What do you think of this design?

-- run within https://akkartik.itch.io/carousel
g = love.graphics
rect = g.rectangle
color = g.setColor
floor = math.floor

Limit = 13
Byo_yomi_period = 30 -- seconds

Curr_color = 'black'
Byo_yomi = {
black=0,
white=0,
}

Curr_time = 0

function car.update(dt)
if Byo_yomi.black == Limit or Byo_yomi.white == Limit then
return
end
Curr_time = Curr_time + dt
if Curr_time > Byo_yomi_period then
Byo_yomi[Curr_color] = Byo_yomi[Curr_color] + 1
Curr_time = Curr_time - Byo_yomi_period
end end

-- initialize space per side
local side_w = floor((Safe_width-60 - 100)/2)

-- initialize font size
local function font_size_for_chess_clock()
local font_size
local min_font_size = 20
local max_font_size = Safe_height
for i=1,100 do
if min_font_size >= max_font_size-5 then
break
end
font_size = floor((min_font_size+max_font_size)/2)
local font = g.newFont(font_size)
local w = font:getWidth('00:00:00')
if w < side_w then
min_font_size = font_size
elseif w > side_w then
max_font_size = font_size
elseif w == side_w then
break
end
end
return font_size
end

local large_font_size = font_size_for_chess_clock()
local large_font = g.newFont(large_font_size)
local small_font_size = 20
local small_font = g.newFont(small_font_size)

function car.draw()
local top = Menu_height+20
local x = 30
local height = Safe_height-80
local gutter_width = 100
-- black side
color(0.2,0.2,0.2)
rect('fill', x, top, side_w, height, 5,5)
color(1,1,1)
local y
if Byo_yomi.black < Limit - 10 then
y = top + (height-large_font_size)/2
print_centered(large_font, Byo_yomi.black, y, x, side_w)
if Curr_color == 'black' then
y = y + large_font_size + 10
print_centered(small_font, floor(Curr_time), y, x, side_w)
end
elseif Byo_yomi.black < Limit-1 then
y = top + (height - large_font_size*2 - 10)/2
local s = ('%d left'):format(Limit - Byo_yomi.black)
print_centered(large_font, s, y, x, side_w)
if Curr_color == 'black' then
y = y + large_font_size + 10
print_centered(large_font, floor(Curr_time), y, x, side_w)
end
elseif Byo_yomi.black == Limit-1 then
y = top + (height - large_font_size - 10 - small_font_size)/2
print_centered(small_font, "no time left", y, x, side_w)
if Curr_color == 'black' then
y = y + small_font_size + 10
print_centered(large_font, floor(Curr_time), y, x, side_w)
end
else
-- out of time; Byo_yomi.black == Limit
-- print nothing
end
-- white side
x = x + side_w + gutter_width
color(0,0,0)
rect('line', x, top, side_w, height, 5,5)
if Byo_yomi.white < Limit-10 then
y = top + (height-large_font_size)/2
print_centered(large_font, Byo_yomi.white, y, x, side_w)
if Curr_color == 'white' then
y = y + large_font_size + 10
print_centered(small_font, floor(Curr_time), y, x, side_w)
end
elseif Byo_yomi.white < Limit-1 then
y = top + (height - large_font_size*2 - 10)/2
local s = ('%d left'):format(Limit - Byo_yomi.white)
print_centered(large_font, s, y, x, side_w)
if Curr_color == 'white' then
y = y + large_font_size + 10
print_centered(large_font, floor(Curr_time), y, x, side_w)
end
elseif Byo_yomi.white == Limit-1 then
y = top + (height - large_font_size - 10 - small_font_size)/2
print_centered(small_font, "no time left", y, x, side_w)
if Curr_color == 'white' then
y = y + small_font_size + 10
print_centered(large_font, floor(Curr_time), y, x, side_w)
end
else
-- out of time; Byo_yomi.white == Limit
-- print nothing
end end

function print_centered(font, msg, y, left, width)
local w = font:getWidth(msg)
local x = left + (width-w)/2
g.setFont(font)
g.print(msg, x,y)
end

function car.mouse_press(x,y, b)
if Byo_yomi.black == Limit or Byo_yomi.white == Limit then
return
end
if y >= Menu_height + 20 then
if Curr_color == 'black' then
-- it's black's move
if x <= 30+side_w then
Curr_color = 'white'
Curr_time = 0
end
else
-- it's white's move
if x >= 30 + side_w + 100 then
Curr_color = 'black'
Curr_time = 0
end end end end

I'm going by the description in https://www.britgo.org/bgj/10643.html, but I haven't actually seen a Go clock before, so feedback appreciated.