[Hydrogen-devel] [PATCH] MIDI-out feature

[Chris M. <cm...@ro...>]

	This patch adds a simple MIDI out feature to Hydrogen. 

Features:

- Each instrument has a configurable channel / note, accessible in the
instrument editor
- MIDI messages are sent when a sample is about to be played in the
sequencer, meaning no change apart from setting the channel/note is
necessary.

Known Issues:

- The UI is less than ideal
- Note off messages are only sent right before a note on, and on
stopping of playback
- Samples are still associated with instruments, so there's no "pure"
MIDI out. However there's nothing stopping anyone from using
empty/silent samples for each instrument.
- ALSA is the only driver supported for now. Once this patch is in an
acceptable state adding support for other platforms / drivers should be
easy.


The added files are:

libs/hydrogen/include/hydrogen/IO/MidiCommon.h
libs/hydrogen/include/hydrogen/IO/MidiOutput.h
libs/hydrogen/src/IO/midi_output.cpp

I've modified the following binaries:

data/img/gray/instrumentEditor/instrumentTab.png


This is a first draft of this feature, so I expect there to be issues
with it. Please let me know what changes are needed to make it more in
line with the overall architecture, and any problems found with it. I've
only tried it with a Roland SonicCell, so I don't know if it works with
any other hardware, though I fully expect it to.