AI & JASS FAQ

This thread will eventually Be locked and Untouchable except by another sticky below it so that All the Important stuff is kept in one easy to read place. It is currently Under construction as is the rest of the forum. But for now I want people to ask lots of AI and JASS questions, so that I can start on getting this FAQ useful. Thanks

What is AI?
Artifical intelligence. It is what causes the computer to act the way it does.

Where is the AI in Warcraft III?
If you are looking for the Muliplayer and Campaign AI that came with the retail. They are located in the .mpq under the Scripts folder. If it is Custom and added by the Map maker it is in the map where ever he placed it or in hte triggers.

What are the files for the AI?
Blizzard.j, common.j, common.ai
human.ai, orc.ai, elf.ai, undead.ai

I looked in the Script folder and there are way more than the ones you named?
Yes, That folder holds all the scripting stuff blizzard used for Warcraft III. Not just AI stuff. Most of them are files for the campagins. There are some .j, .pld, and .ai files.

I don't feel like extracting them can I download them from somewhere?
I know have them hosted on a Quickie page I made. Goto the Files section and it will have those files. www.dkslayer.netfirms.com

What is a .pld file?
It is a file that preloads other files.

What is a .j file?
These two files, Blizzard.j and common.j, contain all the functions and globals that compose JASS.

What is that JASS you mentioned?
JASS is the scripting langauge that Blizzard uses. If you do any Custom Text Triggers or work on your own AI files that is what you will be doing.

So the .ai files are where the AI is?
Yes. The .ai files are basicly just a bunch of the JASS Functions put in a certain way with other Statements in it.

How can I make computer AI?
Their are about 3 ways.
1st and easiest. You can make triggers and cause the compuer to act in certain ways. I don't consider this scripting AI, but it is AI at it's simplest form.
2nd Making a Custom Text Trigger and script AI in it. This is still a form of the above method but you have more flexibilty and it's a step closer to real AI scripting.
3rd Make a real .ai file and script with in it to create the computer AI you want. This is the most difficult but you have Total Freedom and Power.

How can I make a Custom Text Trigger?
Make a new trigger in the Trigger Editor. Then select it, goto the edit menu, and Click Convert to Custom Text. Wammy. Now you can script using JASS.

Any Special Tools needed to make AI
No, just use notepad to make the .ai file. There are two tools in development to make that task easier. For beginners to Experts look at JonahDean's Upcoming AI Builder. Going to be awesome. Provides a great GUI, kind of like triggers but for AI.For Ok to Experts I have an advanced Editor in the works. Think of Notpad on steroids although that's don't do it justice. Both Programs are in beta, yet AI Builder should be done soon.

Here I will talk about JASS functions and the Various parts and things you can do to them. Lets start out with a simple description of a function.

What is a Function?
To me I compare it to a part in a motor. The motor being the trigger or .ai file. Say the Air Filter on your car. It takes in dirty air, and returns clean air. Other parts don't take or return anything, like the lights on you car, they are turned on or in our case called and just do what they were made to do.
So a fuction is like a chunk of your code, it's hard to explain so I will show you.

See all that is our code yet there are two functions. Of course I could put the Displayer code in the main instead of using a function, but What if I use that code 5 times it is less code to just call the function.

Basics of a Function
It's Really Simple a Function executes whatever code is inside when it is called. It can take and return stuff. All delcarations of variables must be done at the begining of the function or causes problems.

Function taking and returning and Calling
Ok Lets start with a main function. Usually your main function does not return anything nore take anything so it looks say like this.
That one does nothing, You could actually do everything in one trigger but that is wasteful. You usually do stuff multiple times, which you could have a function do for you and save code. Plus it is messy.

So lets say you wanted a function that would take 50 away from and integer Multiply by 9 and divide by two. You would do this.
There is our function let me talk about the first line of code first. 2nd Word is your function name. When you do a take you say what type it will take, ie integer, then you put the name of it right after it, like MyNumber so that you can refer to it, it's just like a variable. For return if it is a void function meaning it does not return anything you just say return nothing. If it does return something you say the return type. Make sure your return type and the data you are returning are the same type otherwise you will get an error.

So lets see these functions used together.
There you go. Make sure you have the function your calling above the one you are calling it from. Also to doing multiple arguments is easy for example.
There are many ways you can work with returns. You can store the return in a variable
or I could use it in a statement
There are two examples of how you can use the function return. You never use the word call before the function unless that function returns nothing. If it returns something you do not use call. You can use it but no reason to won't do nothing.

There you go you got the basics of making/creating a function, issuing calls to them, and dealing with Arguments(takes & returns).
Good Luck
DKSlayer

This section will explain variables. We will show you how to use them.

What is a Variable?
To explain this lets pretend a Variable is a Bag. Now the Bag holds an Item(for us Data) so we can put it aside and come back to the bag and it will still be there. So basically a Variable holds one thing of data for us.

The Basics to using a Variable
To use a Variable you must Declare it(Create it). When you create it you also say what kind of data or object it will hold. A couple examples of that is, strings, integers, timers, dialogs, etc.. After you declare it you can put stuff into it and use it for what you need. NOW Very important the Variables must be declared at the begining of the function if you are doing a trigger. If you are using doing this in a .ai file than locals declared at the begining of the function they are in, and globals at the begining of the file.

