Soloing

generator/solo/composer.py

@@ -10,6 +10,7 @@ import generator.scales.selection
 import generator.scales.timeline
 import generator.solo.analysis
 import generator.solo.planning
+import generator.solo.policy
 import generator.solo.realization
 import generator.solo.types
 
@@ -21,27 +22,71 @@ def compose(analysis, measures, part, end, *, scales, sequences, rhythms, initia
     if choice.span.chord and choice.scale is None:
       raise ValueError(f'{part} solo, source measure {choice.span.source_measure}, beat {choice.span.beat}, {generator.harmony.symbol(choice.span.chord)}: No exact match within the permitted catalog')
   plans = generator.solo.planning.plans(analysis, measures, choices, end, part, sequences)
-  # A protected quote may change the local collection, never its individual pitches.
-  for plan in plans:
-    if plan.treatment != 'quote' or plan.motif.duration > plan.end - plan.start:
-      continue
-    retained = tuple((plan.start + n.start, plan.start + n.end, {n.pitch.number() % 12}) for n in plan.motif.notes)
-    if all(pc <= generator.solo.types.permitted(choices, start, finish) for start, finish, pc in retained):
-      continue
-    alternative = generator.scales.selection.select(timeline, region, scales, retained=retained)
-    if all(pc <= generator.solo.types.permitted(alternative, start, finish) for start, finish, pc in retained) and all(c.scale or c.span.chord is None for c in alternative):
-      choices = tuple(dataclasses.replace(c, reason=c.reason + '; retained quotation') if any(a < c.span.end and b > c.span.start for a, b, _ in retained) else c for c in alternative)
-  phrases, previous = [], None
-  for plan in plans:
-    phrase = generator.solo.realization.compose(plan, measures, choices, sequences, rhythms, analysis.tempo, previous)
-    phrases.append(phrase)
-    notes = tuple(n for d in phrase.decisions for n in d.notes)
-    if notes:
-      previous = notes[-1]
-  result = generator.solo.types.Solo(part, choices, tuple(phrases), analysis.tempo, end)
+  retained = tuple((plan.start + n.start, plan.start + n.end, {n.pitch.number() % 12}) for plan in plans if plan.treatment in ('quote', 'exact_quote') for n in plan.motif.notes)
+  if retained and not all(pc <= generator.solo.types.permitted(choices, start, finish) for start, finish, pc in retained):
+    choices = generator.scales.selection.select(timeline, region, scales, retained=retained)
+    if not all(pc <= generator.solo.types.permitted(choices, start, finish) for start, finish, pc in retained):
+      raise ValueError(f'{part} solo: protected quotation has no exact compatible scale collection')
+    choices = tuple(dataclasses.replace(c, reason=c.reason + '; retained quotation') if any(a < c.span.end and b > c.span.start for a, b, _ in retained) else c for c in choices)
+  context = generator.solo.realization.SearchContext()
+
+  def realize(plan, previous):
+    return generator.solo.realization.alternatives(plan, measures, choices, sequences, rhythms, analysis.tempo, previous, context)
+
+  phrases = choose_phrases(plans, realize)
+  context.diagnostics['policy'] = generator.solo.policy.describe()['fingerprint']
+  context.diagnostics['musical_identity'] = generator.solo.analysis.identity(analysis, measures, part)
+  result = generator.solo.types.Solo(part, choices, tuple(phrases), analysis.tempo, end, context.diagnostics)
   validate(result)
   return result
 
+def phrase_notes(phrase):
+  return generator.solo.types.sounding_notes(n for d in phrase.decisions for n in d.notes)
+
+def transition_cost(first, second):
+  before, after = phrase_notes(first), phrase_notes(second)
+  if not before or not after:
+    return 0.0
+  gap = max(0, after[0].start - before[-1].end - first.plan.release)
+  jump = abs(after[0].pitch.number() - before[-1].pitch.number())
+  # The next phrase's local score already includes physical movement. Here we
+  # evaluate pacing and conversational contrast at the join, once per pair.
+  before_shape = tuple(b.pitch.number() - a.pitch.number() for a, b in zip(before, before[1:]))
+  after_shape = tuple(b.pitch.number() - a.pitch.number() for a, b in zip(after, after[1:]))
+  repeated_answer = second.plan.relationship == 'answer' and before_shape == after_shape
+  return min(1, float(gap) / 2) + 0.5 * min(1, max(0, jump - 5) / 12) + 0.5 * repeated_answer
+
+def choose_phrases(plans, realize):
+  """Commit only after the next phrase has been evaluated from each ending."""
+  result, previous = [], None
+  for index, plan in enumerate(plans):
+    options = realize(plan, previous)
+    ranked, failure = [], None
+    for option in options:
+      notes = phrase_notes(option)
+      last = notes[-1] if notes else previous
+      incoming = transition_cost(result[-1], option) if result else 0
+      if index + 1 == len(plans):
+        ranked.append((option.score + incoming, option))
+        continue
+      try:
+        following = realize(plans[index + 1], last)
+      except generator.solo.realization.SearchExhausted as error:
+        failure = error
+        continue
+      length = float(option.plan.end - option.plan.start)
+      next_length = float(plans[index + 1].end - plans[index + 1].start)
+      cost = min((option.score * length + future.score * next_length) / (length + next_length) + transition_cost(option, future) for future in following)
+      ranked.append((cost + incoming, option))
+    if not ranked:
+      raise failure or generator.solo.realization.SearchExhausted(f'{plan.id}: no feasible phrase transition')
+    _, chosen = min(ranked, key=lambda item: (item[0], tuple((n.pitch, n.start, n.end, n.position) for n in phrase_notes(item[1]))))
+    result.append(chosen)
+    notes = phrase_notes(chosen)
+    if notes:
+      previous = notes[-1]
+  return tuple(result)
+
 def validate(solo):
   previous = None
   for note in solo.notes():
@@ -53,6 +98,6 @@ def validate(solo):
       raise ValueError(f'{solo.part} solo: invalid guitar placement at {note.start}')
     previous = note
   for phrase in solo.phrases:
-    notes = tuple(n for d in phrase.decisions for n in d.notes)
+    notes = phrase_notes(phrase)
     if not generator.solo.realization.target_ok(notes, phrase.plan.target):
       raise ValueError(f'{phrase.plan.id}: planned harmonic arrival was not realized')