D023 - Two pad models

Status: decided Date: 2026-09-26

pros-link's Pad is the target's layout: unsigned bytes centred on 128 and one bit per button. Orbistoun's PadState stays host-shaped floats. Only measured button positions are a candidate for sharing; the encoding, the keyboard mapping and tap-versus-hold are not.

Why: matching the measured layout means the payload does no arithmetic, which is arithmetic that cannot be wrong where nobody looks. An emulator decides what a long press means; Prosperous forwards absolute state and the target decides.

Rejected:

• One shared model: one of the two projects then converts at the wrong layer.
• Tap-versus-hold here: duplicates the target's own logic where the result cannot be seen.