timeline.py

from collections import defaultdict

from musical.audio import source

# XXX: Early implementation of timeline/hit concepts. Needs lots of work

# TODO: Associate sound source with Hit instances somehow
# TODO: Amplitude, possibly other dynamics attributes


class Hit:

  ''' Rough draft of Hit class. Stores information about the hit and generates
      the audio array accordingly. Currently implements a basic cache to avoid
      having to rerender identical hits
  '''

  cache = {}

  def __init__(self, note, length):
    self.note = note
    self.length = length

  def render(self):
    # Render hit of "key" for "length" amound of seconds
    # XXX: Currently only uses a string pluck
    key = (str(self.note), self.length)
    if key not in Hit.cache:
      Hit.cache[key] = source.pluck(self.note, self.length)
    return Hit.cache[key]


class Timeline:

  ''' Rough draft of Timeline class. Handles the timing and mixing of Hits
  '''

  def __init__(self, rate=44100):
    self.rate = rate
    self.hits = defaultdict(list)

  def add(self, time, hit):
    # Add "hit" at "time" seconds in
    self.hits[time].append(hit)

  def calculate_length(self):
    # Determine length of playback from end of last hit
    length = 0.0
    for time, hits in self.hits.items():
      for hit in hits:
        length = max(length, time + hit.length)
    return length

  def render(self):
    # Return timeline as audio array by rendering the hits
    out = source.silence(self.calculate_length())
    for time, hits in self.hits.items():
      index = int(time * self.rate)
      for hit in hits:
        data = hit.render()
        out[index:index + len(data)] += data
    return out