Chord spread

[zonkmachine]

Implementing delay for the chord stacking. Works pretty well but I'm a bit uncertain what the wanted combined result with arpeggio should be.

Closes #2380

Milestone 1.3.0 - pulled against stable-1.2 because I can't compile master right now

[WrillicR]

Will there be a way to choose which direction the chords spread?

[zonkmachine]

That's a bit of a real estate problem. There isn't much room for more controllers in there.

[DeRobyJ]

Well the initial thought was made just to add some "humanization" to chords.
So this change applies the idea to have a delay for each note, which can be used as an arpeggio.

If we were to do something more about this, given the space, I'd suggest to have:

• Upward strum (base note -> delay -> second note -> delay -> etc)
• Downward strum (last note -> delay -> secondlast -> delay -> etc)
• Random strum (one random note each time)

As for where to put it, I think we can shrink the drop-down more and include a radio button...
For example this is how it looks on my localization:

Look at the Arpeggio chord drop-down, it's already really short, while the Stacking one is quite long.

[zonkmachine]

Well the initial thought was made just to add some "humanization" to chords.

Yeah, this PR isn't precisely 'humanizing' anything. You wan't some randomness in there then.

[DeRobyJ]

Yeah but for this PR in particular I'd actually prefer it staying like this, maybe implementing the direction options.
On my original issue, I mentioned using an external LFO Controller to change the speed of the strum.

As for humanization, I now think it should be done in a different way (and I don't think many DAWs have this kind of feature).
The general idea is to have a general option for the track (in the Misc tab) to add "inaccuracy", that delays any note event of a small random time. (And yeah I know it's easier said than done, might require serious work for such a small feature)

The issue I'm actually trying to address is Phase Relationship between notes or even instruments: when it's fixed, it gets boring, so it needs some randomization to make it more human-like.

But I should write an issue about this, as the feature request is out of the scope of this PR.

[lukas-w]

I'd suggest to have:

• Upward strum (base note -> delay -> second note -> delay -> etc)
• Downward strum (last note -> delay -> secondlast -> delay -> etc)
• Random strum (one random note each time)

This sounds very similar to what the "Direction" option of Arpeggio offers. Can we unify this? The way I understand it, Chord Spread as suggested in #2380 is just Arpeggio with no repetition + increased note length.

[DeRobyJ]

As far as I know, the arpeggio funcion has to deal with note looping and timing in a way that might be a lot different to what is needed for this feature. But I may be mistaken about this.
Moreover, putting a toggle on the Arpeggio tab would not allow to have an arpeggio of strums, not that it would be used that much.

[zonkmachine]

This sounds very similar to what the "Direction" option of Arpeggio offers. Can we unify this?

I tried to do this in the arpeggiator first but this is what worked fastest for this proof of concept.

I won't have time to implement this properly so if anyone feels up for the task, please grab this code.