TTac

A bouncy, neon Tic-Tac-Toe for Android — plus an unlockable arcade — built with Kotlin and Jetpack Compose. Every mark, board, icon, medal and effect is drawn on a Compose Canvas; sounds are synthesised in code.

All images are rendered from the app's real composables by Roborazzi screenshot tests.

📖 Developer guide — game development with Compose Canvas, beginner to pro, told through this codebase · API reference

Features

Tic-Tac-Toe

• Solo vs AI (Easy, Medium, Hard — Hard is perfect on 3×3), Pass & Play, and LAN play between two phones.
• 3×3, 4×4 and 5×5 boards (the larger two need four in a row).
• Marks draw themselves in Neon, Solid or Sketch style; colours, stroke weight and animation speed are configurable.
• The whole screen washes toward the player whose turn it is.
• Heat: winning lines burn with a heat-gradient stroke and glowing zones; live threat heat marks cells that would finish a line; a heatmap shows where games are won — felt through gradient, never numbers.

Streaks & medals

• A medal every 3 wins in a row: Bronze → Silver → Gold → Platinum → Diamond (Diamond repeats).
• Losing streaks are tracked too, earning Grit badges; snapping a slide earns a Comeback.
• Awards screen with streak meters, a medal cabinet and recent awards.

LAN

• Each phone has a lasting random alias (e.g. Cosmic Otter 42); addresses are never shown.
• Join by auto-discovery (NSD), by scanning the host's QR code, or by typing a session code.
• Rival history, streaks and a LAN leaderboard per alias.

Arcade (unlockable)

• Blocks — endless falling-block play on a full-screen well; difficulty sets well size and speed. Unlocked by a 10-win streak.
• Word Hive — trace neighbouring letters through a honeycomb; targets, extra words, long-word bonuses, hints and shuffles. Unlocked by 3 Blocks wins in a row.
• Each locked game has one free demo.

Architecture

Package	What lives there
game	Pure Kotlin rules: board, AI (alpha-beta), Blocks engine, Word Hive generator
data	Stats reducer, medals, unlocks, LAN leaderboard; DataStore settings + JSON stats file
net	LAN protocol (line-delimited JSON over TCP), NSD discovery, aliases, session codes, QR links
app	AppViewModel (navigation, celebrations) and the Match state machine
fx	Synthesised sound effects and haptics
ui	Theme, Canvas drawing (marks, boards, medals, glyphs), components and screens
baselineprofile	Baseline Profile generator and macrobenchmarks

Everything is stored locally in app-private storage; the only network use is the optional LAN session on your own Wi-Fi.

Building

Requires JDK 17+ (the Android Studio JBR works) and the Android SDK.

./gradlew testDebugUnitTest   # unit tests
./gradlew assembleDebug       # debug APK
./gradlew installDebug        # install on a connected device

Performance

A Baseline Profile ships with release builds (via androidx.profileinstaller), and the home screen reports full display once saved data has loaded.

# Regenerate the profile on an API 33+ device, then commit the result
./gradlew :app:generateReleaseBaselineProfile

# Compare cold start with and without the profile, and in-game frame timing
./gradlew :baselineprofile:connectedBenchmarkReleaseAndroidTest

Fonts

Lilita One (titles, scores) and Fredoka (everything else), both from the google/fonts repository under the SIL Open Font License 1.1.

CI & releases

• CI (.github/workflows/ci.yml) — on every push and pull request: unit & screenshot tests, then a debug build.
• Release (.github/workflows/release.yml) — on a v* tag (or manual run): builds the release APK and AAB, publishes a GitHub release, and deploys the developer guide + API reference to GitHub Pages. A manual run with docs only republishes just the guide.

To sign releases, add these repository secrets: KEYSTORE_BASE64 (base64 of your .jks), KEYSTORE_PASSWORD, KEY_ALIAS, KEY_PASSWORD. Without them the release APK is unsigned.

git tag v1.0.0 && git push origin v1.0.0