Banners: Respawn entity if it got lost

Entity is respawned on load (in an LBM) or when the banner node is punched.
Also, the banner drop is now handled in the node instead of the entity.

mods/ITEMS/mcl_banners/init.lua

@@ -32,6 +32,11 @@ mcl_banners.colors = {
 	["unicolor_light_blue"] = {"light_blue", "Light Blue Banner", "mcl_wool:light_blue", "#4040CF", "mcl_dye:lightblue", "Light Blue" },
 }
 
+local colors_reverse = {}
+for k,v in pairs(mcl_banners.colors) do
+	colors_reverse["mcl_banners:banner_item_"..v[1]] = k
+end
+
 -- Add pattern/emblazoning crafting recipes
 dofile(minetest.get_modpath("mcl_banners").."/patterncraft.lua")
 
@@ -42,28 +47,40 @@ local layer_ratio = 255
 local standing_banner_entity_offset = { x=0, y=-0.499, z=0 }
 local hanging_banner_entity_offset = { x=0, y=-1.7, z=0 }
 
-local on_destruct_standing_banner = function(pos)
+local on_destruct_banner = function(pos, hanging)
+	local offset, nodename
+	if hanging then
+		offset = hanging_banner_entity_offset
+		nodename = "mcl_banners:hanging_banner"
+	else
+		offset = standing_banner_entity_offset
+		nodename = "mcl_banners:standing_banner"
+	end
 	-- Find this node's banner entity and make it drop as an item
-	local checkpos = vector.add(pos, standing_banner_entity_offset)
+	local checkpos = vector.add(pos, offset)
 	local objects = minetest.get_objects_inside_radius(checkpos, 0.5)
 	for _, v in ipairs(objects) do
 		local ent = v:get_luaentity()
-		if ent and ent.name == "mcl_banners:standing_banner" then
-			v:get_luaentity():_drop()
+		if ent and ent.name == nodename then
+			v:remove()
 		end
 	end
+	-- Drop item
+	local meta = minetest.get_meta(pos)
+	local item = meta:get_inventory():get_stack("banner", 1)
+	if not item:is_empty() then
+		minetest.add_item(pos, item)
+	else
+		minetest.add_item(pos, "mcl_banners:banner_item_white")
+	end
+end
+
+local on_destruct_standing_banner = function(pos)
+	return on_destruct_banner(pos, false)
 end
 
 local on_destruct_hanging_banner = function(pos)
-	-- Find this node's banner entity and make it drop as an item
-	local checkpos = vector.add(pos, hanging_banner_entity_offset)
-	local objects = minetest.get_objects_inside_radius(checkpos, 0.5)
-	for _, v in ipairs(objects) do
-		local ent = v:get_luaentity()
-		if ent and ent.name == "mcl_banners:hanging_banner" then
-			v:get_luaentity():_drop()
-		end
-	end
+	return on_destruct_banner(pos, true)
 end
 
 local make_banner_texture = function(base_color, layers)
@@ -96,6 +113,59 @@ local make_banner_texture = function(base_color, layers)
 	end
 end
 
+local spawn_banner_entity = function(pos, hanging, itemstack)
+	local banner
+	if hanging then
+		banner = minetest.add_entity(pos, "mcl_banners:hanging_banner")
+	else
+		banner = minetest.add_entity(pos, "mcl_banners:standing_banner")
+	end
+	if banner == nil then
+		return banner
+	end
+	local imeta = itemstack:get_meta()
+	local layers_raw = imeta:get_string("layers")
+	local layers = minetest.deserialize(layers_raw)
+	local colorid = colors_reverse[itemstack:get_name()]
+	banner:get_luaentity():_set_textures(colorid, layers)
+	local mname = imeta:get_string("name")
+	if mname ~= nil and mname ~= "" then
+		banner:get_luaentity()._item_name = mname
+		banner:get_luaentity()._item_description = imeta:get_string("description")
+	end
+
+	return banner
+end
+
+local respawn_banner_entity = function(pos, node)
+	local hanging = node.name == "mcl_banners:hanging_banner"
+	local offset
+	if hanging then
+		offset = hanging_banner_entity_offset
+	else
+		offset = standing_banner_entity_offset
+	end
+	-- Check if a banner entity already exists
+	local bpos = vector.add(pos, offset)
+	local objects = minetest.get_objects_inside_radius(bpos, 0.5)
+	for _, v in ipairs(objects) do
+		local ent = v:get_luaentity()
+		if ent and (ent.name == "mcl_banners:standing_banner" or ent.name == "mcl_banners:hanging_banner") then
+			return
+		end
+	end
+	-- Spawn new entity
+	local meta = minetest.get_meta(pos)
+	local banner_item = meta:get_inventory():get_stack("banner", 1)
+	local banner_entity = spawn_banner_entity(bpos, hanging, banner_item)
+
+	-- Set rotation
+	local final_yaw
+	local rotation_level = meta:get_int("rotation_level")
+	final_yaw = (rotation_level * (math.pi/8)) + math.pi
+	banner_entity:set_yaw(final_yaw)
+end
+
 local on_rotate
 if minetest.get_modpath("screwdriver") then
 	on_rotate = screwdriver.disallow
@@ -138,6 +208,9 @@ minetest.register_node("mcl_banners:standing_banner", {
 	drop = "", -- Item drops are handled in entity code
 
 	on_destruct = on_destruct_standing_banner,
+	on_punch = function(pos, node)
+		respawn_banner_entity(pos, node)
+	end,
 	_mcl_hardness = 1,
 	_mcl_blast_resistance = 5,
 })
@@ -166,6 +239,9 @@ minetest.register_node("mcl_banners:hanging_banner", {
 	drop = "", -- Item drops are handled in entity code
 
