Gravity Ball

[Element of Water]

This spell creates a big ball of incredibly dense matter which draws nearby units into it. After holding them there spinning around for some time, it explodes, dealing damage to every unit which has been pulled into it and sending them flying.

Requirements:
Jass NewGen Pack for vJass
Rising_Dusk's Knockback (And all of its requirements, all made by Rising_Dusk)
Grim_001's ListModule
Vexorian's Table
Ammorth's LinkedList

NOTE: the test map uses a custom model which I feel makes the spell look much better. Credits to RightField for that.

I believe it is fully MUI and leak-free but please let me know if you find a leak!

Read the "How to Import" trigger for detailed instructions on how to import the spell.

Please give credits to me (Element of Water) if you use it in your map. Oh, and please don't give stupid comments like "OMG WAY TOO IMBA" because you can make it less "IMBA" by configuring the constants...

Spell Code:

//////////////////////////////////////////////////////////////////////////
//                       Gravity Stone                                  //
//                        A spell by:                                   //
//                     Element of Water                                 //
//////////////////////////////////////////////////////////////////////////
library GravityStone initializer Init requires Knockback, ListModule, Table, LinkedList

/////////////////////////////////////////
//            EDITABLE DATA            //
//   Change these to suit your needs   //
/////////////////////////////////////////
    globals
        //how far per second units are knocked back at the end of the spell
        private constant real KNOCKBACK_SPEED           = 500.
        
        //how much the knockback speed is reduced by each second
        private constant real KNOCKBACK_DECREMENT       = 250.
        
        //the special effect which plays when the spell ends
        private constant string SFX                     = "Objects\\Spawnmodels\\NightElf\\NEDeathMedium\\NEDeath.mdl"
        
        //this is the rawcode of the dummy unit
        private constant integer DUMMY_ID               = 'dum0'
        
        //this is the rawcode of the spell
        private constant integer SPELL_ID               = 'A000' 
    
        //the maximum distance units can be from the ball
        private constant real MAX_DIST                  = 250.0
        
        //how fast the units spin round the ball
        private constant real ORBIT_SPEED               = 150.0
        
        //the maximum height of the units when pulled into the ball
        private constant real MAX_HEIGHT                = 750.
        
        //the attack type of the damage - determines how much damage is dealt to different kinds of armour
        private constant attacktype ATTACK_TYPE         = ATTACK_TYPE_MAGIC
        
        //the damage type of the damage - determines which units are immune to the damage.
        private constant damagetype DAMAGE_TYPE         = DAMAGE_TYPE_MAGIC
        
        //the weapon type of the damage - determines the sound played based on the armour type of the target
        //WEAPON_TYPE_WHOKNOWS or null plays no sound
        private constant weapontype WEAPON_TYPE         = WEAPON_TYPE_WHOKNOWS
        
        //the duration of the timer, AKA how often the places the units move to are updated
        private constant real TIMER_INTERVAL            = 0.1
        
        //the interval at which units' positions are updated when being pulled into the Gravity Stone
        //lower values give smoother movement, whilst higher values give better performance
        private constant real PULL_INTERVAL             = 0.035
        
        //the higher this is, the more slowly units will be pulled into the gravity stone
        private constant real PULL_WEIGHT               = 15
        
        //the speed the units are pulled into the gravity stone is multiplied by this, giving an effect like friction
        private constant real PULL_DRAG                 = 0.975
    endglobals
    
    //A helper function - SpellLevel(u) returns the spell level of Gravity Stone for the unit
    private function SpellLevel takes unit u returns integer
        return GetUnitAbilityLevel(u, SPELL_ID)
    endfunction
    
    //How long the spell lasts
    private function Duration takes unit u returns real
        return 2.5 + SpellLevel(u) * 2.5
    endfunction
    
    //how much damage the spell deals
    private function Damage takes unit u returns real
        return 250. + SpellLevel(u) * 250.
    endfunction
    
    //how many units the gravity ball can pull in at once
    private function MaxUnits takes unit u returns integer
        return 5 + SpellLevel(u) * 15
    endfunction
    
    //the range at which the gravity stone pulls in enemy units
    private function AoE takes unit u returns real
        return 250. + SpellLevel(u) * 250.
    endfunction
    
