Add bank editor, easy change channel to drums

[Rafał]

Hello everyone.
It would be a good idea to add a bank editor. I'm using a midi controller via UART and it's great, I just miss the ability to implement my own .wopn bank or add .tfi/.dmp instruments and .wav drums.

Another idea would be to make it easier to switch a channel to drum mode via midi cc, since I can't handle SysEx and the programs I've tested on Windows don't work.

[Robert Hargreaves]

Hi oop32,

At present you can compile in your own .wopn or .dmp instruments using https://github.com/rhargreaves/deflemask-preset-viewer to export the C code for the patches. The built-in presets are defined in https://github.com/rhargreaves/mega-drive-midi-interface/blob/main/src/presets.c. At some point I hope to make it easier to load in presets but for now this is the only way of doing it. Having a dmp/wopn loader which works with the Mega Everdrive SD card would be great, but I'm not sure how feasible it would be to implement!

I hope to implement PCM support at some point, but it will be tricky no doubt as it will require me to make use of the Z80 to play samples. Maybe SGDK has something I can hook into but we'll see!