2D Collision Detection

local world = {}
world.__index = world

local runService = game:GetService("RunService")

local function getPoints(Obj)
    local top = Obj.Position + UDim2.new(0,0,0,Obj.Size.Y.Offset/2)
    local bottom = Obj.Position - UDim2.new(0,0,0,Obj.Size.Y.Offset/2)
    local left = Obj.Position - UDim2.new(0,Obj.Size.X.Offset/2,0,0)
    local right = Obj.Position + UDim2.new(0,Obj.Size.X.Offset/2,0,0)

    return {
        ["Top"] = top,
        ["Bottom"] = bottom,
        ["Left"] = left,
        ["Right"] = right
    }
end

function world.new()
    return setmetatable({
        _Thread = nil,
        _World = {},
        _Yield = false,
        Colliding = {}
    },world)
end

function world:GetObjects()
    return self._World
end

function world:GetCollisions()
    return self.Colliding
end

function world:Pause()
    self._Yield = true
end

function world:Run()
    self._Yield = false

    if not self._Thread then
        self._Thread = coroutine.create(function()
            runService.RenderStepped:Connect(function()
                if self._Yield then
                    coroutine.yield()
                end

                for _,obj in pairs(self._World) do
                    if not self.Colliding[obj] then
                        self.Colliding[obj] = {}
                    end

                    for _,anObj in pairs(self._World) do
                        if anObj ~= obj then
                            local oP = getPoints(obj)
                            local aOP = getPoints(anObj)

                            if aOP.Top.Y.Offset >= oP.Bottom.Y.Offset and aOP.Top.Y.Offset <= oP.Top.Y.Offset or aOP.Bottom.Y.Offset <= oP.Bottom.Y.Offset and aOP.Bottom.Y.Offset >= oP.Top.Y.Offset then
                                if aOP.Right.X.Offset >= oP.Left.X.Offset and aOP.Right.X.Offset <= oP.Right.X.Offset or aOP.Left.X.Offset <= oP.Right.X.Offset and aOP.Left.X.Offset >= oP.Left.X.Offset then
                                    if not table.find(self.Colliding[obj], anObj) then
                                        table.insert(self.Colliding[obj], anObj)
                                    end
                                end
                            end
                        end
                    end
                end
            end)
        end)
    end

    coroutine.resume(self._Thread)
end

function world:RemoveObject(obj)
    local pos = table.find(self._World, obj)
    table.remove(self._World, pos)
    obj:Destroy()
end

local object = {}
object.__index = object

function world:AddObject(Size)
    local obj = Instance.new("ImageLabel")
    obj.Size = Size
    obj.AnchorPoint = Vector2.new(0.5,0.5)
    obj.Name = "Object"..#self._World+1

    self._World[#self._World+1] = obj

    return setmetatable({
        Object = obj
    },object)
end

function object:Destroy()
    local pos = table.find(self._World, self.Object)
    table.remove(self._World, pos)
    self.Object:Destroy()
    self.Object = nil
end

return world