rd8_midi_splitter.lua

ardour {
			["type"] = "EditorAction",
			name = "RD-8 MIDI Splitter",
			license = "MIT",
			author = "dotted_pi",
			description = [[This script exports user-selected RD-8 instruments and filters selected regions of an 'RD8_MIDI_Master' track into a unique MIDI track per instrument.]]
		}

function factory () return function ()

	------------------------------------------------------------------------------------
	--set up the RD-8 class containing all instruments with their midi notes and names--
	------------------------------------------------------------------------------------

	local rd8 = {

		{inst = "kick", note = 36, name = "Kick"},

		{inst = "snare", note = 40, name = "Snare"},

		{inst = "low_ct", note = 45, name = "Low Conga/Tom"},

		{inst = "mid_ct", note = 47,  name = "Mid Conga/Tom"},

		{inst = "high_ct", note = 50,  name = "High Conga/Tom"},

		{inst = "cl_rs", note = 37,  name = "Claves/Rim Shot"},

		{inst = "clap", note = 39,  name = "Maracas/Claps"},

		{inst = "cowbell", note = 56,  name = "Cowbell"},

		{inst = "cymbal", note = 51,  name = "Cymbal"},

		{inst = "openhat", note = 46,  name = "Open Hat"},

		{inst = "closedhat", note = 42,  name = "Closed Hat"},

	}

	--------------------------------------------------------------------------------------
	--search for "RD8_MIDI_Master" track and select the first instance if multiple exist--
	--------------------------------------------------------------------------------------

	local rd8_midi_master_found = false
	local rd8_track_name = "RD8_MIDI_Master"    --the name of the MIDI Master track to match 
	local rd8_master_region_ids = {}
	local n_rd8_regions = 0

	for track in Session:get_tracks():iter() do
		if track:data_type():to_string() == "midi" then                                         	--iterate over all MIDI tracks in the session
			if (not rd8_midi_master_found) and (string.find(track:name(), rd8_track_name)) then 	--check if valid RD8_MIDI_Master exists
				rd8_midi_master_found = true
				rd8["mastertrack"] = track:to_track():to_midi_track()								--select the first valid option 

				for reg in rd8["mastertrack"]:playlist():region_list():iter() do
					rd8_master_region_ids[reg:to_stateful():id():to_s()] = true
					n_rd8_regions = n_rd8_regions + 1
				end
			end

			--check if the MIDI track is an instrument MIDI track as created by the script (and get its ID)
			for rd8_inst_id, rd8_inst in ipairs(rd8) do
				if string.find(track:name(),"RD8_MIDI_"..rd8_inst["inst"]) then
					rd8[rd8_inst_id]["MIDI_track_found"] = true
					rd8[rd8_inst_id]["MIDI_track_id"] = track:to_stateful():id()
				end
			end
		end
	end

	if not rd8_midi_master_found then 	--return if no track is found
		LuaDialog.Message ("Setup Error", "No valid 'RD8_MIDI_Master' track could be found!", LuaDialog.MessageType.Error, LuaDialog.ButtonType.Close):run()
		goto script_end
	end

	--------------------------------------------------------------------------
	--get number (and ID) of selected regions of the 'RD8_MIDI_Master' track--
	--------------------------------------------------------------------------

	local sel_region_ids = {}
	local filtered_region_ids = {}
	local dialog_options = {}
	local continue_on_full_track = false

	for r in Editor:get_selection().regions:regionlist():iter() do
		sel_region_ids[r:to_stateful():id():to_s()] = true
	end

	for reg_id in pairs(rd8_master_region_ids) do
		filtered_region_ids[reg_id] = sel_region_ids[reg_id]
	end

	local n_valid_master_regions = 0
	for _ in pairs(filtered_region_ids) do
		n_valid_master_regions = n_valid_master_regions + 1
	end

	--handle the case of no valid selected regions 
	if (n_valid_master_regions == 0) and not (n_rd8_regions == 0) then
		table.insert(dialog_options, { type = "label", title = "Run RD-8 MIDI Splitter for all regions of the 'RD8_Master_Track'? \nThis will delete all existing regions for selected instruments." })
		local od = LuaDialog.Dialog("No valid region(s) selected!", dialog_options)
		local ok = od:run()

		if (ok) then
			continue_on_full_track = true
		else
			goto script_end
		end
	end

