midi API needs support for ProgramChange, ChannelPressure and PolyPressure events

[steveschow]

Current API module does not have any support for getting or setting ProgramChange, ChannelPressure and PolyPressure midi events. Why not?

[pho70n]

Don't know why, but it's very easy to add those events in:

	pos = pos or 0
	local n = midi.Event(pos, 3)
	n.data[0] = bor(0xd0, channel-1)
	n.data[1] = band(val, 127)
	n.data[2] = 0x00
	return n
end

midi.Event.polyPressure = function (channel, val, noteId, pos)
	pos = pos or 0
	local n = midi.Event(pos, 3)
	n.data[0] = bor(0xa0, channel-1)
	n.data[1] = band(noteId, 127)
	n.data[2] = band(val, 127)
	return n
end

And under MidiEvent_mt

		--- Is a channel aftertouch event.
		-- @treturn boolean whether event is a channel aftertouch event.
		-- @function Event:isControl
		isPressure = function (self)
			return band(self.data[0], 0xf0)==0xd0
		end;

		
		--- Get aftertouch value.
		-- @return pressure value (0-127).
		-- @function Event:getPressureValue
		getPressureValue = function (self)
			if not self:isPressure() then error "not a channel pressure event" end
			return self.data[2]
		end;

		--- Is a polyphonic pressure event.
		-- @treturn boolean whether event is a polyphonic pressure event.
		-- @function Event:isControl
		isPolyPressure = function (self)
			return band(self.data[0], 0xf0)==0xa0
		end;

		--- Get pressure note ID value.
		-- @return note ID (0-127).
		-- @function Event:getPolyPressureValue
		getPolyPressureNoteID = function (self)
			if not self:isPolyPressure() then error "not a polyphonic pressure event" end
			return self.data[1]
		end;

		--- Get poly pressure value.
		-- @return pressure value (0-127).
		-- @function Event:getPolyPressureValue
		getPolyPressureValue = function (self)
			if not self:isPolyPressure() then error "not a channel pressure event" end
			return self.data[2]
		end;

I hadn't implemented program change but it's pretty simple. Replace the modified midi.lua in the protoplugs folder and you're golden.