sy.lua

-- ??? (nc02-rs)
-- @synthetivv

sc = softcut

dirty = false
next_head = 1

onsets = { -- generated by `aubioonset -t 0.66 -O energy nc02-perc.wav`
  0.000000, 0.427479, 0.495688, 0.999646, 1.496604,
  1.993625, 2.499792, 2.996063, 3.089292, 3.191354,
  3.465250, 4.338583, 4.519729, 4.594812, 4.680313,
  4.745062, 4.915563, 4.995354, 5.134729, 5.343125,
  5.981979, 6.270688, 6.463500, 6.521500, 6.780729,
  7.289479, 7.353229, 7.497542, 7.615104, 7.698021,
  7.857584, 7.950875, 8.077105, 8.157979, 8.261771,
  8.419791, 8.547334, 8.718875,
  10, 11, 12, 13
}

instruments = {
  { o = 11, v = 1,   l = 0.45, d = 0.98, e = 0.1 }, -- bd
  { o = 5,  v = 0.7, l = 0.5,  d = 0.7,  e = 0.2 }, -- ch
  { o = 5,  v = 0.7, l = 0.5,  d = 1,    e = 0.5 }, -- oh
  { o = 1,  v = 1,   l = 0.5,  d = 1,    e = 0.6 }, -- hc
  { o = 4,  v = 1,   l = 0.5,  d = 0.98, e = 0.7 }, -- sd
  { o = 39, v = 0.3, l = 16,   d = 1,    e = 0.1 }, -- tonal
  { o = 40, v = 0.3, l = 16,   d = 1,    e = 0.1 } -- tonal
}

Voice = {}
Voice.__index = Voice
function Voice.new(buffer)
  local v = setmetatable({}, Voice)
  local head = next_head
  next_head = head + 1

  sc.enable(head, 1)
  sc.buffer(head, buffer)
  sc.level(head, 1.0)
  sc.loop(head, 0)
  sc.loop_start(head, 1)
  sc.loop_end(head, 2)
  sc.position(head, 0)
  sc.fade_time(head, 0.0025)
  sc.level_slew_time(head, 0.01)
  sc.rate(head, 1.0)
  sc.play(head, 1)
  sc.level_slew_time(head, 0.01)

  v.head = head
  v.sidechain_level = 0
  v.sidechain_factor = 0.9

  return v
end

EchoVoice = {}
EchoVoice.__index = EchoVoice

function EchoVoice.new()
  local v = setmetatable(Voice.new(2), EchoVoice)
  local head = v.head
  sc.loop_start(head, 1)
  sc.loop_end(head, 1.125)
  sc.loop(head, 1)
  sc.position(head, 1)
  sc.rate(head, 1/3)
  sc.level(head, 1)
  sc.rec_level(head, 1)
  sc.pre_level(head, 0.5)
  sc.rec(head, 1)
  sc.play(head, 1)
  sc.pre_filter_fc(head, 9000)
  sc.pre_filter_dry(head, 0)
  sc.pre_filter_lp(head, 1)
  sc.pre_filter_rq(head, 0.8)
  sc.rate_slew_time(head, 0.3)
  return v
end

function EchoVoice:sidechain_decay()
  self.sidechain_level = self.sidechain_level * self.sidechain_factor
  sc.level(self.head, 1 - self.sidechain_level)
end

PercVoice = {}
PercVoice.__index = PercVoice

function PercVoice.new()
  local v = setmetatable(Voice.new(1), PercVoice)
  v.tick = 0
  v.step_index = 1
  v.shift = 0
  v.shift_carry = 0
  v.send = 0
  v.flash_level = 0
  v.decay_level = 0
  v.instrument = instruments[1]
  return v
end

function PercVoice:envelope_decay()
  self.decay_level = self.decay_level * self.instrument.d
  self.sidechain_level = self.sidechain_level * self.sidechain_factor
  local level = self.instrument.v * self.decay_level * (1 - self.sidechain_level)
  sc.level(self.head, level)
  sc.level_cut_cut(self.head, echo.head, self.send * level)
end

function PercVoice:flash_decay()
  if self.flash_level > 0 then
    self.flash_level = math.floor(self.flash_level * 0.6)
    dirty = true
  end
end

function PercVoice:play()
  local head = self.head
  local start = onsets[self.instrument.o]
  local length = self.instrument.l
  local length_sec = clock.get_beat_sec(length)

  local instrument = self.instrument

  local send = 0
  if math.random() <= instrument.e then
    send = 1
  end

  sc.loop_start(head, onsets[instrument.o])
  sc.loop_end(head, start + length)
  sc.position(head, start)
  sc.level(head, instrument.v)
  sc.level_cut_cut(head, echo.head, send * instrument.v)
  sc.play(head, 1)

  drums[3].sidechain_level = drums[3].sidechain_level + instrument.v
  echo.sidechain_level = echo.sidechain_level + instrument.v

  self.send = send
  self.decay_level = 1
  self.start = start
  self.length = length
  self.flash_level = 16
end