	-------------------------------------------
	--create setup dialog and save user input--
	-------------------------------------------

	local dialog_options = {} --reuse variable

	table.insert(dialog_options, { type = "heading", title = "Select instruments to create their MIDI track:" })

	for _, rd8_inst in ipairs(rd8) do
		table.insert(dialog_options, { type = "checkbox", key = "sel_"..rd8_inst["inst"], default = false, title = rd8_inst["name"] })
	end

	table.insert(dialog_options,{ type = "heading", title = "Further options:" })

	table.insert(dialog_options,{ type = "checkbox", key = "auto_connect_to_rd8", default = false, title = "Auto-connect new track outputs to the RD-8"})
    table.insert(dialog_options,{ type = "checkbox", key = "create_audio_tracks", default = false, title = "Create audio tracks (Mono) per instrument" })

	local od = LuaDialog.Dialog("RD-8 MIDI Splitter Setup", dialog_options)
	local rv = od:run()

	if not (rv) then goto script_end end

    ----------------------------------------------------
    --check if RD-8 is connected for MIDI auto-connect--
    ----------------------------------------------------

	if rv["auto_connect_to_rd8"] then

        local _, t = Session:engine():get_backend_ports("", ARDOUR.DataType("midi"), ARDOUR.PortFlags.IsInput | ARDOUR.PortFlags.IsPhysical, C.StringVector ())

        for _, p in pairs(t[4]:table()) do
            if Session:engine():get_pretty_name_by_name(p) == "RD-8" then
                rd8["port"] = p
                rd8["found"] = true
                break
            end
        end
    end

    if (not rd8["found"]) and rv["auto_connect_to_rd8"] then
		LuaDialog.Message("RD-8 disconnected?", "Cannot auto-connect new tracks!", LuaDialog.MessageType.Warning, LuaDialog.ButtonType.Close):run()
	end

	--------------------------------------------
	--main loop (through selected instruments)--
	--------------------------------------------

	for rd8_inst_id, rd8_inst in ipairs(rd8) do
		if rv["sel_"..rd8_inst["inst"]] then
			--if auto-connect is enabled and RD-8 found, connect tracks to RD-8 MIDI input
            if rd8_found then
			    Session:engine():connect("ardour:RD8_MIDI_"..rd8_inst["inst"].."/midi_out 1", rd8["port"])
		    end

            --MIDI track creation if it does not exist 
			if not rd8_inst["MIDI_track_found"] then
				Session:new_midi_track(ARDOUR.ChanCount(ARDOUR.DataType("midi"), 1), ARDOUR.ChanCount(ARDOUR.DataType("midi"), 1), false, ARDOUR.PluginInfo(), nil, nil, 1, "RD8_MIDI_"..rd8_inst["inst"], ARDOUR.PresentationInfo.max_order, ARDOUR.TrackMode.Normal)
				rd8_inst["MIDI_track_id"] = Session:route_by_name("RD8_MIDI_"..rd8_inst["inst"]):to_stateful():id()
			end

			--audio track creation if enabled 
            if rv["create_audio_tracks"] then
                Session:new_audio_track(1,2,nil,1,"RD8_"..rd8_inst["inst"],ARDOUR.PresentationInfo.max_order,ARDOUR.TrackMode.Normal)
            end

            --get the MIDI track for the current instrument 
			local cur_track = Session:route_by_id(rd8_inst["MIDI_track_id"]):to_track()

			for _, region in pairs(rd8["mastertrack"]:playlist():region_list():table()) do	--loop over valid regions 
				if continue_on_full_track or ((not continue_on_full_track) and filtered_region_ids[region:to_stateful():id():to_s()]) then
					local new_region = ARDOUR.RegionFactory.clone_region(region, true, true):to_midiregion()

					local midi_model = region:to_midiregion():midi_source(0):model()
					local midi_command = midi_model:new_note_diff_command("Write MIDI Events")

					local cur_model = new_region:midi_source(0):model()
					local cur_command = cur_model:new_note_diff_command("Filter MIDI Events")

					--filter notes per region and copy them if they belong to the current instrument  
					for note in ARDOUR.LuaAPI.note_list (midi_model):iter() do
						if note:note() == rd8_inst["note"] then
							local filtered_note = ARDOUR.LuaAPI.new_noteptr(rd8_inst_id, note:time(), note:length(), note:note(), note:velocity())  --separate midi channel per instrument per default
							cur_command:add(filtered_note)
						end
						cur_command:remove(note)
					end

					cur_track:playlist():add_region(new_region, region:position(), 1, false, 0, 0, false) 	--add new_region to created instrument track
					midi_model:apply_command(Session, midi_command)
					cur_model:apply_command(Session, cur_command)
				end
			end
		end
	end

	collectgarbage()

	::script_end::
end end


---------------------------------		
--define an icon for the script--
---------------------------------

function icon (params) return function (ctx, width, height, fg)
	ctx:set_source_rgba(0.99, 0.41, 0.12,1) --"RD-8" fontcolor on the device 
	local txt = Cairo.PangoLayout(ctx, "ArdourMono " .. math.ceil(math.min(width, height) * 0.3+2) .. "px")
	txt:set_text("RD-8\nMIDI")
	local tw, th = txt:get_pixel_size()
	ctx:move_to(0.5 * (width - tw)+1, 0.5 * (height - th))
	txt:show_in_cairo_context(ctx)
end end