diff --git a/entity.lua b/entity.lua
new file mode 100644
index 0000000..486e825
--- /dev/null
+++ b/entity.lua
@@ -0,0 +1,32 @@
+
+-- id -> true
+local active_entities = {}
+
+minetest.register_entity("building_lib:display", {
+	initial_properties = {
+		physical = false,
+        static_save = false,
+		collisionbox = {0, 0, 0, 0, 0, 0},
+		visual = "upright_sprite",
+		visual_size = {x=10, y=10},
+		glow = 10
+	},
+	on_step = function(self)
+		if not active_entities[self.id] then
+			-- not valid anymore
+			self.object:remove()
+		end
+	end
+})
+
+function building_lib.add_entity(pos, id)
+	active_entities[id] = true
+	local ent = minetest.add_entity(pos, "building_lib:display")
+	local luaent = ent:get_luaentity()
+	luaent.id = id
+	return ent
+end
+
+function building_lib.remove_entities(id)
+	active_entities[id] = nil
+end
diff --git a/init.lua b/init.lua
index 9e4af27..bc2c67c 100644
--- a/init.lua
+++ b/init.lua
@@ -5,7 +5,8 @@ building_lib = {
 }
 
 local MP = minetest.get_modpath("building_lib")
-dofile(MP .. "/display.lua")
+dofile(MP .. "/entity.lua")
+dofile(MP .. "/preview.lua")
 dofile(MP .. "/api.lua")
 dofile(MP .. "/wield_events.lua")
 dofile(MP .. "/common.lua")
diff --git a/display.lua b/preview.lua
similarity index 50%
rename from display.lua
rename to preview.lua
index 5e7c0f2..815bcf7 100644
--- a/display.lua
+++ b/preview.lua
@@ -1,39 +1,10 @@
 
--- playername => minetest.pos_to_string(pos1) .. "/" .. minetest.pos_to_string(pos2)
-local active_entities = {}
+-- playername => key
+local active_preview = {}
 
-minetest.register_entity("building_lib:display", {
-	initial_properties = {
-		physical = false,
-        static_save = false,
-		collisionbox = {0, 0, 0, 0, 0, 0},
-		visual = "upright_sprite",
-		visual_size = {x=10, y=10},
-		glow = 10
-	},
-	on_step = function(self)
-		local entry = active_entities[self.playername]
-		if not entry or entry ~= self.key then
-			-- not valid anymore
-			self.object:remove()
-		end
-	end
-})
 
-minetest.register_chatcommand("test", {
-	func = function(name)
-		local player = minetest.get_player_by_name(name)
-		local pos = player:get_pos()
-		local mapblock_pos = mapblock_lib.get_mapblock(pos)
-		building_lib.show_preview(name, mapblock_pos, vector.add(mapblock_pos, {x=1, y=1, z=0}))
-	end
-})
-
-local function add_preview_entity(texture, playername, key, visual_size, pos, rotation)
-	local ent = minetest.add_entity(pos, "building_lib:display")
-	local luaent = ent:get_luaentity()
-	luaent.playername = playername
-	luaent.key = key
+local function add_preview_entity(texture, key, visual_size, pos, rotation)
+	local ent = building_lib.add_entity(pos, key)
 	ent:set_properties({
 		visual_size = visual_size,
 		textures = {texture}
@@ -41,19 +12,17 @@ local function add_preview_entity(texture, playername, key, visual_size, pos, ro
 	ent:set_rotation(rotation)
 end
 
-function building_lib.has_preview(playername)
-	return active_entities[playername]
-end
-
 function building_lib.show_preview(texture, playername, mapblock_pos1, mapblock_pos2)
 	mapblock_pos2 = mapblock_pos2 or mapblock_pos1
 	local key = minetest.pos_to_string(mapblock_pos1) .. "/" .. minetest.pos_to_string(mapblock_pos2) .. "/" .. texture
 
-	if active_entities[playername] == key then
+	if active_preview[playername] == key then
 		-- already active on the same region
 		return
 	end
-	active_entities[playername] = key
+	-- clear previous entities
+	building_lib.clear_preview(playername)
+	active_preview[playername] = key
 
 	local min, _ = mapblock_lib.get_mapblock_bounds_from_mapblock(mapblock_pos1)
 
@@ -62,42 +31,42 @@ function building_lib.show_preview(texture, playername, mapblock_pos1, mapblock_
 	local half_size = vector.divide(size, 2) -- 8 .. n
 
 	-- z-
-	add_preview_entity(texture, playername, key,
+	add_preview_entity(texture, key,
 		{x=size.x, y=size.y},
 		vector.add(min, {x=half_size.x-0.5, y=half_size.y-0.5, z=-0.5}),
 		{x=0, y=0, z=0}
 	)
 
 	-- z+
-	add_preview_entity(texture, playername, key,
+	add_preview_entity(texture, key,
 		{x=size.x, y=size.y},
 		vector.add(min, {x=half_size.x-0.5, y=half_size.y-0.5, z=size.z-0.5}),
 		{x=0, y=0, z=0}
 	)
 
 	-- x-
-	add_preview_entity(texture, playername, key,
+	add_preview_entity(texture, key,
 		{x=size.z, y=size.y},
 		vector.add(min, {x=-0.5, y=half_size.y-0.5, z=half_size.z-0.5}),
 		{x=0, y=math.pi/2, z=0}
 	)
 
 	-- x+
-	add_preview_entity(texture, playername, key,
+	add_preview_entity(texture, key,
 		{x=size.z, y=size.y},
 		vector.add(min, {x=size.x-0.5, y=half_size.y-0.5, z=half_size.z-0.5}),
 		{x=0, y=math.pi/2, z=0}
 	)
 
 	-- y-
-	add_preview_entity(texture, playername, key,
+	add_preview_entity(texture, key,
 		{x=size.x, y=size.z},
 		vector.add(min, {x=half_size.x-0.5, y=-0.5, z=half_size.z-0.5}),
 		{x=math.pi/2, y=0, z=0}
 	)
 
 	-- y+
-	add_preview_entity(texture, playername, key,
+	add_preview_entity(texture, key,
 		{x=size.x, y=size.z},
 		vector.add(min, {x=half_size.x-0.5, y=size.y-0.5, z=half_size.z-0.5}),
 		{x=math.pi/2, y=0, z=0}
@@ -105,5 +74,12 @@ function building_lib.show_preview(texture, playername, mapblock_pos1, mapblock_
 end
 
 function building_lib.clear_preview(playername)
-	active_entities[playername] = nil
-end
\ No newline at end of file
+	if active_preview[playername] then
+		building_lib.remove_entities(active_preview[playername])
+		active_preview[playername] = nil
+	end
+end
+
+minetest.register_on_leaveplayer(function(player)
+	building_lib.clear_preview(player:get_player_name())
+end)
\ No newline at end of file
diff --git a/textures/building_lib_arrow.png b/textures/building_lib_arrow.png
new file mode 100644
index 0000000..3d42a7d
Binary files /dev/null and b/textures/building_lib_arrow.png differ