/////////////////////////////////////////
//          END EDITABLE DATA          //
/////////////////////////////////////////
    
    globals
        private constant integer FLY_HACK       = 'Amrf'
        private location TempLoc = Location(0., 0.)
    endglobals
    
    private struct PullUnit
        implement List
        private static timer tim = CreateTimer()
        //Pulled unit's position vector
        real xU
        real yU
        real zU
        //Target point's (or unit's) position vector
        real xT = 0.
        real yT = 0.
        real zT = 0.
        //Offset vector
        real xO = 0.
        real yO = 0.
        real zO = 0.
        //Velocity vector
        real xV = 0.
        real yV = 0.
        real zV = 0.
        //Pulled unit
        unit u
        
        real startHeight = 0.
        real angle = 0.
        
        //Private stuff
        private boolean running = false
        
        static HandleTable tbl
        
        delegate Link link
        
        static method create takes unit whichUnit, List l returns PullUnit
            local PullUnit p = 0
            
            if .tbl[whichUnit] == 0 then
                set p = PullUnit.allocate()
                set p.link = Link.create(l, p)
                
                set p.u = whichUnit
                set p.xU = GetUnitX(p.u)
                set p.yU = GetUnitY(p.u)
                set p.zU = GetUnitFlyHeight(p.u)
                
                call UnitAddAbility(p.u, FLY_HACK)
                call UnitRemoveAbility(p.u, FLY_HACK)
                
                set .tbl[whichUnit] = p
            endif
            
            return p
        endmethod
        
        static method execute takes nothing returns nothing
            local PullUnit this = PullUnit.getFirst()
            
            loop
                exitwhen this == 0
                
                set this.xV = this.xV + (this.xT+this.xO-this.xU)/(PULL_WEIGHT/PULL_INTERVAL)
                set this.yV = this.yV + (this.yT+this.yO-this.yU)/(PULL_WEIGHT/PULL_INTERVAL)
                set this.zV = this.zV + (this.zT+this.zO-this.zU)/(PULL_WEIGHT/PULL_INTERVAL)
                
                set this.xV = this.xV * PULL_DRAG
                set this.yV = this.yV * PULL_DRAG
                set this.zV = this.zV * PULL_DRAG
                
                set this.xU = this.xU + this.xV
                set this.yU = this.yU + this.yV
                set this.zU = this.zU + this.zV
                
                call MoveLocation(TempLoc, this.xU, this.yU)
                
                call SetUnitX(this.u, this.xU)
                call SetUnitY(this.u, this.yU)
                call SetUnitFlyHeight(this.u, this.zU + .startHeight - GetLocationZ(TempLoc), 0.00)
                
                set this = this.getNext()
            endloop
        endmethod
        
        method start takes nothing returns nothing
            if not .running then
                set .running = true
                
                if .getLength() == 0 then
                    call TimerStart(.tim, PULL_INTERVAL, true, function PullUnit.execute)
                endif
                
                call .addList()
                
                call PauseUnit(.u, true)
                
                call MoveLocation(TempLoc, .xT, .yT)
                set .startHeight = GetLocationZ(TempLoc)
            endif
        endmethod
        
        method stop takes nothing returns nothing
            if .running then
                set .running = false
                
                call .removeList()
                
                if .getLength() == 0 then
                    call PauseTimer(.tim)
                endif
                
                call PauseUnit(.u, false)
            endif
        endmethod
        
        private method onDestroy takes nothing returns nothing
            call .stop()
            
            set .tbl[.u] = 0
        endmethod
        
        static method getData takes unit u returns PullUnit
            return .tbl[u]
        endmethod
        
        private static method onInit takes nothing returns nothing
            set .tbl = HandleTable.create()
        endmethod
    endstruct
    
    globals
        private timer    tim            = CreateTimer()
        private boolexpr UnitEnumFilter = null
        private player   TempPlayer     = null
        private group    TempGroup      = CreateGroup()
    endglobals
    
    private function PolarProjectionX takes real startX, real dist, real angle returns real
        return startX + dist * Cos(angle * bj_DEGTORAD)
    endfunction

    private function PolarProjectionY takes real startY, real dist, real angle returns real
        return startY + dist * Sin(angle * bj_DEGTORAD)
    endfunction
    
