box select

local ReplicatedStorage = game:GetService("ReplicatedStorage")
local UserInputService = game:GetService("UserInputService")
local RunService = game:GetService("RunService")
local Players = game:GetService("Players")

local player = Players.LocalPlayer
local selectTemplate = ReplicatedStorage.select
local selecting = false
local select: Instance, mouseStart: Vector2, mouseEnd: Vector2


UserInputService.InputBegan:Connect(function(input, processed)
    if processed then return end
    if input.UserInputType == Enum.UserInputType.MouseButton1 then
        if not selecting then
            selecting = true
            select = ReplicatedStorage.select:Clone()
            select.Parent = player.PlayerGui.selection
            mouseStart = UserInputService:GetMouseLocation()
            select.Position = UDim2.fromOffset(mouseStart.X, mouseStart.Y)
        end
    end
end)

UserInputService.InputEnded:Connect(function(input, processed)
    if input.UserInputType == Enum.UserInputType.MouseButton1 then
        if selecting then
            selecting = false
            select:Destroy()
        end
    end
end)

RunService.Heartbeat:Connect(function(dt)
    if selecting then
        mouseEnd = UserInputService:GetMouseLocation()

        local x = (mouseStart.X - mouseEnd.X)
        local y = (mouseStart.Y - mouseEnd.Y)
        select.Size = -UDim2.fromOffset(x, y)
    end
end)