Declaring a Variable
When you declare a variable there are 5 things you can do state, if it will be a constant, if it will be local or global, if it will be an array or not, the name of the variable, and an initial value if you would like. Lets start with the constant.
Constants
These don't allow the value of the Variable to change. You set the Value when you declare it, and that's it. No, changing it later in the code. Now you are probably asking why the heck would I want to use a Constant than. Well If you have a value that you use a lot across a project and you want to change that value, instead of having to go through each time you want to change that one you could just use a const and change the value where it was declared.
The Above example shows 4 lines of text to a player. If after testing I think the Displayed time was too short I only have to change it where it was declared.
You will use these very rarely if at all. To declare a variable that is not a constant, just leave constant out of the declare statement.
Local and Globals
There are two settings for variables, they can be local meaning they can only be used within that Function or global witch can be used all the way across the code. Globals can only be declared in .ai files. If you want to delcare a Global in a Trigger, you will have to do it in WE by going to the Variable Dialog and doing it there, when you refer to the variable then you add udg_ to the name you gave it in the dialog(you only have to do udg_ thing when you refer to one you made in WE.) Here are examples on how to declare both
For Local Varables you just place local before the variable type, in this case string. Globals you enclose between the words, globals & endglobals.

Arrays will be talked about in next post.
The Name
This is just the name you will use to refer to it later. For easy of finding and knowing what it is it's nice to use naming conventions like, strMsg intNumber blnYea. You are able to tell that strMsg is a string, intNumber is a Integer, and blnYea is a boolean. You don't need to do this just makes t easier for you and those that may look at your code later.

Intial Value
You can set the Initial Value of your variable when declaring the variable or if not. Here is an example of both.
If you do not set an initial value than the value of that variable is either null or 0 depending on the type.

Setting a Variable

Pretty good. I give it 4****s. Sorry for being corny. Gives great insight into ai. You gotta know something about it in the first place, but still nice. And for the dude with the dancing avatar, just make a few triggers, convert them to jass, then learn them a bit that way. Its pretty easy, give it a try.

For you who are too lazy or just too stupid to use Winmpq or another program, i put the files into a .rar file.

I have a site up with those files up as well. If I am right it has unlimited Bandwidth so if the site biffs it tell me. Also I have noticed the views on this thing are rising faster, I will try and get mroe stuff on this. Finish the Variable part and start the array stuff.
Thanks All
DKSlayer

bravo...i wouldn't have the patience to write all that stuff :)

altho I see jass for the first time(well, not first, i do custom trigers a lot) it looks much like java :)
it's very similar....but i think u should first upload a basic programming tutorial before teaching AI making....

that's just my opinion :)

Thank You, I still really need to work on the Setting a Variable and Array part.
Yes it is a lot like JAVA. As a matter of fact, at Beta Time when I was learning JASS, I was also taking a class in JAVA which helped me tons. It worked out nicely.
This part will teach you alot of JASS, then I hope to sit down and do an AI again step by step, while writing a tutorial as well. This might be a little bit since College has started but hope to get it soon.
Thank You
DKSlayer

Pretty cool faq.......

Has the language changed much since the old beta days where we were the pioneers and made the very first AI scripts??

Ive been away from war3 for a while but maybee i can still do something on the scripting scene.
(Im sure i can learn JASS agai pretty quick)

Gof

(Yes it was me who made that human ai for the beta that kept coming in new versions (The aiscript not the beta ))

I rememeber you GOF, I still have your Script on my computer Somewhere. JASS has not changed much at since beta, only a couple of functions changed, added, or removed. Nothing stelar. So it should be easy getting back into it for you. Welcome Totally and hope you enjoy the time here.
Thanks
DKSlayer

I wonder if JASS is able to address details which are not included in the Trigger editor.

I'm talking about Unit Stats like Basic Attack Damage or Attack Cooldown Time.

Couldn't make it work, as shown here

What should I do to get an AI script up and running?

I have tried to stuff my ai script everywhere, in the map file,
outside the map file, in a Scripts directory in an outside the map.
I am trying to start the script with:


function Trig_Melee_Initialization_Actions takes nothing returns nothing
call StartMeleeAI( Player(1), "test.ai" )
endfunction

//===========================================================================
function InitTrig_Melee_Initialization takes nothing returns nothing
set gg_trg_Melee_Initialization = CreateTrigger( )
call TriggerRegisterTimerEventSingle( gg_trg_Melee_Initialization, 3.00 )
call TriggerAddAction( gg_trg_Melee_Initialization, function Trig_Melee_Initialization_Actions )
endfunction


But it doesn't seem that my script run at all, this is the scripts code:

function main takes nothing returns noting
call DisplayTimedTextToForce( GetPlayersAll(), 30, "Hello World, I am ai" )
endfunction

Please help. :(

/Vidstige

In your AI script you use
DisplayTimedTextToForce
and GetPlayersAll .
These are in Blizzard.j and functions in that file cannot be accessed from AI.
So what happens is that War3 finds that error and then just ignores the script. Best test your scripts with the script checker.
What you can access from AI scripts is common.j and common.ai . So to display something to all players use
call DisplayTimedTextToPlayer(GetLocalPlayer(), 0, 0, 20, "Hello, world" )
The right place for scripts is the \Scripts subfolder in the map.

It works! :ggani:

Thanks Andy!

is there is list of functions anywhere that i can get?