I've been trying to figure out the problem for a while. A friend has helped help me occasionally, but I think it's unfair to have him take me step-by-step through every little problem I have while learning JASS (which has been a lot). So I'm finally going to post here, asking for help.
It works if I just call the function instead of using a timer with callback; but once I add the timer, it stops working. And, yes, I know that I have nothing to stop the trigger early if the channeling is interrupted. I figured I should probably get it working through the whole duration before I bother with that.
Drain Blood:
globals
unit Caster
location Loc
integer d
endglobals
function Trig_Drain_Blood_Conditions takes nothing returns boolean
return GetSpellAbilityId( ) == 'A003'
endfunction
function Drain_Blood_Filter takes nothing returns boolean
return IsPlayerEnemy (GetOwningPlayer(GetTriggerUnit()), GetOwningPlayer(GetFilterUnit())) and GetWidgetLife(GetFilterUnit()) > 0.405 and not IsUnitType( GetFilterUnit(), UNIT_TYPE_FLYING)
endfunction
function Drain_Blood_CopyGroup takes group g returns group
set bj_groupAddGroupDest = CreateGroup()
call ForGroup(g, function GroupAddGroupEnum)
return bj_groupAddGroupDest
endfunction
function Drain_Blood_Callback takes nothing returns nothing
local timer t = GetExpiredTimer()
local unit c = Caster
local real x = GetLocationX(Loc)
local real y = GetLocationY(Loc)
local boolexpr b = Condition(function Drain_Blood_Filter)
local group g = CreateGroup()
local group n
local unit f
call GroupEnumUnitsInRange(g, x, y, 400., b)
set n = Drain_Blood_CopyGroup(g)
loop
set f = FirstOfGroup(n)
exitwhen f == null
call UnitDamageTarget(c, f, 10, true, false, ATTACK_TYPE_NORMAL, DAMAGE_TYPE_MAGIC, null)
call GroupRemoveUnit(n, f)
endloop
set d = d - 1
set c = null
set g = null
set n = null
if d == 0 then
call DestroyTimer(t)
set Caster = null
set Loc = null
endif
set t = null
endfunction
function Trig_Drain_Blood_Actions takes nothing returns nothing
local timer t = CreateTimer()
set Caster = GetSpellAbilityUnit()
set Loc = GetSpellTargetLoc()
set d = 10
call TimerStart(t, 1, true, function Drain_Blood_Callback)
set t = null
endfunction
function InitTrig_Drain_Blood takes nothing returns nothing
set gg_trg_Drain_Blood = CreateTrigger( )
call TriggerRegisterAnyUnitEventBJ( gg_trg_Drain_Blood, EVENT_PLAYER_UNIT_SPELL_EFFECT )
call TriggerAddCondition( gg_trg_Drain_Blood, Condition( function Trig_Drain_Blood_Conditions ) )
call TriggerAddAction( gg_trg_Drain_Blood, function Trig_Drain_Blood_Actions )
endfunction
