term.clear()
term.setCursorPos(1, 1)
term.setTextColor(colors.white)

local tw, th = term.getSize()
print(string.format("Terminal: %dx%d", tw, th))
local function printScale(c1, c2, p, fmt, ...)
    local str = string.format(fmt, ...)
    local w1 = math.ceil(p * tw)
    local w2 = tw - w1

    local bg = term.getBackgroundColor()
    term.setBackgroundColor(c1)
    term.write(str:sub(1, w1))
    local rem = w1 - #str
    if rem > 0 then
        term.write(string.rep(" ", rem))
    end

    term.setBackgroundColor(c2)
    term.write(str:sub(w1 + 1, w1 + w2))

    rem = math.min(tw - #str, w2)
    if rem > 0 then
        term.write(string.rep(" ", rem))
    end

    term.setBackgroundColor(bg)
    print()
end


term.setBackgroundColor(colors.black)
local t = 0
while true do
    for i = 1, th do
        local p = 0.5 + 0.5 * math.sin((i + t) * math.pi / 25)
        term.setCursorPos(1, i)
        printScale(colors.red, colors.gray, p, "%7.3f%%", p * 100)
    end
    os.sleep(0.05)
    t = t + 1
end