eye_offset({x = 0, y = eye_y, z = 0}, {x = 0, y = 3, z = -30})
+            player_api.player_attached[name] = true
+            player_api.set_animation(player, "sit")
+            -- make the driver sit
+            minetest.after(1, function()
+                player = minetest.get_player_by_name(name)
+                if player then
+                    airutils.sit(player)
+                    --apply_physics_override(player, {speed=0,gravity=0,jump=0})
+                end
+            end)
+
+            return
+        end
+
         t = {}    -- new array
         for i=1, max_seats - crew do --(the first are for the crew
             t[i] = i