riojoy/docs/INPUT-INTEGRATION.md

# Input integration guide (cockpit → RIOJoy → game)

How a game receives the cockpit's **inputs** — the 72 lighted buttons, two
16-key keypads, and 5 analog axes — and how to build the profile that maps
them. This is the mirror of [OUTPUT-INTEGRATION.md](OUTPUT-INTEGRATION.md)
(game → cockpit); the wire protocol lives in [PROTOCOL.md](PROTOCOL.md), the
profile/auto-switch model in [PLAN.md](PLAN.md).

## What a game sees

RIOJoy translates cockpit events into ordinary Windows input, per profile,
through three surfaces (all can be active at once — each button picks its
route):

| Surface | What the game sees | When |
|---|---|---|
| **Virtual Xbox 360 pad** (ViGEm) | a normal XInput controller: 11 buttons, D-pad, 2 sticks, 2 triggers | default on Windows 10/11 when ViGEmBus is installed |
| **Keyboard / mouse** (`SendInput`) | scancode keystrokes with modifiers; relative mouse moves + clicks | any button routed to a key/mouse action |
| **RioGamepad HID** | a native 6-axis, 96-button, 1-hat joystick | fallback when ViGEm is absent; the XP flavor |

The sink is chosen at activation: ViGEm → RioGamepad feeder → none (keyboard
and mouse always work). Most games — XInput and DirectInput alike — see the
Xbox 360 pad as a standard controller; the practical limit is its **11
mappable buttons**, so keyboard routing carries everything beyond that.

## The input inventory

- **72 lighted buttons**, RIO addresses `0x00–0x47`, grouped into five MFD
  clusters and four columns — the physical map is in
  [OUTPUT-INTEGRATION.md](OUTPUT-INTEGRATION.md#address-map-functional-groups).
- **Two 4×4 keypads**: internal `0x50–0x5F`, external `0x60–0x6F` (key label →
  address = base + hex digit; no lamps).
- **5 analog inputs** — joystick X/Y, throttle, left pedal, right pedal —
  calibrated into **6 virtual axes** (X, Y, Z, Rx, Ry, Rz), each `0..32766`
  with center `16383`.

## Per-button routing

Every mapped address carries one action (the `iRIO` word, PROTOCOL.md §5).
The editor exposes these as the **Action** kinds:

| Kind | What happens on press/release |
|---|---|
| **Keyboard** | key down/up by **scancode** (so DOS-era and raw-input games see it), with optional Shift/Ctrl/Alt held around it and the extended-key flag for nav keys |
| **Joystick** | virtual pad button 1–11 (or 1–96 on the RioGamepad HID) |
| **Hat** | the POV hat / D-pad direction (up/right/down/left; release = centered) |
| **Mouse** | relative move in clean 50-px steps (up/right/down/left) or left/right click — the legacy build's mixed-up move deltas are fixed in the port |
| **RIO command** | internal: axis recalibrations/resets, version/check request, diagnostic toggles — useful on a spare cockpit button so recalibration never needs the desktop |
| **Lit** flag | lamp follows the button (dim idle, bright pressed). Also marks the lamp as *profile-owned*, which shields it from the feedback endpoint (see OUTPUT-INTEGRATION.md) |

### The Xbox 360 button map

RIO joystick buttons are assigned in this fixed order — pick low numbers for
the game's most important actions:

| RIO joy button | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Pad button | A | B | X | Y | LB | RB | Back | Start | L3 | R3 | Guide |

The hat maps to the D-pad. Buttons past 11 are dropped by the pad — route
those to the keyboard instead. (On the RioGamepad HID all 96 buttons exist
natively and no mapping table applies.)

## Axes

### Calibration (per profile)

`Calibration` holds per-axis invert flags and `EnableZR`:

- **Joystick X/Y** auto-range from observed travel with a small deadzone.
- **Throttle (Z)** is the ratcheted lever; calibrated so the detent rest
  position reads **0**, full forward `32766` — i.e. it is naturally
  **unipolar**.
- **Pedals** feed Rx/Ry directly, or — with `EnableZR` — mix into a single
  rudder axis: `Rz = 16383 − left/2 + right/2` (Rx/Ry then idle).

