Solo

generator/solo/analysis.py

@@ -16,6 +16,8 @@ class Analysis:
   boundaries: tuple[fractions.Fraction, ...]
   tempo: fractions.Fraction
   melody: tuple[generator.solo.types.Note, ...]
+  body_offset: fractions.Fraction = fractions.Fraction()
+  source_phrases: tuple[generator.solo.types.SourcePhrase, ...] = ()
 
 def identity(analysis, measures, part):
   anchor = analysis.melody[0].pitch.number() if analysis.melody else 0
@@ -63,16 +65,14 @@ def analyze(document: dict) -> Analysis:
   candidates = []
   for index, measure in enumerate(measures):
     start = boundaries[index]
-    # One- and two-bar ideas retain leading silence and the complete held ending.
-    for count in (1, 2):
+    # Legacy motif consumers also receive complete longer source material.
+    for count in (1, 2, 4, 6, 8):
       if index + count >= len(boundaries):
         continue
       end = boundaries[index + count]
       notes = tuple(n for n in melody if start <= n.start < end)
       if not notes or any(n.end > end for n in notes) or any(a.end > b.start for a, b in zip(notes, notes[1:])):
         continue
-      if len(notes) > 8:
-        continue
       normalized = tuple(dataclasses.replace(n, start=n.start - start, end=n.end - start) for n in notes)
       identity = repr(tuple((n.start, n.end, n.pitch) for n in normalized)).encode('ascii')
       identifier = 'head_' + hashlib.sha256(identity).hexdigest()[:12]
@@ -82,4 +82,56 @@ def analyze(document: dict) -> Analysis:
   # Preserve the opening idea, then favor a contrasting rhythm/contour with space.
   ordered = list(unique.values())
   ordered.sort(key=lambda m: (next(i for i, n in enumerate(melody) if n.sources[0] == m.notes[0].sources[0]), m.duration))
-  return Analysis(tuple(ordered), tuple(boundaries), tempo, melody)
+  offset = boundaries[generator.score.body_start_measure_index(measures)]
+  phrases = source_phrases(melody, offset, boundaries[-1] - offset,
+    generator.model.fraction(measures[-1]['duration']))
+  return Analysis(tuple(ordered), tuple(boundaries), tempo, melody, offset, phrases)
+
+def source_phrases(melody, offset, end, bar):
+  """Partition at musical releases, without slicing a sounding event at bars."""
+  notes = tuple(dataclasses.replace(n, start=n.start-offset, end=n.end-offset,
+    event_id=n.sources[0]) for n in melody if n.end > offset)
+  if any(a.end > b.start for a, b in zip(notes, notes[1:])):
+    raise ValueError('solo source requires a monophonic melody')
+  candidates = sorted({fractions.Fraction(), end, *(n.end for n in notes if 0 < n.end <= end),
+    *(n.start for n in notes if 0 < n.start < end)})
+  candidates = [t for t in candidates if not any(n.start < t < n.end for n in notes)]
+  if not candidates or candidates[0] != 0:
+    candidates.insert(0, fractions.Fraction())
+  best = {end: (0., ())}
+  for start in reversed(candidates[:-1]):
+    options = []
+    for finish in candidates:
+      duration = finish-start
+      if finish not in best or duration <= 0 or duration > 8*bar or duration < 2*bar and finish != end:
+        continue
+      prior = next((n for n in reversed(notes) if n.end <= finish), None)
+      after = next((n for n in notes if n.start >= finish), None)
+      gap = float(max(0, after.start-prior.end)) if prior and after else 0.
+      held = float(prior.end-prior.start) if prior else 0.
+      cost = abs(float(duration/bar)-4)/4 + .7*(held < 2) - .3*min(2,gap)
+      options.append((cost+best[finish][0], (finish,*best[finish][1])))
+    if options:
+      best[start] = min(options)
+  if 0 not in best:
+    # A single extended held event is one musical unit, regardless of length.
+    stops = (end,)
+  else:
+    stops = best[0][1]
+  result, start = [], fractions.Fraction()
+  for finish in stops:
+    actual = tuple(n for n in notes if n.start < finish and n.end > start)
+    cursor, rests = start, []
+    for n in actual:
+      if cursor < n.start:
+        rests.append((cursor,n.start))
+      cursor = n.end
+    if cursor < finish:
+      rests.append((cursor,finish))
+    origin = actual[0].pitch.number() if actual else 0
+    shape = tuple((n.start-start,n.end-start,n.pitch.number()-origin) for n in actual)
+    family = hashlib.sha256(repr(shape).encode()).hexdigest()[:12]
+    pickup = tuple(dataclasses.replace(n,start=n.start-offset,end=n.end-offset,event_id=n.sources[0]) for n in melody if n.end<=offset) if start==0 else ()
+    result.append(generator.solo.types.SourcePhrase(f'source_{start}_{finish}',start,finish,actual,tuple(rests),family,pickup))
+    start = finish
+  return tuple(result)