parts.lua

-- never tried this before... a table for organizing "composed" musical parts
-- verses, choruses, bridges, melodies, generative things...?


local parts = {}

function parts.xox(riddim)
  -- return riddim detector
  return function (beat)
    beat = (beat % #riddim) + 1
    return riddim:sub(beat, beat) ~= '-'
  end
end

function parts.brownian(min, value, max, width)
  math.randomseed(util.time())
  -- return (naive) brownian motion generator
  local delta = math.random(0 - width, width)
  return function()
    delta = (0.9 * delta) + (0.1 * math.random(0 - width, width))
    value = value + delta
    value = math.max(min, math.min(value, max))

    -- U-turn
    if (value == min) or (value == max) then
      delta = (0 - delta)
    end

    return value
  end
end

function parts.init(soundEngine)
  parts.soundEngine = soundEngine
  parts.quarter_beat = 0
  parts.sixteenth_beat = 0
  -- parts.endingMeas is the measure at which the song stops, as determined by an pseudo RNG  with a range between 
  -- the first parameter of the random method and the second, both inclusive
  parts.endingMeas = math.random(450,500)

  -- <3 stepseq fam
  parts.riddims = {
    ['and_a']=
      parts.xox('--xx'),
    ['and_a_ting']=
      parts.xox('--xx--xx--xx---x'),
    ['juke']=
      parts.xox('x--x--x-'),
    ['grey']=
      parts.xox('x--x--x--x--x---'),
    ['like_that']=
      parts.xox('x----x----x----x'),
    ['boom']=
      parts.xox('x--x------x--x--'),
    ['bap']=
      parts.xox('----x---'),
    ['nervous']=
      parts.xox('x-xx')
  }
  -- need to declare these here so they don't get recreated
  parts.state = {
    ['pupil1'] = soundEngine:getSetParam(1, 'cutoff'),
    ['dilation1'] = parts.brownian(50, 800, 5000, 200),
    ['surface1'] = soundEngine:getSetParam(1, 'mod2'),
    ['shine1'] = parts.brownian(0, 100, 300, 20),
    ['is_nervous'] = false
  }

  -- chords
  soundEngine:setSynthParams(3,{amp=0.2,cutoff=1500,attack=clock.get_beat_sec()*4,release=clock.get_beat_sec()*16})

  parts.drumPat = 1

  parts.drums = {}

  for i = 1, 16 do
    parts.drums[i] = {}
    parts.drums[i].kick = {}
    parts.drums[i].snare = {}
    parts.drums[i].hh = {}
  end

  parts.drums[2].kick = {1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0}

  parts.drums[3].hh = {
    0,0,1,0,
    0,0,1,0,
    0,0,1,0,
    0,0,1,0}

  parts.drums[4].kick = {
    1,0,1,0,
    0,0,0,0,
    1,0,0,0,
    0,0,1,0}
  parts.drums[4].snare = {
    0,0,0,0,
    1,0,0,0,
    0,0,0,0,
    1,0,0,0}
  parts.drums[4].hh = {
    1,0,1,0,
    1,0,1,0,
    1,0,1,0,
    1,0,1,0}

end

function parts:whole_notes(phase)
  self.soundEngine:bang_note(69, 2, 0)

  if song.measure == 8 then self.drumPat = 2 
  elseif song.measure == 16 then self.drumPat = 3
  elseif song.measure == 24 then self.drumPat = 4 
  elseif song.measure >= parts.endingMeas then
    song.is_playing = false 
    song.is_screen_dirty = true
  end

  -- trig  condition
  self.state.is_nervous = (math.random(5) == 2)

  if song.measure == 100 then
    self.soundEngine:bang_note(62, 1, 0)
  elseif song.measure % 4 == 1 then
    self.soundEngine:bang_note(62, 1, 0)
  elseif song.measure % 15 == 1 then
    self.soundEngine:bang_note(76, 1, 0)
  end
end

function parts:quarter_notes(phase)
  if math.random(1, 2) == 1 then
    self.soundEngine:bang_note(81, 2, 0)
  end
  self.quarter_beat = self.quarter_beat+1
  local beat = self.quarter_beat


