Nether Swap

[Fulla]

Nether Swap

Instantly swaps location with target unit:





Intro
This is a very basic and simplistic spell, which makes it ideal for starting out with jass.
This tutorial does not cover the introduction to jass but rather goes straight into making a spell.
It also has a brief introduction to the Channel ability

Starters
Firstly go into the object editor and create a nether swap ability.
I recommend basing it of Channel, which is found under Neutral Hostile> Hero Abilities

Here is a screenshot to show how you should modify it


1 & 2 - These are the special effects that will be added to Caster and Target, I chose Blink, its up to you.
3 - Make sure you have the same options.
> Disable other abilities = false
> Follow Through Time = 0.00
> Options = Visible
> Target Type = Unit

Next we need to create the trigger
Go into the Trigger Editor and create a trigger called: Nether Swap
Please Note: NOT NetherSwap or nether swap etc.but Nether Swap

Should look like this:


Next you need to converted it to custom script:


For now we will skip the Conditions/Actions bit as this is quite boring, Once weve made a few spells I'll explain this to you
So Ill give you a base code to copy paste.

This is what you should currently have:


Copy Paste this:

function Trig_Nether_Swap_Conditions takes nothing returns boolean
    return GetSpellAbilityId() == 'A00P'
endfunction

function Trig_Nether_Swap_Actions takes nothing returns nothing
    
endfunction

//===========================================================================
function InitTrig_Nether_Swap takes nothing returns nothing
    set gg_trg_Nether_Swap = CreateTrigger()
    call TriggerRegisterAnyUnitEventBJ(gg_trg_Nether_Swap, EVENT_PLAYER_UNIT_SPELL_EFFECT)
    call TriggerAddCondition(gg_trg_Nether_Swap, Condition(function Trig_Nether_Swap_Conditions))
    call TriggerAddAction(gg_trg_Nether_Swap, function Trig_Nether_Swap_Actions)
endfunction

So now it should look like this:


Now we need to make sure the correct ability is in the condition.
For this go back into the Object Editor and click
View > Display Values as Raw Data


Next we need to get the raw data for the ability
In this case it is A000


Note: In your map if may differ so make sure to check.
Next go back into the trigger editor and lets alter the condition


Notice how Ive changed it to 'A000'

Ok we are now ready to start coding the spell

Method
This is how we will do the spell:
- Create a local to store: Casting Unit
- Create a local to store: Target Unit of Ability Being Cast Unit
- Create locals to store: Casting Unit's co-ordinates
- Create locals to store: Target Unit of Ability Being Cast's co-ordinates

- Move Casting Unit
- Move Target Unit of ability being cast

- Clean up leaks

Jass Code
The following code will go inside the Actions section:


Where the cursor is begin typing in there

Firstly we declare the locals

    local unit c = GetTriggerUnit()
    local unit t = GetSpellTargetUnit()

c = the Casting Unit
t = The Target Unit of ability being cast

Next we create locals for their co-ordinates

    local real xc = GetUnitX(c)
    local real yc = GetUnitY(c)
    local real xt = GetUnitX(t)
    local real yt = GetUnitY(t)

xc & yc = the co-ordinates of the Casting Unit
xt & yt = the co-ordinates of the Target Unit of ability being cast

Now we will set each unit's new position

    call SetUnitX(c, xt)
    call SetUnitY(c, yt)
    call SetUnitX(t, xc)
    call SetUnitY(t, yc)

This will place:
- Casting unit at co-ordinates stored for the Target Unit of ability being cast
- Target Unit of ability being cast at co-ordinates stored for the Casting Unit

Finally we clean up the leaks

    set c = null
    set t = null

This is overall how your code should look

function Trig_Nether_Swap_Conditions takes nothing returns boolean
    return GetSpellAbilityId() == 'A00P'
endfunction

function Trig_Nether_Swap_Actions takes nothing returns nothing
    local unit c = GetTriggerUnit()
    local unit t = GetSpellTargetUnit()
    local real xc = GetUnitX(c)
    local real yc = GetUnitY(c)
    local real xt = GetUnitX(t)
    local real yt = GetUnitY(t)
    call SetUnitX(c, xt)
    call SetUnitY(c, yt)
    call SetUnitX(t, xc)
    call SetUnitY(t, yc)
    set c = null
    set t = null
endfunction

