# BRIEFING — 2026-10-01T21:46:00Z

## Mission
Milestone M4 Implementation: Fog of War Engine, Isometric World Canvas Overlay & Minimap HUD for FreeExile.

## 🔒 My Identity
- Archetype: teamwork_preview_worker
- Roles: implementer, qa, specialist
- Working directory: c:\Projects\FreeExile\.agents\teamwork\worker_m4_1
- Original parent: 1cc48fc5-ce57-4f48-8964-24cab4bfcacc
- Milestone: Milestone M4 (Fog of War & Minimap HUD)

## 🔒 Key Constraints
- Minimal change principle.
- Strict line count caps:
  - client/webapp/js/ui/war_fog.js <= 300 lines (Actual: 300 lines)
  - client/webapp/js/ui/war_fog_renderer.js <= 250 lines (Actual: 192 lines)
  - client/webapp/js/engine/world_renderer.js <= 480 lines (Actual: 473 lines)
  - client/webapp/js/engine/entity_renderer.js <= 450 lines (Actual: 440 lines)
  - client/webapp/js/engine/monster_system.js <= 490 lines (Actual: 486 lines)
  - client/webapp/js/ui/minimap_hud.js <= 280 lines (Actual: 261 lines)
  - client/webapp/index.html <= 200 lines (Actual: 199 lines)
  - tests/unit/test_fog_and_minimap.py <= 300 lines (Actual: 198 lines)
- Strict typing, genuine logic, zero cheating/hardcoding/facades.
- Verify through automated unit, e2e, hygiene audit, and benchmark tests.
- Maintain backward compatibility with modal simulator (#modal-war-fog) and existing test assertions.

## Current Parent
- Conversation ID: 1cc48fc5-ce57-4f48-8964-24cab4bfcacc
- Updated: 2026-10-01T21:46:00Z

## Task Summary
- **What to build**:
  1. `client/webapp/js/ui/war_fog.js` (3-state engine, zero-heap reveal/decay, < 2 KB bit-pack persistence)
  2. `client/webapp/js/ui/war_fog_renderer.js` (2-pass batched shroud + radial vignette falloff)
  3. Wire entity suppression in `world_renderer.js`, `entity_renderer.js`, `monster_system.js`, `canvas_renderer.js`, `tile_grid_loader.js`
  4. `client/webapp/js/ui/minimap_hud.js` (120x80 canvas, uniform projection, offscreen caching, 30 Hz throttling)
  5. `client/webapp/index.html` (mount #minimap-container and import script)
  6. `tests/unit/test_fog_and_minimap.py` (comprehensive test coverage)
- **Success criteria**:
  - `pytest tests/unit/test_fog_and_minimap.py -v` PASS (11/11)
  - `pytest tests/unit/test_tile_collision.py -v` PASS (11/11)
  - `pytest tests/unit/test_mobile_webapp_config.py -v` PASS (15/15)
  - `pytest tests/e2e/test_poe2_map_system_e2e.py -v` PASS (81/81)
  - `node tools/perf/map_render_benchmark.js` PASS (0 stationary re-bakes)
  - `pytest tests/unit/ -q` PASS (960 passed)
  - `python tools/lint/check_code_and_doc_hygiene.py --strict` 0 violations

## Change Tracker
- **Files modified**:
  - `client/webapp/js/ui/war_fog.js` (300 lines) — Complete 3-state engine, zero-heap reveal/decay, bitpacked persistence, modal simulator backward-compatible.
  - `client/webapp/js/ui/war_fog_renderer.js` (192 lines) — 2-pass isometric batched shroud + smooth radial horizon vignette falloff.
  - `client/webapp/js/engine/world_renderer.js` (473 lines) — Suppress ground drops outside visible tiles; suppress unrevealed waypoints/boss gate; wire WarFogRenderer.render hook.
  - `client/webapp/js/engine/entity_renderer.js` (440 lines) — Suppress active monsters and NPCs outside visible tiles; suppress unrevealed props; dim explored props.
  - `client/webapp/js/engine/monster_system.js` (486 lines) — Exclude non-visible monsters from getBestCombatTarget.
  - `client/webapp/js/engine/canvas_renderer.js` (332 lines) — Added WarFog.updatePlayerVision and MinimapHUD.update frame hooks.
  - `client/webapp/js/engine/tile_grid_loader.js` (163 lines) — Added initFog and MinimapHUD.setMap hooks on map load.
  - `client/webapp/js/ui/minimap_hud.js` (261 lines) — Created 120x80 minimap with aspect-ratio preserving projection, dual-layer caching, 30 Hz throttling.
  - `client/webapp/index.html` (199 lines) — Added #minimap-container and minimap_hud.js script import.
  - `tests/unit/test_fog_and_minimap.py` (198 lines) — 11 comprehensive automated tests.
- **Build status**: All tests passing.
- **Pending issues**: None.

## Quality Status
- **Build/test result**: 960 unit tests passed, 81 e2e tests passed, benchmark passed.
- **Lint status**: 0 hard cap violations across 560 files.
- **Tests added/modified**: `tests/unit/test_fog_and_minimap.py` (11 tests).

## Loaded Skills
- None explicitly loaded.

## Key Decisions Made
- Maintained "BỊ CHẶN BỞI RÀO CẢN" notification in `war_fog.js` stepPlayer to preserve `test_mobile_webapp_config.py` expectations.
- Zero-heap batch path generation for `WarFogRenderer` to sustain 120 FPS ProMotion render performance.
- Fixed 120x80 px canvas with uniform scale and centering offsets in `MinimapHUD` to prevent anisotropic aspect distortion.

## Artifact Index
- DISPATCH.md — Assignment instructions
- BRIEFING.md — Situational awareness
- progress.md — Liveness heartbeat
- handoff.md — Final completion report