Switch 2 Pro profile-input boundary¶

Status: profile boundary and runtime registration are implemented. This document's tests verify the pure projection, not the live transport matrix; consult the dated controller-platform validation ledger for hardware evidence.

This boundary connects the existing generation-fenced Switch 2 canonical input frame to the existing DS4Windows profile state. It does not create a second mapping engine and does not open a controller handle. The exact 12-bit source observation remains attached to DS4State as metadata. Logical signed16 axes now seed mapping-owned fractional coordinates with explicit byte compatibility access. The shared precision migration is incomplete; raw metadata is never a shortcut around profile mapping.

Admitted input¶

Switch2ProProfileInputMapper accepts only all of the following:

• canonical contract version 1;
• Pro Controller 2;
• either the exact native USB identity (ProUsbCommon05Bcd0201, 057E:2069, bcdDevice 0201) or the exact source-pinned BLE identity (BluetoothLeCommon05V1, Nintendo service/Common05 characteristic, exactly Read|Notify properties with no additional property flags);
• common input report 0x05;
• a calibration snapshot bound to the same nonzero device generation; and
• for BLE, a first, forward, or duplicate counter observation.

For the admitted Pro USB Common05 path, native read-claim order and host QPC establish delivery order. Its raw counter is diagnostic: a discontinuity must not suppress input or disconnect the runtime. The session and offline replay both retain the raw modular delta/classification and compare the next valid arrival against the new value. BLE counter admission is unchanged pending its own hardware evidence. See USB counter continuity. Unknown button bits are preserved but never promoted to controls.

Axis contract¶

The profile pipeline carries these distinct representations:

The generation-bound factory calibration is used when it passed the existing adoption checks. Otherwise the calibration snapshot already names and owns the symmetric fallback. Values outside an adopted endpoint clamp rather than wrap. X is not inverted. Y is inverted so normalized negative means up and positive means down. Center remains exactly zero/128.

The orientation is source-pinned to upstream SDL at commit c71abd08605b8bb7078372307a93274725c99fe0, zlib license:

• src/joystick/hidapi/SDL_hidapi_switch2.c:203-220, MapJoystickAxis, establishes calibration/fallback normalization and its explicit inversion parameter;
• the same file at :944-1028, HandleSwitchProState, maps left/right X without inversion and left/right Y with inversion, and independently corroborates positional face buttons, shoulders, digital triggers, system buttons, D-pad, C, and paddles.

The BLE service, Common05 characteristic, exact Read|Notify property tuple, and applicability to all controller models are pinned separately to ndeadly/switch2_controller_research@d1c5a7f7ba298f83017fae84952a4e6d2ef8fc92, bluetooth_interface.md (GATT table and Common05 HID-report section). SDL does not establish the BLE identity. The native USB tuple and observed report 0x05 come from the project-owned passive evidence ledger in switch2-phase1-codec.md; that capture is not evidence for BLE.

No PadForge code was used. PadForge remains behavioral evidence only under its noncommercial/share-alike license boundary.

Existing profile compatibility¶

Face buttons use the profile-selected Xbox physical-position or Nintendo printed-label projection documented in switch2-face-button-layout.md. Legacy profiles retain Xbox physical-position behavior. Minus/Plus map to Share/Options. Home, Capture, shoulders, stick clicks, digital ZL/ZR, D-pad, and the two back paddles use their existing DS4Windows semantic slots.

The Switch 2 C button has its own DS4Controls.Switch2C source. It remains explicit in Switch2ProProfileInputFrame.CButton and DS4State.Switch2RawInputStatus.CButton. It is not aliased to DS4State.Mute; doing so would incorrectly invoke DualSense microphone/mute-LED policy. The profile field map, schema and UI expose that distinct C source; there is no DualSense mute alias.

The Pro compatibility write also clears the separate Joy-Con 2 raw sidecar so metadata cannot stick when a reused DS4State changes physical source. The Pro sidecar retains the source transport and exact selected protocol revision, so the newly admitted USB and BLE Common05 paths cannot become indistinguishable.

Every compatibility write clears represented button, trigger, touch, and paddle controls absent from this source. The sidecar also clears any stale DualSense raw-status metadata. DS4State.PacketCounter remains owned by the input lane; the physical 32-bit counter is retained in the sidecar instead of replacing the host packet sequence. DS4State.Motion likewise remains caller-owned and is not mutated by this pure mapper. Motion publication and its source ownership belong to Switch2RuntimeInputDevice and the runtime motion pipeline; these projection tests alone do not establish its hardware scaling or fidelity.

Verification¶

Switch2ProProfileInputTests covers:

• every evidenced Pro semantic exactly once;
• the C-versus-Mute non-alias rule;
• fallback and factory-calibrated centers/endpoints/clamping;
• Y orientation;
• released/unsupported-control clearing;
• raw metadata survival through constructor, CopyTo, and CopyExtrasTo;
• exact identity and stale-sequence rejection; and
• zero managed allocations across 20,000 warm-state map/write operations.

These pure projection tests do not establish hardware motion/output/haptics, game visibility, full profile precision, or end-to-end latency. Runtime and UI implementation exist separately and require their own relevant evidence.