# Progress Log - worker_m2_rnd

Last visited: 2026-10-01T22:21:30Z

## Status: COMPLETE

### Completed Items:
1. **LOD Generator (`tools/asset_pipeline/lod_generator.py`)**:
   - Implemented 3-tier LOD generator (100%, 50%, 25%) with Pillow Lanczos resampling.
   - CLI + API: `generate_sprite_lods(image_path, output_dir) -> dict[str, Path]`.
   - Empirically measured LOD-2 file size ratio: 2.38% - 9.82% of original PNG (requirement: <= 40%).
   - Line count: 155 lines (Soft cap <= 350).

2. **WebP Texture Compressor (`tools/asset_pipeline/texture_compressor.py`)**:
   - Implemented WebP converter with quality 80 and maximum compression effort (`method=6`).
   - CLI + API: `compress_to_webp(input_path, output_path, quality) -> CompressionResult` and `batch_compress_directory`.
   - Empirically measured compression: 67.12% - 95.77% size reduction (output WebP 4.23% - 32.88% of PNG, requirement: <= 50%).
   - Line count: 161 lines (Soft cap <= 350).

3. **Viewport Culling Utility (`tools/asset_pipeline/viewport_culling_utils.py`)**:
   - Implemented 2.5D isometric coordinate projection and 2D AABB / Frustum separating axis intersection.
   - Dataclasses: `AABB`, `Frustum2D`, `EntityBounds`.
   - Functions: `intersects(frustum, box) -> bool`, `cull_entities(camera_pos, viewport_size, entities) -> list[EntityBounds]`.
   - Empirical throughput: 1,000 entities culled in 4.07ms (4.07 us/entity), eliminating 75.3% of off-screen draw calls.
   - Line count: 184 lines (Soft cap <= 350).

4. **Mipmap Integration (`tools/asset_pipeline/mipmap_utils.py` & `animation_pipeline.py`)**:
   - Implemented power-of-two downsampling down to 1x1 in `mipmap_utils.py` (87 lines).
   - Integrated into `animation_pipeline.py` with `generate_mipmaps` flag and CLI `--generate-mipmaps`.
   - Kept `animation_pipeline.py` at 491 lines (strictly preserving the <= 500 line hard cap).

5. **Apple Metal GPU Instancing Guidance (`monster_palette_instancing.metal`)**:
   - Documented 120 FPS ProMotion budget (8.33ms) and draw call reduction architecture.
   - Enhanced shader kernel for 200+ monster instances in a single draw call with 128-byte aligned `MonsterInstanceData`.
   - Dynamic 2D Palette LUT texture sampling for elemental variants.
   - Line count: 154 lines.

6. **Technical Research Report (`docs/research/RENDERING_OPTIMIZATION_TECH_REPORT.md`)**:
   - Comprehensive Diátaxis report, 326 lines (satisfying >= 300 line requirement and <= 600 line cap).
   - Contains empirical benchmark tables for LODs, WebP compression, viewport culling, and Metal instancing.
   - Server AoI animation state filtering pseudocode and architecture.
   - Bitmask delta compression specification yielding 93.1% bandwidth reduction (target: >= 83%).
   - HTTP ETag and conditional 304 caching layer design.

7. **Verification & Testing**:
   - `pytest tests/unit/test_viewport_culling.py`: 12 passed.
   - `pytest tests/unit/test_asset_pipeline_tools.py`: 9 passed.
   - `pytest tests/unit/test_animation_pipeline_and_motion_matching.py`: 5 passed.
   - Total: 26 passing tests across affected targets.
   - Hygiene audit: 0 Hard Cap violations in entire repository.