function PercVoice:run()
  self.clock = clock.run(function()
    while true do
      clock.sync(0.25) -- 16th notes
      local tick = self.tick
      tick = tick + 1
      local step_index = self.step_index
      local step = self.pattern[step_index]
      if tick > (step._l or step.l) then
        tick = 1
        step_index = step_index % #self.pattern + 1
        step = self.pattern[step_index]
        local shift_carry = self.shift_carry
        local _l = step.l
        if math.random() <= step.r then
          _l = _l - shift_carry
          shift_carry = 0
        end
        if math.random() <= step.s then
          _l = _l + 1
          shift_carry = shift_carry + 1
        end
        if math.random() <= step.s then
          _l = _l - 1
          shift_carry = shift_carry - 1
        end
        self.shift_carry = shift_carry
        step._l = _l
        self.instrument = instruments[step.i]
        if math.random() <= step.p then
          self:play()
        end
        self.step_index = step_index
      end
      self.tick = tick
    end
  end)
end

function PercVoice:stop()
  if self.clock ~= nil then
    clock.cancel(self.clock)
  end
end

echo = EchoVoice.new()

drums = {}
for d = 1, 3 do
  local drum = PercVoice.new()
  drum.start = d
  drum.length = 0.25
  drum.rate = 0.25
  drums[d] = drum
end

drums[1].start = onsets[11] -- kick
drums[1].length = 0.45
drums[2].decay_factor = 0.98
drums[1].pattern = {
  { p = 1,    i = 1, l = 4, s = 0.25, r = 0.7 },
  { p = 0.33, i = 1, l = 2, s = 0.25, r = 0.5 },
  { p = 0.05, i = 4, l = 2, s = 0.25, r = 0.5 },
  { p = 1,    i = 1, l = 4, s = 0.25, r = 0.7 },
  { p = 0.1,  i = 4, l = 4, s = 0.25, r = 0.5 }
}

drums[2].pattern = {
  { p = 0.2,  i = 2, l = 2, s = 0,    r = 1 },
  { p = 0.8,  i = 2, l = 2, s = 0,    r = 1 },
  { p = 0.2,  i = 3, l = 2, s = 0,    r = 1 },
  { p = 0.8,  i = 2, l = 2, s = 0,    r = 1 }
}

drums[3].start = 11
drums[3].length = 16
drums[3].sidechain_factor = 0.9
drums[3].decay_factor = 1
drums[3].pattern = {
  { p = 1,    i = 7, l = 16, s = 0,   r = 0.25 },
  { p = 0.2,  i = 7, l = 8,  s = 0,   r = 0.25 },
  { p = 0.2,  i = 7, l = 8,  s = 0,   r = 0.25 },
  { p = 0.7,  i = 7, l = 16, s = 0,   r = 0.25 },
  { p = 1,    i = 7, l = 8,  s = 0,   r = 0.25 },
  { p = 0.2,  i = 7, l = 8,  s = 0,   r = 0.25 },
  { p = 0.2,  i = 7, l = 8,  s = 0,   r = 0.25 }
}
sc.rate(drums[3].head, 2)

function load_file(filename, buffer, buffer_start)
  local path = _path.code .. 'nc02-rs/lib/' .. filename
  sc.buffer_read_mono(path, 0, buffer_start, -1, 1, buffer) -- -1 = read whole file, I guess?
end

envelope_metro = metro.init()
envelope_metro.time = 0.01
envelope_metro.event = function()
  for d = 1, 3 do
    drums[d]:envelope_decay()
  end
end

redraw_metro = metro.init()
redraw_metro.time = 1/15
redraw_metro.event = function()
  for d = 1, 3 do
    drums[d]:flash_decay()
  end
  if dirty then
    redraw()
  end
end

flutter_metro = metro.init()
flutter_metro.time = 0.3
flutter_metro.event = function()
  local deviation = (math.random() - 0.5) * 0.05
  sc.rate(echo.head, 1/3 * math.pow(2, deviation))
end

function init()
  load_file('nc02-perc.wav', 1, 0)
  load_file('nc02-tonal.wav', 1, 10)
  params:set('clock_tempo', 120)

  drums[1]:run()
  drums[2]:run()
  drums[3]:run()

  envelope_metro:start()
  redraw_metro:start()
  flutter_metro:start()
end

function enc(n, d)
  if n == 3 then
    params:delta('drum_onset', d)
  end
end

function redraw()
  screen.clear()
  for d = 1, 3 do
    local drum = drums[d]
    local x = 26 + (d - 1) * 32
    screen.level(drum.flash_level)
    screen.rect(x, 27, 10, 10)
    screen.fill()
    for e = 1, 4 do
      screen.level(math.floor(drum.send * drum.flash_level / (e + 1)))
      screen.move(x, 37 + e * 3)
      screen.line_rel(10, 0)
      screen.stroke()
      screen.move(x, 28 - e * 3)
      screen.line_rel(10, 0)
      screen.stroke()
    end
  end
  screen.update()
end

function cleanup()
  redraw_metro:stop()
  envelope_metro:stop()
  flutter_metro:stop()
end