# MRPCI — Monster Robot Party Creative Interpreter

The **SCI generation** of the Monster Robot Party engine family. Where
[MRPGI](../mrpgi) reimagines Sierra's 1980s AGI (16 colors, text parser,
one merged priority buffer), MRPCI reimagines the tech behind *King's Quest V*
and *Space Quest IV* — and then fixes everything Sierra never could:

| Sierra SCI (1990) | MRPCI (now) |
|---|---|
| 256-color VGA, hand-cut palettes | 256-color palettes **quantized live from any PNG** (median cut), EGA/gray/ember ranges kept stable for sprites & cycles |
| Palette cycling (waterfalls, neon) | Same trick, `cycles` are room data + script-toggleable |
| Priority + control screens | **Four** screens: visual / priority / control / hotspot — hit-testing any pixel is one array read |
| Polygon avoidance that wedged egos into corners | Real **A\*** with LOS-verified edges + string-pulling; actors walk the exact verified line, so a legal path can never clip |
| Scale tables (SCI1.1) | Per-room perspective: actors shrink toward the horizon, walk speed scales to match |
| CPU-speed timers → Error 52, instant Sequel Police | Fixed **30Hz deterministic cycles**; `after()` timers count ticks; the only RNG is seeded xorshift — replays are byte-identical |
| `Error 47: Not an object` → crash to DOS | Missing resources = placeholders + an `error` event. A compile-error script = a log line, not a hang |
| Die 3 hours after the dead-end | **Checkpoint at every room entry; death rewinds to it.** Save-anywhere slots on top |
| OOP bytecode scripts, priest-tier tooling | **rhai** room scripts: `on_enter`, `on_verb(v,n)`, `on_trigger`, `after(ticks,"fn")` — hot-swappable over the bus |
| Icon bar (SCI1) *or* parser (SCI0) | **Both.** Clicks and typed commands converge on one verb pipeline |

The architecture is inherited from MRPGI and kept sacred: **`mrpci-core` is
headless** (zero windowing deps — a compile error is the guardrail). The
whole sim is a `GameState` behind a typed Command/Event bus, and every
control surface — GUI, JSONL stdio, HTTP, MCP — is a thin adapter.

## Run it

```sh
cargo run -p mrpci-core --bin mrpci-headless -- --sample   # write the demo game
cargo run -p mrpci                                         # play Neon Precinct
```

**Neon Precinct**: you are Officer Morp-9. Rain, neon that actually cycles,
a vend-bot with a tip, a keycard behind crates (watch the A\* go around),
a lethal fusebox (watch death *not* ruin your evening), and a case to close.
25 points.

Controls: left-click applies the verb, right-click cycles verbs, F1–F4 pick
one, `I` inventory, **Enter types a command** (the parser is always alive),
F5/F7 save/restore, F9 new game, M mute, N scanlines.

## Drive it headless (the point)

```sh
cargo build -p mrpci-core
target/debug/mrpci-headless --game games/neon-precinct              # JSONL stdio
target/debug/mrpci-headless --game games/neon-precinct --serve 8093 # HTTP
target/debug/mrpci-headless --game games/neon-precinct --mcp        # MCP for Claude
target/debug/mrpci-headless --game games/neon-precinct --script play.jsonl  # golden replay
target/debug/mrpci-headless --game games/neon-precinct --room 2 --ticks 45 --render-room out.png
target/debug/mrpci-headless --game games/neon-precinct --screens shots/  # all four screens
```

Register with Claude:

```sh
claude mcp add mrpci -- $PWD/target/debug/mrpci-headless --mcp --game $PWD/games/neon-precinct
```

Claude can then *play* the game (verbs, walks, dialogue), *see* it
(`mrpci_render_frame`, plus the invisible priority/control/hotspot screens),
and *author* it (upsert rooms and rhai scripts live, validated before commit).
See [docs/CONTROL.md](docs/CONTROL.md) for the full bus reference.

