# TODO

## ~~Distance-based sound effects~~ ✓
Implemented: `audio_set_listener()`, `audio_play_sound_at()` with linear
attenuation and stereo panning. Used by enemy death, asteroid impact, and
powerup pickup.

## ~~Spacecraft art and entity~~ ✓
Implemented: spacecraft PNG spritesheet (5 frames, 80x48 each), full entity
with state machine (FLYING_IN → LANDING → LANDED → TAKEOFF → FLYING_OUT →
DONE), engine/synth sounds, thruster particles, level intro sequence with
deferred player spawn.

## Large map support (5000x5000)
Audit the engine for anything that breaks or becomes slow at very large map
sizes. Key areas to check:
- Tile layer allocation (`uint16_t *` for 25M tiles)
- Tilemap rendering culling (already viewport-clipped, verify correctness)
- Physics / collision queries (should only check nearby tiles)
- Entity updates (currently iterates full pool regardless of distance)
- Camera bounds and coordinate overflow (float precision at large coords)
- Level file parsing (row lines could exceed fgets buffer at 5000+ columns)

## ~~Spacecraft at level exit~~ ✓
Implemented: `spacecraft_spawn_exit()` with `is_exit_ship` flag. Proximity
trigger in `level.c` spawns exit ship when player is within ~2 screen widths
of an exit zone. Ship flies in, lands near exit. Player overlaps landed ship →
player deactivated, ship takes off, camera holds still, level transition fires
after ship departs (SC_DONE).

## ~~Asteroid refinement~~ ✓
Implemented: base speed 120→200, accel 200→350, respawn 3→6s, stagger 0-3→0-8s,
random horizontal drift (±60 px/s), moon level reduced from 24 to 8 asteroids.

## Moon campaign: 3 levels with spacecraft transitions
Extend the moon into a 3-level sequence connected by spacecraft takeoff/landing:
- **moon01.lvl** — Current level. Exit triggers spacecraft takeoff, transitions
  to moon02.
- **moon02.lvl** — Second moon level (new terrain, new hazards). Starts with
  spacecraft landing intro. Exit triggers takeoff to moon03.
- **moon03.lvl** — Third/final moon level. Starts with spacecraft landing.
  Exit triggers takeoff and transitions to level01 (space station).
- **level01.lvl** (space station roof) — Starts with spacecraft landing on the
  station rooftop. Ship stays landed (no takeoff). First armed level.
- Moon exit transitions require the "spacecraft at level exit" feature so
  the ship flies in when the player approaches the exit zone.

## Level generator: height zones (verticality)
Add vertical variety to generated levels using a "height zones" approach:
- Double tilemap height from 23 to ~46 tiles (two screens tall)
- Define two elevation bands: HIGH (ground ~row 17) and LOW (ground ~row 40)
- Existing segment generators get a `y_offset` parameter so internal logic
  barely changes — platforms, enemies, corridors all shift by offset
- New vertical connector segments (ramps/climbs) bridge between zones
- Theme decides zone usage: Surface stays LOW, Station uses both, Base uses HIGH
- Camera needs vertical look-ahead when player has vertical velocity

### Implementation steps
1. Add vertical camera look-ahead (small Y lead when player moves vertically)
2. Create a handcrafted tall test level (~40x46) to validate camera, physics,
   rendering, and entities all work with vertical scrolling
3. Refactor `set_tile()` / `fill_ground()` to accept a height parameter instead
   of hardcoded `SEG_HEIGHT`
4. Add `y_offset` parameter to all segment generators
5. Add `SEG_CLIMB` connector segment type (shaft/platforms between zones)
6. Update `levelgen_generate()` to assign zones per segment and insert climbs
7. The station generator stays at 23 tiles (corridor envelope already constrains)

## Jetpack boost blue flame effects
- Add continuous blue flame particles trailing from the player during jetpack
  boost (while boost is active, not just on burst)
- Add blue accents to the jetpack burst effect itself — mix blue flame particles
  into the existing yellow/orange exhaust plume