Custom Roblox TweenService

local Chrome = require(script.Parent)
local Utility = require(Chrome.Utility)

local RBXTweenService = game:GetService("TweenService")
local RunService = game:GetService("RunService")

local Heartbeat = RunService.Heartbeat

local TweenHandlerObjectLimit = 126

local HandlersLength = 0

local function LerpNumber(a,b,c)
    return a + (b-a) * c
end

local function RemoveFromList(List, Value, Index)
    table.remove(List, Index or table.find(List, Value))
    Value = nil
end

local function SortFunction(a, b)
    return a.Length < b.Length
end

local AvaibleHandlers = {}

local function SortAvaibleHandlers()
    table.sort(AvaibleHandlers, SortFunction)
end

local function RunTweening(TweenHandler)
    local TweenList = TweenHandler.TweenList

    coroutine.wrap(function()
        while TweenHandler.Length > 0 do
            local Step = Heartbeat:Wait()
            for i = TweenHandler.Length, 1, -1 do
                local TweenObject = TweenList[i]
                local Object = TweenObject[1]
                local Info = TweenObject[2]
                local GoalData = TweenObject[3]

                local Progress = TweenObject[6] + Step * TweenObject[5]
                Progress = Progress > 1 and 1 or Progress

                for i = 1, TweenObject[4] do
                    local CurrentGoalData = GoalData[i]
                    Object[CurrentGoalData[1]] = CurrentGoalData.Type == "number" and LerpNumber(CurrentGoalData[2], CurrentGoalData[3], Progress) or CurrentGoalData[2]:Lerp(CurrentGoalData[3], RBXTweenService:GetValue(Progress, Info[2], Info[3]))
                end

                if Progress == 1 then
                    RemoveFromList(TweenList, TweenObject, i)
                    TweenHandler.Length -= 1
                    TweenObject.Completed:Fire()

                    SortAvaibleHandlers()
                    continue
                end

                TweenObject[6] = Progress
            end
        end

        --// After TweenList is empty ( completed tweening all scheduled objects) removes the list
        HandlersLength -= 1
        RemoveFromList(AvaibleHandlers, TweenHandler)
    end)()
end

local function CreateTweenHandler()
    local TweenHandler = {
        Length = 0,
        TweenList = {},
        Running = false
    }

    --// Cache into avaible Handlers
    HandlersLength += 1
    AvaibleHandlers[HandlersLength] = TweenHandler

    SortAvaibleHandlers()

    return TweenHandler
end

local function PlayMethod(TweenObject)
    local TweenHandler = AvaibleHandlers[1] or CreateTweenHandler()
    local Length = TweenHandler.Length + 1

    if Length > TweenHandlerObjectLimit then
        --// Remove from avaible
        table.remove(AvaibleHandlers, table.find(AvaibleHandlers, TweenHandler))
        HandlersLength -= 1

        ----// Add to avaible
        TweenHandler = CreateTweenHandler()
        Length = 1
    end

    TweenHandler.Length = Length

    TweenHandler.TweenList[Length] = TweenObject

    TweenObject.Handler = TweenHandler
    TweenObject.ListIndex = Length

    if not TweenHandler.Running then TweenHandler.Running = true RunTweening(TweenHandler) end
end

local function StopMethod(TweenObject)
    local Handler = TweenObject.Handler

    Handler.Length -= 1
    table.remove(Handler.TweenList, TweenObject.ListIndex)
end

local Module = {}

function Module.new(Object, Info, Goal)
    Info = type(Info) == "number" and {Info} or Info
    Info[2] = Info[2] or "Linear"
    Info[3] = Info[3] or "In"

    local GoalData = {}
    local GoalLength = 0

    for Property, EndValue in pairs(Goal) do
        GoalLength += 1
        GoalData[GoalLength] = {Property, Object[Property], EndValue, Type = type(EndValue)}
    end

    local TweenObject = {
        Object,
        Info,
        GoalData,
        GoalLength,

        1 / Info[1], --// 1 / Time, Time represents how much time it takes to Tween the object
        0, --// Progress

        Play = PlayMethod,
        Stop = StopMethod,

        Completed = Utility.NewEvent()
    }

    return TweenObject
end

return Module