### Routing onto the pad (`AxisRouting`, JSON-only)

Each of the six axes picks a `Target` and `Mode`
(`src/RioJoy.Core/Output/AxisRoutingConfig.cs`; null section = the legacy
default routing):

| Axis | Default target | Conversion |
|---|---|---|
| X | LeftThumbX | Centered |
| Y | LeftThumbY | Centered |
| Z | LeftTrigger | trigger byte `value×255/32766` |
| Rx | RightThumbX | Centered |
| Ry | RightThumbY | Centered |
| Rz | RightTrigger | trigger byte |

Modes for thumb targets: **`Centered`** (`(value−16383)×2` → stick range) for
axes that rest mid-travel, **`UnipolarPositive`** (rest 0 = stick center,
32766 = stick max — only the upper half is used) for the ratcheted throttle.
`Target: "None"` suppresses an axis entirely.

**The triggers-are-buttons trap:** many games hard-bind the pad triggers to
fire/actions. If the throttle rides `LeftTrigger` (the default), advancing the
throttle *fires*. The shipped Descent profile
([`profiles/descent-d1x.json`](../profiles/descent-d1x.json)) is the worked
example: throttle → `RightThumbY` `UnipolarPositive`, rudder mix → 
`RightThumbX`, pedals `None`, keeping both triggers free for the game.

## Choosing a strategy per game

- **Modern XInput game** — pad buttons + axes for the flight controls, keyboard
  routing for the long tail (MFD pages, systems). Check the game's own binding
  UI to see the pad.
- **DOS / emulated game (DOSBox, source ports)** — mostly keyboard routing (it
  arrives as scancodes, which DOSBox maps cleanly); axes via the pad if the
  emulator supports a controller, else map coarse throttle steps to keys.
- **Legacy DirectInput sim** — the x360 pad appears as a DirectInput device
  too; if the game needs more than 11 buttons on the *stick itself*, prefer
  keyboard routing or run the RioGamepad HID (96 native buttons).
- **Anything with a clickable cockpit** — mouse routing gives you cursor
  nudges and clicks from cockpit buttons.

## Building the profile

1. **Create/edit** from the tray: *Edit profile*. The editor shows the cockpit
   panel in its functional groups; click a button, set its label, action,
   modifiers, and **Lit**, then Apply. Save writes the config.
2. **Live check**: with the RIO (or vRIO) connected, physical presses light the
   panel and the axis gauges move — before any game is involved. The "Send
   button output to the PC" toggle turns real keystroke injection on when you
   want to test into an editor/notepad.
3. **Triggers**: comma-separated executable names that auto-activate the
   profile when their window is foreground (`d1x-rebirth, descent`). Matching
   is basename, case-insensitive, `.exe` optional. First matching profile
   wins; DOSBox-hosted games all share the DOSBox exe name (rename per game or
   switch manually); native games (Firestorm, Red Planet) go in
   `NativeGameExecutables` instead — RIOJoy releases the ports for them.
4. **RIO port**: leave `(app default)`, or a COM name, or `pipe:vrio` for the
   emulator.
5. **JSON-only settings** (edit `%APPDATA%\RIOJoy\config.json`): `AxisRouting`,
   `Calibration` fine points, `PlasmaComPort`/`PlasmaGreeting`, and the
   `Feedback` section (see FEEDBACK.md).
6. **Legacy import**: `RioJoy.Tray.exe --import-profile <file>` merges a
   single-profile JSON document; the `Import .ini` menu converts an original
   `RIO.ini` (buttons, inverts, greeting).

## Testing without hardware or game

- **vRIO** (`pipe:vrio`): click buttons on the emulator's panel and watch them
  arrive — the editor lights up, the pad reacts.
- **joy.cpl** (Game Controllers): shows the virtual pad's axes/buttons moving.
- Keyboard routes: open Notepad, enable the editor's output toggle, press
  cockpit buttons.

## Checklist for a new game

1. Find the game's real executable name (foreground window process) → Triggers.
2. Decide the axis story first: does the game hard-use triggers? If yes, route
   the throttle to a thumb axis `UnipolarPositive` (copy the Descent pattern).
3. Map the few primary actions to pad buttons 1–11, everything else to
   keyboard; mark cockpit-lit buttons **Lit**.
4. Set `EnableZR` if the game wants one rudder axis rather than two pedals.
5. Live-check in the editor, then in-game; bind a spare cockpit button to
   *RIO command → recalibrate* for the cabinet.
6. Add the `Feedback` section if the game will drive lamps/plasma back
   (OUTPUT-INTEGRATION.md).