Resonator class overview
A Resonator filter:
The Resonator class takes up to three inputs and generates one
output. The 0-index input is the incoming signal, 1-index input is
the Resonator frequency, and the 2-index input is the gain.
The function setFeedback() can set a constant feedback coefficient
which will be used if no input signal is connected to input 1. If no
signal is connected to input 2, a default value of 1 will be used for
the gain a0, which can be set to a different value with setGain. If a
signal is connected to input 2, then the default or value set by
setGain will be ignored. Here is a diagram of the inputs and outputs
to the Resonator class:
