Divine Shield (Damage Absorb) Problem!

[spectre37]

I try to make a Divine Shield which absorb all damage taken on target unit, but target still takes damage from the first damage that inflicted it. I don't know what part in my code is bugged.

Thanks for your help

function Divine_Shield_Con takes nothing returns boolean
    return GetSpellAbilityId() == 'A00R'
endfunction

function Divine_Shield takes nothing returns nothing
    local trigger t = GetTriggeringTrigger()
    local unit c = GetTriggerUnit()    
    local real dmg = GetEventDamage()
          
function Divine_Shield takes nothing returns nothing
    local trigger t = GetTriggeringTrigger()
    local unit c = GetTriggerUnit()    
    local real dmg = GetEventDamage()
          
    if UnitHasBuffBJ(c, 'BHds') == false then
        call DisableTrigger(t)
        call DestroyTrigger(t)        
    elseif dmg > 0 then 
        call SetUnitState(c, UNIT_STATE_LIFE, GetUnitState(c, UNIT_STATE_LIFE) + dmg)
    endif    
endfunction  
endfunction

function Divine_Shield_Act takes nothing returns nothing
    local trigger t
    local unit c = GetSpellTargetUnit()
    
    call UnitRemoveBuffs(c, false, true)
    if UnitHasBuffBJ(c, 'BHds') == false then [COLOR="#008000"]//======= Prevent Trigger Overlaps[/COLOR]
        
        set t = CreateTrigger()
        call TriggerRegisterUnitEvent( t, c, EVENT_UNIT_DAMAGED )
        call TriggerAddAction( t, function Divine_Shield )
    endif
endfunction

//===========================================================================
function InitTrig_Divine_Shield takes nothing returns nothing
    set gg_trg_Divine_Shield = CreateTrigger(  )
    call TriggerRegisterAnyUnitEventBJ( gg_trg_Divine_Shield, EVENT_PLAYER_UNIT_SPELL_EFFECT )
    call TriggerAddCondition( gg_trg_Divine_Shield, Condition( function Divine_Shield_Con ) )
    call TriggerAddAction( gg_trg_Divine_Shield, function Divine_Shield_Act )
endfunction

 

[Ayanami]

First of all, this should belong in the JASS section, not here.

It's not a bug. The event "Unit takes damage" is fired right before the damage is actually dealt. So your trigger doesn't work if unit's current hp + damage received exceeds the unit's max hp. And it also doesn't work when the damage is greater than your unit's max hp. For example:

Unit has 50/100 HP. Unit receives 20 pure damage. The trigger is ran and Unit's HP is set to current HP (50) + Damage (20). Thus, Unit's HP is now 70. Then, the damage is dealt, causing your Unit to have 50 HP. Thus, you "prevented" damage. Works fine.

Another scenario. Unit has 100/100 HP. Unit receives 20 pure damage. The trigger is ran and Unit's HP is set to current HP (100) + Damage (20). However, notice that Unit's HP still remains at 100 as your maximum is already at 100. Then damage is dealt, causing your unit to have 80 HP. Your damage prevention failed here.

Again, another scenario. Unit has 100/100 HP. Unit receives 200 pure damage. The trigger is ran and Unit's HP is set to current HP (100) + Damage (200). But since your max HP is 100, your HP remains at 100. Damage is dealt and your unit dies. Damage prevention failed again.

To successfully overcome all these scenarios, you need to add an ability that adds extremely high amount of max HP (99999) when (Current HP + Damage > Max HP) and when (Damage > Max HP). Then, run a 0-seconds timer and remove the max HP.

globals
    timer BlockTimer = CreateTimer()
    integer BlockCount = -1
    integer BlockAbil = 'A000' // ability that adds 100000 max life
    
    real array BlockLife
    unit array BlockUnit
endglobals

function BlockFunc takes nothing returns nothing
    loop
        exitwhen BlockCount == -1
        
        call UnitRemoveAbility(BlockUnit[BlockCount], BlockAbil)
        call SetWidgetLife(BlockUnit[BlockCount], BlockLife[BlockCount])
        set BlockCount = BlockCount - 1
    endloop
endfunction

function OnDamage takes nothing returns nothing
    local unit u = GetTriggerUnit()
    local real currHp = GetWidgetLife(u)
    local real dmg = GetEventDamage()

    if currHp + dmg > GetUnitState(u, UNIT_STATE_MAX_LIFE) then
        set BlockCount = BlockCount + 1
        set BlockUnit[BlockCount] = u
        set BlockLife[BlockCount] = currHp + dmg
        
        call UnitAddAbility(u, BlockAbil)
        call SetWidgetLife(u, GetUnitState(u, UNIT_STATE_MAX_LIFE))
        call TimerStart(BlockTimer, 0, false, function BlockFunc)
    else
        call SetWidgetLife(u, currHp + dmg)
    endif
    
    set u = null
endfunction

Okay, now re-imagine the scenario again with the above code.

Unit has 100/100 HP. Unit receives 20 damage. Since Current HP + Damage (120) is greater than Unit's Max HP (100), the trigger 100000 max life is added to Unit and Unit's HP is set to its max HP (100100). Unit receives 20 damage, thus now has 100080 HP. The max life is removed and then Unit's HP is set back to his HP before taking damage (100 HP). Damage prevention successful.

Next scenario, Unit has 100/100 HP. Unit receives 200 damage. Since Current HP + Damage (120) is greater than Unit's Max HP (100), the trigger 100000 max life is added to Unit and Unit's HP is set to its max HP (100100). Unit receives 200 damage, thus now has 99800 HP. The max life is removed and then Unit's HP is set back to his HP before taking damage (100 HP). Damage prevention successful.

 

[Dirac]

With this system you can code a shield in 1 line
>Damage<

 

[spectre37]

Thanks a lot it's work now, sry for post in wrong section.