Add crates for packing up, transporting, and unpacking digtron arrays

class_layout.lua

@@ -25,7 +25,7 @@ end
 
 function DigtronLayout.create(pos, player)
 	local self = {}
-	setmetatable(self,DigtronLayout)
+	setmetatable(self, DigtronLayout)
 
 	--initialize. We're assuming that the start position is a controller digtron, should be a safe assumption since only the controller node should call this
 	self.traction = 0
@@ -314,7 +314,7 @@ function DigtronLayout.write_layout_image(self, player)
 
 	-- create the new one
 	for k, node_image in pairs(self.all) do
-		minetest.add_node(node_image.pos, node_image.node)
+		minetest.set_node(node_image.pos, node_image.node)
 		minetest.get_meta(node_image.pos):from_table(node_image.meta)
 		minetest.log("action", string.format("%s adds Digtron component %s at (%d, %d, %d)", player:get_player_name(), node_image.node.name, node_image.pos.x, node_image.pos.y, node_image.pos.z))
 
@@ -324,3 +324,36 @@ function DigtronLayout.write_layout_image(self, player)
 		end
 	end
 end
+
+
+---------------------------------------------------------------------------------------------
+-- Serialization. Currently only serializes the data that is needed by the crate, upgrade this function if more is needed
+
+function DigtronLayout.serialize(self)
+	-- serialize can't handle ItemStack objects, convert them to strings.
+	for _, node_image in pairs(self.all) do
+		for k, inv in pairs(node_image.meta.inventory) do
+			for index, item in pairs(inv) do
+				inv[index] = item:to_string()
+			end
+		end
+	end
+
+	return minetest.serialize({controller=self.controller, all=self.all})
+end
+
+function DigtronLayout.deserialize(layout_string)
+	local self = {}
+	setmetatable(self, DigtronLayout)
+	
+	if not layout_string or layout_string == "" then
+		return nil
+	end
+	deserialized_layout = minetest.deserialize(layout_string)
+
+	self.all = deserialized_layout.all
+	self.controller = deserialized_layout.controller
+	self.old_pos_pointset = Pointset.create() -- needed by the write_layout method, leave empty
+
+	return self
+end

