gistfile1.txt

engine.name = 'PolyPerc'

local sync_first = true

function key(n,z)
  if n == 3 and z == 1 and not transport_running then
    print("starting link")
    clock.link.start() -- start Link clock
  elseif n == 3 and z == 1 and transport_running then
    print("stopping link")
    clock.link.stop() -- stop Link clock
  end
end

function clock.transport.start()
  print("clock.transport.start")
  sync_first = false
  id = clock.run(clock_loop)
  transport_running = true
  redraw()
end

function clock.transport.stop()
  print("clock.transport.stop")
  clock.cancel(id)
  transport_running = false
  pulse_count = 0
  redraw()
end

function clock_loop()
  -- if sync_first then 
  clock.sync(1) 
  -- else sync_first = true end
  local quantum = params:get('link_quantum')
  while true do
    print("------")
    local hz
    pulse_count = math.fmod(math.floor(clock.get_beats()), quantum)
    print("beats: " .. tostring(clock.get_beats()))
    if pulse_count == 0 then hz = 330
    else hz = 220 end
    engine.hz(hz)
    redraw()
    clock.sync(1)
  end
end

function redraw()
  screen.clear()
  screen.move(20,40)
  screen.text(transport_running and 'running' or 'not running')
  screen.move(pulse_count * 20,60)
  screen.text('|')
  screen.update()
end

function init()
  transport_running = false
  pulse_count = 0
  capture_preinit()
end

function capture_preinit()
  preinit_clock_source = params:get('clock_source')
  preinit_sync = params:get('link_start_stop_sync')
  preinit_quantum = params:get('link_quantum')
  preinit_tempo = params:get('clock_tempo')
  print('setting clock source to Link')
  params:set('clock_source',3)
  print('enabling start/stop sync')
  params:set('link_start_stop_sync',2)
  print('setting quantum to 1 beat')
  params:set('link_quantum', 4)
  print('setting tempo to 95 bpm')
  params:set('clock_tempo',95)
end

function cleanup()
  -- important! stop Link clock with script cleanup:
  clock.link.stop()
  
  print('resetting parameters')
  params:set('clock_source',preinit_clock_source)
  params:set('link_start_stop_sync',preinit_sync)
  params:set('link_quantum',preinit_quantum)
  params:set('clock_tempo',preinit_tempo)
end