AquaSynth

C# patch authoring, analysis, and Faust toolchain for AquaSynth. It parses the .aqua DSL into a serializable patch graph, emits Faust .dsp, and owns the path from patch intent to generated DSP artifacts.

This repo is the C# bridge for AquaSynth/Vortice-land. Rust remains the reference lab; this project is the tool that lets the engine script Faust without dragging the AquaSynth-rs crate into the room by the ankle.

Run

dotnet test

DX7 reference-render tests use dexed-py when a Python with dexed and numpy is available. Set AQUASYNTH_DX7_PYTHON to that interpreter to force a specific runtime; otherwise the tests skip the render path and still parse the vendored public-domain fixture.

ZynAddSubFX is pinned as a GPL test/development reference under external/zynaddsubfx. Initialize it with:

git submodule update --init --recursive

That source is a parity oracle only. AquaSynth does not ship Zyn code, link it from published packages, or treat it as runtime machinery.

Package Boundary

Downstream consumers should pin the NuGet packages from this repo, not use live project references. Breaking synth-library work should happen here freely, then consumers should intentionally update only after new package versions are packed and tested.

dotnet pack src\AquaSynth.Core\AquaSynth.Core.csproj -c Release
dotnet pack src\AquaSynth.Faust\AquaSynth.Faust.csproj -c Release

AquaSynth.Core owns patch meaning: model records, the .aqua parser, authoring helpers, analysis/scoring tools, presets, and Faust source emission. AquaSynth.Faust depends on Core and owns toolchain/rendering work: Faust CLI validation, target-code generation, live patch compilation, native libfaust loading, compile manifests, DSP factory lifetime, and offline/sample rendering.

The test suite verifies that development fixtures, Python render helpers, external reference synth sources, and SysEx banks do not ship in published packages.

Shape

• PatchScript.Parse(script) lowers terse script into SynthPatch.
• FaustEmitter.Emit(patch) emits Faust source.
• FaustCompiler.ValidateAsync(source) compile-checks with Faust when present from AquaSynth.Faust.
• FaustCompiler.CompileAsync(source, options) writes generated backend code through an installed or resolved Faust compiler from AquaSynth.Faust.
• FaustCompiler.CompileWebAssemblyScriptAsync(...) and CompileWebAssemblyAsync(...) emit browser-ready .dsp, .wasm, and Faust JSON UI metadata artifacts.
• AquaSynthPatchCompiler from AquaSynth.Faust is the live host-facing boundary for compiling .aqua scripts into hosted DSP factories.
• AquaSynthNativeCompiler remains the lower native libfaust compiler machinery behind that boundary.
• BuiltInScripts.ReferenceScripts() carries readable SFXR, BFXR-flavored, 808, FM bell, wobble bass, syrinx-voice, subtractive-drum, additive/PAD, and advanced layered patches. They are stable references for testing and for judging whether the DSL can express useful sound designs cleanly.
• SfxrParams, PatchScriptScoring, AudioAnalyzer, and Presets carry the reusable AquaSynth-rs-side analysis, scoring, SFXR, and preset tools.

The authoring/test lane can compile Faust-generated C# for easy .NET rendering and parity checks:

var patch = PatchScript.Parse("""
    voice
        wave=saw
        freq=55
        gain=0.2
        sustain=0.5
        decay=0.2
    """);
var export = FaustEmitter.Emit(patch, new FaustExportOptions("bass"));
await FaustCompiler.CompileAsync(
    export.Source,
    new FaustCompileOptions(FaustTargetLanguage.CSharp, "Generated/Bass.cs"));

The browser lane uses Faust's WebAssembly backend and keeps the same ownership: AquaSynth emits the .dsp, .wasm, and JSON UI description; the host supplies WebAudio scheduling and parameter binding.

await FaustCompiler.CompileWebAssemblyScriptAsync(
    "v w=sin f=880 g=.12 sustain=.04 decay=.2",
    new FaustWebAssemblyCompileOptions("Generated/Web", "ui_select"));

The runtime lane is different. AquaSynth should own Faust toolchain selection, compile cache identity, generated artifacts, parameter manifests, and dynamic patch compilation outside the realtime path. Aquarium Engine should load and host the finished artifact, bind controls, and schedule audio. Native Faust targets are the preferred shipping path when the platform allows them; C# output is convenient authoring machinery, not the ceiling.

AquaSynthPatchCompiler is the live runtime-facing version of that boundary: it owns native libfaust loading policy, script parsing, Faust emission, compile keys, DSP source artifacts, manifests, and compiled products. Engine callers keep their device and scheduling code, and ask AquaSynth for compiled/renderable synth products.

See docs/faust-toolchain-boundary.md.

Status

The current center of gravity is the speech-learning lane: structured utterance metadata -> utterance embedding -> synth automation -> vocal-tract/rendered-loss parity. The first proof path uses tiny eSpeak NG fixtures, log-mel evidence, packed C# backprop, and compiled Faust speech controls so many candidate weights can be tested against generated speech references without recompiling topology. The named audible witness for that lane lives at tests/AquaSynth.Dsl.Tests/Fixtures/Speech/WetVoice01/: Weksa-owned structured utterance in, AquaSynth-owned automation/render receipts out, all inspectable enough to diff when the machine mutates.

The modular graph surface, SFXR atoms, DX7/Zyn reference work, script scoring, audio comparison, presets, Faust emission, native Faust compilation/rendering, and installed Faust validation remain active foundations. The broader reference-synth digestion project is paused unless it directly improves the speech harness or render-loss machinery. Migration coverage is tracked in docs/migration-checklist.md, because leaving important things behind in the old repo would be a very efficient way to become our own haunted house.

Reference-driven DSL growth is tracked in docs/reference-synth-roadmap.md. The vocal tract curriculum is tracked in docs/ipa-vocal-tract-roadmap.md, with prior-work notes in docs/utterance-parity-research.md. Agent handoff state lives in state/spine.yaml.