Add example Lua DSP script with multiple MIDI outputs

1 files changed, 48 insertions, 0 deletions

diff --git a/share/scripts/_midigenerator_multi_ports.lua b/share/scripts/_midigenerator_multi_ports.lua
new file mode 100644
index 0000000000..a61db04e5a
--- /dev/null
+++ b/share/scripts/_midigenerator_multi_ports.lua
@@ -0,0 +1,48 @@
+ardour {
+	["type"]    = "dsp",
+	name        = "MIDI generator with multiple ports",
+	category    = "Example",
+	license     = "MIT",
+	author      = "R8000",
+	description = [[An Example Midi Generator for prototyping.]]
+}
+
+function dsp_ioconfig () return { { midi_out = 5} } end
+
+local tme = 0 -- sample-counter
+local seq = 0 -- sequence-step
+local spb = 0 -- samples per beat
+
+local midi_sequence_one = {
+	{ 0x90, 64, 127 },
+	{ 0x80, 64,   0 },
+}
+local midi_sequence_two = {
+	{ 0x90, 60,  70 },
+	{ 0x80, 60,   0 },
+}
+
+local midi_sequences = { midi_sequence_one, midi_sequence_two }
+
+function dsp_init (rate)
+	local bpm = 120
+	spb = rate * 60 / bpm
+	if spb < 2 then spb = 2 end
+end
+
+function dsp_run (_, _, n_samples)
+	assert (type(midiout) == "table")
+	assert (spb > 1)
+
+	for time = 1,n_samples do -- not very efficient
+		-- TODO, timestamp the sequence in beats, calc/skip to next event
+		tme = tme + 1
+		if tme >= spb then
+			for m = 1, 5 do
+				midiout[m] = {time = time, data = midi_sequences[m % 2 + 1][seq + 1]}
+			end
+			tme = 0
+			seq = (seq + 1) % 2
+		end
+	end
+end