Tab Generation

generator/arrange/generate.py

@@ -1,96 +1,24 @@
 from __future__ import annotations
 
 import copy
-import warnings
 from fractions import Fraction
 from pathlib import Path
 
 from generator.arrange.form import full_arrangement_sections
-from generator.arrange.fretboard import pitches_for_voicing
-from generator.model import beat_lengths, fraction, key_label, make_event, meter_label, rational
+from generator.guitar import place_guitar
+from generator.parts import PART_TYPES, build_measure, propagated_chords, validate_source
+from generator.model import fraction, key_label, make_event, meter_label, rational
 from generator.musicxml import load_musicxml
-from generator.transposition import concert_document, shift_pitch
-from generator.score import copy_source_voices, make_arranged_document, make_measure, measure_notes, reidentify, slugify, source_staff, write_json
+from generator.pitch import concert_document
+from generator.score import copy_source_voices, make_arranged_document, reidentify, slugify, source_staff, write_json
 
-PART_TYPES = ('acoustic', 'electric', 'vocal')
 FINAL_SECTION_INDEX = 6
 
-def propagated_chords(measures: list[dict], *, include_optional: bool = True) -> list[dict | None]:
-  result = []
-  current = None
-  for measure in measures:
-    result.append(current)
-    for h in measure.get('harmonies', []):
-      if include_optional or not h.get('chord_optional'):
-        current = h
-  return result
-
-def active_chord(measure: dict, onset: Fraction, previous: dict | None) -> dict | None:
-  active = previous
-  for h in measure['harmonies']:
-    if fraction(h['onset']) > onset:
-      break
-    active = h
-  return active if active and active['kind'] != 'none' else None
-
-def generated_voice(measure: dict, role: str, previous: dict | None) -> list[dict]:
-  length = fraction(measure['duration'])
-  if role == 'rest':
-    return [make_event('rest', Fraction(), length, 'rest', written={'type': 'whole', 'dots': 0}) | {'measure_rest': True}]
-  if role == 'rhythm' and measure['time_signature'] == '4/4' and not measure.get('attributes'):
-    attacks = [(Fraction(n, 2), Fraction(1, 2)) for n in (0, 3, 4, 5, 7)]
-  elif role == 'accompaniment' and measure['time_signature'] == '4/4' and not measure.get('attributes'):
-    attacks = [(Fraction(1, 2), Fraction(1, 2))]
-  else:
-    attacks = []
-    states = [(Fraction(), measure['meter'])]
-    states.extend((fraction(a['onset']), a['meter']) for a in measure.get('attributes', []) if 'meter' in a)
-    for index, (onset, meter) in enumerate(states):
-      end = states[index + 1][0] if index + 1 < len(states) else length
-      beats = beat_lengths(meter)
-      beat_index = 0
-      while onset < end:
-        beat = min(beats[beat_index % len(beats)] if beats else end - onset, end - onset)
-        duration = beat if role == 'slash' or not beats else min(beat / 2, Fraction(1, 2))
-        attacks.append((onset, duration))
-        onset += beat
-        beat_index += 1
-  events = []
-  cursor = Fraction()
-  for onset, duration in attacks:
-    if onset >= length:
-      break
-    if onset > cursor:
-      events.append(make_event(f'rest-{len(events)}', cursor, onset - cursor, 'rest'))
-    duration = min(duration, length - onset)
-    chord = active_chord(measure, onset, previous)
-    source_attack = any(fraction(n['onset']) == onset and n['kind'] == 'note' and not n.get('grace') and any(not p.get('tie_from') for p in n['pitches']) for n in measure_notes(measure))
-    if role == 'slash':
-      event = make_event(f'slash-{len(events)}', onset, duration, 'note')
-      event['notehead'] = 'slash'
-    elif not chord or role == 'accompaniment' and source_attack:
-      event = make_event(f'rest-{len(events)}', onset, duration, 'rest')
-    else:
-      pitches = pitches_for_voicing(chord)
-      event = make_event(f'chord-{len(events)}', onset, duration, 'note', pitches)
-      if not pitches:
-        warnings.warn(f'{measure["id"]}: no playable voicing for {chord["symbol"]}; using labelled rhythmic slashes', stacklevel=2)
-        event['notehead'] = 'slash'
-    events.append(event)
-    cursor = onset + duration
-  if cursor < length:
-    events.append(make_event(f'rest-{len(events)}', cursor, length - cursor, 'rest'))
-  return events
-
