Definitions of plug-in Parameter, and its many variants.
A boolean parameter
A float parameter This is an abstract class, mapping from normalized to parmeter values is left to the user.
A parameter with [-inf to value] dB log mapping
An integer parameter
Linear-mapped float parameter (eg: dry/wet)
Float parameter following an exponential type of mapping (eg: cutoff frequency)
Plugin parameter. Implement the Observer pattern for UI support. Note: Recursive mutexes are needed here because getNormalized() could need locking an already taken mutex.
Float parameter following a x^N type mapping (eg: something that doesn't fit in the other categories)
Parameter listeners are called whenever a parameter is changed, start being edited, or stops being edited. The most common usage being UI controls calling setDirty() (directly or through animation) as a result.