//===========================================================================
function InitTrig_Nether_Swap takes nothing returns nothing
    set gg_trg_Nether_Swap = CreateTrigger()
    call TriggerRegisterAnyUnitEventBJ(gg_trg_Nether_Swap, EVENT_PLAYER_UNIT_SPELL_EFFECT)
    call TriggerAddCondition(gg_trg_Nether_Swap, Condition(function Trig_Nether_Swap_Conditions))
    call TriggerAddAction(gg_trg_Nether_Swap, function Trig_Nether_Swap_Actions)
endfunction

You can make the code, slightly more efficient by replacing:

    local real xt = GetUnitX(t)
    local real yt = GetUnitY(t)
    call SetUnitX(c, xt)
    call SetUnitY(c, yt)

with:

    call SetUnitX(c, GetUnitX(t))
    call SetUnitY(c, GetUnitY(t))

Your jass spell should now work, have fun and enjoy and stay tuned for more step by step mini jass tuts

thx
Fulla

 

[PurplePoot]

you can skip either (xt,yt) or (xc,yc), since SetUnitX/Y ignore pathing

 

[Fulla]

What do you mean by skip sorry?
Anyways to improve the tut?

 

[Diablo-dk]

Use jass tags instead of code tags?
By skipping i think he means that you can shorten it to this:

    local real x = GetUnitX(c)
    local real y = GetUnitY(c)
    call SetUnitX(c, GetUnitX(t))
    call SetUnitY(c, GetUnitY(t))
    call SetUnitX(t, x)
    call SetUnitY(t, y)

 

[Fulla]

- I intitially used jass tags, but it kept placing the entire code in 1 single line.

- I thought for beginners, would be best to keep it very basic/simple.

 

[PurplePoot]

Yeah, diablo, that's what I meant.

And less variables would be simpler for beginners, I would imagine. However, that's your choice.

And yes, JASS tags are preferrable. try replacing [code][/code] with [code=jass][/code] and making no other changes, and seeing if it works. If not, you should probably report it in the bug report forum.

 

[Fulla]

Ok updated, jass tags & added that bit at the end.

Is it possible to get the topic title changed

from: Jass Tut: (Level 1) - Nether Swap
to: Jass Tut: 1.01 - Nether Swap

thx

 

[PurplePoot]

try double-clicking right beside the name, in the thread list. If a thing pops up where you can change it, change it. Otherwise, PM wolverabid or someone.

I know the double-click thing works on some vBulletin forums, but I'm not sure about THW

 

[Wolverabid]

I renamed the thread for you Fulla: Jass Tut: 1.01 - Nether Swap

Before we can approve it you will have to review:
[self="http://hiveworkshop.com/forums/announcement.php?f=283"]General Tutorial Submitting Rules and Guidelines - Read Before Posting![/self]
and bring the tutorial up to those standards.

• All image files must be attached to your post. We don't wish to be dependent on other sites (to avoid situations in which the server that hosts images fails, thus damaging the tutorial).
  
  
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You should detach your siggy from the tut and use the [ATTACH][/ATTACH] tags instead of the [IMG][/IMG] tags.

 

[paskovich]

IMO, this tutorial is way too long for one spell only. Too detailed, and the main thing (triggering part) is pretty simple.

 

[PurplePoot]

It is supposed to be introducing basic concepts, after all

 

[RedBlade]

Wait... cant you just do it with GUI ?

Event - Unit castes and ability
Condition - Casting ability equal to Nether Swap
Action - Create Effect over casting unit (an effect)
- Move instantly casting unit to position of (the unit targeted by ability)
- Create Effect over unit targeted by ability (an effect)

I did it, i used it in a map of mine, i played it multiplayer and i had no leaks.

 

[GST_Nemisis]

Wait... cant you just do it with GUI?

its not about the spell its about teaching someone to learn jass.

 

[PurplePoot]

Also, it's a helluva lot harder, due to some *ahem* issues *ahem* with "Move Unit"

 

[Wolverabid]

Tutorial Submissions

I renamed the thread for you Fulla: Jass Tut: 1.01 - Nether Swap

[EDIT] ~ Tutorial approved and moved to JASS/AI Scripts Tutorials.