# To-Do List

**High-level task tracker.** See design docs for details. Completed: `doc/COMPLETED.md`

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## Priority 1: Spectral Brush Editor (Task #5) [IN PROGRESS]

Procedural spectrogram tool: 50-100× compression (5 KB .spec → ~100 bytes C++).

**Design:** `doc/SPECTRAL_BRUSH_2.md` (MQ-based v2)

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## Priority 2: Test Infrastructure Maintenance [ONGOING]

**Status:** 38/38 tests passing

**Outstanding TODOs:**

1. **test_fft.cc:87** - Investigate FFT-DCT algorithm discrepancy

## Priority 4: Audio System Enhancements [LOW PRIORITY]

1. **`synth.cc`: use `ola_decode()` from `src/audio/ola.h`** — the OLA decode logic in
   `synth_render()` is currently inlined for frame-by-frame lazy decoding. Refactor to
   call `ola_decode()` for consistency with `spectool` and the test (requires decoupling
   the per-frame lazy path, e.g. decode a full block on demand then serve samples).

2. **GPU-Accelerated PCM Synthesis:**
   - Compute shader for direct PCM generation (bypass spectrogram)
   - Write to compute buffer, readback to synth

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## Priority 4: 3D System Enhancements (Task #18)

Pipeline for importing complex 3D scenes to replace hardcoded geometry.

**Status:** C++ object data loading complete. Shader SDF integration pending.

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## Priority 4: WGSL Modularization (Task #50) [RECURRENT]

Ongoing shader code hygiene for granular, reusable snippets.

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## Priority 4: Wine/Windows Black Screen

`demo64k.exe` runs under Wine (wgpu-native v27, Vulkan/MoltenVK) but shows a black window — no visuals rendered. Audio and timeline progress correctly. GPU device/adapter init succeeds.

**Likely causes to investigate:**
- Swapchain format mismatch (Wine Vulkan may prefer BGRA8 over RGBA8)
- Surface present failing silently (check `WGPUSurfaceGetCurrentTexture` status)
- Render pass output not reaching the surface (missing present call or wrong texture view)

**To reproduce:** `./scripts/run_win.sh` — window opens, stays black.

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## CNN v3 — U-Net + FiLM [IN PROGRESS]

**Design:** `cnn_v3/docs/CNN_V3.md` | All phases 1–7 complete. Runtime pipeline operational.

**Current pipeline:** `GBufferEffect` → `GBufDeferredEffect` → `GBufViewEffect` → sink

**Shadow pass status:** ✅ Fixed and re-enabled. Cube + sphere shadows correct. Pulsating sphere scale confirmed correct end-to-end. Scene is currently simplified (1 cube + 1 sphere, 1 light) for debugging.

**Active work:**
- [ ] Restore full scene in `GBufferEffect::set_scene()` (20 cubes + 4 spheres, 2 lights)
- [ ] Run first real training pass — see `cnn_v3/docs/HOWTO.md` §3

**Pending (lower priority):**
- [ ] GBufferEffect: Pass 3 transparency (transp=0 placeholder)
- [ ] GBufferEffect: `resize()` support

## Future: CNN v3 "2D Mode" (G-buffer-free)

Allow `CNNv3Effect` to run on a plain screen buffer / photo without a real G-buffer.
Fake the missing feature vectors (normals, depth, material IDs, shadow, transp) from
the RGB input alone:
- normals: approximate from local luminance gradient (Sobel)
- depth: constant (e.g. 0.5) or estimated from a simple heuristic
- material IDs / shadow / transp: neutral defaults (e.g. 0)

This would let the effect be applied to any rendered frame (post-NTSC, post-Scratch, etc.)
without requiring a 3D G-buffer pass upstream, and enable training/inference on photos.

Implementation sketch:
- New `CNNv3Effect2D` subclass (or a mode flag) that synthesizes `feat_tex0`/`feat_tex1`
  internally from a single `rgba8unorm` input, then runs the same 5-pass U-Net.
- Separate `gbuf_pack_2d.wgsl` compute shader that fills feat0/feat1 from a photo buffer.

## Future: CNN v2 8-bit Quantization

Reduce weights from f16 (~3.2 KB) to i8 (~1.6 KB).

**Requirements:** Quantization-aware training (QAT)
**Design:** `cnn_v2/docs/CNN_V2.md`

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## Future: Size Optimization (64k Target)

- Task #22: Windows Native Platform (Win32)
- Task #28: Spectrogram Quantization
- Task #34: Full STL Removal
- Task #35: CRT Replacement

**Measure:** `./scripts/measure_size.sh`

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**Backlog:** `doc/BACKLOG.md` for untriaged ideas