crate.lua

@@ -0,0 +1,149 @@
+minetest.register_craft({
+	output = "digtron:empty_crate",
+	recipe = {
+			{"","default:chest",""},
+			{"","digtron:digtron_core",""},
+			{"","default:mese",""}
+			}
+})
+
+minetest.register_node("digtron:empty_crate", {
+	description = "Empty Digtron Crate",
+	groups = {cracky = 3, oddly_breakable_by_hand=3},
+	drop = "digtron:empty_crate",
+	sounds = default.node_sound_wood_defaults(),
+	tiles = {"digtron_crate.png"},
+	is_ground_content = false,
+	drawtype = "nodebox",
+	paramtype = "light",
+	
+	on_rightclick = function(pos, node, clicker, itemstack, pointed_thing)
+		local layout = DigtronLayout.create(pos, clicker)
+		if layout.contains_protected_node then
+			local meta = minetest.get_meta(pos)
+			minetest.sound_play("buzzer", {gain=0.5, pos=pos})
+			meta:set_string("infotext", "Digtron can't be packaged, it contains protected nodes")
+			-- no stealing other peoples' digtrons
+			return
+		end
+
+		local layout_string = layout:serialize()
+		
+		-- destroy everything. Note that this includes the empty crate, which will be bundled up with the layout.
+		for _, node_image in pairs(layout.all) do
+			minetest.remove_node(node_image.pos)
+		end
+		
+		-- Create the loaded crate node
+		minetest.set_node(pos, {name="digtron:loaded_crate", param1=node.param1, param2=node.param2})
+		
+		local meta = minetest.get_meta(pos)
+		meta:set_string("crated_layout", layout_string)
+		meta:set_string("title", "Crated Digtron")
+		meta:set_string("infotext", "Crated Digtron")
+	end,
+})
+
+local loaded_formspec =  "size[4,1.5]" ..
+	default.gui_bg ..
+	default.gui_bg_img ..
+	default.gui_slots ..
+	"field[0.3,0.5;4,0.5;title;Digtron Name;${title}]" ..
+	"button_exit[0.5,1.2;1,0.1;save;Save Title]" ..
+	"tooltip[save;Saves the title of this Digtron]" ..
+	"button_exit[2.5,1.2;1,0.1;unpack;Unpack]" ..
+	"tooltip[unpack;Attempts to unpack the Digtron on this location]"
+
+minetest.register_node("digtron:loaded_crate", {
+	description = "Loaded Digtron Crate",
+	groups = {cracky = 3, oddly_breakable_by_hand=3, not_in_creative_inventory=1, digtron=1},
+	stack_max = 1,
+	sounds = default.node_sound_wood_defaults(),
+	tiles = {"digtron_plate.png^digtron_crate.png"},
+	is_ground_content = false,
+	
+	on_construct = function(pos)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("formspec", loaded_formspec)
+	end,
+	
+	on_receive_fields = function(pos, formname, fields, sender)
+		local meta = minetest.get_meta(pos)
+		
+		if fields.unpack or fields.save then
+			meta:set_string("title", fields.title)
+			meta:set_string("infotext", fields.title)
+		end
+		
+		if not fields.unpack then
+			return
+		end
+		
+		local layout_string = meta:get_string("crated_layout")
+		local layout = DigtronLayout.deserialize(layout_string)
+		
+		if layout == nil then
+			meta:set_string("infotext", meta:get_string("title") .. "\nUnable to read layout from crate metadata, regrettably this Digtron may be corrupted or lost.")
+			minetest.sound_play("buzzer", {gain=0.5, pos=pos})			
+			-- Something went horribly wrong
+			return
+		end
+		
+		local pos_diff = vector.subtract(pos, layout.controller)
+		layout.controller = pos
+		for _, node_image in pairs(layout.all) do
+			node_image.pos = vector.add(pos_diff, node_image.pos)
+			
+			if minetest.is_protected(node_image.pos, sender:get_player_name()) and not minetest.check_player_privs(sender, "protection_bypass") then
+				meta:set_string("infotext", meta:get_string("title") .. "\nUnable to deploy Digtron due to protected nodes in target area")
+				minetest.sound_play("buzzer", {gain=0.5, pos=pos})
+				return
+			end
+			
+			if not minetest.registered_nodes[minetest.get_node(node_image.pos).name].buildable_to
+			  and not vector.equals(layout.controller, node_image.pos) then
+				meta:set_string("infotext", meta:get_string("title") .. "\nUnable to deploy Digtron due to obstruction in target area")
+				minetest.sound_play("buzzer", {gain=0.5, pos=pos})
+				return
+			end
+		end
+		
+		-- build digtron. Since the empty crate was included in the layout, that will overwrite this loaded crate and destroy it.
+		if layout then
+			layout:write_layout_image(sender)
+		end
+	end,
+		
+	on_dig = function(pos, node, player)
+	
+		local meta = minetest.get_meta(pos)
+		local to_serialize = {title=meta:get_string("title"), layout=meta:get_string("crated_layout")}
+		
+		local stack = ItemStack({name="digtron:loaded_crate", count=1, wear=0, metadata=minetest.serialize(to_serialize)})
+		local inv = player:get_inventory()
+		local stack = inv:add_item("main", stack)
+		if stack:get_count() > 0 then
+			minetest.add_item(pos, stack)
+		end		
+		-- call on_dignodes callback
+		minetest.remove_node(pos)
+	end,
+	
+	on_place = function(itemstack, placer, pointed_thing)
+		local pos = minetest.get_pointed_thing_position(pointed_thing, true)
+		local deserialized = minetest.deserialize(itemstack:get_metadata())
+		if pos and deserialized then
+			minetest.set_node(pos, {name="digtron:loaded_crate"})
+			local meta = minetest.get_meta(pos)
+			
+			meta:set_string("crated_layout", deserialized.layout)
+			meta:set_string("title", deserialized.title)
+			meta:set_string("infotext", deserialized.title)
+			meta:set_string("formspec", loaded_formspec)
+			
+			itemstack:take_item(1)
+			return itemstack
+		end
+		-- after-place callbacks
+	end,
+})

init.lua

@@ -8,6 +8,7 @@ dofile( minetest.get_modpath( "digtron" ) .. "/node_diggers.lua" ) -- contains a
 dofile( minetest.get_modpath( "digtron" ) .. "/node_builders.lua" ) -- contains all builders (there's just one currently)
 dofile( minetest.get_modpath( "digtron" ) .. "/node_controllers.lua" ) -- controllers
 dofile( minetest.get_modpath( "digtron" ) .. "/node_axle.lua" ) -- Rotation controller
+dofile( minetest.get_modpath( "digtron" ) .. "/crate.lua" ) -- Digtron portability support
 dofile( minetest.get_modpath( "digtron" ) .. "/recipes.lua" )
 
 digtron.creative_mode = false -- this causes digtrons to operate without consuming fuel or building materials.