    private function UnitEnum takes nothing returns boolean
        local unit u = GetFilterUnit()
        local boolean array b
        set b[0] = IsUnitEnemy(u, TempPlayer)
        set b[1] = not IsUnitType(u, UNIT_TYPE_MAGIC_IMMUNE)
        set b[2] = not IsUnitType(u, UNIT_TYPE_STRUCTURE)
        set b[3] = GetWidgetLife(u) > 0.405
        set b[4] = PullUnit.getData(u) == 0
        return b[0] and b[1] and b[2] and b[3] and b[4]
    endfunction
    
    private struct Data
        implement       List
        
        real            x
        real            y
        
        real            time
        real            maxdist
        real            maxspeed
        real            maxheight
        real            damage
        unit            dummy
        unit            caster
        real            aoe
        integer         numUnits = 0
        integer         maxUnits
        List            pulledUnits
        
        boolean ended = false
        
        private method pullMore takes nothing returns nothing
            local unit u
            
            local PullUnit p
            
            if .numUnits  < .maxUnits then
                set TempPlayer = GetOwningPlayer(.caster)
                call GroupEnumUnitsInRange(TempGroup, .x, .y, .aoe, UnitEnumFilter)
                
                loop
                    set u = FirstOfGroup(TempGroup)
                    exitwhen u == null or .numUnits  == .maxUnits
                    
                    set p = PullUnit.create(u, .pulledUnits)
                    set .numUnits = .numUnits + 1
                    
                    set p.xT = .x
                    set p.yT = .y
                    call p.start()
                    
                    call GroupRemoveUnit(TempGroup, u)
                endloop
                
                call GroupClear(TempGroup)
            endif
            
            set u = null
        endmethod
        
        private static method execute takes nothing returns nothing
            local Data this = .getFirst()
            local PullUnit p
            
            local real dist
            
            loop
                exitwhen this == 0
                
                call this.pullMore()
                
                set p = this.pulledUnits.first.data
                
                loop
                    exitwhen p == 0
                    
                    set p.angle = p.angle+GetRandomReal(-this.maxspeed/2, this.maxspeed)
                    if p.angle >= 360 then
                        set p.angle = p.angle-360
                    elseif p.angle <= 0 then
                        set p.angle = p.angle + 360
                    endif
                    
                    set dist = GetRandomReal(0., this.maxdist)
                    
                    set p.xO = dist * Cos(p.angle * bj_DEGTORAD)
                    set p.yO = dist * Sin(p.angle * bj_DEGTORAD)
                    set p.zO = GetRandomReal(0.0, this.maxheight)
                    
                    set p = p.next.data
                endloop
                
                set this.time = this.time - TIMER_INTERVAL
                
                if this.time <= 0 then
                    call this.destroy()
                endif
                
                set this = this.getNext()
            endloop
        endmethod
        
        static method create takes unit caster, real duration, real x, real y, real damage, integer maxUnits, real range, real dist, real orbitspeed, real height returns Data
            local Data this = Data.allocate()
            
            set this.x = x
            set this.y = y
            
            set this.time = duration
            set this.damage = damage
            set this.aoe = range
            set this.dummy = CreateUnit(Player(12), DUMMY_ID, x, y, 0.00)
            
            set this.caster = caster
            
            set this.maxUnits = maxUnits
            
            set this.pulledUnits = List.create()
            
            call this.pullMore()
            
            set this.maxdist = dist
            set this.maxspeed = orbitspeed
            set this.maxheight = height
            
            if .getLength() == 0 then
                call TimerStart(tim, TIMER_INTERVAL, true, function Data.execute)
            endif
            
            call this.addList()
            return this
        endmethod
        
        method onDestroy takes nothing returns nothing
            local PullUnit p = PullUnit(.pulledUnits.first.data)
            
            set .ended = true
            
            loop
                exitwhen p == 0
                
                call KnockbackTarget(this.caster, p.u, p.angle, KNOCKBACK_SPEED, KNOCKBACK_DECREMENT, true, false, false)
                
                call UnitDamageTarget(.caster, p.u, .damage, false, false, ATTACK_TYPE, DAMAGE_TYPE, WEAPON_TYPE)
                call SetUnitFlyHeight(p.u, GetUnitDefaultFlyHeight(p.u), KNOCKBACK_SPEED * KNOCKBACK_SPEED / KNOCKBACK_DECREMENT)
                
