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moony.lv2 random note drop
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| -- MIDI Note Event Filter/Processor | |
| --- | |
| -- This is an example, which passes all events unfiltered / unaltered. | |
| -- Change the 'do_filter' function to customize the filter. | |
| -- affected MIDI channels | |
| -- 0..15 or set to -1 to apply to events on all channels | |
| local filter_chan = -1 | |
| -- affected note range(s) | |
| -- string with comma-separated list of single MIDI note numbers or | |
| -- ranges (min-max separated by a dash, whitespace is ignored) | |
| -- example: local note_ranges = "0-12, 36,48, 60 - 96" | |
| local note_ranges = "0-127" | |
| -- whether to pass non-note events or note events outside of affected range(s) | |
| local pass_other = true | |
| -- the probability (percent) that the note is dropped | |
| local drop_prob = 10 | |
| -- NO NEED TO CHANGE ANYTHING BELOW | |
| local _filter_notes | |
| local function clamp(val, min, max) | |
| return val < min and min or (val > max and max or val) | |
| end | |
| -- http://rosettacode.org/wiki/Range_expansion#Lua | |
| function range(i, j) | |
| local t = {} | |
| for n = i, j, i<j and 1 or -1 do | |
| t[#t+1] = n | |
| end | |
| return t | |
| end | |
| function expand_ranges(rspec) | |
| local ptn = "([-+]?%d+)%s?-%s?([-+]?%d+)" | |
| local t = {} | |
| for v in string.gmatch(rspec, '[^,]+') do | |
| local s, e = v:match(ptn) | |
| if s == nil then | |
| t[tonumber(v)] = true | |
| else | |
| for i, n in ipairs(range(tonumber(s), tonumber(e))) do | |
| t[] = true | |
| end | |
| end | |
| end | |
| return t | |
| end | |
| local function do_filter(frames, forge, chan, note, vel) | |
| -- decide randomly whether to drop the note | |
| if math.random() > drop_prob then | |
| return true, clamp(chan, 0, 16), clamp(note, 0, 127), clamp(vel, 0, 127) | |
| else | |
| return false, 0, 0, 0 | |
| end | |
| -- note responder function factory | |
| local function note_responder(cmd) | |
| return function(self, frames, forge, chan, note, vel) | |
| local pass = pass_other | |
| if (filter_chan == -1 or chan == filter_chan) and _filter_notes[note] then | |
| pass, chan, note, vel = do_filter(frames, forge, chan, note, vel) | |
| end | |
| if (pass) | |
| -- send event | |
| forge:time(frames):midi(cmd | chan, note, vel) | |
| end | |
| end | |
| end | |
| function once(n, control, notify, seq, forge) | |
| _filter_notes = expand_ranges(note_ranges) | |
| math.randomseed(os.time()) | |
| -- define a MIDIResponder object to handle note-on and note-off events | |
| _midiR = MIDIResponder({ | |
| [MIDI.NoteOn] = note_responder(MIDI.NoteOn), | |
| [MIDI.NoteOff] = note_responder(MIDI.NoteOff) | |
| }, pass_other) | |
| end | |
| function run(n, control, notify, seq, forge) | |
| -- iterate over incoming events | |
| for frames, atom in seq:foreach() do | |
| -- call responder for event | |
| local handled = _midiR(frames, forge, atom) | |
| end | |
| end |
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