hansdezwartandClaude Opus 5
92bb31b18e
Match length is a new first row in the settings, 1 to 29 points, stepping by
2 so it can only ever be odd. The Time setting now means time *per point* and
each clock starts at time × points, which the settings sheet spells out.
The middle bar icon opens a score sheet. Edits are staged there and only
reach the state on Done, which then does one of three things:
nothing changed turn, delay position and moves all untouched
score changed displayed times become the reserves, then back to the
first tap with moves zeroed — the clocks keep their value
clock changed the spent delay is added back on so the panel shows
exactly what was typed, and the turn carries on
Tapping outside the sheet discards the staged edits, so a stray tap can't
restart a game.
reset() was called both by the Reset button and by every settings change, so
clearing the score in it would have wiped a live match whenever the delay was
nudged. It splits into resetClocks() and resetAll(); only the button clears
the score. Shortening a match clamps a score that no longer fits.
The whole game now persists, not just the settings: score, both reserves,
moves, whose turn and how much delay was left, saved on the discrete
transitions and on pagehide/visibilitychange. Time passing while the app is
dead can't be charged to anyone, so a running clock is stored as paused and
comes back on the play button. A malformed saved game is ignored rather than
half-applied.
Each panel shows its own score first, stacked above its move count at the
top left.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
6.2 KiB
Backgammon Clock
A two-player match clock with simple delay you can actually see. Reserve time plus a fixed number of free seconds each turn that never carry over — the Backgammon Galaxy control. Defaults to 3:00 + 15s.
Plain HTML, CSS and JavaScript. No frameworks, no fonts, no images, no network.
Getting it onto your phone
Chrome will only offer a real install over HTTPS, so the file needs a host. GitHub Pages is free and takes about two minutes:
- Create a new public repository, e.g.
bgclock. - Upload all six files to the root:
index.html,manifest.webmanifest,sw.js,icon-192.png,icon-512.png,icon-maskable-512.png. - Settings → Pages → Source: Deploy from a branch →
main/(root)→ Save. - Wait a minute, then open
https://<you>.github.io/bgclock/on your phone. - Android, Chrome: menu (⋮) → Add to Home screen → Install. iOS, Safari: Share (□↑) → Add to Home Screen → Add. It has to be Safari — Chrome and Firefox on iOS can't install a web app.
Open it from the home-screen icon and it runs fullscreen with no browser chrome, offline, with the screen kept awake while a game is on.
On iOS a few things behave differently, none of them fatal:
- Install from Safari, and play from the home-screen icon. In a Safari tab you lose a strip of the screen to the toolbar, and iOS clears the saved settings of a site you haven't visited for a week. The installed app keeps its own storage and doesn't get pruned that way.
- There's no vibration — iOS gives web pages no haptics at all, so the turn-change buzz is silent there. The sounds still play.
- The ringer switch doesn't mute the clock. The page claims a playback
audio session so you can hear the delay tick with the phone silenced, which
in exchange pauses any music you had going. If you'd rather keep the music,
delete the
navigator.audioSessionline inindex.html. - Screen wake needs iOS 16.4 or newer. Below that the screen dims on its usual schedule mid-game.
If you're using a different path than /bgclock/, edit the "id" field in
manifest.webmanifest to match, or just delete that line.
To try it before hosting, open index.html in any browser — everything works
except installation and the service worker.
Using it
- Tap your own half to end your turn and start your opponent's clock. At the start, whoever taps first sets the other player going.
- The waiting player's taps are ignored, so a stray hand won't stop the clock.
- The bar under the big time is the delay draining. When it empties you get a soft tick and your reserve starts moving. That's the moment worth hearing.
- Reset starts a whole new match: clocks back to full and the score back to 0–0. It takes two taps: the first arms the button — it lights up and a ring unwinds around it — and a second tap within those two seconds does it. One stray thumb can't wipe a live match.
- Pause freezes mid-turn and resumes exactly where it stopped, delay included. Opening either sheet pauses automatically, and leaves it paused so the clock only restarts when both players are ready.
Backgammon clocks pause between games, and after a cocked die the delay is normally restarted — use pause and reset for those.
Matches
Set Match in the settings to the number of points you're playing to — 1, 3, 5 and up to 29. The time you set is per point, so a 5-point match at 2:00 a point puts 10:00 on each clock, and the settings sheet shows you that sum.
The score sheet is the middle icon in the bar. It reads You for whoever is
holding the phone — the bottom half — and Them for the far end, and each
panel shows its own score first, so both players read their own score on the
left: Score: 1 - 3, out of 5.
Nothing in that sheet takes effect until you press Done:
- Done with nothing changed leaves everything exactly as it was — same turn, same delay part-spent, same move counts. Tapping outside the sheet is the same as changing nothing, so a stray tap can't restart a game.
- Change a score and the game restarts when you press Done: move counters back to zero and the turn back to the first tap, waiting on whoever rolls the lower die. The clocks keep whatever they were showing.
- Change only a clock — the sheet also lets you correct either player's time to the second — and the game carries on undisturbed: same turn, same delay position, same moves.
Shortening the match to fewer points than someone has already won pulls their score down to fit.
Settings
At the top of the sheet are three presets — 2m / 12s, 3m / 12s and 3m / 15s. Tapping one jumps both timers there and lights it up. Change the time or delay by hand and the highlight goes out; land back on a preset's numbers and it comes back on.
| Setting | Range | Default |
|---|---|---|
| Match | 1 – 29 points, odd | 1 |
| Time | 0:15 – 99:00 per point | 3:00 |
| Delay | 0 – 60 s | 15 s |
| Colour | Sage, Brass, Slate, Teal, Plum | Sage |
| Sound | on / off | on |
Brass is the colour in the chess.com app, if you want the exact original look. Changing match, time or delay resets the clocks — the score is left alone, so you can fix the delay mid-match without losing where you are.
Settings and the match in progress are kept in localStorage, so they
survive closing the tab, force-quitting the installed app and rebooting the
phone — the app also asks for persistent storage so they aren't evicted when the
device runs low on space (Chrome honours that request; Safari ignores it).
Reopening restores the score, both clocks, the move counts, whose turn it is and
how much delay was left. The one thing it can't restore is time passing while
the app was closed, so it comes back paused rather than charging anyone for the
gap: a crash shouldn't decide a game.
Sounds
All three are generated with the Web Audio API, so there are no audio files to download and nothing to attribute.
- Turn change — a soft rising fifth with an octave partial, marimba-like.
- Delay expiry — a single quiet 300 Hz tick, deliberately easy to miss unless you're listening for it.
- Time out — a falling triad, loud and unambiguous.
Licence
Do whatever you like with it.