## A game is a folder

```
games/mygame/
  game.json          # manifest: name, start_room, intro, verbs, flags, max_score
  rooms/room0.json   # RoomDoc: ops (paint), background, palette, cycles, scale,
                     #   spawn, exits, hotspots, props, npcs, music, script
  pics/street.png    # optional backgrounds (+ street-pri.png / street-ctl.png masks)
  sprites/*.png      # quantized per-room; filename = sprite name
  scripts/*.rhai     # main.rhai + room scripts
  sfx/ music/        # optional audio overrides (else the built-in chip synth plays)
  saves/             # save-anywhere slots (gitignored)
```

Rooms paint with `PicOp`s — rects, polygons, floods, **dithered gradients**,
plus procedural fills: **fBm noise** (clouds, asphalt, grime), **Voronoi
cells** (cobbles, slabs) and **scatter** (stars, glints) — all seeded, all
deterministic — through an `Ink` that writes any subset of the four screens
at once. Or drop a PNG in `pics/` and let the quantizer fold it into the
palette. Rooms can also set `weather` (rain / snow / embers): a particle
layer on its own RNG stream, so visuals never perturb gameplay replays.

## Source map

| Crate / file | Role |
|---|---|
| `mrpci-core/screens.rs` | the four aligned screens + depth bands |
| `mrpci-core/palette.rs` | 256-color palettes, cycling LUTs |
| `mrpci-core/pic.rs` | vector paint ops, Bayer-dithered gradients |
| `mrpci-core/assets.rs` | median-cut quantizer, masks, sprite pipeline |
| `mrpci-core/view.rs` | loops/cels, ASCII sprites, mirroring |
| `mrpci-core/actor.rs` | ego + NPCs: scaling, line-exact path following |
| `mrpci-core/path.rs` | A\*, LOS smoothing, `walk_line` |
| `mrpci-core/room.rs` | RoomDoc / World / game folders / validation |
| `mrpci-core/script.rs` | rhai host: hooks, Fx airlock, tick timers |
| `mrpci-core/state.rs` | **the bus**: GameState, Command/Event, checkpoints |
| `mrpci-core/render.rs` | headless compositing → RGBA/PNG |
| `mrpci-core/audio.rs` | multi-voice chip synth (square/pulse/tri/noise) |
| `mrpci-core/bin/mrpci-headless/` | stdio / HTTP / MCP / replay / sample |
| `mrpci/` | the macroquad GUI (icon bar, dialogue windows, sound) |

Headless frames are **annotated**: `--render-room`, HTTP `/frame.png` and
MCP `mrpci_render_frame` stamp the room name, score, open dialogue window
and transcript strip into the frame with the built-in 5x7 font — an LLM
sees exactly what a player reads (add `--raw` / `/frame-raw.png` to skip).
The GUI renders via a **GPU palette shader**: the frame ships to the card
as indices + a 256x1 palette strip, and the fragment shader does the lookup
plus the whole CRT (curvature, scanlines, vignette, room fades).

## The AI parser lane

When the deterministic parser shrugs at a typed sentence, a small local LLM
(Ollama by default; OpenRouter optional) translates it into ONE command from
the *already-legal* verb/noun tables — then that command runs through the
real game logic. The AI can suggest; only the sim decides. Configure with
`MRPCI_AI` (`ollama`/`openrouter`/`off`), `MRPCI_AI_MODEL`, `MRPCI_AI_URL`.
`--script` replays force the lane off, so golden tests stay byte-identical.

## Roadmap

- [x] v0.1 — the engine above + Neon Precinct
- [x] v0.2 — procedural fills (fBm/Voronoi/scatter), weather particles,
      in-core font + annotated frames, GPU palette/CRT shader
- [x] v0.3 — world bundles carry art (`--export-bundle`/`--bundle`, the
      wasm path), AI parser lane, dialogue talker portraits
- [ ] Priority-mask art workflow polish (paint depth in any image editor)
- [ ] In-engine room editor (MRPGI's, upgraded to four screens)
- [ ] wasm build → see the [MRP3GI](../mrp3gi) sibling (three.js + rigged GLBs over this core)