  if beat>32 then
    -- rest
    if parts.riddims.like_that(beat) then
      parts.state.pupil1(parts.state.dilation1())
    end
    if parts.riddims.juke(beat) then
      -- math.random() h8z floats
      parts.state.surface1(parts.state.shine1() / 100)
    else
      parts.state.surface1(0)
    end
  else
    if beat%31==0 then self.soundEngine:bang_note(59, 1, 0)
    elseif beat%29==0 then self.soundEngine:bang_note(60, 1, 0)
    elseif beat%27==0 then self.soundEngine:bang_note(55, 1, 0)
    elseif beat%25==0 then self.soundEngine:bang_note(52, 1, 0)
    elseif beat%23==0 then self.soundEngine:bang_note(52, 1, 0)
    elseif beat%21==0 then self.soundEngine:bang_note(52, 1, 0)
    elseif beat%17==0 then self.soundEngine:bang_note(48, 1, 0)
    elseif beat%15==0 then self.soundEngine:bang_note(52, 1, 0)
    elseif beat%11==0 then self.soundEngine:bang_note(52, 1, 0)
    elseif beat%9==0 then self.soundEngine:bang_note(47, 1, 0)
    elseif beat%7==0 then self.soundEngine:bang_note(52, 1, 0)
    elseif beat%5==0 then self.soundEngine:bang_note(52, 1, 0)
    elseif beat%1==0 then self.soundEngine:bang_note(45, 1, 0)
    end
  end
end

function parts:sixteenth_notes(phase)
  self.sixteenth_beat = self.sixteenth_beat+1
  local beat = self.sixteenth_beat

  local shift_shape1 = self.soundEngine:getSetParam(1, 'algo')

  if beat<64 then
    -- nothing

  else
    if self.riddims.boom(beat) then
      shift_shape1('sinfmlp')
    elseif self.riddims.bap(beat) then
      shift_shape1('sinfb')
    elseif self.riddims.and_a(beat) then
      shift_shape1('square_mod2')
    end

    if self.state.is_nervous and self.riddims.nervous(beat) then
      self.soundEngine:bang_note(81, 1, 0)
    end

    if beat%31==0 then self.soundEngine:bang_note(71, 1, 0)
    elseif beat%29==0 then self.soundEngine:bang_note(72, 1, 0)
    elseif beat%27==0 then self.soundEngine:bang_note(67, 1, 0)
    elseif beat%25==0 then self.soundEngine:bang_note(64, 1, 0)
    elseif beat%23==0 then self.soundEngine:bang_note(64, 1, 0)
    elseif beat%21==0 then self.soundEngine:bang_note(64, 1, 0)
    elseif beat%17==0 then self.soundEngine:bang_note(60, 1, 0)
    elseif beat%15==0 then self.soundEngine:bang_note(64, 1, 0)
    elseif beat%11==0 then self.soundEngine:bang_note(64, 1, 0)
    elseif beat%9==0 then self.soundEngine:bang_note(59, 1, 0)
    elseif beat%7==0 then self.soundEngine:bang_note(64, 1, 0)
    elseif beat%5==0 then self.soundEngine:bang_note(64, 1, 0)
    elseif beat%1==0 then self.soundEngine:bang_note(57, 1, 0)
    end
  end

  if song.measure<16 then
  elseif beat%128==113 then
    self.soundEngine:bang_note(67,3,0)
  elseif beat%128==97 then
    print("chord4")
    self.soundEngine:bang_note(59,3,0)
    self.soundEngine:bang_note(64,3,0)
    self.soundEngine:bang_note(62,3,0)
    self.soundEngine:bang_note(55,3,0)
  elseif beat%128==65 then
    self.soundEngine:bang_note(57,3,0)
    self.soundEngine:bang_note(64,3,0)
    self.soundEngine:bang_note(53,3,0)
    self.soundEngine:bang_note(60,3,0)
  elseif beat%128==33 then
    self.soundEngine:bang_note(64,3,0)
    self.soundEngine:bang_note(59,3,0)
    self.soundEngine:bang_note(55,3,0)
  elseif beat%128==1 then
    self.soundEngine:bang_note(60,3,0)
    self.soundEngine:bang_note(64,3,0)
    self.soundEngine:bang_note(57,3,0)
  end


  local noteIndex = (self.sixteenth_beat % 16) + 1

  local pat = self.drums[self.drumPat]

  if pat.kick[noteIndex] == 1 then
    self.soundEngine:bang_note(32, 4, 0)
  end

  if pat.snare[noteIndex] == 1 then
    self.soundEngine:bang_note(38, 5, 0)
  end

  if pat.hh[noteIndex] == 1 then
    self.soundEngine:bang_note(60, 6, 0)
  end
end


return parts