A control-signal generator that outputs a slowly varying frequency value, in hertz, for driving the frequency input of oscillators, filters and other control-fed blocks. Its value follows a sine wave: Average sets the centre frequency in Hz, Depth how far above and below that centre the value swings, and Rate (Hz) how fast it oscillates. It has no audio input or output, only a single control output.
A sine wavetable is precomputed and rescaled so its output spans the Average frequency plus or minus Average times Depth, in hertz; the table is scanned at Rate using a reduced internal control rate, and the current value is written to the control output. One control value is produced per tick, in step with WaveWarp's sample-per-sample engine.