JUCE-free, real-time-safe, header-only C++20 DSP core for the Darwin's Cat audio plugins
(TabbyEQ, OrbitCab, …). A set of independent process()-RT-safe modules — each its own namespace +
CMake target, each with framework-free self-tests. No external dependencies by default: pure C++20 standard
library — plus one opt-in, vendored SIMD FFT backend (fftpffft, -DFELITRONICS_WITH_PFFFT=ON, default OFF).
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📊 EQ Filter Quality Atlas — auto-rendered
quality maps of every eq filter vs independent analog references, regenerated by CI on every push to main
(green <0.1 dB … red ≥3 dB; black = broken). If a filter regresses, it shows here before anyone hears it.
⚡ Convolver benchmark — vs juce::dsp::Convolution — the EQ's MatrixConvolverNupc
(non-uniform, Gardner) holds a flat, block-independent cost at every one of 129 real DAW buffers (16→4096) —
~0.6 % RT on an Apple M5 Pro, ~1.08 % on an Intel i9-13900H — cheaper than JUCE across the small, low-latency
buffers a live rig runs (JUCE only wins the mean at large power-of-two blocks); true sample-zero-latency
(two-machine chart + tables).
core (FFT seam · smoother · delay · denormal flush) · eq (Vicanek matched biquads · SVF · EQ engine ·
crossovers) · lineareq (linear- & mixed-phase "Natural" FIR EQ over partitioned convolution) ·
convolution (zero-latency partitioned convolver · click-free IR swap) ·
dynamics (detectors · compressor · noise gate · transient shaper) · multiband ·
dynamiceq · deesser · stereo · saturation · dither · oversampling · limiter (true-peak) ·
analysis (LUFS/LRA · dBTP true-peak · correlation) · neural (inference seam) ·
fftpffft (optional compiled SIMD FFT backend — vendored pffft, -DFELITRONICS_WITH_PFFFT=ON).
Each module links on its own (felitronics::eq, felitronics::lineareq, …) — pull only what you use.
Every module ships JUCE-free self-tests (measured audio == analytic truth).
cmake -S . -B build -DFELITRONICS_BUILD_TESTS=ON
cmake --build build -j
ctest --test-dir buildinclude(FetchContent)
FetchContent_Declare(felitronics_core
GIT_REPOSITORY https://github.com/darwinscat/felitronics-core.git
GIT_TAG <pinned-tag>)
FetchContent_MakeAvailable(felitronics_core)
target_link_libraries(app PRIVATE felitronics::eq felitronics::lineareq) # link only what you use#include <felitronics/eq/EqEngine.h>AGPL-3.0-or-later · © 2026 Darwin's Cat.