Build a ControlDescriptor from a declared range plus the availability the caller
resolved — a thin read of descriptorOfLimit, the one constructor, through the one
range→limit transcription (gainTravelOf).
Every parameter but the range has a default, because a shared element must be usable with no
configuration: descriptorOf(range) is a live, unitless control over that travel.
Build a ControlDescriptor from a declared range plus the availability the caller resolved — a thin read of descriptorOfLimit, the one constructor, through the one range→limit transcription (
gainTravelOf).Every parameter but the range has a default, because a shared element must be usable with no configuration:
descriptorOf(range)is a live, unitless control over that travel.