splatter-tennis/PLAN.md

# PLAN — Zombie mode expansion (for implementation by a follow-up session)

Read HANDOFF.md FIRST (module map, verify recipes, gotchas — especially the stale-module
cache one and "always Read current file state before editing"). This plan is ordered so
every phase is independently shippable: implement → verify → commit → push (push = deploy,
Oliver tests on his phone). Do NOT start a phase before the previous one is pushed.

Ground rules for the implementer:
- Zero dependencies, no build step, vanilla ES modules. Match the existing code style
  (compact, commented for intent, TUNE knobs for anything Oliver might want to tune).
- The tennis benchmarks in HANDOFF ("Tennis feel — CONFIRMED GOOD") MUST keep holding
  after every phase. Run them via window.T (Browser pane, RAF paused, T.step manual).
- New TUNE knobs go in config.js TUNE so they appear in the live T panel.
- Mobile portrait one-handed is the primary target. Every new interaction must work with
  one thumb: tap, flick, drag. No new buttons.
- Sounds: synth sfx live in audio.js; umpire lines are recorded m4a in assets/audio/
  (macOS `say -v Daniel`). Generation commands are given in Phase 2.

---

## Phase 1 — Tighten the shooting loop (serve-again latency, "missing balls")

Problem (diagnosed): two independent causes.
1. Input swallowed: taps/flicks during `G.phase === 'over'` (even the short 0.25s splatter
   one) hit `keyPressed` and match NO branch — the tap is lost and a stored flick expires.
   The player feels "I flicked and nothing came".
2. Spent balls die slowly: a staggered ball (`lastHit === 'X'`) or a shot that missed
   everything stays alive until it physically rolls out (|vy| < 0.8 after bounces), which
   can take seconds when it flies long. Only then does the 0.25s over-timer even start.

Changes (gameplay.js unless noted):
- keyPressed: in splatter mode, treat `phase === 'over'` like pretoss — first force the
  reset inline (`ball.active = false; setupPoint();`) then fall through to the existing
  pretoss serve logic (flick → quick serve, tap → toss). The finger is now the only
  cadence limit.
- Ball physics block: in splatter mode kill spent/hopeless balls early:
  `lastHit === 'X' && ball.bounces >= 1` OR out of bounds (`z < -2 || z > 25.5 ||
  |x| > 7.5`) → `ball.active = false; G.phase = 'over'; G.overT = TUNE.splatterOverT`.
- New TUNE knob: `splatterOverT: 0.1` (replace the hardcoded 0.25 in the dead-ball branch).

Verify (Browser pane, force splatter via 3 synthetic umpire taps — see HANDOFF):
- Flick during 'over' fires a serve the same frame (phase goes rally, ball active).
- Spent ball dies within ~10 frames of its first post-stagger bounce.
- Serve→serve cycle with immediate flicks ≤ 20 frames.
- Tennis regression: 'over' handling in tennis mode UNCHANGED (points still pause 2.2s).

## Phase 2 — Multi-kill applause + umpire appreciation

Mechanic: one ball (or bomb, Phase 4) that splatters ≥ 2 zombies gets escalating fanfare.
- state.js ball: add `kills: 0`. Reset to 0 in doHit and hitServe (any new shot).
- zombies.js splatter(): `ball.kills++`. After the existing splatPoint call:
  kills === 2 → `G.flash = {text:'DOUBLE KILL', t:0.9}; cheer(1.6, 0.45); voice('double_kill', 0.4)`
  kills === 3 → 'TRIPLE KILL', cheer(2.2, 0.6), voice('triple_kill', 0.4)
  kills >= 4 → `MASSACRE ×${kills}`, cheer(2.8, 0.7), voice('unbelievable', 0.4)
  (cheer/voice are imported from gameplay/audio already; check zombies.js imports.)
- Make natural pierce-doubles possible: splatter() currently halves pace
  (`ball.vx *= 0.5; ball.vz *= 0.5`). Change 0.5 → `TUNE.zPierce` (new knob, 0.75), so a
  hot ball can plow through a lined-up pair.
- New umpire lines (record on this Mac, same voice as existing files — inspect audio.js
  first for the exact name→file mapping):
    say -v Daniel "Double kill. Quiet, please." -o /tmp/dk.aiff && afconvert -f m4af -d aac /tmp/dk.aiff assets/audio/double_kill.m4a
    say -v Daniel "Triple kill. Remarkable." -o /tmp/tk.aiff && afconvert -f m4af -d aac /tmp/tk.aiff assets/audio/triple_kill.m4a
    say -v Daniel "Unbelievable." -o /tmp/ub.aiff && afconvert -f m4af -d aac /tmp/ub.aiff assets/audio/unbelievable.m4a
  Listen-check the files (afplay) before committing.

