ofxModulation

Reusable LFO oscillators and step-sequencer parameter recording for live video performance.

CPU-only and GL-version agnostic. Depends only on ofMain (+ ofxMidi, which is included so MIDI-binding examples compile; the core classes do not use it).

Components

Class	Purpose
Oscillator	Phase-accumulator waveform generator. Waves: SINE, TRIANGLE, SAW, SQUARE, NOISE (smooth per-cycle), RANDOM (sample-and-hold). tick(dt) advances an internal phase; valueAt(t) evaluates at an absolute time.
Lfo	A named oscillator with a modulation depth, a per-LFO scale, string Targets (pass, paramName), and depthBindable/rateBindable flags for MIDI routing. value() = osc depth scale.
StepSequencer	Multi-channel step recorder/player (the p_lock pattern). setChannelValue() records at the current step; getChannelValue() returns the one-pole-smoothed playback. start() back-fills all steps from current values.
ModulationEngine	Thin owner: a bank of named LFOs plus one StepSequencer, advanced with one tick(dt) per frame.

Usage

#include "ofxModulation.h"

ModulationEngine mod;

void ofApp::setup()
{
    Lfo *x = mod.createLfo("x");
    x->setDepth(0.5f);
    x->setScale(0.1f);                 // parameter coefficient
    x->oscillator().setFrequency(0.25f); // cycles/sec
    x->oscillator().setWave(Oscillator::TRIANGLE);

    mod.setupSequencer(17, 240);       // channels, steps
    mod.sequencer().setSmoothing(0.5f);
}

void ofApp::update()
{
    mod.tick(ofGetLastFrameTime());    // advance all LFOs + one sequencer step

    // Apply an LFO additively to a shader param. Reading the base fresh after
    // MIDI apply each frame avoids frame-to-frame compounding.
    float base = shaders.getParam(0, "uHue");
    shaders.setParam(0, "uHue", base + mod.getLfoValue("x"));
}

MIDI glue stays in the app: bind a CC to an LFO depth with midi.bindContinuous(cc, "xDepth") and assign midi.get("xDepth") to lfo->setDepth().

License

MIT