Dialogues: Added function to select random dialogues for NPCs from random data.

Modified NPCs so random dialogues are chosen on initialization.
Added function to start a dialogue, choosing randomly NPCs dialogues.
Changed NPC code to use new dialogue code

chat.lua

@@ -1,28 +1,4 @@
--- NPC Chat code by Zorman2000
--- Chat system consists of chatline and options objects that are re-used to create a conversation. 
--- The objects are the following:
--- 
--- chatline = { text = "", options = {}, name = "", flag = "" }
---  1. text: What the NPC says on this chat line
---  2. options: What the player can answer to the chat line. Options are of another type of chat lines.
---              If you want the player to have no options to answer, set to nil
---  3. name: The name of the NPC that will use this line. Use this when you want a specific NPC
---           to speak this line.
---  4. flag: When the NPC speaks this line, this flag will be set into the entity's metadata.
---
--- options = { opt = "", answer = { chatline }
---  1. opt: The text that the player can say to the NPC
---  2. answer: A chatline object (as described above)
--- 
--- Example of conversation hierarchy
--- chat_options = {
---  	chatline1 = { text = "Q1", options = { 
---  		option1 = { opt = "O1", answer = { 
---  			chatline = { text = "A1", options = nil } 
---  		} 
---  	},
---  	chatline2 = { text = "Q2", options = nil }
---  }
+-- NPC dialogue code by Zorman2000
 
 npc.dialogue = {}
 
@@ -34,9 +10,11 @@ npc.dialogue.dialogue_results = {
 	yes_no_dialogue = {}
 }
 
----------------------------------------------------------------------
--- Creates a formspec for dialog
+-- Dialogue box definitions
+-- The dialogue boxes are used for the player to interact with the
+-- NPC in dialogues.
 --------------------------------------------------------------------
+-- Multi-option dialogue
 local function create_formspec(options, close_option) 
 	local options_length = table.getn(options) + 1	
 	local formspec_height = (options_length * 0.7) + 1
@@ -76,10 +54,9 @@ function npc.dialogue.show_yes_no_dialogue(prompt,
 	minetest.show_formspec(player_name, "advanced_npc:yes_no", formspec)
 end
 
----------------------------------------------------------------------
+-- Dialogue methods
 -- Returns all chatlines for a specific NPC
----------------------------------------------------------------------
-local function get_chatline_for_npc(chat_options, npc_name)
+function npc.dialogue.select_random_dialogues_for_npc(sex, )
 	local result = {}
 	for i,chatline in ipairs(chat_options) do
 		if chatline.name == npc_name then

