014e636889
- section-energy: track activity matrix + volume/velocity multipliers per section - smart-chords: ChordEngine with voice leading, inversions, 4 emotion modes - hook-melody: melody engine with hook/stabs/smooth styles, call-and-response - mix-calibration: Calibrator module (LUFS volumes, HPF/LPF, stereo, sends, master) - transitions-fx: FX track with risers/impacts/sweeps at section boundaries - sidechain: MIDI CC11 bass ducking on kick hits via DrumLoopAnalyzer - presets-pack: role-aware plugin presets (Serum/Decapitator/Omnisphere per role) Full SDD pipeline (propose→spec→design→tasks→apply→verify) for all 7 changes. 302/302 tests passing.
81 lines
4.0 KiB
Markdown
81 lines
4.0 KiB
Markdown
# Design: presets-pack
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## Technical Approach
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Restructure `PLUGIN_PRESETS` to `{(plugin, role): chunks}`, add `PresetTransformer` class with per-plugin decoders (Serum=JSON, SoundToys=key=value text, Omnisphere=SynthMaster text), and thread `role` parameter through `make_plugin()` → `_build_plugin()`. No new dependencies — pure Python `base64`, `json`, `re`.
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## Architecture Decisions
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| Decision | Choice | Rationale |
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|----------|--------|-----------|
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| Data structure | `dict[tuple[str,str], list[str]]` — `{(plugin, role): chunks}` | Avoids dict-of-dicts nesting; simpler iteration in tests |
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| Transformation | Separate `PresetTransformer` class per plugin format | Serum/JSON, SoundToys/text, Omnisphere/text are different parsers; isolation = testability |
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| Role threading | Optional `role` param on `make_plugin()` and `_build_plugin()` | Zero breaking changes; None = current behavior |
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| Fallback chain | role → default → None | Backward compatible; existing tests don't break |
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## Data Flow
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```
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compose.py: make_plugin("Serum_2", 0, role="bass")
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→ _resolve_preset("Serum_2", "bass")
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→ PLUGIN_PRESETS[("Serum_2", "bass")] ← PresetTransformer output
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→ PluginDef(preset_data=bass_chunks)
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reaper_builder: _build_plugin(plugin)
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→ entry = PLUGIN_REGISTRY.get(resolved_name)
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→ preset_data = PLUGIN_PRESETS.get((resolved_name, plugin.role))
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or PLUGIN_PRESETS.get((resolved_name, "default"))
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→ _build_plugin_element(display, file, uid, preset_data)
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```
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## File Changes
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| File | Action | Description |
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|------|--------|-------------|
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| `src/reaper_builder/__init__.py` | Modify | Restructure `PLUGIN_PRESETS` to `{(k,role): chunks}`; `_build_plugin()` reads `plugin.role` for lookup |
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| `src/reaper_builder/preset_transformer.py` | Create | `PresetTransformer` class with `decode()`, `transform(role)`, `encode()`; per-plugin transformers |
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| `src/composer/templates.py` | Modify | `_parse_vst_block()` and `_make_plugin_template()` handle new `PLUGIN_PRESETS` structure |
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| `scripts/compose.py` | Modify | `make_plugin()` accepts `role` param, threads from `FX_CHAINS` key |
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| `src/core/schema.py` | Modify | `PluginDef` gets optional `role: str \| None = None` field |
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| `tests/test_preset_transform.py` | Create | Round-trip tests for 3 plugins × N roles |
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## PresetTransformer Design
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```python
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class PresetTransformer:
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TRANSFORMERS: dict[str, Callable] = {
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"Serum_2": _transform_serum,
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"Decapitator": _transform_decapitator,
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"Omnisphere": _transform_omnisphere,
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}
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@staticmethod
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def derive(plugin: str, default_chunks: list[str], role: str) -> list[str]:
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transformer = PresetTransformer.TRANSFORMERS.get(plugin)
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if not transformer:
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return default_chunks # no transform = use default unchanged
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return transformer(default_chunks, role)
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```
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Per-transformer functions:
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- `_transform_serum(chunks, role)` — decode JSON body, modify `processor.osc.type`, `processor.filter.cutoff`, `processor.fx`
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- `_transform_decapitator(chunks, role)` — decode text body, modify `Drive`, `Tone`, `Style` lines
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- `_transform_omnisphere(chunks, role)` — decode SynthMaster body, modify `Atk`, `Dec`, `Filter Freq` lines
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## Testing Strategy
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| Layer | What | Approach |
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|-------|------|----------|
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| Unit | PresetTransformer per plugin | decode → modify → encode for each (plugin, role); verify JSON/keys changed |
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| Integration | make_plugin + _build_plugin with role | Build PluginDef, verify preset_data differs per role |
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| Regression | `test_make_plugin_known_key` | Existing tests pass unchanged (role=None fallback) |
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| Round-trip | encode(decode(chunks)) == chunks | Each plugin × role; verify chunk count, base64 charset, structure integrity |
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## Migration / Rollout
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No migration required. `PluginDef.role` defaults to None. Existing callers that don't pass role continue working with `"default"` preset. Revert: flatten `PLUGIN_PRESETS` back to single-level dict, remove `role` param.
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## Open Questions
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None.
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