Poly synth lua template

poly_template.lua

-- Poly Template
--
-- v1.0.2 Mark Eats
--

local MusicUtil = require "musicutil"

engine.name = "PolyTemplate"

local midi_in_device


local function note_on(note_num, vel)
  engine.noteOn(note_num, MusicUtil.note_num_to_freq(note_num), vel)
end

local function note_off(note_num)
  engine.noteOff(note_num)
end

local function note_off_all()
  engine.noteOffAll()
end

local function note_kill_all()
  engine.noteKillAll()
end

local function set_key_pressure(note_num, pressure)
  engine.pressure(note_num, pressure)
end

local function set_channel_pressure(pressure)
  engine.pressureAll(pressure)
end

local function set_timbre(note_num, timbre)
  engine.timbre(note_num, timbre)
end

local function set_timbre_all(timbre)
  engine.timbreAll(timbre)
end

local function set_pitch_bend(bend_st)
  engine.pitchBendAll(MusicUtil.interval_to_ratio(bend_st))
end


-- Encoder input
function enc(n, delta)
  
end

-- Key input
function key(n, z)
  if z == 1 then
    if n == 2 then
      note_off_all()
    elseif n == 3 then
      note_kill_all()
    end
  end
end

-- MIDI input
local function midi_event(data)
  
  local msg = midi.to_msg(data)
  local channel_param = params:get("midi_channel")
  
  if channel_param == 1 or (channel_param > 1 and msg.ch == channel_param - 1) then
    
    -- Note off
    if msg.type == "note_off" then
      note_off(msg.note)
    
    -- Note on
    elseif msg.type == "note_on" then
      note_on(msg.note, msg.vel / 127)
      
    -- Key pressure
    elseif msg.type == "key_pressure" then
      set_key_pressure(msg.note, msg.val / 127)
      
    -- Channel pressure
    elseif msg.type == "channel_pressure" then
      set_channel_pressure(msg.val / 127)
      
    -- Pitch bend
    elseif msg.type == "pitchbend" then
      local bend_st = (util.round(msg.val / 2)) / 8192 * 2 -1 -- Convert to -1 to 1
      set_pitch_bend(bend_st * 2) -- 2 Semitones of bend
      
    end
  
  end
  
end


function init()
  
  midi_in_device = midi.connect(1)
  midi_in_device.event = midi_event
  
  -- Add params
  
  params:add{type = "number", id = "midi_device", name = "MIDI Device", min = 1, max = 4, default = 1, action = function(value)
    midi_in_device.event = nil
    midi_in_device = midi.connect(value)
    midi_in_device.event = midi_event
  end}
  
  local channels = {"All"}
  for i = 1, 16 do table.insert(channels, i) end
  params:add{type = "option", id = "midi_channel", name = "MIDI Channel", options = channels}
  
  redraw()
end


function redraw()
  screen.clear()
  screen.aa(1)
  
  screen.level(15)
  screen.move(10, 15)
  screen.text(engine.name)
  
  screen.update()
end