Distortion module with pre and post filters.

**image 2-Parametres_Distorsion.png**

Sliders under the graph:
\begin{itemize}
\item Pre-Filter Freq: Center or cut-off frequency of the filter applied before distortion.
\item Pre-Filter Q: Q factor of the filter applied before distorsion.
\item Drive: Amount of distortion applied on the signal.
\item Post-Filter Freq: Center or cut-off frequency of the filter applied after distortion.
\item Post-Filter Q: Q factor of the filter applied after distortion.
\end{itemize}

Dropdown menus and toggles:
\begin{itemize}
\item Pre-Filter Type: Type of filter used before distortion (lowpass, highpass, bandpass or bandstop).
\item Post-Filter Type: Type of filter used after distortion (lowpass, highpass, bandpass or bandstop).
\item Balance: Adjust the signal amplitude by comparing it with a sinusoidal wave with a fixed amplitude (see "compress") or with the amplitude of the source (see "source").
\item **à vérifier** # of Polyphony: Number of voices played simultaneously (polyphony); only available at initialization time.
\item **à vérifier** Polyphony Spread: Pitch variation between polyphony voices (chorus); only available at initialization time.
\end{itemize}

Graph only parameters:
\begin{itemize}
\item Overall Amplitude: The amplitude curve applied on the total duration of the performance.
\end{itemize}