Summary

Add doors to procedural world generation. Doors spawn opportunistically in single-width hallways with low odds, providing tactical options for players.

Behavior

Player interaction:

• Player walks through a door → it opens automatically
• Door closes behind the player after they pass through
• Opening/closing is seamless with movement (extra turn cost TBD)

Enemy interaction:

• Closed doors block enemy movement and pathing
• Enemies cannot open doors (at least initially — could be a higher-threat-level ability later)
• If an enemy moves into the door tile as it would close, the door stays open (contested close — TBD)

Spawn Rules

• Low spawn chance — doors should feel like a welcome find, not every hallway
• Single-width hallways only — detect tiles where the walkable path is exactly 1 tile wide (wall on both perpendicular sides)
• Should not spawn adjacent to exits, stairs, or other special tiles
• Per-level config for spawn rate (some floors might have more/fewer doors)

Open Design Questions

• Does opening a door cost an extra turn? (Tactical cost vs. flow)
• Can a door be blocked from closing by an enemy in the doorway?
• Can players manually close doors they've opened? (Could be useful tactically)
• Should doors have HP / be destructible by enemies?
• Visual/audio feedback — creak sound, animation?
• Do doors block line-of-sight for attacks?

Implementation Notes

• New tile type or world entity for doors (open/closed state)
• Hallway detection algorithm: for each floor tile, check if perpendicular axis has walls on both sides and parallel axis is open
• Integration with Grid3D for pathfinding (closed door = impassable for enemies, passable for player)
• Door state needs to persist per-chunk
• Enemy AI pathfinding should treat closed doors as walls

References

• scripts/procedural/chunk_manager.gd — chunk gen, hallway cutting
• scripts/procedural/sub_chunk.gd — tile types, tile data
• scripts/autoload/pathfinding_manager.gd — A* pathfinding (needs door awareness)
• scripts/ai/behaviors/entity_behavior.gd — enemy movement/pathing