                set p = PullUnit(p.next.data)
            endloop
            
            call .pulledUnits.destroy()
            
            call DestroyEffect(AddSpecialEffect(SFX, GetUnitX(.dummy), GetUnitY(.dummy)))
            
            call .removeList()
            
            if this.getLength() == 0 then
                call PauseTimer(tim)
            endif
            
            call KillUnit(.dummy)
            set this.dummy = null
            set this.caster = null
        endmethod
        
    endstruct

    private function SpellActions takes nothing returns boolean
        local unit u
        local real x
        local real y
        local real dur
        local real rad
        local real dmg
        local integer units
        if GetSpellAbilityId() == SPELL_ID then
            set u = GetTriggerUnit()
            set dur = Duration(u)
            set x = GetSpellTargetX()
            set y = GetSpellTargetY()
            set dmg = Damage(u)
            set units = MaxUnits(u)
            set rad = AoE(u)
            call Data.create(GetTriggerUnit(), dur, x, y, dmg, units, rad, MAX_DIST, ORBIT_SPEED*TIMER_INTERVAL, MAX_HEIGHT)
        endif
        return false
    endfunction
    
    private function DeathActions takes nothing returns boolean
        local PullUnit p = PullUnit.getData(GetTriggerUnit())
        if p != 0 then
            call SetUnitFlyHeight(p.u, GetUnitDefaultFlyHeight(p.u), KNOCKBACK_SPEED * KNOCKBACK_SPEED / KNOCKBACK_DECREMENT)
            call p.destroy()
        endif
        return false
    endfunction

    //===========================================================================
    private function Init takes nothing returns nothing
        local trigger t = CreateTrigger(  )
        call TriggerRegisterAnyUnitEventBJ(t, EVENT_PLAYER_UNIT_SPELL_EFFECT)
        call TriggerAddCondition(t, Condition(function SpellActions))
        
        set t = CreateTrigger()
        call TriggerRegisterAnyUnitEventBJ(t, EVENT_PLAYER_UNIT_DEATH)
        call TriggerAddCondition(t, Condition(function DeathActions))
        
        call Preload(SFX)
        
        set UnitEnumFilter = Condition(function UnitEnum)
    endfunction

endlibrary

Changelog UPDATE (v1.0.1): Fixed a small leak in the trigger. UPDATE (v1.1.0): Kinda big update... - Replaced Silvenon's Knockback with Rising_Dusk's Knockback which is approved as a resource on wc3c.net - I now use Grim_001's ListModule for extra efficiency. - Recoded the PullUnit library completely so it is now useable separately if you want. There is currently little documentation, however, so using it might be a pain - Changed lots of little bits in the code to make it more efficient. It's still not as efficient as it could be, however. UPDATE (v1.1.1) - Fixed a bug that caused a thread crash when no units are affected by the spell. - Now I use GetSpellTargetX/Y instead of locations. UPDATE (v1.1.5) - I merged the PullUnit library with the main spell library. UPDATE (v1.2.0) - The gravity ball now pulls in enemies which come close to it after the spell has started as long as the maximum hasn't already been reached. - I now use Table to associate gravity balls with units so I can release the units from the ball when they die in mid-air. - Due to Table being used a single unit may not be attracted by two separate gravity balls any longer. - I now preload the effect so it doesn't lag the first time the spell ends. - Probably lots of other stuff that I can't remember. UPDATE (v1.2.5) - I now take into account the height of the terrain when moving the units. - Fixed a bug caused by using IMaxBJ when I should have used IMinBJ which meant 100 units could be affected by the spell no matter what level it was. UPDATE (v1.3.0) - I made the attack, damage and weapon types configurable. - Linked lists have been implemented, so there is no longer a need for the MAX_UNITS constant! - A few other minor changes.

A screenshot of RightField's permission to use his model is attached.

[fX_]

nc spell.
good that they actually have some inertia thing and dont just get moved to the center.

but the ground below caught - then flying - units remains unpathable. give them the flying type?
edit: sometimes the units dont approach the ball sideways. this might be because they collide. maybe turn this off too, along with pathing.

also, i dont think this site approves of resources that use unapproved resources. i dont think PullUnit is approved here so this spell might not be admitted for that. maybe you should get that admitted first or 'sneak it in' by putting the code in that library in library of the spell.

