library ImageTrail requires MapFunctions
    
    globals
        //integer IMAGETRAILSPAWNTIME = 4
        //integer IMAGETRAILFADEINTERVAL = 7
        real IMAGEDURATION = 1.0928
        real IMAGETRAILSEPERATION = .1
    endglobals

    struct TrailData
        unit caster
        boolean on
        LinkedList list
        real x
        real y
        real maxtime
        real duration = 0
        player p
        integer constraint = 0
        integer spawntime
        integer fadeinterval
        integer num = 0
        effect blur
        
        static method create takes real ImgDur, real ImgSep, real MaxTime, unit u returns TrailData
            local TrailData td = TrailData.allocate()
            local real imgdur
            local real imgsep
            local real maxtime
            if ImgDur == 0 then
                set imgdur = IMAGEDURATION
            else
                set imgdur = ImgDur
            endif
            if ImgSep == 0 then
                set imgsep = IMAGETRAILSEPERATION
            else
                set imgsep = ImgSep
            endif
            if MaxTime == 0 then
                set maxtime = HYPERTIME
            else
                set maxtime = MaxTime
            endif
            set td.spawntime = R2I(imgsep/TIMEREXEC)
            set td.fadeinterval = R2I((255/IMAGEDURATION)/TIMEREXEC)
            set td.caster = u
            set td.list = LinkedList.create()
            set td.p = GetOwningPlayer(u)
            set td.on = true
            set td.x = GetUnitX(u)
            set td.y = GetUnitY(u)
            return td
        endmethod
    endstruct

    function ImageTrailChild takes nothing returns nothing
        local timer t = GetExpiredTimer()
        local TrailData td = GHInt(t,"data")
        local integer i = 0    
        local real x = GetUnitX(td.caster)
        local real y = GetUnitY(td.caster)
        local real distsquared = ( (x-td.x)*(x-td.x) ) + ( (y-td.y)*(y-td.y) )
        local unit trailimage
        local integer fade
        local Node node
        local Node temp
        if(not(GHBoolean(t,"cleartimer"))) then
            if(td.on and td.constraint==0) then
                if distsquared != 0 then
                    set node = td.list.add()
                    set trailimage = CreateUnit(td.p,'h00A',x,y,GetUnitFacing(td.caster))
                    set node.part = trailimage
                    call SetUnitTimeScale(trailimage,.01)
                    call SetUnitX(trailimage,x)
                    call SetUnitY(trailimage,y)
                    call SetUnitFlyHeight(trailimage,GetUnitFlyHeight(td.caster),100000)
                    call SHInt(trailimage,"fade",255)
                    set td.num = td.num+1
                endif
                call DestroyEffect(td.blur)
                set td.blur = AddSpecialEffectTarget("Abilities\\Spells\\Orc\\MirrorImage\\MirrorImageCaster.mdl", td.caster, "origin")
            endif

            if td.num > 0 then
                set trailimage = td.list.end.part
                set node = td.list.front
                loop
                    set trailimage = node.part
                    set fade = GHInt(trailimage,"fade")
                    if (fade<=1) then
                        set temp = node.next
                        call td.list.remove(node,temp)
                        call FHLocals(trailimage)
                        call RemoveUnit(trailimage)
                        set node = temp
                        set td.num = td.num-1
                    else
                        call SetUnitVertexColor(trailimage,200,200,200,fade)
                        call SHInt(trailimage,"fade",fade-td.fadeinterval)
                    endif 
                    exitwhen node == td.list.end or td.num == 0
                    set node = node.next
                endloop
            endif
            set td.duration = td.duration+TIMEREXEC
            if td.duration >= td.maxtime then
                set td.on = false
            endif
            set td.x = x
            set td.y = y
            if (td.constraint == td.spawntime) then
                set td.constraint = 0
            else
                set td.constraint = td.constraint + 1
            endif
            if td.list.size == 0 and not(td.on) then
                call SHBoolean(t,"cleartimer",true)
            endif
        else
            call FHLocals(t)
            call DestroyTimer(t)
            call LinkedList.destroy(td.list)
            call TrailData.destroy(td)
        endif

        set t = null
        set trailimage = null
    endfunction

    function EnableImageTrail takes real ImgDur, real ImgSep, real MaxTime, unit u returns TrailData
        local timer t = CreateTimer()
        local TrailData td = TrailData.create(ImgDur,ImgSep,MaxTime,u)
        call SHInt(t,"data",td)
        call TimerStart(t,TIMEREXEC,true,function ImageTrailChild)
        set t = null
        return td
    endfunction

endlibrary
function InitTrig_Image_Trail takes nothing returns nothing
endfunction