Changing Filter knob configuration while another Filter is active, does not correctly restore to the default state of the selected filter

[jus]

Latest master, Deere skin

* Select an effect in the filter knob configuration drop-down ( e.g. Bitcrusher)
* Turn the filter to max right
* Select a new effect in the drop-down (e.g. Moog ladder)

Notice how the Bitcrusher is audible turned off, but the filter knob stays far right. Turning the knob then does nothing, unless you cross the 12 o`clock position.Then the Moog ladder effect jumps in and changes the sound audible.

There is also the special case, when you change from an active filter to NONE in the filter knob configuration, that the previous filter stays active, and the filter knob does not disappear in the skin.

[Daniel Schürmann (daschuer)]

This is an open issue.
For the standard effect deck this is the intended behavior.
The suer knob is mapped with soft takeover to the parameters. This way it is possible to change the single parameters even if they are mapped to super.

If we present only the super knob in a GUI we have no control about this, and that is the issue you have reported here.

I have purposed to introduce a new type of super knob with his own mapping rules:
See:
https://github.com/mixxxdj/mixxx/pull/372#issuecomment-63771376

My original Idea was to introduce a mapping controller class that cares about the mapping of a morphic Filter/SubEQ Knob.

[RJ Skerry-Ryan (rryan)]

Added a band-aid in https://github.com/mixxxdj/mixxx/commit/841cec93c3276b2b249bfd4e910642f707a3e460

[RJ Skerry-Ryan (rryan)]

If we load a new effect, I think the quick effect superknob should reset to the "neutral" (i.e. no effect) setting of the superknob and the superknob default value should change to this so right-clicks reset the effect.

For bitcrusher, it's 0, for a filter (split) button it's 0.5.

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/7673