Full Code

local termOS = require(script.Parent.Parent.Parent)

local nsUIBuffer = {}
    -- res: 20x20 (sq)
    local resolution = 20
    local display = script.Parent.Parent.Parent.Parent.Frame

    function nsUIBuffer:createRenderMap()
        termOS.eol()
        termOS.wl("Creating a nsUIImageBuffer")
        termOS.eol()
        termOS.wl("Progress:")
        termOS.eol()

        -- create uiBuffer
        local uiBuffer = Instance.new("Frame")
        uiBuffer.Parent = display
        uiBuffer.Size = UDim2.new(1,0,1,0)
        uiBuffer.BackgroundColor3 = Color3.fromRGB(0,0,0)
        uiBuffer.Visible = false

        --create uiDisplayMatrix
        local matrix = {}
        local bmp = {x=0,y=0}
        for x=0, resolution, display.Size.X.Scale/resolution do
            bmp.x = bmp.x + 1
            matrix[tostring(bmp.x)] = {}
            for y=0, resolution, display.Size.Y.Scale/resolution do
                bmp.y = bmp.y + 1
                local pixel = Instance.new("Frame")
                pixel.Size = UDim2.new(display.Size.X.Scale/resolution, display.Size.Y.Scale/resolution)
                pixel.Position = UDim2.new(x,0,y,0)
                pixel.BackgroundColor3 = Color3.fromRGB(0,0,0)
                pixel.BorderSizePixel = 0
                pixel.Parent = uiBuffer
                matrix[tostring(bmp.x)][tostring(bmp.x)] = {r=0,g=0,b=0,a=1, o=pixel} -- R G B Alpha (1=Opaque, 0=Transparent) Object
            end
            local bfr = ""
            -- a * d / c = b
            for j=0, math.floor( ( x * 100 / resolution ) ) do
                bfr = bfr .. "#"
            end
            for j=0, 100-#bfr do
                bfr = bfr .. " "
            end
            termOS.wl("[ " .. bfr .. " ]")
            wait()
        end

        termOS.eol()
        termOS.wl("Done; clearing TerminalUIBuffer")

        display.buffer:ClearAllChildren()
        display.buffer.Visible = false

        rawset(self, "buffer", uiBuffer)
        rawset(self, "matrix", matrix)

        return self
    end

    function nsUIBuffer:render(displayMatrix)
        for a,x in pairs(displayMatrix) do
            if (x=={}) then
            else
                for c,y in pairs(x) do
                    if (y=={}) then
                    else
                        for d,pixel in pairs(y) do
                            if (pixel=={}) then
                            else
                                local pixel = rawget(self, "matrix")
                                print(unpack(pixel))
                                pixel = pixel[tostring(x)][tostring(y)]["o"]
                                pixel.BackgroundColor3 = Color3.fromRGB(pixel.r,pixel.g,pixel.b)
                            end
                            wait()
                        end
                    end
                    wait()
                end
            end
            wait()
        end
    end

return function(args)
    if #args==1 then
        termOS.eol()
        termOS.wl("This is an API, not an app!")
    else
        return setmetatable(nsUIBuffer,{})
    end
end