Files
punktfunk/clients/android
enricobuehler a9aa5357cf
windows / build (aarch64-pc-windows-msvc) (pull_request) Successful in 1m11s
ci / docs-site (pull_request) Successful in 1m9s
apple / swift (pull_request) Successful in 1m27s
apple / screenshots (pull_request) Skipped
android / android (pull_request) Successful in 3m6s
windows / build (x86_64-pc-windows-msvc) (pull_request) Successful in 2m8s
ci / web (pull_request) Successful in 3m38s
ci / rust-arm64 (pull_request) Successful in 6m11s
ci / rust (pull_request) Failing after 10m53s
feat(clients/gamepad-ui): multi-tone palettes, and a UI that takes its colours from them
The first pass built each palette by rotating ONE colour field's hue, and it
showed: every option was a single tone at several brightnesses, which reads flat
next to any real gradient. A palette is now an ordered ramp of DISTINCT hues.
The 4×4 mesh samples that ramp along the diagonal with a fixed per-cell offset
table, so neighbouring cells land on different parts of it and the colours pool
and swirl instead of banding; the control points' existing drift then moves the
pools around. Violet keeps its explicit sixteen colours, so the default is
untouched.

Twelve of them now, dark first then pale: Violet, Nebula, Abyss, Ember, Moss,
Graphite, then Holo, Sunset, Bloom, Dawn, Mint, Opal. Holo and Sunset are
straight takes on the two reference gradients — foil and poster.

`every_palette_is_multi_tone` measures the hue spread across all sixteen cells
and fails under 45° (20° for Graphite and Opal, which are meant to be
restrained). It caught Ember at 35°, all reds and oranges — the very flatness
this rework exists to remove — and Graphite at 3° despite a comment claiming it
drifted cool to warm. Both were rebuilt until the numbers matched the prose.

The UI follows the palette now, rather than wearing brand violet over whatever
happens to be behind it. Each palette carries an accent and a light flag, and an
Ink derived from those (foreground, accent, on-accent, glass, scrim and its
strength) is published to the whole tree — a thread-local in the console, an
environment value on Apple, a CompositionLocal on Android. Pale palettes flip
the ink: dark text on white frost, with the materials, tray scrims and every
wash that sits under text following suit.

Three things only the renders could have told us:

  - Additive blending blows out over a pale ground. Android's blobs and Apple's
    legacy field composite with Plus/plusLighter, which over near-white
    saturates every blob to white — Holo rendered as a grey wash. Pale palettes
    blend normally.
  - A white scrim at the dark field's strength BLEACHES the gradient. Mixing
    toward black at 0.4 reads as depth; toward white at 0.4 destroys the chroma
    it is drawn over. The scrim now carries a per-palette strength.
  - White glass over a bright field has far less separating it from its backdrop
    than dark glass over a dark one, and needed more body.

Verified: console build + clippy -D warnings + 173 tests, Apple build + 200
tests + an iOS-triple typecheck, Android compile + 62 tests, and eyeball passes
on real renders of both the vivid and the pale ends (console CPU rasters; a new
Roborazzi light-palette scene, which is what exposed the blend-mode bug).
2026-08-06 15:40:58 +02:00
..

punktfunk — Android client (phone & TV)

The native Android app for streaming a punktfunk host to your phone, tablet, or Android TV. A Compose app that finds hosts on your network, pairs with a PIN, and streams at the display's own resolution — with hardware HEVC decode, HDR10, and controller support, built for both touch and the couch (D-pad / gamepad focus navigation).

Features

  • Hardware decode — NDK AMediaCodec HEVC → SurfaceView, including HDR10 (Main10 / BT.2020 PQ), with low-latency tuning and a live stats HUD.
  • Audio both ways — Opus + AAudio playback with a jitter ring, plus mic uplink to the host.
  • Controller support — buttons + axes with rumble and HID feedback (lightbar / adaptive triggers); D-pad / gamepad focus navigation for TV and phone.
  • Find hosts automatically — native mDNS discovery; first connect does a one-time SPAKE2 PIN pairing (or TOFU on trusted LANs), then reconnects on a Keystore-wrapped, pinned identity.
  • Compose UI — Connect / Settings / Stream screens with Material You theming.

Built for arm64-v8a + armeabi-v7a + x86_64 — the 32-bit armeabi-v7a slice is what keeps the app installable on the many 32-bit Google TV / Android TV streamers (Walmart onn. 4K, Chromecast with Google TV, budget Amlogic boxes) that otherwise reject a 64-bit-only build as "not compatible".

Get it

Published to Google Play (Internal Testing) — join the beta via the Discord. Per-device setup and pairing: docs.punktfunk.unom.io/docs/install-client.

How it's built — Rust-heavy

Kotlin can't import the cbindgen C header the way Swift can, so a native bridge is unavoidable. We write it in Rust and link punktfunk-core directly — so the Android client reuses the Linux client's orchestration (audio jitter ring, VK keymap inverse, latency/skew math, capture state machine, trust logic) instead of re-porting it into Kotlin.

Side Owns
Rust (native/libpunktfunk_android.so) the JNI seam, NativeClient (QUIC control + UDP data plane), AnnexB → AMediaCodec decode (incl. HDR10), Opus + AAudio audio + mic, controller feedback, latency math, trust/pairing, mdns-sd discovery
Kotlin (app/, kit/) Compose UI, SurfaceView lifecycle, input capture, the Wi-Fi MulticastLock + permission UX, Keystore identity

The single seam is io.unom.punktfunk.kit.NativeBridgeJava_io_unom_punktfunk_kit_NativeBridge_*.

native/           Rust cdylib (workspace member) — links punktfunk-core directly
  src/lib.rs        crate doc · JNI_OnLoad · version probes
  src/session/      session lifecycle: connect/pair + trust, plane start/stop, input shims
  src/decode.rs     AnnexB → AMediaCodec HEVC hardware decode → SurfaceView (incl. HDR10)
  src/audio.rs · src/mic.rs   Opus + AAudio playback / mic uplink
  src/feedback.rs · src/stats.rs   rumble + HID feedback; live video stats
  src/discovery.rs  native mdns-sd browse of the host's _punktfunk._udp advert
app/              :app — Compose UI: Connect / Settings / Stream (phone + TV)
kit/              :kit — NativeBridge · native mDNS discovery · Gamepad · Keymap · Keystore identity

Build & run

Prerequisites: Android SDK + NDK r30 (30.0.14904198), platforms;android-37.0, build-tools;37.0.0, cmake;3.22.1 (builds libopus); JDK 21 (AGP 9.2 runs on JDK 1721, not a newer default); Rust with rustup target add aarch64-linux-android armv7-linux-androideabi x86_64-linux-android and cargo install cargo-ndk. Toolchain is pinned (AGP 9.2 · Gradle 9.4.1 · Kotlin 2.3.21 · Compose BOM 2026.05.01 · compileSdk 37 · minSdk 28).

Android Studio: open clients/android — it uses its bundled JBR 21, and the cargoNdk* task builds the .so as part of the normal build.

CLI (point Gradle at JDK 21 if your machine default is newer):

export JAVA_HOME="$(/usr/libexec/java_home -v 21)"   # or your Temurin 21 path
cd clients/android
./gradlew :app:assembleDebug     # cargo-ndk cross-compiles libpunktfunk_android.so first
./gradlew :app:installDebug      # onto a running emulator/device
# emulators from env setup:  emulator -avd pf_phone   |   emulator -avd pf_tv

The debug APK lands in app/build/outputs/apk/debug/. Launch it, pick a host, pair, and stream.