Verify: T-script — line up 3 zombies on one lane (`T.spawnZombie(0, 8/10/12, 'a')`),
serve a perfect-quality ball down that lane (TUNE.zSplatQ low temporarily), step, expect
kills to accumulate, flash text escalating, no crash when the ball dies mid-streak.

## Phase 3 — Gore piles (procedural graphics, no sprite pipeline)

Goal: the court gets progressively more disgusting. Stains (existing) + NEW 3D-ish piles
that grow when kills happen near each other. Ball boys shave them slowly but net growth
wins over a long match.

- zombies.js: new export `piles = []` — {x, z, size (1..4 float), seed}.
  In splatter(): if an existing pile within 0.6m → `size = min(4, size + 1)` else push
  new {size: 1, seed: Math.random()*1e4}. Cap 30 piles (shift oldest).
  Boy mopping loop: overlapping pile → `size -= dt * 0.25` (slower than stain mopping);
  remove pile at size <= 0.3. Keep stains as-is (they're the ground layer).
- render.js: `drawGorePile(p)` — procedural pixel-art, deterministic from p.seed so piles
  don't shimmer frame to frame. Algorithm: seeded PRNG (inline mulberry32 is fine);
  N = 6 + size*5 blobs; each blob an ellipse at radius ≤ size*0.28m around (x,z), with a
  vertical lift up to size*0.14m (projected: `y` offset via proj scale) so the pile has
  HEIGHT, not just a stain; blob radii 1–3px * proj scale; colors weighted:
  '#6e1414' '#8c1212' '#4e0e0e' '#7a2a18' + '#cfc9b0' (bone flecks, ~10%).
  Draw order: with the gore stains (after court, before characters), split far/near of
  the net like zombies are (a pile at z > netZ must occlude correctly). Sort by z.
- More particles per kill: 14 → 24 in splatter(), and give ~1/3 of them longer life
  (t up to 1.2) with darker color — check render's parts loop for where color is set.

Verify: force splatter, TUNE.zSplatQ = 0, kill ~10 zombies in one area, screenshot:
piles visible, taller/denser where kills clustered, boys visibly shrink them but slower
than they grow. Frame time sane (no per-frame allocation in drawGorePile — precompute
blob offsets ONCE per pile on creation, store on the pile object, don't re-run the PRNG
every frame).

## Phase 4 — Bomb balls

Design (decided, but flag to Oliver if it plays badly): ball boys deliver a black bomb
ball as a REWARD every `TUNE.bombEvery = 8` splatter kills. It's a stock (max
`TUNE.bombMax = 3`), shown on the HUD, and the NEXT serve automatically consumes one
(no extra input — one-handed rule). Alternative delivery ideas Oliver floated: umpire
throws it, or court pickup — do NOT build those, just note them in the commit message.

- state.js: G.bombs = 0, G.killMeter = 0.
- zombies.js splatter(): `G.killMeter++`; at bombEvery → reset meter, and if
  bombs < bombMax: `G.bombs++`, sendBoy() (the delivery run), voice('new_balls', 0.2)
  + flash 'BOMB BALL'.
- gameplay.js hitServe: in splatter mode, if `G.bombs > 0` → `G.bombs--`,
  `ball.bomb = true` (cleared on every other serve/hit).
- zombies.js: `explode(x, z)` — all zombies with `hypot(zx-x, zz-z) < TUNE.bombRadius`
  (2.5) splatter (iterate a COPY or walk the array backwards — splatter() splices; each
  kill still increments ball.kills so Phase 2 fanfare fires naturally); one big stain
  (r ~1.4), a pile of size 3, 40 particles, `G.hitstop = 0.1`, boom sound.
  Trigger: in the zombie-contact check, `ball.bomb` → explode at ball pos (regardless of
  pow), ball.active = false. Also in gameplay's bounce handling: splatter && ball.bomb &&
  first bounce → explode there.
- audio.js: `boom()` — synth: ~80Hz sine with fast pitch drop + white-noise burst,
  0.4s, follow the style of splat()/pock().
- render.js: bomb ball drawn black with a 1px flickering orange fuse pixel on top
  (drawBall gets a variant flag or check ball.bomb where the match ball is drawn).
  HUD: when G.bombs > 0, draw that many small black circles right of the YOU score line.

Verify: T-script — set killMeter to 7, kill one → bomb appears on HUD; serve → ball
renders black; land it amid 4 clustered zombies → all die, 'MASSACRE ×4' fires, boom
plays, big pile + stain remain. Confirm bombs don't leak into tennis mode (mode guard).

