Roblox 2D Triangle Drawer

local Quality = 2

--Points are based on offset, do not account for scale!
local function DrawTriangle(Parent,Point1,Point2,Point3)
    local X1,Y1 = Point1.X.Offset,Point1.Y.Offset
    local X2,Y2 = Point2.X.Offset,Point2.Y.Offset
    local X3,Y3 = Point3.X.Offset,Point3.Y.Offset

    local function Lerp(S,E,A)
        return S + (E-S)*A
    end


    local function GetLeftAndRightPointsOnY(PosY)
        local ReturnPoint1,ReturnPoint2
        local function SetPoint(UDim1,UDim2)
            if not ReturnPoint1 then
                ReturnPoint1 = {UDim1,UDim2}
            elseif not ReturnPoint2 then
                ReturnPoint2 = {UDim1,UDim2}
            end
        end

        if (Y1 < PosY and Y2 >= PosY) or (Y2 < PosY and Y1 >= PosY) then
            SetPoint(Point1,Point2)
        end
        if (Y3 < PosY and Y2 >= PosY) or (Y2 < PosY and Y3 >= PosY) then
            SetPoint(Point2,Point3)
        end
        if (Y1 < PosY and Y3 >= PosY) or (Y3 < PosY and Y1 >= PosY) then
            SetPoint(Point1,Point3)
        end

        return ReturnPoint1,ReturnPoint2
    end

    local function GetLeftAndRightPointsOnX(PosX)
        local ReturnPoint1,ReturnPoint2
        local function SetPoint(UDim1,UDim2)
            if not ReturnPoint1 then
                ReturnPoint1 = {UDim1,UDim2}
            elseif not ReturnPoint2 then
                ReturnPoint2 = {UDim1,UDim2}
            end
        end

        if (X1 < PosX and X2 >= PosX) or (X2 < PosX and X1 >= PosX) then
            SetPoint(Point1,Point2)
        end
        if (X3 < PosX and X2 >= PosX) or (X2 < PosX and X3 >= PosX) then
            SetPoint(Point2,Point3)
        end
        if (X1 < PosX and X3 >= PosX) or (X3 < PosX and X1 >= PosX) then
            SetPoint(Point1,Point3)
        end

        return ReturnPoint1,ReturnPoint2
    end

    local function DrawLineOnY(PosY)
        local Pos1T,Pos2T = GetLeftAndRightPointsOnY(PosY)
        if Pos1T and Pos2T then
            local function GetRatio(Point1Y,Point2Y)
                local Point2Y,PosY = Point2Y - Point1Y,PosY - Point1Y
                return PosY/Point2Y
            end

            local R1,R2 = GetRatio(Pos1T[1].Y.Offset,Pos1T[2].Y.Offset),GetRatio(Pos2T[1].Y.Offset,Pos2T[2].Y.Offset)
            local LerpedPos1,LerpedPos2 = UDim2.new(0,Lerp(Pos1T[1].X.Offset,Pos1T[2].X.Offset,R1),0,PosY),UDim2.new(0,Lerp(Pos2T[1].X.Offset,Pos2T[2].X.Offset,R2),0,PosY)

            if LerpedPos1.X.Offset > LerpedPos2.X.Offset then
                local TempPos = LerpedPos2
                LerpedPos2,LerpedPos1 = LerpedPos1,TempPos
            end

            local Length = LerpedPos2.X.Offset - LerpedPos1.X.Offset
            if Length > 0 then
                local Frame = Instance.new("Frame")
                Frame.Position = LerpedPos1
                Frame.Size = UDim2.new(0,Length,0,Quality)
                Frame.BorderSizePixel = 0
                Frame.Parent = Parent
            end
        end
    end

    local function DrawLineOnX(PosX)
        local Pos1T,Pos2T = GetLeftAndRightPointsOnX(PosX)
        if Pos1T and Pos2T then
            local function GetRatio(Point1X,Point2X)
                local Point2X,PosX = Point2X - Point1X,PosX - Point1X
                return PosX/Point2X
            end

            local R1,R2 = GetRatio(Pos1T[1].X.Offset,Pos1T[2].X.Offset),GetRatio(Pos2T[1].X.Offset,Pos2T[2].X.Offset)
            local LerpedPos1,LerpedPos2 = UDim2.new(0,PosX,0,Lerp(Pos1T[1].Y.Offset,Pos1T[2].Y.Offset,R1)),UDim2.new(0,PosX,0,Lerp(Pos2T[1].Y.Offset,Pos2T[2].Y.Offset,R2))

            if LerpedPos1.Y.Offset > LerpedPos2.Y.Offset then
                local TempPos = LerpedPos2
                LerpedPos2,LerpedPos1 = LerpedPos1,TempPos
            end

            local Length = LerpedPos2.Y.Offset - LerpedPos1.Y.Offset
            if Length > 0 then
                local Frame = Instance.new("Frame")
                Frame.Position = LerpedPos1
                Frame.Size = UDim2.new(0,Quality,0,Length)
                Frame.BorderSizePixel = 0
                Frame.Parent = Parent
            end
        end
    end

    local MinX = math.min(Point1.X.Offset,Point2.X.Offset,Point3.X.Offset)
    local MaxX = math.max(Point1.X.Offset,Point2.X.Offset,Point3.X.Offset)
    local MinY = math.min(Point1.Y.Offset,Point2.Y.Offset,Point3.Y.Offset)
    local MaxY = math.max(Point1.Y.Offset,Point2.Y.Offset,Point3.Y.Offset)

    if (MaxY - MinY) < (MaxX - MinX) then
        for Add = 1, (MaxY - MinY)/Quality do
            DrawLineOnY(MinY + (Quality*Add))
        end
    else
        for Add = 1, (MaxX - MinX)/Quality do
            DrawLineOnX(MinX + (Quality*Add))
        end
    end
end


local Point1 = UDim2.new(0,220,0,20)
local Point2 = UDim2.new(0,25,0,100)
local Point3 = UDim2.new(0,170,0,260)

local Point4 = UDim2.new(0,300,0,500)
local Point5 = UDim2.new(0,500,0,500)
local Point6 = UDim2.new(0,500,0,300)

game.StarterGui.ScreenGui.Container:ClearAllChildren()
DrawTriangle(game.StarterGui.ScreenGui.Container,Point1,Point2,Point3)
DrawTriangle(game.StarterGui.ScreenGui.Container,Point4,Point5,Point6)