insta-fun 2.4.0

Snapshot testing of fundsp units. Visualize output in svg and compare using insta
Documentation
use fundsp::prelude::*;
use insta_fun::prelude::*;

fn main() {
    const CHART_SAMPLES: usize = 2000;
    const ONE_SECOND_SAMPLES: usize = fundsp::DEFAULT_SR as usize;

    // Helpers to build configs per snapshot
    let chart_cfg = || {
        SnapshotConfigBuilder::default()
            .num_samples(CHART_SAMPLES)
            .with_inputs(true)
            .build()
            .unwrap()
        // output_mode defaults to SvgChart, macro will set chart title from name
    };
    let wav_cfg = || {
        SnapshotConfigBuilder::default()
            .output_mode(WavOutput::Wav16)
            .num_samples(ONE_SECOND_SAMPLES)
            .build()
            .unwrap()
    };

    let input = Box::new(
        sine_hz::<f32>(110.0)
            + sine_hz::<f32>(220.0)
            + sine_hz::<f32>(440.0)
            + sine_hz::<f32>(880.0),
    ) as Box<dyn AudioUnit>;

    // --- State Variable Filters and biquad-like filters ---

    // Lowpass 1 kHz, Q=0.707
    assert_audio_unit_snapshot!(
        "filter_svf_lowpass_1k_q0_707",
        lowpass_hz(1_000.0, 0.707),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_svf_lowpass_1k_q0_707",
        lowpass_hz(1_000.0, 0.707),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // Highpass 1 kHz, Q=0.707
    assert_audio_unit_snapshot!(
        "filter_svf_highpass_1k_q0_707",
        highpass_hz(1_000.0, 0.707),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_svf_highpass_1k_q0_707",
        highpass_hz(1_000.0, 0.707),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // Bandpass 1 kHz, Q=1.0
    assert_audio_unit_snapshot!(
        "filter_svf_bandpass_1k_q1_0",
        bandpass_hz(1_000.0, 1.0),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_svf_bandpass_1k_q1_0",
        bandpass_hz(1_000.0, 1.0),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // Notch 1 kHz, Q=1.0
    assert_audio_unit_snapshot!(
        "filter_svf_notch_1k_q1_0",
        notch_hz(1_000.0, 1.0),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_svf_notch_1k_q1_0",
        notch_hz(1_000.0, 1.0),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // Peak 1 kHz, Q=1.0
    assert_audio_unit_snapshot!(
        "filter_peak_1k_q1_0",
        peak_hz(1_000.0, 1.0),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_peak_1k_q1_0",
        peak_hz(1_000.0, 1.0),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // Bell 1 kHz, Q=0.707, gain=+3.5 dB approx (1.5 linear)
    assert_audio_unit_snapshot!(
        "filter_bell_1k_q0_707_gain1_5",
        bell_hz(1_000.0, 0.707, 1.5),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_bell_1k_q0_707_gain1_5",
        bell_hz(1_000.0, 0.707, 1.5),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // Low shelf 500 Hz, Q=0.707, gain=1.5
    assert_audio_unit_snapshot!(
        "filter_lowshelf_500hz_q0_707_gain1_5",
        lowshelf_hz(500.0, 0.707, 1.5),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_lowshelf_500hz_q0_707_gain1_5",
        lowshelf_hz(500.0, 0.707, 1.5),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // High shelf 2 kHz, Q=0.707, gain=1.5
    assert_audio_unit_snapshot!(
        "filter_highshelf_2k_q0_707_gain1_5",
        highshelf_hz(2_000.0, 0.707, 1.5),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_highshelf_2k_q0_707_gain1_5",
        highshelf_hz(2_000.0, 0.707, 1.5),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // --- Resonant/ladder and simple poles ---

    // Moog ladder 1 kHz, Q=0.5
    assert_audio_unit_snapshot!(
        "filter_moog_lowpass_1k_q0_5",
        moog_hz(1_000.0, 0.5),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_moog_lowpass_1k_q0_5",
        moog_hz(1_000.0, 0.5),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // Lowrez 1 kHz, Q=1.0
    assert_audio_unit_snapshot!(
        "filter_lowrez_lowpass_1k_q1_0",
        lowrez_hz(1_000.0, 1.0),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_lowrez_lowpass_1k_q1_0",
        lowrez_hz(1_000.0, 1.0),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // Bandrez 1 kHz, Q=3.0
    assert_audio_unit_snapshot!(
        "filter_bandrez_bandpass_1k_q3_0",
        bandrez_hz(1_000.0, 3.0),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_bandrez_bandpass_1k_q3_0",
        bandrez_hz(1_000.0, 3.0),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // One-pole lowpass 800 Hz
    assert_audio_unit_snapshot!(
        "filter_lowpole_800hz",
        lowpole_hz(800.0),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_lowpole_800hz",
        lowpole_hz(800.0),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // One-pole highpass 300 Hz
    assert_audio_unit_snapshot!(
        "filter_highpole_300hz",
        highpole_hz(300.0),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_highpole_300hz",
        highpole_hz(300.0),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // --- Morphing SVF mode ---

    // Morph lowpass at 1 kHz, Q=0.8, morph=-1 (lowpass)
    assert_audio_unit_snapshot!(
        "filter_morph_lowpass_1k_q0_8",
        morph_hz(1_000.0, 0.8, -1.0),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_morph_lowpass_1k_q0_8",
        morph_hz(1_000.0, 0.8, -1.0),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // --- Utility ---

    // DC blocker 10 Hz
    assert_audio_unit_snapshot!(
        "filter_dcblock_10hz",
        dcblock_hz(10.0),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_dcblock_10hz",
        dcblock_hz(10.0),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // --- Other Fundamental Filters ---
    // Representative examples: allpass, butterworth, FIR3 (Nyquist gain shaping), pinking filter, amplitude follower.

    // Allpass at 1 kHz, Q=0.707
    assert_audio_unit_snapshot!(
        "filter_allpass_1k_q0_707",
        allpass_hz(1_000.0, 0.707),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_allpass_1k_q0_707",
        allpass_hz(1_000.0, 0.707),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // Butterworth lowpass 1 kHz (2nd order)
    assert_audio_unit_snapshot!(
        "filter_butter_lowpass_1k",
        butterpass_hz(1_000.0),
        InputSource::AudioUnit(input.clone()),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_butter_lowpass_1k",
        butterpass_hz(1_000.0),
        InputSource::AudioUnit(input.clone()),
        wav_cfg()
    );

    // FIR3 with Nyquist gain 0.50 on white noise input
    assert_audio_unit_snapshot!(
        "filter_fir3_gain0_50_white",
        fir3(0.50),
        InputSource::AudioUnit(Box::new(white())),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_fir3_gain0_50_white",
        fir3(0.50),
        InputSource::AudioUnit(Box::new(white())),
        wav_cfg()
    );

    // Pink noise (white() filtered to 3 dB/octave slope)
    assert_audio_unit_snapshot!(
        "filter_pinkpass_white",
        pinkpass::<f32>(),
        InputSource::AudioUnit(Box::new(white())),
        chart_cfg()
    );
    assert_audio_unit_snapshot!(
        "filter_pinkpass_white",
        pinkpass::<f32>(),
        InputSource::AudioUnit(Box::new(white())),
        wav_cfg()
    );
}