Central class to realize control values which can come from different sources
and flow to different consumers.
In practice, the following situations must be freely combinable:
- programmatic, suprious setting by imperative code
- clocked read of some signal source
- irregular, but predictable setting by a kind of sequencer
- spontanuous GUI input by slider / checkbox / textinput
- Midi input (key, ctrl, etc.)
- other external sensors
The current value may flow into:
- continuous output as a signal source
- programmatic/event like reaction in case of change
- GUI visualization of current value
- visualization plot of recent history
- protocol of changes, either discrete or continuously sampled
The domain can be
- some scalar domain like float or int
- boolean
- (seldom: text)
- some PRODUCT of these
- (seldom: a CO-product)