-- NPC trading abilities by Zorman2000 npc.trade = {} npc.trade.CASUAL = "casual" npc.trade.TRADER = "trader" npc.trade.NONE = "none" npc.trade.OFFER_BUY = "buy" npc.trade.OFFER_SELL = "sell" -- This table holds all responses for trades npc.trade.results = { single_trade_offer = {}, trade_offers = {} } -- Casual trader NPC dialogues definition -- Casual buyer npc.trade.CASUAL_TRADE_BUY_DIALOGUE = { text = "I'm looking to buy some items, are you interested?", casual_trade_type = npc.trade.OFFER_BUY, responses = { [1] = { text = "Yes, let's see what are you looking for", action_type = "function", response_id = 1, action = function(self, player) npc.trade.show_trade_offer_formspec(self, player, npc.trade.OFFER_BUY) end } } } -- Casual seller npc.trade.CASUAL_TRADE_SELL_DIALOGUE = { text = "I have some items to sell, are you interested?", casual_trade_type = npc.trade.OFFER_SELL, responses = { [1] = { text = "Yes, let's see what you have", action_type = "function", response_id = 1, action = function(self, player) npc.trade.show_trade_offer_formspec(self, player, npc.trade.OFFER_SELL) end } } } function npc.trade.show_trade_offer_formspec(self, player, offer_type) -- Strings for formspec, to include international support later local prompt_string = " offers to buy from you" local for_string = "for" local buy_sell_string = "Sell" -- Get offer. As this is casual trading, NPCs will only have -- one trade offer local trade_offer = self.trader_data.buy_offers[1] if offer_type == npc.trade.OFFER_SELL then trade_offer = self.trader_data.sell_offers[1] prompt_string = " wants to sell to you" buy_sell_string = "Buy" end local formspec = "size[8,4]".. default.gui_bg.. default.gui_bg_img.. default.gui_slots.. "label[2,0.1;"..self.nametag..prompt_string.."]".. "item_image_button[2,1.3;1.2,1.2;"..trade_offer.item..";item;]".. "label[3.75,1.75;"..for_string.."]".. "item_image_button[4.8,1.3;1.2,1.2;"..trade_offer.price..";price;]".. "button_exit[1,3.3;2.9,0.5;yes_option;"..buy_sell_string.."]".. "button_exit[4.1,3.3;2.9,0.5;no_option;"..npc.dialogue.NEGATIVE_ANSWER_LABEL.."]" -- Create entry into results table npc.trade.results.single_trade_offer[player:get_player_name()] = { trade_offer = trade_offer, npc = self } -- Show formspec to player minetest.show_formspec(player:get_player_name(), "advanced_npc:trade_offer", formspec) end function npc.trade.get_random_trade_status() local chance = math.random(1,10) if chance < 3 then -- Non-trader return npc.trade.NONE elseif 3 <= chance and chance <= 7 then -- Casual trader return npc.trade.CASUAL elseif chance > 7 then -- Trader by profession return npc.trade.TRADER end end -- This function will return an offer object, based -- on the items the NPC has. -- Criteria: If having a near empty inventory, (< 6) NPC -- will offer to buy with a 70% chance. -- If NPC has a near full inventory (> 10 items), NPC -- will offer to sell. The prices will be selected using: -- item_price * (+/- price_item * 0.2) so item will be -- more or less 20% of the item price. function npc.trade.get_casual_trade_offer(self, offer_type) return { offer_type = offer_type, item = "default:wood 10", price = "default:iron_lump 20" } end function npc.trade.perform_trade(self, player_name, offer) local item_stack = ItemStack(offer.item) local price_stack = ItemStack(offer.price) local inv = minetest.get_inventory({type = "player", name = player_name}) -- Check if offer is a buy or sell if offer.offer_type == npc.trade.OFFER_BUY then -- If NPC is buying from player, then player loses item, gets price -- Check player has the item being buyed if inv:contains_item("main", item_stack) then -- Check if there is enough room to add the price item to player if inv:room_for_item("main", price_stack) then -- Remove item from player inv:remove_item("main", item_stack) -- Add item to NPC's inventory npc.add_item_to_inventory_itemstring(self, offer.item) -- Add price items to player inv:add_item("main", price_stack) -- Send message to player minetest.chat_send_player(player_name, "Thank you!") else minetest.chat_send_player(player_name, "Looks like you can't what I'm giving you for payment!") end else minetest.chat_send_player(player_name, "Looks like you don't have what I want to buy...") end else -- If NPC is selling to the player, then player gives price and gets -- item, NPC loses item and gets price -- Check NPC has the required item to pay if inv:contains_item("main", price_stack) then -- Check if there is enough room to add the item to player if inv:room_for_item("main", item_stack) then -- Remove item from player inv:remove_item("main", price_stack) -- Add item to NPC's inventory npc.add_item_to_inventory_itemstring(self, offer.price) -- Add price items to player inv:add_item("main", item_stack) -- Send message to player minetest.chat_send_player(player_name, "Thank you!") else minetest.chat_send_player(player_name, "Looks like you can't carry anything else...") end else minetest.chat_send_player(player_name, "Looks like you don't have what I'm asking for!") end end end -- Handler for chat formspec minetest.register_on_player_receive_fields(function (player, formname, fields) -- Additional checks for other forms should be handled here -- Handle yes/no dialogue if formname == "advanced_npc:trade_offer" then local player_name = player:get_player_name() if fields then local player_response = npc.trade.results.single_trade_offer[player_name] if fields.yes_option then npc.trade.perform_trade(player_response.npc, player_name, player_response.trade_offer) elseif fields.no_option then minetest.chat_send_player(player_name, "Talk to me if you change your mind!") end end end end)