Dialog system & quests

[Crayz]

My first task was to create a "metadata" system for characters. Basically it lets me read and write values with names assigned to each value, and all metadata saves and loads with the character. This is so quest scripts could read and write dynamic character data on the fly, i.e. a counter for how many demons you've slain.

Once that was in, I started on the quest system. The basic idea is to "activate" a quest which then begins observing and reads/writes metadata based on its observations. This is what a quest script looks like:

KillDemonBaby = BaseQuest:extend()
KillDemonBaby.targetName = "killDemonBaby"
KillDemonBaby.printName = "Tainted Birth"
KillDemonBaby.description = "Slay 5 Demon Babies"

function KillDemonBaby:activate(event)
    event.EventSystem:Add("OnUnitKilled", self, self.onUnitKilled, event)
end

function KillDemonBaby:deactivate(event)
    event.EventSystem:Remove("OnUnitKilled", self, self.onUnitKilled)
end

function KillDemonBaby:canStart(event)
    -- check prerequisites here
-- i.e if player needs to finish another quest first,
-- event.Character.Meta:GetQuestState("otherQuest") == QuestState.Completed
    return true
end

function KillDemonBaby:onStart(event)
    CS.UnityEngine.Debug.Log("START DEMON BABBY")
end

function KillDemonBaby:onComplete(event)
    CS.UnityEngine.Debug.Log("COMPLETE DEMON BABY")
end

function KillDemonBaby:onUnitKilled(unit, event)
    if unit.LuaTargetName ~= "demonBaby" then return end
    local counter = event.Character.Meta:GetInt("killDemonBaby_Counter") + 1
    if counter >= 5 then
        self:complete(event)
    else
        event.Character.Meta:SetInt("killDemonBaby_Counter", counter)
    end
end

The dialog system gives players a way to activate quests and learn about characters. I wasn't really sure where to start with this, so I just opened up notepad++ and started writing some random Lua script in attempt to get an idea. I whipped up a very simple dialog script format. The first line is what the NPC is saying to you, the following lines represent the player's responses. Between parentheses indicates the method name to execute if that response is chosen, between square brackets is the text shown in the dialog box.

I need you to kill babby.
(decline)[No thanks]
(accept)[Sure thing]
(closeDialog)[Goodbye]

TestDialog = BaseDialog:extend()
TestDialog.targetName = "testDialog"

function TestDialog:activate(event)
    if event.Character.Meta:GetQuestState("testQuest") == QuestState.None then
        event.Dialog:Print(self, [[
            I need you to kill babby.
            (decline)[No thanks]
            (accept)[Sure thing]
            (closeDialog)[Goodbye]
        ]], event)
    else
        event.Dialog:Print(self, [[
            Have you kill babby?
            (closeDialog)[I should go do that!]
        ]], event)
    end
end

function TestDialog:decline(event)
    event.Dialog:Print(self, [[
        Whatever dude.
        (closeDialog)[Goodbye]
    ]], event)
end

function TestDialog:accept(event)
    if event.Character.QuestBook:TryStartQuest("testQuest") then
        event.Dialog:Print(self, [[
            Great!
            (closeDialog)[I'll be back]
        ]], event)
    else
        event.Dialog:Print(self, [[
            You can't do this quest yet
            (closeDialog)[Hm]
        ]], event)
    end
end

function TestDialog:closeDialog(event)
    event.Dialog:Close()
end

This combines data with logic, but I'm really happy with how it works. Here it is in action:

https://crayz.tv/files/sharex/2018-05-23%2023-03-04.mp4