# params module

## Related source files

This directory contains guidance; the implementation remains in `../Params.h`
and `../Params.cpp`.

## Rules

- Use the `ids::` namespace for every APVTS parameter ID string.
- Require one `ids::` entry per audio parameter, and one entry only.
- Use `enum class` for every enum. Give each a trailing `Count` enumerator.
- Use `inline constexpr` for parameter ID strings and `k`-prefixed integer constants.
- Keep all 0..1 to physical unit conversions in the `maps::` namespace.
- Keep the wavetable name table (`kWavetableNames`) in sync with `kNumWavetables`.
- Return an empty `juce::String` from enum-to-string switches for unknown values.
- Never re-declare a parameter ID string literal outside Params.h.
- Never add a physical unit mapping anywhere but `maps::`.

## IF-THEN

- IF you add an audio parameter THEN add its ID to `ids::` and, when it has physical units, add its mapping to `maps::` before any engine or GUI code reads it.
- IF a switch converts an enum to a string THEN include a default case that returns an empty string.

## Examples

```cpp
// BAD: re-declares the ID and drifts from Params.h
if (auto* p = apvts.getParameter ("f1Cutoff"))
    return p->getValue();
```

```cpp
// GOOD: one source of truth
if (auto* p = apvts.getParameter (ids::f1Cutoff))
    return p->getValue();
```

This file overrides /AGENT.md where they conflict.