[mesecons_doors] Improve code quality and fix Voxelgarden support (#671)

now trapdoors are also overridden using their own function, and both
`meseconify_door` and `meseconify_trapdoor` are now ran inside loops
In the future, this could help refactor this mod entirely to not list doors
manually but parse through the `doors.registered_*` variables,
ensuring that every door works.

As a nice bonus, Voxelgarden support is fixed, and potentially so is
support for other games with exotic implementations of the doors mod. No
longer are we assuming that the existence of doors.get means that all
the trapdoors exist too; now, if the meseconify function doesn't find
their definition, it just returns without crashing.

mesecons_doors/init.lua

@@ -73,68 +73,67 @@ local function meseconify_door(name)
 	end
 end
 
-meseconify_door("doors:door_wood")
-meseconify_door("doors:door_steel")
-meseconify_door("doors:door_glass")
-meseconify_door("doors:door_obsidian_glass")
-meseconify_door("xpanes:door_steel_bar")
+local doors_list = {
+	"doors:door_wood",
+	"doors:door_steel",
+	"doors:door_glass",
+	"doors:door_obsidian_glass",
+	"xpanes:door_steel_bar",
+}
+for i=1,#doors_list do meseconify_door(doors_list[i]) end
 
 -- Trapdoor
-local function trapdoor_switch(pos, node)
-	local state = minetest.get_meta(pos):get_int("state")
-
-	if state == 1 then
-		minetest.sound_play("doors_door_close", { pos = pos, gain = 0.3, max_hear_distance = 10 }, true)
-		minetest.set_node(pos, {name="doors:trapdoor", param2 = node.param2})
-	else
-		minetest.sound_play("doors_door_open", { pos = pos, gain = 0.3, max_hear_distance = 10 }, true)
-		minetest.set_node(pos, {name="doors:trapdoor_open", param2 = node.param2})
+local function trapdoor_switch(name)
+	return function(pos, node)
+		local state = minetest.get_meta(pos):get_int("state")
+		if state == 1 then
+			minetest.sound_play("doors_door_close", { pos = pos, gain = 0.3, max_hear_distance = 10 }, true)
+			minetest.set_node(pos, {name=name, param2 = node.param2})
+		else
+			minetest.sound_play("doors_door_open", { pos = pos, gain = 0.3, max_hear_distance = 10 }, true)
+			minetest.set_node(pos, {name=name.."_open", param2 = node.param2})
+		end
+		minetest.get_meta(pos):set_int("state", state == 1 and 0 or 1)
 	end
-
-	minetest.get_meta(pos):set_int("state", state == 1 and 0 or 1)
 end
 
-if doors and doors.get then
-	local override = {
-		mesecons = {effector = {
-			action_on = function(pos)
-				local door = doors.get(pos)
-				if door then
-					door:open()
-				end
-			end,
-			action_off = function(pos)
-				local door = doors.get(pos)
-				if door then
-					door:close()
-				end
-			end,
-		}},
-	}
-	minetest.override_item("doors:trapdoor", override)
-	minetest.override_item("doors:trapdoor_open", override)
-	minetest.override_item("doors:trapdoor_steel", override)
-	minetest.override_item("doors:trapdoor_steel_open", override)
-
-	if minetest.registered_items["xpanes:trapdoor_steel_bar"] then
-		minetest.override_item("xpanes:trapdoor_steel_bar", override)
-		minetest.override_item("xpanes:trapdoor_steel_bar_open", override)
-	end
-
-else
-	if minetest.registered_nodes["doors:trapdoor"] then
-		minetest.override_item("doors:trapdoor", {
+local function meseconify_trapdoor(name)
+	local override
+	if doors and doors.get then
+		override = {
 			mesecons = {effector = {
-				action_on = trapdoor_switch,
-				action_off = trapdoor_switch
+				action_on = function(pos)
+					local door = doors.get(pos)
+					if door then
+						door:open()
+					end
+				end,
+				action_off = function(pos)
+					local door = doors.get(pos)
+					if door then
+						door:close()
+					end
+				end,
 			}},
-		})
-
-		minetest.override_item("doors:trapdoor_open", {
+		}
+	else
+		override = {
 			mesecons = {effector = {
-				action_on = trapdoor_switch,
-				action_off = trapdoor_switch
+				action_on = trapdoor_switch(name),
+				action_off = trapdoor_switch(name)
 			}},
-		})
+		}
+	end
+
+	if minetest.registered_items[name] then
+		minetest.override_item(name, override)
+		minetest.override_item(name.."_open", override)
 	end
 end
+
+local trapdoors_list = {
+	"doors:trapdoor",
+	"doors:trapdoor_steel",
+	"xpanes:trapdoor_steel_bar"
+}
+for i=1,#trapdoors_list do meseconify_trapdoor(trapdoors_list[i]) end