The pen plane from design/pen-tablet-input.md, protocol side only (the P1 uinput
tablet injector will consume it): 0xCC kind 0x05 carries batches of state-full
PenSamples (pressure, polar tilt + azimuth, barrel roll, hover distance, eraser
tool, barrel buttons); PenTracker diffs samples into injector transitions so a
lost datagram self-heals; HOST_CAP_PEN (0x10) gates sending and stays
unadvertised until a real backend exists. C ABI: PunktfunkPenSample +
punktfunk_connection_send_pen, documented in docs/embedding-the-c-abi.md §8.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Developer integration guide for building a punktfunk client on any platform
by linking punktfunk-core through its stable C ABI: what the core does vs.
what the embedder supplies, build/link/cross-compile, the full client
lifecycle (identity/pairing, connect ladder, video+recovery loop, audio,
input, feedback planes, teardown), plus worked blueprints for webOS, Xbox
(GDK), and Tizen.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehlerandClaude Fable 5