## Phase 5 — Horde waves + machine-gun racket

Trigger (decided): first horde when the player wins his 2nd splatter GAME, then every
game won after. Plus the test/fun cheat: triple-tap the umpire while already in splatter
mode → force a horde (main.js umpire listener currently calls forceZombies() which
no-ops outside tennis — extend it: in splatter, call startHorde()).

Flow: splatPoint's gameOver branch (splatter) → startHorde():
- G.horde = {t: TUNE.hordeLen (12s), spawnT: 0}. voice('remain_seated', 0.3) + flash
  'THEY KEEP COMING'. (Optionally record a dedicated line "They keep coming." →
  they_keep_coming.m4a, same pipeline as Phase 2.)
- During horde (updateZombies): ignore zMax; spawn every 1/TUNE.hordeRate (2.5/s),
  from the far baseline AND the sides (x = ±6, z random 0..8). Zombie speed ramp applies.
- Machine gun: while horde active the racket AUTO-FIRES — no taps needed. The thumb
  DRAG steers the player left/right (existing touchAxis movement; disable auto-assist
  during horde). Pellets fire straight up-court (-z) with ±4° random spread, every
  1/TUNE.mgRate s (6/s).
- Pellets are NOT the match ball — new lightweight array in zombies.js
  `pellets = []` {x, y, z, vx, vz, t}: flat trajectory (no gravity, y fixed ~0.9),
  speed ~26 m/s, t = 1.2s despawn, kill on zombie contact d < 0.55 (always splatter-
  quality: gore + pile + splatPoint). Update them in updateZombies, render as 2×2 yellow
  rects with a tiny ground shadow, drawn with the ball layer.
- Umpire spam control: splatPoint gains an optional `quiet` param — during horde,
  point voices are rate-limited (only speak if > 2s since last score line; game-win
  lines always speak). Keep the score ticking on the HUD regardless.
- Horde end (t ≤ 0): stop auto-fire, existing serve loop resumes (setupPoint),
  voice('quiet_dark', 0.5, 0.85). Any zombies still alive stay alive — the player
  mops up by serving. Eaten rule stays ON during hordes (swarms are lethal).
- Match ball during horde: kill it (ball.active = false) at horde start; serve prompt
  suppressed while G.horde (render gate, same spot as the eaten gate).
- Firing sound: rapid low-vol pock(0.25, 1400) per pellet is fine — verify it doesn't
  clip; if it does, only sound every 2nd pellet.

Verify: force horde via umpire triple-tap; step 12s: spawn count ≈ 30, pellets stream
and kill, piles accumulate, score advances with rate-limited voices, horde ends cleanly
back into serve loop, no console errors, eaten still triggers if a zombie reaches you.
Then the full ladder: tennis benchmarks + Phase 1–4 verifies still green.

## Phase 6 — Racket zombies (NOT in the first cut — design checkpoint first)

STOP: before implementing, show Oliver a one-paragraph design + the generated sprite
sheet for approval. Rough shape agreed so far:
- A special zombie (`variant 'r'`, has a racket) takes up residence on the FAR side and
  RETURNS your shots — the tennis rally skill stays alive inside zombie mode.
- Reuse the existing CPU machinery, don't rebuild it: give the racket zombie the same
  shape trySwing/doHit need (side:'O', x, z, facing, pose, poseT, swingT) and run a
  slimmed copy of the tennis-mode AI block for it (slower aiSpeed ~2.8, quality capped
  ~0.55, flub ~0.2, shambling run). Your non-splat-quality shots it can return; a
  splat-quality ball that reaches it kills it (existing contact path).
- Its returns are live balls: if one gets past you → splatPoint('O') via the existing
  baseline rule; you can also RALLY it back (doHit already works in splatter for the
  player — zombieTarget will need a "prefer the racket zombie when rallying" tweak).
- Sprite: the ONLY sprite-pipeline task in this plan (generate-image skill + scratchpad
  slice.py — the full pipeline gotchas are in HANDOFF). Idle/run/swing poses, magenta bg.
- Spawn: one per horde survived, or one per N games — decide with Oliver.

## New TUNE knobs (summary)
splatterOverT 0.1 · zPierce 0.75 · bombEvery 8 · bombMax 3 · bombRadius 2.5 ·
mgRate 6 · hordeLen 12 · hordeRate 2.5

## Benchmarks that must stay green after EVERY phase (scripts in HANDOFF)
- Tennis: CPU returns ~11/12 serves; human-like tap sim = all hits, no whiffs;
  feet-bounce tap sweep ≈ 19/30.
- Splatter: serve→serve ≤ 20 frames with immediate flicks (Phase 1 onward);
  eaten flow (zombie at <0.7m → EATEN overlay → tap restarts).
- No console errors after each phase's full verify run.