 	on_destruct = on_destruct_hanging_banner,
+	on_punch = function(pos, node)
+		respawn_banner_entity(pos, node)
+	end,
 	_mcl_hardness = 1,
 	_mcl_blast_resistance = 5,
 	on_rotate = on_rotate,
@@ -269,48 +345,61 @@ for colorid, colortab in pairs(mcl_banners.colors) do
 				end
 				hanging = true
 			end
-
 			local place_pos
 			if minetest.registered_nodes[node_under.name].buildable_to then
 				place_pos = under
 			else
 				place_pos = above
 			end
-			if hanging then
-				place_pos = vector.add(place_pos, hanging_banner_entity_offset)
-			else
-				place_pos = vector.add(place_pos, standing_banner_entity_offset)
+			local bnode = minetest.get_node(place_pos)
+			if bnode.name ~= "mcl_banners:standing_banner" and bnode.name ~= "mcl_banners:hanging_banner" then
+				minetest.log("error", "[mcl_banners] The placed banner node is not what the mod expected!")
+				return itemstack
 			end
+			local meta = minetest.get_meta(place_pos)
+			local inv = meta:get_inventory()
+			inv:set_size("banner", 1)
+			local store_stack = ItemStack(itemstack)
+			store_stack:set_count(1)
+			inv:set_stack("banner", 1, store_stack)
 
-			local banner 
+			-- Spawn entity
+			local entity_place_pos
 			if hanging then
-				banner = minetest.add_entity(place_pos, "mcl_banners:hanging_banner")
+				entity_place_pos = vector.add(place_pos, hanging_banner_entity_offset)
 			else
-				banner = minetest.add_entity(place_pos, "mcl_banners:standing_banner")
+				entity_place_pos = vector.add(place_pos, standing_banner_entity_offset)
 			end
-			local imeta = itemstack:get_meta()
-			local layers_raw = imeta:get_string("layers")
-			local layers = minetest.deserialize(layers_raw)
-			banner:get_luaentity():_set_textures(colorid, layers)
-			local mname = imeta:get_string("name")
-			if mname ~= nil and mname ~= "" then
-				banner:get_luaentity()._item_name = mname
-				banner:get_luaentity()._item_description = imeta:get_string("description")
-			end
-
+			local banner_entity = spawn_banner_entity(entity_place_pos, hanging, itemstack)
 			-- Set rotation
-			local final_yaw
+			local final_yaw, rotation_level
 			if hanging then
 				local pdir = vector.direction(pointed_thing.under, pointed_thing.above)
 				final_yaw = minetest.dir_to_yaw(pdir)
+				if pdir.x > 0 then
+					rotation_level = 4
+				elseif pdir.z > 0 then
+					rotation_level = 8
+				elseif pdir.x < 0 then
+					rotation_level = 12
+				else
+					rotation_level = 0
+				end
 			else
 				-- Determine the rotation based on player's yaw
 				local yaw = placer:get_look_horizontal()
 				-- Select one of 16 possible rotations (0-15)
-				local rotation_level = round((yaw / (math.pi*2)) * 16)
+				rotation_level = round((yaw / (math.pi*2)) * 16)
+				if rotation_level >= 16 then
+					rotation_level = 0
+				end
 				final_yaw = (rotation_level * (math.pi/8)) + math.pi
 			end
-			banner:set_yaw(final_yaw)
+			meta:set_int("rotation_level", rotation_level)
+
+			if banner_entity ~= nil then
+				banner_entity:set_yaw(final_yaw)
+			end
 
 			if not minetest.settings:get_bool("creative_mode") then
 				itemstack:take_item()
@@ -392,30 +481,6 @@ local entity_standing = {
 		self.object:set_armor_groups({immortal=1})
 	end,
 
-	-- This is a custom function which causes the banner to be dropped as item and destroys the entity.
-	_drop = function(self)
-		local pos = self.object:get_pos()
-		pos.y = pos.y + 1
-
-		if not minetest.settings:get_bool("creative_mode") and self._base_color then
-			-- Spawn item
-			local banner = ItemStack("mcl_banners:banner_item_"..mcl_banners.colors[self._base_color][1])
-			local meta = banner:get_meta()
-			meta:set_string("layers", minetest.serialize(self._layers))
-			if self._item_name ~= nil and self._item_name ~= "" then
-				meta:set_string("description", self._item_description)
-				meta:set_string("name", self._item_name)
-			else
-				meta:set_string("description", mcl_banners.make_advanced_banner_description(banner:get_definition().description, self._layers))
-			end
-
-			minetest.add_item(pos, banner)
-		end
-
-		-- Destroy entity
-		self.object:remove()
-	end,
-
 	-- Set the banner textures. This function can be used by external mods.
 	-- Meaning of parameters:
 	-- * self: Lua entity reference to entity.
@@ -436,6 +501,17 @@ local entity_hanging = table.copy(entity_standing)
 entity_hanging.mesh = "amc_banner_hanging.b3d"
 minetest.register_entity("mcl_banners:hanging_banner", entity_hanging)
 
+-- FIXME: Prevent entity destruction by /clearobjects
+minetest.register_lbm({
+	label = "Respawn banner entities",
+	name = "mcl_banners:respawn_entities",
+	run_at_every_load = true,
+	nodenames = {"mcl_banners:standing_banner", "mcl_banners:hanging_banner"},
+	action = function(pos, node)
+		respawn_banner_entity(pos, node)
+	end,
+})
+
 minetest.register_craft({
 	type = "fuel",
 	recipe = "group:banner",