Obviously the incoming pad values from the Launchpad need to be transformed into the required chromatic scale; is that all simply just down to how the Controlmap is set up, or does another app need to be created to handle that?
Not exactly. The purpose of the controlmap is to describe the controller - which buttons that send what (type of) messages. Usually in Duplex, each controller comes with a “base” controlmap which describe the most likely settings (factory defaults).
Also, the controlmap organizes those buttons into layouts (groups) - which is why there are often many different controlmaps - the more specialized a configuration, the more likely it is to have a dedicated controlmap layout.
So what you essentially need to do is to create a new controlmap - the “base” Launchpad.xml would be a good starting point. Then, using a text editor, break the central grid into four equally sized groups (like in your image).
Basically, each group would each contain 16 parameters - note values and everything else should be left intact, it’s only the organization into groups you should be interested in (you can use the existing controlmaps as a reference)
Don’t forget that each group need some sort of name so you can identify it later on. E.g. “pad1”, “pad2” etc.
Once you have this controlmap you can begin creating a configuration file. This file is the one which is picked up by Duplex on startup - it specifies “mappings” to applications that should be running in your groups.
Since you’re splitting the grid into four groups, you will need four Keyboard applications running, side by side. Best thing here would be to take a look at the example Keyboard configuration which does something very similar, splitting the central grid into 3 parts instead of four.
Final steps would involve setting up default options etc. But this is not really essential as you can edit the options visually, from the Duplex GUI…well, once the configuration is able to launch which might not be in first attempt ;).
Also, don’t know if you’ve seen this:https://forum.renoise.com/t/how-to-start-editing-duplex-files/30979