[JASS] Acceleration system, drag not working

[Diehard@Azeroth]

alright, im not a really good mathematician, so im guesing i messed up in the math in the drag, anyways, let me tell you the story first: i started creating a movement acceleration system that deaccelerates units when they go over higher terrains, and accelerates them when going down, the only problem i got was that the player can turn down, gain acceleration and go over a higher terrain that he isnt supposed to be able to pass due to his deacceleration.

so i decided to create a movement drag, triggering isnt that efficient yet tho, but il improve it later on:

library Acceleration
    
    globals
        private timer t = CreateTimer()
        private group accelUnits = CreateGroup()
        private location Zloc = Location(0.,0.)
        private integer maxAccel = 0
        private real tIteration = 0.15 // timer periodic iteration
        private real checkDist = 10. 
        private constant real gravity = -9.81 // gravity's real value, make it lower to lower the acceleration/deacceleration change
        // drag globals
        private timer d = CreateTimer()
        private real dragIteration = 0.06 // drag timer periodic iteration
        private group dragGroup = CreateGroup()
        private integer maxDrag = 0
        private real array drag
        private real array angle
        private constant real dragGravity = gravity*dragIteration*-1
        private boolean array isDrag
        private real NoDrag = 15. //maximum difference in Z that cannot cause any drag
    endglobals
    
    private function GetLocZ takes real x, real y returns real
        call MoveLocation(Zloc, x, y)
        return GetLocationZ(Zloc)
    endfunction
    
    private function coreDrag takes nothing returns nothing
        local unit e = GetEnumUnit()
        local integer i = GetHandleId(e)
        local real a = angle[i]
        local real x = GetUnitX(e)
        local real y = GetUnitY(e)
        local real x2 = x+checkDist*Cos(a)
        local real y2 = y+checkDist*Sin(a)
        local real diffZ = GetLocZ(x2,y2)-GetLocZ(x,y)
        if diffZ < -NoDrag or diffZ > NoDrag then
            set drag[i] = drag[i] + dragGravity
            call SetUnitPosition(e, x+drag[i]*Cos(a), y+drag[i]*Sin(a))
        else
            call GroupRemoveUnit(dragGroup, e)
            set isDrag[i] = false
           set maxDrag = maxDrag - 1
            if maxDrag == 0 then
                call PauseTimer(d)
            endif
        endif
        set e = null
    endfunction
    
    private function DragUnits takes nothing returns nothing
        call ForGroup(dragGroup, function coreDrag)
    endfunction
    
    private function coreAccel takes nothing returns nothing
        local unit e = GetEnumUnit()
        local real f = GetUnitFacing(e)*bj_DEGTORAD
        local real x = GetUnitX(e)
        local real y = GetUnitY(e)
        local real x2 = x+checkDist*Cos(f)
        local real y2 = y+checkDist*Sin(f)
        local real defaultSpeed = GetUnitDefaultMoveSpeed(e)
        local real newSpeed = defaultSpeed+(gravity*(GetLocZ(x2,y2)-GetLocZ(x,y)))
        if newSpeed > defaultSpeed then
            if isDrag[GetHandleId(e)] == false then
                set isDrag[GetHandleId(e)] = true
                set drag[GetHandleId(e)] = defaultSpeed*dragIteration
                set angle[GetHandleId(e)] = f
                set maxDrag = maxDrag + 1
                call GroupAddUnit(dragGroup, e)
                call TimerStart(d, dragIteration, true, function DragUnits)
            endif
        else
            call SetUnitMoveSpeed(e, newSpeed)
        endif
        set e = null
    endfunction
    
    private function AccelerateUnits takes nothing returns nothing
        call ForGroup(accelUnits, function coreAccel)
    endfunction
    
    function AddUnitAcceleration takes unit u returns nothing
        if u == null then
            return
        endif
        call GroupAddUnit(accelUnits, u)
        set maxAccel = maxAccel + 1
        call TimerStart(t, tIteration, true, function AccelerateUnits)
    endfunction

    function RemoveUnitAcceleration takes unit u returns nothing
        if u == null then
            return
        endif
        call GroupRemoveUnit(accelUnits, u)
        call SetUnitMoveSpeed( u, GetUnitDefaultMoveSpeed(u) )
        set maxAccel = maxAccel - 1
        if maxAccel == 0 then
            call PauseTimer(t)
        endif
    endfunction

endlibrary

btw it may be because im using GetHandleId(), but thats a native and should work accordingly :/

ty for your time

PROBLEM FIXED: IT WAS WITH HANDLES