[Element of Water]

also, i dont think this site approves of resources that use unapproved resources. i dont think PullUnit is approved here so this spell might not be admitted for that. maybe you should get that admitted first or 'sneak it in' by putting the code in that library in library of the spell.

That doesn't count as another resource, it's just part of the spell! It isn't released anywhere...

Anyway, thanks for the feedback. I'll turn off the collision like you suggested.

EDIT:
Weird, I can't seem to be able to disable the units' collision. I couldn't work out how to make the unit's movement type flying - I don't think it's possible - and SetUnitPathing(u, false) didn't work. I also tried giving the unit the ghost (visible) ability but that also failed. Any ideas anyone?

[Rising_Dusk]

You will need to include your spell's code in the first post to facilitate the approval process.

Originally Posted by Element of Water

Silvenon's Knockback function (many credits to him for that)

You cannot use unapproved resources in your own resources submitted to this website. There is an approved Knockback System that you can use for your spell in the database, should you choose to pursue this further.

[Element of Water]

Ok, will do, just give me some time.

EDIT: Silvenon's knockback is approved as a tutorial here. Does that count?

[Rising_Dusk]

Originally Posted by Element of Water

EDIT: Silvenon's knockback is approved as a tutorial here. Does that count?

No, because it is not an approved library, but rather an approved manner of instruction on how someone could make a library. That tutorial has not passed this website's rigorous review process for code, but rather for being informative.

[Element of Water]

Ok, then, I'll change that. Currently I'm recoding the PullUnit library in the spell so it works on its own, but when I'm done with that I'll fix it so it's approvable here.

[Element of Water]

*Update*

Fixed all that was requested + made a few minor efficiency improvements. Is it approveable now?

[Rising_Dusk]

Originally Posted by Rising_Dusk

You will need to include your spell's code in the first post to facilitate the approval process.

[Element of Water]

Ok, sorry. Done.

[Viikuna-]

This spell is bugged. Try casting few of those balls without any enemy units around you, and see what happens.

Also, you should probably use those new GetSpellTargetX & GetSpellTargetY natives.

[Rising_Dusk]

Well, first of all, that PullUnit library is again not an approved resource in our database. Your submitted spells cannot require other libraries that are not approved. If you are attempting to submit that library, then you will need to submit it in its own topic and get it approved before this spell can be considered for approval.

Originally Posted by Viikuna-

Also, you should probably use those new GetSpellTargetX & GetSpellTargetY natives.

Yes.

[Rising_Dusk]

Quit being a dick, Kara. That post helps no one.

[Element of Water]

@ Viikuna
Ok, I see the problem, I loop through the picked units even if there are none, added a check for that in the new version. Also, the spell was made originally ages before the 1.24 patch, and I haven't gone through and checked it all since then. I'll change that now.

@ Rising_Dusk
The PullUnit library is just part of the spell. Yes I made it usable on its own, but it's not meant to be a resource, just part of the spell. I thought wc3c was all for modularity; the fact I used a separate library for it should be a good thing right?

Anyway, do you think it's approveable on its own? I don't think so. It doesn't have enough features to be really useful.

EDIT: Updated.

[Rising_Dusk]

Originally Posted by Element of Water

The PullUnit library is just part of the spell. Yes I made it usable on its own, but it's not meant to be a resource, just part of the spell. I thought wc3c was all for modularity; the fact I used a separate library for it should be a good thing right?

Modularity, yes, but we also don't want to approve of something that can get hacksawed into something else. What if some random person, upon this being approved with PullUnit used, wants to use your PullUnit library in another spell? Well, PullUnit was never approved, just as some chunk of another spell. So how does he get the library? He has to find your spell, which makes no sense.

Modularity without common sense is as useless as no modularity at all. If you want to use PullUnit, submit it individually and get it approved first. If you can simplify the PullUnit math (Really, friction? Just use a knockback in a different direction!) then do so and embed it. Those are the rules.

Originally Posted by Element of Water

Anyway, do you think it's approveable on its own? I don't think so. It doesn't have enough features to be really useful.

I agree.