# BRIEFING — 2026-10-01T20:28:00Z

## Mission
Investigate test vectors, stationary caching assertions, and design updated map_render_benchmark.js with realistic open-field traversal, stationary 0-rebake verification, and performance bounds.

## 🔒 My Identity
- Archetype: explorer
- Roles: Benchmark Trajectory & Stress Harness Explorer
- Working directory: c:\Projects\FreeExile\.agents\teamwork\explorer_m2_fix_3
- Original parent: 1cc48fc5-ce57-4f48-8964-24cab4bfcacc
- Milestone: M2 Fix 3

## 🔒 Key Constraints
- Read-only investigation — do NOT implement changes directly to production files outside working folder
- Files for content delivery, Messages for coordination
- Benchmark metrics: FPS >= 30, blits within budget, RAM <= 8.0 MB
- Script line limit: keep map_render_benchmark.js <= 200 lines

## Current Parent
- Conversation ID: 1cc48fc5-ce57-4f48-8964-24cab4bfcacc
- Updated: not yet

## Investigation State
- **Explored paths**: `ORIGINAL_REQUEST.md` (R2), `tools/perf/stress_test_lru_cache.js`, `reviewer_m2_2/handoff.md`, `challenger_m2_1/handoff.md`, `tools/perf/map_render_benchmark.js`, `client/webapp/js/engine/tile_map_renderer.js`, peer explorer scripts.
- **Key findings**:
  1. Stationary camera thrashing reproduced: 50 frames at (30, 30) triggers 250 chunk re-bakes on unpatched 4-slot renderer.
  2. Open-field traversal (15, 15) -> (90, 65) over 1000 frames produces avg 6.69 blits and peak 8 blits per frame.
  3. Redesigned benchmark prototype `map_render_benchmark_proposed.js` (187 lines, <= 200 hard cap) successfully catches both failures (exiting code 1) and passes cleanly (exiting code 0) when cache capacity/culling is corrected.
- **Unexplored areas**: None, all test vectors and benchmark redesign parameters verified.

## Key Decisions Made
- Redesigned benchmark blueprint includes: (1) Warmup + 50-frame static camera test asserting strictly 0 re-bakes at (30, 30); (2) 1,000-frame full-map traversal (15, 15) -> (90, 65) measuring FPS >= 30, blits <= 6, and RAM <= 8.02 MB; (3) Dynamic path resolution supporting both repo tools/perf and subagent evaluation.

## Artifact Index
- DISPATCH.md — Assignment instructions
- BRIEFING.md — Persistent context memory
- progress.md — Liveness heartbeat and task tracker
- map_render_benchmark_proposed.js — Redesigned benchmark blueprint (187 lines)