Collision system v2: binary format, close-doors, and overlay visualization

[PapaBlooD]

Summary

Builds on the binary collision cache concept from PR #29 by @grumpyowlbear. Migrates the collision system to a v2 binary format, adds close-door handling, and generates a collision overlay PNG with dungeons.

• Binary v2 format: 18MB JSON → 7MB binary (67% smaller, 13x faster init)
• Close-doors: Detect default-open doors (op1=Close) and add wall collision so pathfinder treats them as blocked
• Wall diagnostics: Export endpoint returns all wall-layer locs for debugging
• PNG overlay: Auto-generated visualization with overworld, dungeons, wilderness dungeons, and legend key

Detailed File Changes

sdk/pathfinding.ts (+93/-60 lines)

• Replaced JSON import (collision-data.json) with binary file reader (collision-data.bin)
• Added unpackCoord() to decompress packed 32-bit coordinates (z:14, x:14, level:2)
• Added binary header validation (magic "COLL", version 1 or 2)
• Added close-doors section: reads v2 closeDoors and calls rsmod.changeWall(..., add=true) to wall off default-open doors
• Added close-doors to doorIndex so findDoorsAlongPath can detect them
• Changed tile/zone/door loading from array iteration to sequential binary reads

server/engine/src/web/pages/api.ts (+21/-7 lines)

• Added closeDoors array — locs with "Close" option (default-open doors)
• Added wallLocs array — ALL wall-layer locs with blockwalk for diagnostics (locId, name, shape, angle, blockrange)
• Changed door scanning to categorize: hasOpen → doors, hasClose → closeDoors, all → wallLocs
• Updated response to return { tiles, zones, doors, closeDoors, wallLocs }

server/engine/tools/export-collision.ts (+424/-3 lines)

• Added binary v2 output (24-byte header + packed tiles/zones/doors/closeDoors sections)
• Added full PNG overlay generation with 3 map sections:
  • Overworld (X=2300-3600, Z=2800-3600)
  • Dungeons (X=2240-3520, Z=9216-9984)
  • Wilderness Dungeons (X=1856-3072, Z=4608-4928)
• Added large legend key panel with scaled font, color swatches, and stats
• Added diagonal wall rendering (NW/NE/SE/SW) with perpendicular-offset thickness
• Added pure JS PNG encoder (zlib deflate, no dependencies)
• Output always overwrites sdk/collision-overlay.png

sdk/collision-data.json (data change)

• Now includes closeDoors (104 entries) and wallLocs (94,441 entries) fields

sdk/collision-data.json.gz (data change)

• Updated compressed version (2.8MB → 3.2MB due to new fields)

sdk/collision-data.bin (NEW — 6.96 MB)

• Binary v2 format used by pathfinding.ts (replaces JSON loading)
• 67.5% smaller than JSON, loads in <20ms vs ~260ms

sdk/collision-overlay.png (NEW — 1.1 MB)

• Generated collision visualization with overworld, dungeons, wilderness dungeons, and legend

Test plan

• Export script produces all 4 outputs (JSON, gzip, binary, PNG)
• Pathfinding tests: 30/30 pass with binary loader
• Close-doors: 104 default-open doors correctly walled
• PNG overlay: 5700x7600 with all 3 map sections and legend key

🤖 Generated with Claude Code