PrePostView can show the raw audio level and the post-monitor audio level of a node proxy. It is used by the ProxyMeter class to show these levels on top of MonitorGuis, e.g. in NdefGuis or ProxyMixer/NdefMixer.
One con customize its display color scheme.
get and set Color for the pre-volume level meter
get and set Color for the post-volume level meter
make a new PrePostView
make a new PrePostView on top of a MonitorGui
the userview used to display the levels
set the levels to display on the view. range for both is [0.0, 1.0] display is with amp warp, i.e. center of view is -12 dB, or 0.25.
get the preAmp and postAmp level
remove the view