 def arrange_document(document: dict, part_type: str) -> dict:
   if part_type not in PART_TYPES:
     raise ValueError(f'unknown arrangement part: {part_type}')
-  for measure in source_staff(document)['measures']:
-    specialized_staff = any(state.get('clef', {}).get('sign') in ('TAB', 'percussion') for state in [measure, *measure.get('attributes', [])])
-    specialized_notes = any('unpitched' in pitch or 'tablature' in pitch for note in measure_notes(measure) for pitch in note['pitches'])
-    if specialized_staff or specialized_notes:
-      raise ValueError(f'{measure["id"]}: automatic performance arranging requires a pitched non-TAB lead; percussion/TAB conversion is not qualified')
-  document = concert_document(document)
+  validate_source(document)
+  document = concert_document(document, octave_transposing=True)
   staff = source_staff(document)
   source = staff['measures']
   sections = full_arrangement_sections(source, part_type)
@@ -109,20 +37,7 @@ def arrange_document(document: dict, part_type: str) -> dict:
       m['harmonies'] = [h for h in m['harmonies'] if section.section_index != FINAL_SECTION_INDEX or not h.get('chord_optional')]
       for h in m['harmonies']:
         h.pop('chord_optional', None)
-      source_voices = copy_source_voices(m, strip_lyrics=section.role == 'melody') if section.role in ('vocal', 'melody') else None
-      notes = [n for v in source_voices for n in v['notes']] if source_voices else generated_voice(m, section.role, previous[si])
-      if section.role == 'melody':
-        for note in notes:
-          note['pitches'] = [shift_pitch(p, 7, 12) for p in note['pitches']]
-      result = make_measure(f'measure-{len(output) + len(segment) + 1}', m, [] if source_voices else notes, section_label=section.label if not segment else '')
-      if source_voices:
-        result['voices'] = source_voices
-      if part_type != 'vocal':
-        result['clef'] = {'sign': 'G', 'line': 2, 'octave_change': 0}
-        result['transpose'] = {'diatonic': 0, 'chromatic': 0, 'octave_change': -1}
-        for change in result.get('attributes', []):
-          change.pop('clef', None)
-          change.pop('transpose', None)
+      result = build_measure(m, f'measure-{len(output) + len(segment) + 1}', section.role, part_type, previous[si], section.label if not segment else '')
       segment.append(result)
     identity_segment = segment
     segment_length = sum((fraction(m['duration']) for m in segment), Fraction())
@@ -133,7 +48,7 @@ def arrange_document(document: dict, part_type: str) -> dict:
         if low < high:
           octave_shifts.append({**shift, 'id': f'section-{section.section_index}-{shift["id"]}', 'start': rational(absolute + low - start), 'end': rational(absolute + high - start)})
     if part_type == 'vocal' and section.section_index in (1, 5) and section.source_measure_index == 1 and source[0].get('implicit') and output:
-      pickup = copy.deepcopy(source[0])
+      pickup = build_measure(source[0], source[0]['id'], 'vocal', part_type, None)
       destination = output[-1]
       pad = fraction(destination['duration']) - fraction(pickup['duration'])
       if pad < 0:
@@ -170,6 +85,8 @@ def arrange_document(document: dict, part_type: str) -> dict:
     absolute += segment_length
   result = make_arranged_document(document, staff, staff_id='staff-arranged-' + part_type, staff_name=part_type.capitalize(), role='vocal' if part_type == 'vocal' else 'guitar', arrangement_part_type=part_type, measures=output, tuplets=tuplets, octave_shifts=octave_shifts)
   result['metadata'].setdefault('tempo', 124)
+  if part_type != 'vocal':
+    place_guitar(result)
   return result
 
 def generate_performance_scores(source_dir: Path, output_dir: Path) -> int:
@@ -179,6 +96,9 @@ def generate_performance_scores(source_dir: Path, output_dir: Path) -> int:
   for path in sorted(source_dir.glob('*.xml')):
     document = load_musicxml(path)
     for part in PART_TYPES:
-      write_json(output_dir / f'{slugify(path.stem)}-{part}.json', arrange_document(document, part))
+      try:
+        write_json(output_dir / f'{slugify(path.stem)}-{part}.json', arrange_document(document, part))
+      except ValueError as error:
+        raise ValueError(f'{path}, part {part}: {error}') from error
       count += 1
   return count