dialogue.lua

@@ -0,0 +1,189 @@
+-- NPC dialogue code by Zorman2000
+
+npc.dialogue = {}
+
+npc.dialogue.POSITIVE_GIFT_ANSWER_PREFIX = "Yes, give "
+npc.dialogue.NEGATIVE_ANSWER_LABEL = "Nevermind"
+
+npc.dialogue.MIN_DIALOGUES = 2
+npc.dialogue.MAX_DIALOGUES = 4
+
+-- This table contains the answers of dialogue boxes
+npc.dialogue.dialogue_results = {
+	yes_no_dialogue = {}
+}
+
+-- Dialogue box definitions
+-- The dialogue boxes are used for the player to interact with the
+-- NPC in dialogues.
+--------------------------------------------------------------------
+-- Multi-option dialogue
+local function create_formspec(options, close_option) 
+	local options_length = table.getn(options) + 1	
+	local formspec_height = (options_length * 0.7) + 1
+	local formspec = "size[7,"..tostring(formspec_height).."]"
+	for i, opt in ipairs(options) do
+		local y = 0.7;
+		if i > 1 then
+			y = (y * i)
+		end
+		formspec = formspec.."button[0.5,"..y..";6,0.5;opt"..tostring(i)..";"..options[i].opt.."]"
+	end
+	formspec = formspec.."button_exit[0.5,"..(formspec_height - 1)..";6,0.5;exit;"..close_option.."]"
+	return formspec
+end
+
+-- This function is used for showing a yes/no dialogue formspec
+function npc.dialogue.show_yes_no_dialogue(prompt, 
+										   positive_answer_label,
+										   positive_callback,
+										   negative_answer_label,
+										   negative_callback,
+										   player_name)
+
+	local formspec = "size[7,3]"..
+					 "label[0.5,0.1;"..prompt.."]"..
+						"button_exit[0.5,1.15;6,0.5;yes_option;"..positive_answer_label.."]"..
+						"button_exit[0.5,1.95;6,0.5;no_option;"..negative_answer_label.."]"	
+
+	-- Create entry into responses table
+	npc.dialogue.dialogue_results.yes_no_dialogue[1] = {
+		name = player_name, 
+		response = "",
+		yes_callback = positive_callback,
+		no_callback = negative_callback
+	}
+
+	minetest.show_formspec(player_name, "advanced_npc:yes_no", formspec)
+end
+
+-- Dialogue methods
+-- Select random dialogue objects for an NPC based on sex
+-- and the relationship phase with player
+function npc.dialogue.select_random_dialogues_for_npc(sex, phase)
+	local result = {}
+	local dialogues = npc.data.DIALOGUES.female
+	if sex == npc.MALE then
+		dialogues = npc.data.DIALOGUES.male
+	end
+	dialogues = dialogues[phase]
+
+	-- Determine how many dialogue lines the NPC will have
+	local number_of_dialogues = math.random(npc.dialogue.MIN_DIALOGUES, npc.dialogue.MAX_DIALOGUES)
+
+	for i = 1,number_of_dialogues do
+		result[i] = dialogues[math.random(1, #dialogues)]
+	end
+
+	return result
+end
+
+-- This function will choose randomly a dialogue from the NPC data
+-- and process it. 
+function npc.dialogue.start_dialogue(self, player)
+	-- Choose a dialogue randomly
+	local dialogue = self.dialogues[math.random(1, #self.dialogues)]
+	npc.dialogue.process_dialogue(dialogue, player:get_player_name())
+end
+
+-- This function processes a dialogue object and performs
+-- actions depending on what is defined in the object 
+function npc.dialogue.process_dialogue(dialogue, player_name)
+	-- Send dialogue line
+	if dialogue.text then
+		minetest.chat_send_player(player_name, dialogue.text)
+	end
+	-- TODO: Add support for flag, multi-option dialogue
+	-- and their actions
+end
+
+-----------------------------------------------------------------------------
+-- Functions for rotating NPC to look at player (taken from the API itself)
+-----------------------------------------------------------------------------
+local atan = function(x)
+	if x ~= x then
+		return 0
+	else
+		return math.atan(x)
+	end
+end
+
+
+local function rotate_npc_to_player(self)
+	local s = self.object:getpos()
+	local objs = minetest.get_objects_inside_radius(s, 4)
+	local lp = nil
+	local yaw = 0
+	
+	for n = 1, #objs do
+		if objs[n]:is_player() then
+			lp = objs[n]:getpos()
+			break
+		end
+	end
+	if lp then
+		local vec = {
+			x = lp.x - s.x,
+			y = lp.y - s.y,
+			z = lp.z - s.z
+		}
+
+		yaw = (atan(vec.z / vec.x) + math.pi / 2) - self.rotate
+
+		if lp.x > s.x then
+			yaw = yaw + math.pi
+		end
+	end
+	self.object:setyaw(yaw)
+end
+
+---------------------------------------------------------------------
+-- Drives conversation
+---------------------------------------------------------------------
+local function show_chat_option(npc_name, self, player_name, chat_options, close_option)
+	rotate_npc_to_player(self)
+	self.order = "stand"
+	
+	local chatline = get_random_chatline(chat_options)
+	minetest.chat_send_player(player_name, chatline.text)
+	if chatline.options ~= nil then
+		minetest.log("Current options: "..dump(chatline.options))
+		local formspec = create_formspec(chatline.options, close_option)
+		minetest.show_formspec(player_name, "rndform", formspec)
+	end
+	
+	self.order = "follow"
+end
+
+-- Function to get response by player name
+local function get_yes_no_dialogue_response_by_player_name(player_name)
+	for i = 1,#npc.dialogue.dialogue_results.yes_no_dialogue do
+		local current_result = npc.dialogue.dialogue_results.yes_no_dialogue[i]
+		if current_result.name == player_name then
+			return current_result
+		end
+	end
+	return nil
+end
+
+-- Handler for chat formspec
+minetest.register_on_player_receive_fields(function (player, formname, fields)
+	-- Additional checks for other forms should be handled here
+	if formname == "advanced_npc:yes_no" then
+		local player_name = player:get_player_name()
+
+		if fields then
+			local player_response = get_yes_no_dialogue_response_by_player_name(player_name)
+			if fields.yes_option then
+				player_response.response = true
+				player_response.yes_callback()
+			elseif fields.no_option then
+				player_response.response = false
+				player_response.no_callback()
+			end
+			minetest.log(player_name.." chose response: "
+				..dump(get_yes_no_dialogue_response_by_player_name(player_name).response))
+		end
+	end
+
+end)

init.lua

@@ -25,7 +25,7 @@ mobs.intllib = S
 
 -- NPC
 dofile(path .. "/npc.lua")
-dofile(path .. "/chat.lua")
+dofile(path .. "/dialogue.lua")
 dofile(path .. "/random_data.lua")
 --dofile(path .. "/trader.lua")
 

npc.lua

@@ -613,17 +613,17 @@ mobs:register_mob("advanced_npc:npc", {
         npc.dialogue.POSITIVE_GIFT_ANSWER_PREFIX..item_name,
         function()
           if receive_gift(self, clicker) == false then
-            start_chat(self, clicker)
+            npc.dialogue.start_dialogue(self, clicker)
           end
         end,
         npc.dialogue.NEGATIVE_ANSWER_LABEL,
         function()
-          start_chat(self, clicker)
+          npc.dialogue.start_dialogue(self, clicker)
         end,
         name
       )
     else
-      start_chat(self, clicker)
+      npc.dialogue.start_dialogue(self, clicker)
     end
 
 	end,
@@ -703,6 +703,9 @@ local function npc_spawn(self, pos)
   -- Determines if NPC is married or not
   ent.is_married_to = nil
 
+  -- Initialize dialogues
+  ent.dialogues = npc.dialogue.select_random_dialogues_for_npc(ent.sex, "phase1")
+  
   minetest.log(dump(ent))
   
   -- Refreshes entity

random_data.lua

@@ -4,7 +4,7 @@
 npc.data = {}
 
 npc.data.DIALOGUES = {
-	female = {}
+	female = {},
 	male = {}
 }
 
@@ -33,8 +33,8 @@ npc.data.DIALOGUES.female["phase1"] = {
 				text = "No, never before",
 				action_type = "function",
 				action = function(player_name, item)
-					minetest.chat_send_player(player_name, "Oh, never? How come! You should.
-						\nHere, take this. It will guide you to the sea...")
+					minetest.chat_send_player(player_name, "Oh, never? How come! You should."..
+						"\nHere, take this. It will guide you to the sea...")
 				end
 			},
 			{