memlnaut-nisps/tests/cpp/test_dsp_reverb.cpp
w1n5t0n 973455b158 feat(nisps/dsp): lean DSP primitives ported from maximilian (meml-1v6)
Header-only, heap-free, sample-rate-aware DSP primitives for stream 3:
- Biquad (LPF/HPF/BPF/Notch/Peak/LowShelf/HighShelf, denormal flush)
- Delay<N> + DynamicDelay<N> (fixed-length feedback + power-of-two
  ring with fractional read & smoothed offset)
- AllPass / Comb / LpComb (Schroeder-Moorer reverb sections, split per
  role rather than maximilian's one-class-many-roles maxiReverbFilters)
- DCBlocker (one-pole HPF)
- ChamberlinSVF + OnePoleSmoother<NCh> + EnvelopeFollower
- ADSR envelope generator
- SineOsc/SawOsc/SquareOsc, PAFOperator (port of maxiPAFOperator with
  static gauss/cauchy tables), FMOp single-operator FM building block
- PitchShifter<N> granular two-head crossfade (replaces daisysp PitchShifter)

Tests: biquad freq-domain attenuation, delay tap timing, reverb
boundedness, pitch-shifter ratio + finite output. All pass under
-Wall -Wextra -Werror -Wpedantic, C++20.
2026-04-29 16:08:49 +03:00

37 lines
1.1 KiB
C++

// tests/cpp/test_dsp_reverb.cpp — bounded-output sanity for reverb sections.
#include <cmath>
#include "test_helpers.hpp"
#include "../../nisps/dsp/reverb.hpp"
NISPS_TEST(allpass_finite_and_bounded) {
nisps::AllPass<256> ap;
for (int n = 0; n < 10000; ++n) {
const float x = std::sin(static_cast<float>(n) * 0.05f) * 0.5f;
const float y = ap.process(x, 137u, 0.7f);
NISPS_EXPECT(std::isfinite(y));
NISPS_EXPECT(std::fabs(y) < 50.f); // generous bound
}
}
NISPS_TEST(comb_decays_after_impulse) {
nisps::Comb<256> c;
c.process(1.f, 100u, 0.5f); // impulse
float max_after = 0.f;
for (int n = 1; n < 1000; ++n) {
const float y = c.process(0.f, 100u, 0.5f);
if (std::fabs(y) > max_after) max_after = std::fabs(y);
NISPS_EXPECT(std::isfinite(y));
}
NISPS_EXPECT(max_after < 5.f);
}
NISPS_TEST(lpcomb_finite_with_lp) {
nisps::LpComb<512> lp;
for (int n = 0; n < 5000; ++n) {
const float x = (n % 20 == 0) ? 1.f : 0.f;
const float y = lp.process(x, 200u, 0.7f, 0.3f);
NISPS_EXPECT(std::isfinite(y));
}
}