Start new fade from current fade level
If a new fade is started from the REST API during another fade, then it should take the current volume level of the fade as the starting point for the new fade.
Example
- Volume is at
1.0
- A 2-second linear fade to
0.0
is requested - After 1 second, there is another fade request for
1.0
- Volume level smoothly fades from
0.5
back to1.0
-- taking0.5
as the start value for the second fade.