# MRPGI — Monster Robot Party Game Interpreter

A **new-school, Apple-Silicon-native reimagining of Sierra's 1980s AGI engine** —
the tech behind *King's Quest*, *Space Quest*, and *Police Quest* — rebuilt in
Rust + [macroquad](https://macroquad.rs) so you can make cool, fun adventure games.

It keeps the *soul* of AGI (vector rooms, the invisible priority/depth screen,
loops-and-cels sprites, a verb-noun parser, flags & vars, the ego) and bridges
it forward (Retina-crisp rendering, hand-editable text resources, a real
embedded scripting language, and an optional AI parser).

## Run it

```sh
cargo run            # dev build (fast to recompile)
cargo run --release  # smooth, optimized build
```

A window opens with the demo room. **Walk the robot with the arrow keys or by
clicking** — and stroll *behind the column* to watch the priority system place
you correctly in depth. `N` toggles CRT scanlines. `Esc` quits.

## How it works (the AGI model, faithfully)

Every room is drawn into **two buffers at once**:

| Buffer | What it holds | Why |
|--------|---------------|-----|
| **visual** | palette indices (0–15, EGA) | what you see |
| **priority** | depth bands (4–15) + control lines (0–3) | depth sorting & collision |

Lower on screen ⇒ higher priority ⇒ drawn nearer the camera. The ego is drawn a
pixel at a time, *only where its priority ≥ the scenery's* — that's the whole
"walk behind the tree" trick, with zero per-object Z bookkeeping. Control lines
(priority `0`) are walls the ego can't cross.

## Source map

| File | Role |
|------|------|
| `palette.rs` | the 16-color EGA palette (indices → RGBA) |
| `framebuffer.rs` | the visual + priority buffers and the `band(y)` depth table |
| `picture.rs` | vector room painting (`PicOp` rectangles / lines / pixels) |
| `view.rs` | sprites as loops + cels, authored from tiny ASCII grids |
| `sprite.rs` | the ego: movement, click-to-walk, collision, walk animation |
| `room.rs` | the hand-authored demo room |
| `main.rs` | window, game loop, fixed-step cycles, compositing, HUD |

## Asset pipeline (the new-school bit)

Images don't sit *on top* of the game — they're folded *into* it. Any PNG is
quantized to the EGA palette (optional Bayer dithering for smooth retro
gradients) and becomes indexed pixels, so from that moment it depth-sorts, gets
occluded, and walks-behind exactly like hand-authored art. Three ways in:

- **Tile** an image across a region (textures — e.g. the floor)
- **Pour** an image into a shape via `stamp_cel_fit` with a fit mode
  (stretch / tile / center) — *the shape also stamps depth & collision.*
  This is the "draw a shape, load an image into it" idea, realized.
- **Objects** — a PNG becomes a `Prop` that sorts with the ego

Drop your own art into `assets/`, then press **R** in-game to hot-reload it.

## Roadmap

- [x] **v0.1 — rendering core**: vector room, priority depth, walkable ego, click-to-walk, CRT toggle
- [x] **v0.2 — asset pipeline**: PNG → EGA quantize + dither, tile / pour-into-shape / object insertion, hot-reload (`R`)
- [x] **v0.3 — room editor**: in-engine paint tool with edit/play modes, dual-layer LOOK+MEANING painting, flood-fill, tools (brush/line/rect/fill/pick/erase), undo, and JSON room save/load — see [EDITOR_GUIDE.md](EDITOR_GUIDE.md)
- [ ] **Priority-mask backgrounds**: a full-room art PNG + a companion mask PNG whose colors encode depth bands & control lines (the pro art workflow)
- [ ] **True-color "HD" layer mode**: skip quantization for painted backdrops; the priority buffer stays indexed
- [ ] **Polygon shapes** for `stamp_cel_fit` (not just rectangles)
- [ ] **Directional views** (4 loops + horizontal mirroring) for the robot
- [ ] **Text parser**: vocabulary with synonyms → `said("open","door")` matching, plus an on-screen input line
- [ ] **Rhai room logic**: rooms scripted in an AGI-flavored embedded language (`if said(...) { print(...) }`), hot-reloadable
- [ ] **Room transitions** (`new_room`), inventory, flags & vars
- [ ] **AI parser adapter**: when the classic parse misses, an LLM maps free text onto an *already-allowed* room command (deterministic core stays authoritative; works offline without it)
- [ ] **3-voice + noise chiptune synth**
- [ ] **Loadable game folders** (text/JSON resources) so games ship without recompiling the engine