biggy
05fd6440bd
Add root AGENT.md with project conventions, build verification steps, source layout, style rules, and real-time/concurrency requirements. Add per-module AGENT.md files for each existing and proposed source subdirectory. Add AUDIT_REPORT.md as a historical Phase 1 snapshot documenting memory management, error handling, concurrency model, naming conventions, and anti-pattern catalog.
59 lines
2.0 KiB
Markdown
59 lines
2.0 KiB
Markdown
# synth module
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## Related source files
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This directory contains guidance. All files listed below remain in the parent
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`Source/` directory. The preparation rules below are requirements for changes,
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not a claim that lazy wavetable allocation has already been fixed.
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- Wavetable.h, Wavetable.cpp
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- Oscillator.h, Oscillator.cpp
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- SubOscillator.h, SubOscillator.cpp
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- NoiseOscillator.h, NoiseOscillator.cpp
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- Envelope.h, Envelope.cpp
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- LFO.h, LFO.cpp
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- Filter.h, Filter.cpp
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- FilterBank.h, FilterBank.cpp
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- SynthVoice.h, SynthVoice.cpp
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## Rules
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- Use `noexcept` on every per-sample DSP path and cheap getter.
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- Use `std::array` for fixed-size state and `std::vector<float>` for delay lines and table buffers.
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- Size every buffer and delay line in `prepare()`, never in `process` or `render`.
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- Clamp filter and envelope state so extreme settings cannot produce NaN or inf.
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- Use `juce::MathConstants<T>::pi` and `twoPi` instead of raw pi literals.
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- Use `(size_t)` casts when indexing containers with int loop variables.
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- Pass global per-block state into voices as a `const RenderContext&`.
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- Never allocate memory in the audio path.
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## IF-THEN
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- IF a wavetable is read in the render path THEN build all tables in `prepare()` by calling `WavetableLibrary::prebuild()` before the first block.
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- IF a parameter is read every block THEN snapshot it into a struct (`OscParams`, `RenderContext`) instead of reading the APVTS per sample.
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## Examples
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```cpp
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// BAD: lazy table build reached from the render path allocates on the audio thread
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const Wavetable& wt = library.getTable (wave);
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```
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```cpp
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// GOOD: build once at prepare time, then only read const references
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library.prebuild(); // in prepareToPlay
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const Wavetable& wt = library.getTable (wave); // lookup, no allocation
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```
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```cpp
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// BAD: raw pi literal duplicated across files
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const double step = 6.28318530717958647692 * freq / sr;
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```
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```cpp
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// GOOD: single source
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const double step = juce::MathConstants<double>::twoPi * freq / sr;
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```
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This file overrides /AGENT.md where they conflict.
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