ai.lua

ai.lua

--[[
	From a high-level perspective, NPCs follow a fairly simple (and real-world logical) process for making decisions. 
	The easiest way to understand it is to examine the basic outline first, and then dig further into the necessary exceptions afterwards.
	Each time an NPC thinks, it follows this routine:
	
		- Perform Sensing -
		
			NPC Sensing generates a list of entities that it can see, 
			and another list of NPC sounds that it can hear. 
			The NPC ignores entities and sounds that it doesn't care about.
		
		
		- Generate a list of Conditions -
		
			Conditions are key pieces of information that the NPC will be using to make a decision. 
			They are extracted from the sensed lists of entities & sounds, and from the state of the world and the NPC. 
			Conditions might include:
				- I can see an enemy
				- I have taken some damage
				- My weapon's clip is empty
		
		
		- Choose an appropriate State -
			
			The State is the overall assessment of the NPC based upon the list of Conditions. 
			For example:
				- NPCs with a visible enemy enter Combat
				- NPCs who have no enemies left will drop back to Alert
				- NPCs with a health of 0 would move to Dead
				
	
		- Select a new Schedule if appropriate -
			
			The Schedule is the overall action being taken by the NPC, which is then broken down into Tasks (see below) 
			for the NPC to actually perform. Schedules are chosen based upon the NPC's current State and Conditions. 
			Examples might include:
				- I'm taking cover to reload my gun
				- I'm chasing after my enemy
				- I'm moving to a position where I have line-of-sight to my enemy
			NPCs will choose a new schedule for one of two reasons:
				- They finish performing their last schedule
				- They generate a condition that their current schedule has specified as an "Interrupt"
			
			
		- Perform the current Task -
			
			The Task is a component of a Schedule that describes a discrete action. 
			Tasks must be performed one by one for the schedule to be completed. 
			For example, the "I'm taking cover to reload my gun" schedule would be broken down into the following tasks:
				- Find a position to take cover at
				- Generate a path to that position
				- Run the path
				- Reload my gun
			Many tasks, like the one above, take time to perform, 
			so the NPC will keep performing that task each time it thinks until the task is completed. 
			Then, it'll move onto then next task in the current schedule, or pick a new schedule if there are no tasks left. 
			If a task fails, the schedule fails.
	
--]]





local Orakel = require(game.ReplicatedStorage.Orakel.Main)
local pathLib = Orakel.LoadModule("PathLib")
local npcLib = Orakel.LoadModule("NpcLib")
local map = workspace.Map


local ai = {}


ai.PreThink = Instance.new("BindableEvent")
ai.PostThink = Instance.new("BindableEvent")



ai.States = {
	Alive = true;
	EnemySeen = false;
	EnemyHeard = false;
	Combat = false;
	Alert = false;
	ActBusy = false;
	Scripted = false;
}

ai.Config = {
	VisRange = 512;
	HearRange = 64;
}


local schedules = {}
local npc, ignoreEnts, initState, initSched, masterTable, mnt_index



function ai.Init(Npc, IgnoreEnts, States, Schedules, InitState, InitSched)
	npc = Npc
	ignoreEnts = IgnoreEnts
	if States ~= nil then
		ai.States = States
	end
	if Schedules ~= nil then
		schedules = Schedules
	end
	if InitState ~= nil then
		initState = InitState
	end
	if InitSched ~= nil then
		initSched = InitSched
	end
	masterTable, mnt_index = pathLib.CollectNodes(map.Nodes)
end



function ai.SetValue(name, value)
	ai[name] = value
end



function ai.Think()
	ai.PreThink:Fire()
	local tHear, tVis = ai.Sense()
	local conds = ai.ChooseConditions(tHear, tVis)
	local state = ai.ChooseState(conds)
	local tasks = ai.SelectSchedule()
	for numTask, task in pairs(tasks) do
		local interrupt = ai.PerformTask(task)
		if interrupt then
			break
		end
	end
	ai.PostThink:Fire()
end



function ai.Sense()
	local tHear = {}
	local tVis = {}
	for _, sound in pairs(map.Sounds:GetChildren()) do
		local dist = (sound.Position - npc.Torso.Position).magnitude
		if dist <= ai.Config.HearRange then
			table.insert(tHear, sound)
		end
	end
	for _, ent in pairs(map.Entities:GetChildren()) do
		local entIsModel = (ent.Classname == "Model")
		local lineOfSight
		if entIsModel then
			lineOfSight = npcLib.LineOfSight(npc.Head, ent.Primary, ai.Config.VisRange, ignoreList)
		else
			lineOfSight = npcLib.LineOfSight(npc.Head, ent, ai.Config.VisRange, ignoreList)
		end
		if lineOfSight then
			table.insert(tVis, ent)
		end
	end
	for _, mapNpc in pairs(map.NPCs:GetChildren()) do
		local lineOfSight = npcLib.LineOfSight(npc.Head, mapNpc.Torso, ai.Config.VisRange, ignoreList)
		if lineOfSight then
			table.insert(tVis, mapNpc)
		end
	end
	for _, plr in pairs(game.Players:GetPlayers()) do
		local lineOfSight = npcLib.LineOfSight(npc.Head, plr.Character.Torso, ai.Config.VisRange, ignoreList)
		if lineOfSight then
			table.insert(tVis, plr.Character);
		end
	end
	return tHear, tVis
end



function ai.ChooseConditions(tHear, tVis)
	
	
	
	
	
end



function ai.ChooseState(conds)
	
	
end



function ai.CreateSchedule(tasks)
	
	
end

function ai.SelectSchedule(sched)
	
end



function ai.PerformTask(task)
	
end



function ai.SetState(state, value)
	
end








return function() 
	return ai
end