enricobuehler 42a0dd52be refactor(haptics): one copy of each thing every rumble path was transcribing ...

Twelve findings from the sweep's DRY/docs/dead-code tail. Most are small; three found
real defects hiding behind the duplication.

**The UHID event ABI existed five times.** Every UHID gamepad backend — DualSense,
DualShock 4, Switch Pro, Steam Controller, Steam Controller 2 — carried its own verbatim
copy of the kernel's constants plus its own `put_cstr`, and they had already drifted:
`switch_pro` was missing the SET_REPORT pair entirely, and `steam_controller` read a
FIXED 16-byte SET_REPORT window instead of the event's own `size`. That last one is a
bug in both directions — a longer report was truncated, and a shorter one had the parser
reading whatever the reused event buffer still held past the payload, i.e. acting on
rumble values the game never wrote. Now one `uhid_abi` module owns the numbers plus the
two accessors that are easy to get subtly wrong, with tests on exactly that.

**A dead force-feedback id fallback.** ff-core's `input_ff_upload` picks a free effect
slot and writes it into the effect BEFORE uinput forwards the request, so the `id == -1`
branch could never run — and allocating from a local counter would have been the wrong
answer anyway, since the kernel owns that id space. Removed, with a `debug_assert` where
it stood.

**Apple's HID path silently dropped weak rumble.** `hidByte` took the top byte with no
non-zero floor, so every amplitude below 0x0100 rendered as exactly nothing. Android has
always floored it at 1; this was the odd one out. That converter also existed twice
byte-identically inside one Gradle module — now one `wireAmplitudeToByte`.

Also: the DS5 output-report layout gets named offsets (`dualsense_proto::out_report`)
documenting all three transport bases — USB 0, SDL payload −1, Bluetooth +2 — since the
differing bases are transport-forced, not drift. `pf-client-core` cannot import them (it
and `pf-inject` do not depend on each other, and a DualSense layout has no business in
`punktfunk-core`, their only shared crate), so its copy now DERIVES its offsets by
explicit subtraction and a test pins the relationship. `PUNKTFUNK_HID_EFFECT_MAX` sizes
the struct it describes instead of a second literal 11 — the header now emits
`uint8_t effect[PUNKTFUNK_HID_EFFECT_MAX]`. The rumble policy engine's `min_pulse_ms`
and `keepalive_ms` docs stop naming cases nothing implements: no in-tree caller sets
`min_pulse_ms`, and the macOS DualSense-over-BT keepalive the doc cited CANNOT be served
by the quirk, because that renderer skips writes whose levels are unchanged and would
swallow the engine's re-emit — it keeps its own keepalive instead. `TrackpadHaptic` is
marked as staged scaffolding (the tag is on a shipped wire; removing the variant would
not reclaim it). Three ×257-vs-`<<8` doc comments corrected — the scaling itself is fine,
both round-trip to 255. `backstop_ms.max(160)` deleted as unreachable (the engine floors
at 500). New tests for `Ds5Feedback` and for the Android rumble JNI packing on BOTH sides,
with `MAX_PADS <= 16` now a compile-time assertion rather than a comment.

Closes S1-S9, S11, T2, T3 (design/haptics-sweep-2026-08-03.md M12).

S11's second half is NOT a defect and was left alone: `clients/session/src/main.rs`
calls `set_forwarding` unconditionally on every params-build (its own comment explains
why — browse mode reuses one service across launches), so `Ctl::Forwarding` routinely
arrives unchanged and that early-out is what stops a redundant `sync_open` + Valve-HIDAPI
cycle each launch.

Verified: pf-inject clippy -D warnings 0 / 91 tests; pf-client-core + punktfunk-core
clippy 0 / 437 tests (amd64 container); punktfunk-client-android 7 tests; Android :kit:
6 tests; Apple swift build + 189 tests / 0 failures; cargo fmt --all --check clean. Each
new test probed by reverting its fix — the fixed SET_REPORT window fails 3, a broken pack
shift fails 3, dropping the amplitude floor fails 1, and a wrong DS5 offset either fails
the pin or refuses to compile.

2026-08-04 22:52:38 +02:00

..

punktfunk_core.h

refactor(haptics): one copy of each thing every rumble path was transcribing

2026-08-04 22:52:38 +02:00