barkour/MAP.md

# MAP.md — Barkour code index

Vanilla-JS canvas game, no build step. ES modules under `js/`, served statically.

- `index.html` — DOM shell: all screens (menu/host/join/charselect/game/result) as overlay divs; loads PeerJS from CDN (online play only), then `js/main.js`.
- `style.css` — overlay/menu styling; canvas letterboxed to 16:9 via CSS.
- `js/consts.js` — grid (TILE=12, 80×45 → 960×540), tile enum `T`, input bitmask `B`, item ids, physics constants, snapshot rate.
- `js/rng.js` — seeded mulberry32 (`makeRng`); `randomSeed()` is UI-side only.
- `js/mapgen.js` — `generateMap(seed)`: ground heightmap, pits, towers, islands, one-way platforms, crystals (hp 3), pads, spikes, rail saws, spawns; `PALETTES`; `sawPos()` polyline eval (ping-pong or loop).
- `js/physics.js` — center-based AABB vs tile grid: `moveEntity` (per-axis, one-way platform aware), `raycast`, `boxFree`, `standingOnPlat`.
- `js/characters.js` — `CHARS` data (stats + visual params) and `updateCharacter()`: per-dog special movement (air dash / charge+pound / grapple constraint / blink / jetpack).
- `js/sim.js` — **authoritative, DOM-free sim**: `createGame`, `step(game, inputs)` (60 Hz), combat (`hurt`: damage% → knockback), mining/items/hazards/KO/respawn/match-end, `snapshot`/`applySnapshot` for netplay.
- `js/input.js` — keyboard → bitmasks; slot 0 = WASD+FGH, slot 1 = arrows+KL;.
- `js/net.js` — PeerJS wrapper: `hostRoom`/`joinRoom`; room key = host peer id suffix; signaling via PeerJS cloud, game traffic pure P2P.
- `js/render.js` — canvas: cached seeded background, tiles, procedural dog drawing, particles/ghosts driven by sim events (`fxEvents`), HUD, banners.
- `js/audio.js` — WebAudio-synthesized sfx; `playEvents` maps sim events → sounds.
- `js/main.js` — app state machine: screens, char select, three match drivers (local / host / client) sharing one rAF fixed-timestep loop.
- `test/smoke.mjs` — `npm test`: headless mapgen determinism + chaotic full matches + targeted mining/stocks scenarios.

## Conventions & gotchas

- **Client never simulates.** In netplay the joiner only sends input bits and renders `applySnapshot` state; anything render reads must survive the snapshot round-trip (player `st` is re-shaped there).
- **Sim events are the only side-channel**: fx, audio, *and* client tile mutations (`tile`/`crack` events) ride on them. Host accumulates `pendingEvs` between snapshots.
- All sim/mapgen randomness must use the seeded RNG — never `Math.random()` inside `js/sim.js`/`js/mapgen.js`/`js/characters.js` paths.
- Velocities must stay < TILE (12 px/tick) or AABB collision tunnels.
- 7 as an arc end-angle in render means "> 2π" (full circle), a deliberate shorthand.
-												feat: initial Barkour — movement-PvP dog fighting game

5 dogs with distinct movement physics, seeded procedural arenas with
traps and mineable powerups, smash-style knockback/stocks combat,
local 2P and P2P netplay (PeerJS room keys), procedural art and sfx,
headless sim smoke tests.

											
										
										
											2026-06-10 14:26:58 +02:00
+								# MAP.md — Barkour code index
 								Vanilla-JS canvas game, no build step. ES modules under `js/`, served statically.
 								- `index.html` — DOM shell: all screens (menu/host/join/charselect/game/result) as overlay divs; loads PeerJS from CDN (online play only), then `js/main.js`.
 								- `style.css` — overlay/menu styling; canvas letterboxed to 16:9 via CSS.
 								- `js/consts.js` — grid (TILE=12, 80×45 → 960×540), tile enum `T`, input bitmask `B`, item ids, physics constants, snapshot rate.
 								- `js/rng.js` — seeded mulberry32 (`makeRng`); `randomSeed()` is UI-side only.
 								- `js/mapgen.js` — `generateMap(seed)`: ground heightmap, pits, towers, islands, one-way platforms, crystals (hp 3), pads, spikes, rail saws, spawns; `PALETTES`; `sawPos()` polyline eval (ping-pong or loop).
 								- `js/physics.js` — center-based AABB vs tile grid: `moveEntity` (per-axis, one-way platform aware), `raycast`, `boxFree`, `standingOnPlat`.
 								- `js/characters.js` — `CHARS` data (stats + visual params) and `updateCharacter()`: per-dog special movement (air dash / charge+pound / grapple constraint / blink / jetpack).
 								- `js/sim.js` — **authoritative, DOM-free sim**: `createGame`, `step(game, inputs)` (60 Hz), combat (`hurt`: damage% → knockback), mining/items/hazards/KO/respawn/match-end, `snapshot`/`applySnapshot` for netplay.
 								- `js/input.js` — keyboard → bitmasks; slot 0 = WASD+FGH, slot 1 = arrows+KL;.
 								- `js/net.js` — PeerJS wrapper: `hostRoom`/`joinRoom`; room key = host peer id suffix; signaling via PeerJS cloud, game traffic pure P2P.
 								- `js/render.js` — canvas: cached seeded background, tiles, procedural dog drawing, particles/ghosts driven by sim events (`fxEvents`), HUD, banners.
 								- `js/audio.js` — WebAudio-synthesized sfx; `playEvents` maps sim events → sounds.
 								- `js/main.js` — app state machine: screens, char select, three match drivers (local / host / client) sharing one rAF fixed-timestep loop.
 								- `test/smoke.mjs` — `npm test`: headless mapgen determinism + chaotic full matches + targeted mining/stocks scenarios.
 								## Conventions & gotchas
 								- **Client never simulates.** In netplay the joiner only sends input bits and renders `applySnapshot` state; anything render reads must survive the snapshot round-trip (player `st` is re-shaped there).
 								- **Sim events are the only side-channel**: fx, audio, *and* client tile mutations (`tile`/`crack` events) ride on them. Host accumulates `pendingEvs` between snapshots.
 								- All sim/mapgen randomness must use the seeded RNG — never `Math.random()` inside `js/sim.js`/`js/mapgen.js`/`js/characters.js` paths.
 								- Velocities must stay < TILE (12 px/tick) or AABB collision tunnels.
 								- 7 as an arc end-angle in render means "> 2π" (full circle), a deliberate shorthand.