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product-vamp/generator/harmonic_time.py
T
2026-10-05 19:44:33 -05:00

34 lines
1.2 KiB
Python

from __future__ import annotations
import dataclasses
import fractions
import generator.model
@dataclasses.dataclass(frozen=True)
class ChordSpan:
start: fractions.Fraction
end: fractions.Fraction
measure: int
source_measure: str
beat: fractions.Fraction
key: dict
chord: dict | None
def read(staff: dict, *, initial: dict | None = None) -> tuple[ChordSpan, ...]:
result = []
absolute = fractions.Fraction()
active = initial
for number, measure in enumerate(staff['measures'], 1):
length = generator.model.fraction(measure['duration'])
harmonies = {generator.model.fraction(h['onset']): h for h in measure['harmonies']}
changes = {generator.model.fraction(a['onset']): a['key'] for a in measure.get('attributes', []) if 'key' in a}
boundaries = sorted({fractions.Fraction(), length} | set(harmonies) | set(changes))
key = measure['key']
for start, end in zip(boundaries, boundaries[1:]):
key = changes.get(start, key)
active = harmonies.get(start, active)
result.append(ChordSpan(absolute + start, absolute + end, number, str(measure['number']), start + 1, key, active if active and active['kind'] != 'none' else None))
absolute += length
return tuple(result)